Дисертації з теми "Polluted waters"

The chemical contamination of natural waters is a global problem with a worldwide impact. Considering the relevance of this problem, this thesis is intended, on one hand, to develop different separation/preconcentration techniques based on membranes ability to permeate anions for the transport of toxic oxyanions of chromium(VI) and arsenic contained in aqueous matrices. In particular, we have investigated supported liquid membranes and polymer inclusion membranes, both of which contain the commercial quaternary ammonium salt Aliquat 336 as a carrier, as well as commercial anion exchange membranes. On the other hand, we have focused on the development of chemical sensors to facilitate the monitoring of several metals from different aqueous matrices. Thus, a selective optical sensor for Cr(VI) based on polymeric membranes containing Aliquat 336 as an ionophore has been designed. Additionally, mercury-based screen-printed electrodes have been evaluated for for cadmium, lead, copper and zinc detection.
La contaminació química de les aigües naturals és un problema global amb repercussió a nivell mundial. Donada la rellevància que té aquesta problemàtica, en la present tesi s’han desenvolupat d’una banda tècniques de separació/preconcentració basades en diferents sistemes de membrana en què el mecanisme de transport proposat és un bescanvi aniònic per als oxoanions tòxics de crom(VI) i arsènic presents en matrius aquoses. Concretament, s’ha treballat amb membranes líquides suportades que contenien el portador comercial Aliquat 336, membranes d’inclusió polimèriques amb el mateix portador i membranes de bescanvi aniònic comercials. D’altra banda, s’ha treballat en el desenvolupament de diferents sensors químics per monitoritzar diversos metalls presents en matrius aquoses. Així, s’ha dissenyat un sistema de sensor òptic selectiu a Cr(VI) basat en membranes polimèriques utilitzant també el portador Aliquat 336 i s’ha desenvolupat un sistema de monitorització per plom, coure, cadmi i zinc basat en microelèctrodes serigrafiats modificats amb mercuri.

A new technology for Cr(VI) and divalent metal ions removal based on metal sorption onto exhausted coffee waste has been developed. Physical and chemical characterization of exhausted coffee waste was explored as well as the role of structural and non structural compounds of the waste in metal ions sorption. Kinetics of Cr(VI) sorption from binary mixtures containing different Cr(VI) and Cu(II) molar ratios were carried out in a batch reactor. A synergistic effect of Cu(II) in Cr(VI) reduction and sorption was found. From the kinetic sets of data a kinetic model taking into account Cr(VI) reduction/sorption, reduced Cr(III) sorption and Cu(II)synergistic effect on sorption was developed. The model described quite accurately the overall process of Cr(VI) removal. Biosorption by coffee wastes followed by precipitation resulted to be an efficient and low cost technology to remove Cr(VI) and divalent metals from synthetic and industrial effluents from metal finishing industries
S'ha desenvolupat una tecnologia nova per a l'eliminació de Cr(VI) i metalls divalents basada en l'adsorció dels metalls en residus de marro de café. Es va dur a terme la caracterització físicoquímica del marro de café i es va investigar el paper dels components estructurals i no estructurals en l'adsorció de metalls. Emprant un tanc agitat es va estudiar la cinètica d'adsorció de Cr(VI) de mescles binàries de Cr(VI)-Cu(II) amb diferents relacions molars d'ambdos metalls. Es va trobar un efecte sinèrgic del coure sobre l'adsorció i la reducció de Cr(VI). Un model basat en la reducció/adsorció de Cr(VI), adsorció del Cr(III) format i l'efecte sinèrgic del coure va ser desenvolupat. El model va descriure adequadament el procés. La bioadsorció seguida de precipitació va resultar ser una tecnologia eficaç i de baix cost per eliminar Cr(VI) i metalls divalents d'aigües sintètiques i efluents d’indústries de tractament de superfícies

L'étude de l'application de la télédétection à la pollution de l'eau dans les bassins industriels est d'un grand intérêt pour une surveillance rapide et peu coûteuse de la pollution. Cette étude présente une méthode permettant de détecter les polluants et cartographier leur distribution spatiale dans les bassins industriels en utilisant les propriétés optiques inhérentes (IOPs) de l'eau, à savoir les coefficients d'absorption et de rétrodiffusion, dérivées de images hyperspectrales. Les IOPs des polluants des eaux industrielles restent mal connues. Les méthodes actuelles de télédétection sont spécifiques au site d'étude et nécessitent des mesures in situ pour calibrer des modèles empiriques. Une approche générique est proposée ici, basée sur le modèle semi-analytique de transfert radiatif de Lee et al. (1998), adapté pour prendre en compte les coefficients d'absorption et de rétrodiffusion des particules de polluants. Le modèle est ensuite inversé à l'aide d'une méthode multi-pixel alternée, appelée IWOC (Industrial Wastewater Optical Characterization), afin de cartographier la distribution spatiale des polluants. Les performances d'IWOC sont évaluées à l'aide de jeux de données modélisés sans bruit et avec bruit pour des cas d'eaux naturelles, des cas d'eaux dominées par l'absorption des cas d'eaux dominées par la rétrodiffusion. Les performances de la méthode IWOC sont également évaluées à l'aide d'images hyperspectrales aéroportées acquises au-dessus de zones d'étude d'intérêts. L'approche menée dans cette étude est un premier pas vers une méthode d'inversion générique pour la caractérisation optique des eaux issues de rejets industriels et la pollution dans l'eau. Avec plus de recherches, cette méthode pourrait déboucher sur une méthode opérationnelle
Investigating the application of remote sensing to water pollution in industrial ponds is of great interest for rapid and cost-effective pollution monitoring. This study presents a method to detect pollutants and map their spatial distribution in industrial ponds using the water inherent optical properties (IOPs), namely the absorption and backscattering coefficients, derived from hyperspectral imaging. The IOPs of industrial water pollutants remain poorly known. Current remote sensing methods are site-specific and require in situ measurements to calibrate empirically-based models. Here, a generic approach is proposed based on the semi-analytical radiative transfer model by Lee et al. (1998) adapted to take into account both the absorption and backscattering coefficients of pollutant particles. The model is then inverted using an alternating multi-pixel method, named IWOC (Industrial Wastewater Optical Characterization), to map the spatial distribution of the pollutants. The performances of IWOC are evaluated using noise-free and noisy simulated datasets for natural waters, absorption-dominated water cases and backscattering-dominated water cases. The performances of the IWOC method are also examined through hyperspectral airborne images acquired over relevant study areas. The approach conducted in this study is a first step towards a generic inversion method for the optical characterization of in waters from industrial discharges and pollution in water. Further research could lead to an operational method

A feasibility study was planned to determine the efficiency of immobilized algal cells growing in a packed bed for removing Cd from commercial effluents. To select appropriate material for an immobilized cell system, twenty-five strains of algae isolated from heavy-metal contaminated environments of known water chemistry were tested for their ability to accumulate Cd. Before accumulation experiments were initiated, ion exchange resin was employed to demonstrate that EDTA in the medium did not complex Cd to a significant degree. Svnechococcus D562 cells subcultured in Cd accumulated the most metal; little was bound to the cell wall. A continuous culture of steady- state Svnechococcus D562 cells tolerated a lower maximum concentration of metal (3.4 mg 1(^-1) Cd) than batch- cultured cells (5 mg 1(^-1) Cd), indicating that metabolic status influences the toxicity of Cd. When flasks of calcium-alginate beads were challenged with Cd, up to 60 % of the added metal was bound within 16 h; however, further incubation did not reduce the pollutant concentration. Two axenic strains which accumulated the metal to a high concentration were then immobilized and tested for their capacity to remove Cd from the circulating medium. A packed-bed reactor containing Mougeotia D536 cells proved more effective at metal removal than Svnechococcus D562, but both species grew to a lower cell density at the effluent end of the column. The medium was then aerated to overcome such growth-limiting conditions, but this treatment inhibited Cd accumulation. Column-immobilized cells reduced Cd levels more effectively than inoculated, alginate beads in stationary flasks or free cells. Energy dispersive X-ray microanalysis located Cd only in particular Svnechococcus D562 polyphosphate bodies (those with a high Ca to K ratio); peaks for Zn, Pb, Fe, Mn and Ba were also detected in algae isolated from the field. Scanning proton microanalysis provided information on the distribution of macro- and micro-elements throughout the two strains of cyanobacteria and two strains of algae selected from the Durham Culture Collection and demonstrated the presence of Cd in Klebsormidium rivulare D537.Detergent-sensitive spheroplasts of Svnechococcus D562 were produced by lysozyme and protease digestion, but were not viable for growth. To observe the extracellular mucilage of this strain by EM, lysozyme digestion proved imperative for effective ruthenium red staining to convert the material into an electron opaque material. From cultures of Svnechococcus D562 grown with or without Cd a 14 kD plasmid was isolated, which contained two Eco RI, two Bam HI and five Hind III restriction sites. A radiolabelled oligonucleotide probe based on part of the nucleotide sequence of a metallothionein from Svnechococcus FCC 6301 did not bind to a genomic and plasmid blot of Svnechococcus D562 DNA. The putative Cd-binding peptides ((yEC)(_n)G's) that were discovered only bound significant quantities of the metal when cells were exposed to 6.17 mg 1(^-1) Cd for 2 days at the end of their log-growth phase. Indigenous peptides failed to bind substantial amounts of the metal and the presence of Cd throughout growth did not influence the quantity of chelated Cd, except for Mougeotia D536. The pH of half displacement for (yEQjp's from this strain is comparable with that of other species. Reversed-phase HPLC of the peptides from Mougeotia D536 generated a thiol profile similar to that recorded for the Cd-binding peptides of Datura innoxia. The Cd-induced ultrastructural distortions that were recorded include potential Ca / P / Cd precipitates in Mougeotia D536, the loss of polyglucoside granules from Calothrix D184 together with a relaxation of its thylakoid packing and a lack of plastoglobuli in Cd-exposed Klebsormidium D537. The space between an immobilized cell and the matrix either represents shrinkage of the matrix during dehydration or mucilage which does not bind electron dense stains. Release of alkaline phosphatase into the medium by Svnechococcus D562, provided suitable material to study the inhibitory effects of Cd upon P hydrolysis. Ultrafiltration membranes proved effective as initial step towards enzyme purification and for the determination of activity under sub-optimal pH conditions. At pH 7.0, the activity of an enzyme concentrate was inhibited when 1 and 10 mg 1(^-1) Cd were added to the assay medium, but the presence of this metal in the growth medium did not reduce activity. One-dimensional SDS PAGE revealed only one protein difference between strains grown with or without Cd; a reduction in the staining intensity of a 17 kD band of Calothrix D184.

Phytoremediation has been intensively studied during the past decade due to its cost-effectiveness and environmental harmonies. Most of the studies on treatment of heavy metal pollution in soil and water by plant species have been done in developed countries but are limited in Vietnam. In this study, we presented some research results of phytoremediation of polluted soils and water with heavy metals that were done by Institute of Environmental Technology for several last years. For treatment of heavy metal pollution in the water, some plants have great ability to accumulate heavy metals such as Vetiveria zizanioides, Phragmites australis, Eichhornia crassipes, Pistia stratiotes, Ipomoea aquatica, Nypa fruticans and Enhydra fluctuans. The heavy metal uptake into shoots and roots of 33 indigenous plant species in Thai Nguyen province was also determined. Two species of the plants investigated, Pteris vittata L. and Pityrogramma calomelanos L. were As hyperaccumulators, containing more than 0.1% As in their shoots while Eleusine indica, Cynodon dactylon, Cyperus rotundus and Equisetum ramosissimum accumulated very high Pb (0.15-0.65%) and Zn (0.22-1.56%) concentrations in their roots. Some experiments to clarify the potential of several plants as good candidates for phytoremediation of polluted soil by heavy metals were carried out in our institute
Phương pháp sử dụng thực vật để xử lý ô nhiễm đã được nghiên cứu nhiều trong thập kỷ qua do chi phí thấp và thân thiện với môi trường. Hầu hết các nghiên cứu về xử lý ô nhiễm kim loại nặng trong đất và nước bằng thực vật đã được thực hiện ở các nước phát triển nhưng ít có tại Việt Nam. Trong nghiên cứu này, chúng tôi giới thiệu một số kết quả dùng công nghệ thực vật để xử lý ô nhiễm kim loại nặng trong đất và nước tại Viện Công nghệ môi trường trong những năm gần đây. Dối với xử lý ô nhiễm kim loại nặng trong nước, một số thực vật có khả năng tích lũy tốt kim loại nặng như Vetiveria zizanioides, Phragmites australis, Eichhornia crassipes, Pistia stratiotes, Ipomoea aquatica, Nypa fruticans và Enhydra fluctuans. Sự hấp thụ và tích lũy kim loại nặng trong phần trên mặt đất và rễ của 33 loài thực vật bản địa tại Thái Nguyên cũng đã được xác định. Hai loài thực vật khảo sát là Pteris vittata và Pityrogramma calomelanos là những loài siêu tích lũy As, chứa hơn 0,1% As trong phần trên mặt đất của cây. leusine indica, Cynodon dactylon, Cyperus rotundus và Equisetum ramosissimum tích lũy Pb (0,15-0,65%) và Zn (0,22-1,56%) rất cao trong rễ. Một số thí nghiệm đánh giá tiềm năng của một số thực vật là đối tượng tốt cho xử lý ô nhiễm kim loại nặng trong đất đã được tiến hành trong phòng thí nghiệm của Viện Công nghệ môi trường

Phytoremediation has been intensively studied during the past decade due to its cost-effectiveness and environmental harmonies. Most of the studies on treatment of heavy metal pollution in soil and water by plant species have been done in developed countries but are limited in Vietnam. In this study, we presented some research results of phytoremediation of polluted soils and water with heavy metals that were done by Institute of Environmental Technology for several last years. For treatment of heavy metal pollution in the water, some plants have great ability to accumulate heavy metals such as Vetiveria zizanioides, Phragmites australis, Eichhornia crassipes, Pistia stratiotes, Ipomoea aquatica, Nypa fruticans and Enhydra fluctuans. The heavy metal uptake into shoots and roots of 33 indigenous plant species in Thai Nguyen province was also determined. Two species of the plants investigated, Pteris vittata L. and Pityrogramma calomelanos L. were As hyperaccumulators, containing more than 0.1% As in their shoots while Eleusine indica, Cynodon dactylon, Cyperus rotundus and Equisetum ramosissimum accumulated very high Pb (0.15-0.65%) and Zn (0.22-1.56%) concentrations in their roots. Some experiments to clarify the potential of several plants as good candidates for phytoremediation of polluted soil by heavy metals were carried out in our institute.
Phương pháp sử dụng thực vật để xử lý ô nhiễm đã được nghiên cứu nhiều trong thập kỷ qua do chi phí thấp và thân thiện với môi trường. Hầu hết các nghiên cứu về xử lý ô nhiễm kim loại nặng trong đất và nước bằng thực vật đã được thực hiện ở các nước phát triển nhưng ít có tại Việt Nam. Trong nghiên cứu này, chúng tôi giới thiệu một số kết quả dùng công nghệ thực vật để xử lý ô nhiễm kim loại nặng trong đất và nước tại Viện Công nghệ môi trường trong những năm gần đây. Dối với xử lý ô nhiễm kim loại nặng trong nước, một số thực vật có khả năng tích lũy tốt kim loại nặng như Vetiveria zizanioides, Phragmites australis, Eichhornia crassipes, Pistia stratiotes, Ipomoea aquatica, Nypa fruticans và Enhydra fluctuans. Sự hấp thụ và tích lũy kim loại nặng trong phần trên mặt đất và rễ của 33 loài thực vật bản địa tại Thái Nguyên cũng đã được xác định. Hai loài thực vật khảo sát là Pteris vittata và Pityrogramma calomelanos là những loài siêu tích lũy As, chứa hơn 0,1% As trong phần trên mặt đất của cây. leusine indica, Cynodon dactylon, Cyperus rotundus và Equisetum ramosissimum tích lũy Pb (0,15-0,65%) và Zn (0,22-1,56%) rất cao trong rễ. Một số thí nghiệm đánh giá tiềm năng của một số thực vật là đối tượng tốt cho xử lý ô nhiễm kim loại nặng trong đất đã được tiến hành trong phòng thí nghiệm của Viện Công nghệ môi trường.

Conventional wisdom in ecotoxicology predicts reductions in organismal fitness to follow from exposure-related physiological effects. This expectation may be appropriate for controlled laboratory environments, but may not necessarily reflect what is likely to take place in the wild. In an extensive review of the ecotoxicology literature, it was revealed that fish condition factor (an index of energetic fitness) is just as likely to respond favourably to pollutant exposure as it is to respond negatively. The remainder of this thesis examines some of the ecological reasons for this apparent paradox. One possible cause of altered energetic status in wild, pollutant-exposed fish is variable food availability. Addressing this possibility, I showed that consumption rates (estimated using a 137Cesium mass-balance approach) were not related to growth reductions in hormonally-impaired yellow perch ( Perca flavescens) from metal-contaminated lakes. Another possibility is that fish forage less efficiently in metal-polluted lakes as a result of lowered prey choice. In this thesis, I develop an enzymatic and individual-based biomarker for fish activity costs (muscle lactate dehydrogenase, LDH, activity) and show, through the use of this tool that the cost of fish activity is intimately tied to prey type and the ability to make normal ontogenetic diet shifts. Through the application of LDH measurements, as well as through bioenergetic modelling, diet and prey community analyses, a link between decreased prey choice and high perch activity costs leading to zero growth efficiency (energetic bottlenecks) was demonstrated in yellow perch from metal-contaminated lakes. This finding provided one of the first examples in ecotoxicology of a mechanistic link between community and organismal endpoints. The findings of this thesis emphasize the need for ecotoxicology to consider ecology when looking for and interpreting ecologically relevant endpoints. The final chapter of this thesis ex

The worldwide persistence of nitrate (NO -) in groundwater is worrying since this compound has been related to human illnesses and to eutrophication of aquatic ecosystems. The main sources of pollution are linked to intensive use of fertilizers and septic system leakage. Since 1991, European directives have been applied to mitigate NO - pollution by limiting N application in agricultural lands. However, due to the long residence time of N in the soil organic matter pool, the outcome of the implemented management practices can be delayed for decades. Consequently, remediation strategies must be developed and optimized. The NO3- reduction to innocuous dinitrogen gas (N2), can occur intrinsically in many environments due to the ubiquity of denitrifying microorganisms. However, the electron donor presence is usually a limiting factor in the contaminated aquifers. Hence, one feasible treatment involves inducing the denitrification by application of an external electron donor. During the implementation of bioremediation strategies, the contaminant removal can be estimated by monitoring its concentrations before and after the treatment. However, this method does not reveal the specific processes involved in the attenuation, making it challenging to focus on the improvement of the remediation approach. Isotopic analyses have proved to be a powerful tool in identifying the sources and transformation processes of groundwater contaminants. During the enzymatic NO3- reduction, the unreacted residual substrate becomes enriched in the heavy isotopes 15N and 18O, allowing to distinguish the biotic reduction from processes such as dilution with non-polluted water that could also lead to a concentration decrease without influencing the isotopic signature. The present thesis focusses on investigating the use of low-cost electron donors to promote the denitrification, and on using isotopic tools to evaluate the denitrification efficiency at field- scale. The tested materials in batch and flow-through experiments were: whey, corn stubble, wheat hay, animal compost, magnetite, siderite and olivine. Different parameters that could affect the biotic NO3- reduction efficiency were evaluated (e.g., temperature, ratio between electron donor and acceptor, harmful by-product accumulation, abiotic reactivity or coexistence of other contaminants) and the isotopic fractionation values (ε15N and ε18O) were determined for all tested conditions. At field-scale, three different polluted water bodies were studied, in which the determined ε15N and ε18O at the laboratory were applied to quantify the natural and/or induced denitrification. In a polluted aquifer in Spain, the NO3- attenuation was evaluated during a long-term induced denitrification strategy by acetic acid injections. In a polluted aquifer in Argentina, the natural NO3- attenuation was evaluated considering changes in the reactivity and isotopic fractionation due to the simultaneous presence of NO - and Cr6+. Finally, in a constructed wetland (CW) treating agricultural runoff water, the NO - attenuation was evaluated before and after application of an electron donor both in the autumn-winter and spring-summer seasons. The laboratory experiments demonstrated that magnetite nanoparticles, corn stubble, wheat hay, animal compost and whey could efficiently promote the denitrification in polluted water bodies. In these biotic experiments, the complete NO3- reduction to N2 was demonstrated by transient or negligible accumulation of other nitrogen compounds such as nitrite (NO2-), ammonium (NH +) or nitrous oxide (N O). However, the N O was found to be the end- product of the abiotic NO - reduction, which can be mediated by ferrous iron, if present. The ε15NNO3/N2 and ε18ONO3/N2 values were calculated for all the batch experiments and for the periods of the flow-through experiment that allowed complete denitrification. For the non- complete denitrification periods, the NO - isotopic characterization showed a mix of denitrified and non-denitrified water at the outflow. The isotopic characterization of NO - and N2O allowed to distinguish the biotic from the abiotic NO - reduction by ferrous iron at the laboratory-scale. A two-stage isotopic fractionation pattern was found for Cr6+, which can be reduced simultaneously to NO -. Also, the carbon compounds isotopic analysis allowed to assess the fate of the studied organic carbon materials to be used as electron donors. In the field-scale studies, the chemical and isotopic characterization allowed to trace the extent of the natural or induced denitrification and to evaluate the safety of the treatments. In a pilot plant to remediate groundwater NO3- pollution (Spain), acetic acid was injected by pulses to an alluvial aquifer for 22 months. According to the isotopic results, the induced denitrification achieved at least 50 % NO3- attenuation. The isotopic analyses also allowed to identify the reoxidation of NO2- to NO3- during the treatment and to recognize a mixture between the denitrified and partially or non-denitrified groundwater in one of the sampling points. In a polluted aquifer with both NO3- and Cr6+ (Argentina), the calculated natural attenuation was 20 % for NO3- and 60 % for Cr6+. For this calculation, the two stage trend observed for the ε53Cr was considered. The attenuation of Cr6+ in a few samples was found to be due by both reduction and dilution. In a CW treating agricultural runoff water, a slight natural NO3- attenuation was only observed when the flow was below 5.5 L/s. According to the isotopic results, after the biostimulation by stubble application, at least 60 % NO3- was removed at 16 L/s. The biostimulation treatment in autumn lasted in one month, while in spring the attenuation remained for three months.
La persistència del nitrat (NO -) en aigües subterrànies és preocupant ja que aquest, pot provocar malalties en humans i eutrofització d’ecosistemes aquàtics. Els principals orígens de contaminació són l’ús intensiu de fertilitzants i les pèrdues dels sistemes sèptics. Tot i que els darrers anys s’ha limitat la quantitat de N aplicat en zones agrícoles, degut al llarg temps de residència del N en la matèria orgànica del sòl, el resultat de les pràctiques implementades, es pot ajornar fins dècades. Per tant, és necessari desenvolupar i optimitzar estratègies de remediació. La reducció del NO - a dinitrogen gas (N ), que és un gas innocu, es dona intrínsecament en molts ambients degut a la ubiqüitat dels microorganismes amb capacitat de desnitrificar. Malauradament, la presència de donadors d’electrons sol ser un factor limitant en aqüífers contaminats per NO -. Per això, un possible tractament consisteix en induir la desnitrificació gràcies a l’aplicació d’un donador d’electrons extern.Durant la implementació d’estratègies de bioremediació, l’eliminació del contaminant es pot determinar mitjançant la monitorització de les seves concentracions abans i després del tractament. Però aquest mètode no mostra el procés específic involucrat en l’atenuació i això dificulta l’optimització de l’estratègia de remediació. Els anàlisis isotòpics resulten útils per identificar fonts i processos de transformació de diversos contaminants en aigües subterrànies. Durant la reducció enzimàtica del NO3-, el substrat residual es va enriquint en els isòtops pesats 15N i 18O. Això permet distingir la reducció biòtica d’altres processos com la dilució amb aigua no contaminada que també podria donar lloc a una disminució de la concentració del NO3- però sense influenciar la seva signatura isotòpica.Aquesta tesi es centra en investigar l’ús de donadors d’electrons de baix cost (sèrum làctic, restes vegetals (blat i panís), compost animal, magnetita, siderita i olivina) per induir la desnitrificació i l’ús d’eines isotòpiques per avaluar l’eficiència de desnitrificació a escala de camp. Durant els experiments al laboratori s’han avaluat diferents paràmetres que poden afectar l’eficiència de la reducció biòtica del NO3- (ex. temperatura, ràtio entre el donador i acceptor d’electrons, acumulació de productes intermedis tòxics, reactivitat abiòtica o coexistència d’altres contaminants) i s’han calculat els valors de fraccionament isotòpic (ε15N i ε18O) per totes les condicions investigades. A escala de camp, s’han estudiat tres masses d’aigua contaminades en les que s’han aplicat els valors de ε15N i ε18O determinats al laboratori per quantificar la desnitrificació natural o induïda. En un aqüífer contaminat a Espanya, l’atenuació del NO3- s’ha avaluat durant una estratègia de desnitrificació induïda mitjançant la injecció d’àcid acètic. En un aqüífer contaminat a Argentina, l’atenuació natural del NO3- s’ha avaluat considerant canvis en la reactivitat i el fraccionament isotòpic degut a la presencia simultània de NO - i Cr6+. En un aiguamoll construït en el qual es tracta aigua d’escorrentia agrícola, l’atenuació del NO - s’ha avaluat abans i després de l’aplicació d’un donador d’electrons tant a la tardor-hivern com a la primavera-estiu.Els experiments de laboratori han demostrat que les nanopartícules de magnetita, les restes vegetals (blat i panís), el compost animal i el sèrum làctic poden induir la desnitrificació en aigües contaminades. En aquests experiments biòtics, la reducció completa del NO - a N ha estat demostrada per una acumulació transient o negligible d’altres compostos nitrogenats com el nitrit (NO -), l’amoni (NH +) o l’òxid nitrós (N O). Tot i això, s’ha vist que el N2O és el producte final de la reducció abiòtica del NO - provocada per l’oxidació de Fe2+, si és present en l’aigua. Els valors de ε15NNO3/N2 i ε18ONO3/N2 s’han calculat pels experiments de tipus batch i pels períodes d’un experiment de tipus flux continu durant els que es va assolir una desnitrificació completa. La caracterització isotòpica del NO - i el N O ha permès distingir la reducció del NO2- biòtica de l’abiòtica per oxidació de Fe2+ al laboratori. Per al Cr6+, un contaminant que es pot reduir simultàniament al NO3-, s’ha observat un fraccionament isotòpic en dos estadis. A més, l’anàlisi isotòpic dels compostos de carboni ha permès avaluar el consum dels donadors d’electrons de carboni orgànic estudiats.En els estudis a escala de camp, la caracterització química i isotòpica ha permès traçar l’eficiència de la desnitrificació natural i/o induïda i avaluar la seguretat dels tractaments. En una planta pilot per remeiar la contaminació de NO3- d’aigües subterrànies (Espanya), s’ha injectat àcid acètic a l’aqüífer durant 22 mesos. D’acord amb els resultats isotòpics, la desnitrificació induïda ha assolit almenys un 50% d’atenuació del NO3-. La caracterització isotòpica també ha permès identificar la reoxidació de NO2- a NO3- durant el tractament i reconèixer una barreja entre aigua desnitrificada i aigua parcialment o no desnitrifricada en un dels punts de mostreig. En un altre aqüífer contaminat amb NO3- i Cr6+ (Argentina), l’atenuació natural calculada ha estat del 20% per al NO3- i del 60 % per al Cr6+. Per a aquest càlcul s’ha tingut en compte el fraccionament isotòpic en dos estadis observat pel Cr6+ en els experiments de laboratori. L’atenuació del Cr6+ en algunes mostres ha estat deguda en part a dilució i en part a reducció. En l’aiguamoll construït, l’atenuació natural del NO3- només es dona quan el flux és inferior a 5.5 L/s. D’acord amb els resultats isotòpics, després de la bioestimulació per aplicació de restes vegetals (panís), s’ha aconseguit una reducció del 60 % del NO3-, a un flux de 16 L/s. El tractament de bioestimulació a l’octubre-hivern ha durat un mes, mentre que a la primavera-estiu s’ha mantingut durant tres mesos.

Thesis (MSc Food Sc)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Fresh produce irrigation water from Western Cape Rivers carries faecal coliforms (FC) (Escherichia coli) at concentrations which often exceed the suggested limit of 1 000 FC per 100 mL and presents a health risk to consumers. On-farm ultraviolet (UV) irradiation presents several advantages for water disinfection but is an uncommon practice in South Africa. The aim of this study was to investigate the use of UV irradiation for river water disinfection prior to irrigation. Escherichia coli (E. coli) strains were exposed to low-pressure (LP) UV (4 mJ.cm-2) and UV/Hydrogen peroxide (H2O2) (4 mJ.cm-2/20 mg.L-1) treatments in Sterile Saline Solution (SSS). Strain variation in reductions was observed and ranged from 1.58 to 3.68 and 1.34 to 3.60 log for the UV and UV/H2O2 treatments, respectively. The UV/H2O2 treatment (4 mJ.cm-2/20 mg.L-1) was more effective, compared to UV singly, against some of the E. coli strains. Selected strains showed increased sensitivity at higher UV doses (8, 10 and 13 mJ.cm-2) and H2O2 concentrations (100 and 200 mg.L-1 with 4 mJ.cm-2) but a 3 log target reduction was not always reached. For all UV and UV/H2O2 treatments maximum resistance was shown by an environmental strain. Reference strains should, therefore, not be used for the optimisation of UV based disinfection parameters. At 10 mJ.cm-2 an American Type Culture Collection (ATCC) reference strain and an environmental strain (ATCC 25922 and F11.2) were both significantly less inactivated in sterilised river water compared to SSS. Enhanced water quality allowed for improved inactivation of the ATCC strain. Also, the efficiency of LP UV (5, 7 and 10 mJ.cm-2) and medium-pressure (MP) UV (13, 17 and 24 mJ.cm-2) radiation was investigated using water from the Plankenburg River. Water was sampled and treated on three respective days (Trials 1 to 3). Physico-chemical and microbiological water quality was always poor. The FC concentration reached a maximum of 6.41 log cfu.100 mL-1 while UV transmission was always below 38%. For LP and MP UV irradiation increased doses resulted in increased disinfection but a 3 log reduction of FC was only attained when MP UV light was used in Trial 1. Disinfection efficiency was dependent on water quality and on the characteristics of the microbial population in the water. Since FC were never reduced to below 3 log cfu.100 mL-1, the water did not adhere to guidelines for produce irrigation. Photo-repair following irradiation was investigated in river water using MP UV doses of 13 and 24 mJ.cm-2 and 3.5 kLux reactivating light, initially. Ultraviolet transmission was close to 50% and total coliform (TC) reduction exceeded 3 log, even at 13 mJ.cm-2. However, TC were reactivated from below 1 000 cfu.100.mL-1 to 3.93 and 4.41 log cfu.100 mL-1 for the 13 and 24 mJ.cm-2 treatments, respectively. A higher MP dose (40 mJ.cm-2) and a different treatment regime (2 x 20 mJ.cm-2) inhibited photo-repair (compared to 13 and 24 mJ.cm-2) but TC were always recovered to a final concentration surpassing 3 log cfu.100 mL-1, even under lower light intensities (1.0 to 2.0 kLux). In the current study UV irradiation did not produce water of acceptable standards for produce irrigation, mainly as a result of extremely poor water quality. However, on farm-scale, UV efficiency could be enhanced by improving water quality before irradiation. Also, stronger lamps that deliver higher UV doses may result in adequate disinfection, irrespective of water quality. Higher UV doses and the use of combination treatments (such as UV/Chlorine and UV/Peracetic acid) should be further investigated also to determine its disinfection efficiency and possible capability to inhibit post-disinfection repair.
AFRIKAANSE OPSOMMING: Varsproduk besproeiingswater vanuit Wes-Kaapse riviere bevat fekale kolivorme (FK) (Escherichia coli) in konsentrasies wat dikwels die voorgestelde limiet van 1 000 FK per 100 mL oorskry en hou `n gesondheidsrisiko vir verbruikers in. Plaasvlak ultraviolet (UV) bestraling bied verskeie voordele met verwysing na water dekontaminering, maar word selde aangewend in Suid-Afrika. Die doel van hierdie studie was om die gebruik van UV bestraling vir die dekontaminering van rivierwater, voor besproeiing, te ondersoek. Escherichia coli (E. coli) isolate is blootgestel aan lae-druk (LD) UV (4 mJ.cm-2) en UV/Waterstofperoksied (H2O2) (4 mJ.cm-2/20 mg.L-1) behandelings in Steriele Sout Oplossing (SSO). Isolaat variasie in reduksies is waargeneem en het gewissel tussen 1.58 tot 3.68 en 1.34 tot 3.60 log vir die UV en UV/H2O2 behandelings, onderskeidelik. In vergelyking met UV bestraling alleen was die UV/H2O2 behandeling (4 mJ.cm-2/20 mg.L-1) meer effektief teen sommige E. coli isolate. Geselekteerde isolate was meer sensitief tot hoër UV dosisse (8, 10 en 13 mJ.cm-2) en H2O2 konsentrasies (100 en 200 mg.L-1 met 4 mJ.cm-2), maar `n 3 log teikenreduksie was nie altyd haalbaar nie. Vir alle UV en UV/H2O2 behandlinge was die meeste weerstand deur `n omgewingsisolaat gebied. Verwysingsisolate behoort daarom nie aangewend te word vir die optimisering van UV-gebaseerde behandelingsparameters nie. By 10 mJ.cm-2 was beide `n ATCC verwysingsisolaat en `n omgewingsisolaat (ATCC 25922 en F11.2) betekenisvol minder gedeaktiveer in rivierwater as in SSO. Verbeterde waterkwaliteit het verhoogde inaktivering van die ATCC isolaat toegelaat. Die doeltreffendheid van LD UV (5, 7 en 10 mJ.cm-2) en medium-druk (MD) UV (13, 17 en 24 mJ.cm-2) bestraling is ook ondersoek deur watermonsters vanuit die Plankenburg Rivier te gebruik. Watermonsters was getrek en behandel op drie verskillende dae (Proewe 1 tot 3). Fisies-chemiese en mikrobiologiese kwaliteit van die water was deurentyd swak. Die FK konsentrasie het `n maksimum van 6.41 log kve.100 mL-1 bereik terwyl UV transmissie altyd laer as 38% was. Vir beide LD en MD UV bestraling het verhoogde dosisse gelei tot verbeterde dekontaminering, maar `n 3 log reduksie is slegs bereik toe MD UV lig gebruik is in Proef 1. Die effektiwiteit van die behandelings was afhanklik van waterkwaliteit en die eienskappe van die mikrobiese populasie in die water. Aangesien FK nooit tot onder 3 log kve.100 mL-1 verminder is nie het die water nie voldoen aan riglyne vir varsproduk-besproeiing nie. Fotoherstel na bestraling was ondersoek in rivierwater deur aanvanklik gebruik te maak van MD UV dosisse van 13 en 24 mJ.cm-2 en 3.5 kLux heraktiverende lig. Ultraviolettransmissie het byna 50% bereik en reduksie van totale kolivorme (TK) het 3 log oorskry, selfs by 13 mJ.cm-2. Totale kolivorme was egter geheraktiveer van onder 1 000 kve.100.mL-1 tot 3.93 en 4.41 log kve.100 mL-1 vir die 13 en 24 mJ.cm-2 behandelings, onderskeidelik. In vergelyking met 13 en 24 mJ.cm-2 het `n hoër MD dosis (40 mJ.cm-2) en `n veranderde bestralingstegniek (2 x 20 mJ.cm-2) fotoherstel onderdruk, maar TK was in elke geval geheraktiveer tot `n finale konsentrasie hoër as 3 log kve.100 mL-1, selfs onder laer intensiteit lig (1.0 tot 2.0 kLux). In hierdie ondersoek het UV bestraling nie water van aanvaarbare standaarde vir varsproduk besproeiing gelewer nie, hoofsaaklik as gevolg van swak waterkwaliteit. Nietemin, op plaasvlak mag die effektiwiteit van UV bestraling verhoog word deur waterkwaliteit voor bestraling te verbeter. Die gebruik van sterker lampe, om hoër UV dosisse te produseer, mag verder bydra tot voldoende dekontaminasie, ongeag van waterkwaliteit. Hoër UV dosisse en die gebruik van kombinasie behandelinge (soos UV/Chloor en UV/Perasynsuur) moet ook verder ondersoek word om die dekontaminasie effektiwiteit, en vermoë daarvan om heraktivering na dekontaminering te onderdruk, vas te stel.

Three systems for filtering polluted river water for use in subsurface irrigation have been designed, operated and evaluated. One system consisted of filtering the water through filter basins covered with grass. The second system used geotextiles in filter basins. The third system consisted of flooding a section of a field. In this system, the water was filtered as it moved through the soil towards the subsurface drainage/irrigation drain pipes.
It was found that grass filter basins are very efficient in removing sediment from river water. Grass filter basins having drain pipes placed in trenches 30 cm wide backfilled with sand gave the best results. More than 90% of sediments were removed from the river water. From the outflow measurements, it was found that less than 0.2% of the field to be irrigated needs to be devoted to the filtration system.
Important filter design parameters, namely filtration rates per unit area of filter basin and per unit length of filter trench and drain pipe, were determined.
Due to the fast clogging of the geotextile, filtration of river water through basins covered with geotextile was found to be impractical and expensive, as compared to filtration using water tolerant grasses as a basin cover.
Flooding a section of the crop land combined with controlled drainage was found to be an efficient way of irrigating maize crop. The yields obtained with this system were comparable with those obtained with conventional subsurface irrigation. Flood irrigation combined with controlled drainage would be particularly commendable on relatively flat fields which have subsurface drains.

In all areas of hydrology, where one or several variables are measured as a function of time, it might be necessary to interpolate the measured variable(s). There is a form of artificial intelligence (AI) called neural networks, which seem to be appropriate for this application. In an environmental project in Bolivia, where, among others, the concentrations of arsenic (As), cadmium (Cd) and lead (Pb) in the polluted Huanuni river was measured, a data set appropriate for application of the neural network method was available. Several neural networks with different configurations were used to interpolate concentration values of the three sampled metals. The neural networks interpolated concentrations at time steps where actual, measured, values existed so that an estimate of the method’s capacity could be obtained. The neural networks’ interpolating capability were compared to that of linear interpolation and linear equations derived by multiple regression. In the case of cadmium, the linear interpolation was the best method, whereas the neural network method was best at interpolating arsenic and lead concentrations. The conclusions of this study are that the neural network method was the most succesful method; that this method was the most complicated to implement; that this method was not fully optimised; and that, to evaluate the neural network method’s general applicability as an interpolation method in hydrology, further studies have to be conducted.
Inom alla områden av hydrologin, där man mäter en eller flera variabler som funktion av tid, kan det finnas ett behov av att interpolera glesa tidsseriedata. Det finns en form av artificiell intelligens (AI) som kallas för neurala nät, vilken verkar vara lämplig att applicera på detta problem. Genom ett miljöprojekt i Bolivia, där bl.a. arsenik-, bly-, och kadmiumkoncentrationer i den förorenade floden Huanuni mättes, blev data lämpliga för applicering av den neurala nätmetoden tillgängliga. Flera neurala nät med olika konfigurationer användes för att interpolera koncentrationsvärden av de tre metallerna. De neurala näten interpolerade värden längs tidssteg där verkliga, uppmätta, koncentrationsvärden fanns, så att en uppskattning av metodens kapacitet kunde göras. Dess kapacitet jämfördes med kapaciteten hos två andra metoder: linjär interpolation och linjära ekvationssystem härledda med hjälp av multipel regression. Den linjära interpolationsmetoden var bäst i fallet kadmium, medan den neurala nätmetoden var bäst i de två andra fallen. Slutsatserna av den här studien är att den neurala nätmetoden var den bästa; att denna metod var den mest komplicerade att använda; att denna metod inte var helt optimerad, och att det krävs ytterligare studier för att utvärdera den neurala nätmetodens allmänna lämplighet som metod att interpolera glesa hydrologiska tidsseriedata.

Freshwater ecosystems are under increasing pressure from a variety of contaminants, including heavy metals from mining operations, which can have complex effects that are difficult to evaluate. To detect early warnings from elevated concentrations of metals, organisms are sought to be used as monitoring tools. For example, mouthpart deformities in Chironomid larvae have been proposed as a bioindicator of stress in aquatic environments. However, the frequency and cause of these deformations, and their sensitivity to different stressors remain uncertain. In this study, I evaluated the usefulness of mouthpart deformities as a tool to monitor the effects of heavy metals from mining in northern Sweden. To do this, the mouthparts of 3789 Chironomid individuals analyzed from 17 sites closely located to mining operations and tested against concentrations of metals and DOC in the water chemistry of lakes and rivers. The frequency of deformities ranged from 0.00 – 4.79 % across all sites. Metal concentrations ranged from ‘very low’ to ‘low’ based on biological effect risk assessments. Of these, copper (R2 = 0.73) and cobalt (R2 = 0.66) were found to be significantly correlated with frequency of deformities. Additionally, the occurrence of deformities declined with DOC concentration, this was a nonlinear relationship. Frequencies of deformities observed in this study were lower than what have been reported to similar studies. The result from this study, together with other studies, suggest that deformities in Chironomid larvae are sensitive to even low levels of certain metals and could potentially be a good biomonitoring tool for early warnings of contamination in freshwater environments.

La double fonction absorption-photodégradation des composites CA-TiO2 vis-à-vis des polluants biorécalcitrants est une alternative prometteuse pour le traitement de l’eau par voie solaire. Dans ce travail, des composites CA-TiO2 sont élaborés suivants trois méthodes simples basées sur l’utilisation des biomasses trouvées dans la sous région ensoleillée de l’Afrique subsaharienne. Les charbons actifs (CA) obtenus après pyrolyse des biomasses développent une structure poreuse qui se modifie ensuite en fonction de la voie de fixation des nanoparticules TiO2 (NPs-TiO2) pour l’obtention des composites. Parmi les trois vois de fixation du TiO2, l’imprégnation du CA avec le sol de NPs-TiO2 préformées conduit à des matériaux (CAT.SX) avec du TiO2 déposé de façon homogène à la « surface externe » du CA. Cette microtexture permet un meilleur couplage des propriétés adsorption-photodégradation, favorables aux performances de dépollution évaluées à l’échelle de laboratoire sur des solutions de phénol à 100 mg.L-1. Le réseau pores/surface spécifique est moins développé sur les composites obtenus par fixation in situ des NPs-TiO2 sur du CA imprégné de gel de TiO2 (CAT.GX), ou par pyrolyse directe de biomasse pré-imprégnée de NPs-TiO2 (CAT.SBX) ; ce qui explique les performances de dépollution moins élevées enregistrées pour ces deux dernières familles de catalyseurs. Les cinétiques d’élimination du polluant obtenues après plusieurs cycles successifs d’utilisation des catalyseurs CAT.SX ont été correctement simulées avec un modèle dont le formalisme tient compte de la double fonctionnalité des catalyseurs. Ce modèle permet d’envisager le dimensionnement d’installations solaires en condition réelle d’utilisation de ces nouveaux catalyseurs en zones fortement ensoleillée
Adsorption/photodegradation dual property of AC-TiO2 composites materials towards biorefractory pollutants is a promising issue for solar water treatment. In this work, AC-TiO2 hybrid materials have been synthesized through 03 novel routes based on the conversion of typical biomasses, abundantly found in the subsaharian African sunny areas. Biomasses pyrolysis derived activated carbon (AC) developed a porous structure which is modified differently according to the method used to fix TiO2 nanoparticules (TiO2-NPs). AC impregnated with a sol containing TiO2-NPs suspension provides the derived composite material (CAT.SX) with TiO2-NPs regularly deposited at the “external surface”, leading to a good coupling of adsorption/photodegradation activities towards phenol elimination in 100 mg.L-1 polluted water, carried out on lab scale experiments. Pore/surface area network is less developed on composites obtained after in situ fixation of TiO2-NPs on TiO2 gel impregnated AC (CAT.GX), or obtained after direct pyrolysis of TiO2-NPs impregnated biomass (CAT.SBX) – which infers lesser decontamination performances for these two latter families of catalysts. Pollutant elimination kinetics curves depicted after recycling of CAT.SX over several running water treatment was simulated with a suitable mathematical model which takes into consideration the dual functionalities of the elaborated material. The established model is a promising attempt for future dimensioning of real solar water treatment plants, operating in sunny areas with the new composite catalysts

Aromatic hydrocarbons are a prevalent constituent of crude oil. The refined products of crude oil such as petroleum and diesel can find their way into groundwater though oil-spillages and are also present in the oil and gas industry’s produced water. These aromatics are biorecalcitrant, however upon ingestion with water, may be metabolised to toxic intermediates that are carcinogenic or mutagenic in nature. Although some treatment technologies are available most of these are under development and are yet to be proven in the field. This illustrates the need for novel, economical and environmentally friendly technologies to be developed with a view to remediating aqueous systems that have been polluted with aromatics hydrocarbons. The supramolecular cyclodextrin molecule, with its hydrophobic interior and hydrophobic exterior seems to be an excellent molecule for the trapping of the pollutant molecules, however the inclusion complexes with this cyclic sugar are water-soluble therefore there is a need for the cyclodextrin to be rendered waterinsoluble. A study of the aqueous solubilities of some aromatic hydrocarbons that may be present in crude oil has been carried out and shows that the majority of these molecules have a degree of water solubility that may increase upon environmental weathering. The successful reaction between a solid-phase resin and the β-cyclodextrin molecule has been achieved, with the total dryness of the system being required including Soxhlet extraction of the resin with anhydrous acetone before the reaction. The reaction between β-cyclodextrin and a range of isocyanates proved unsuccessful, but a range of symmetrical aryl ureas were synthesised from their isocyanates with the influence that different activating or deactivating groups on the ring have on the propensity to form the ureas being shown. The successful alkylation between β-cyclodextrin and a series of haloalkanes has shown the effect of increasing chain length on the degree of alkylation. This reaction involved the deprotonation of the cyclodextrin by sodium hydride in anhydrous dimethyl sulphoxide followed by reaction with the alkyl iodide. Increasing the equivalents of hydride or iodide, or the reaction time did not have a noticeable effect on the degree of reaction indicating that steric constraints were limiting the degree of reaction. Testing several of these alkyl iodides gave an indication as to their tendency to uptake and remove several model pollutants that had been dissolved in water with the propylated β-cyclodextrin displaying potential for the remediation of aqueous systems that had been polluted. Several of these results were very promising leading to the conclusion that further derivatives of these alkylated sugars may be even more suitable for future research into the remediation of organically polluted aqueous systems.

Oil and gas were recovered from alum shale (black shale) at Kvarntorp, Närke,during a period of 24 years. One of the remnants of this industry is a 100 m highdeposit with high contents of uranium, arsenic, molybdenum, vanadium and otherelements. Presently the leakage of metals from the deposit into nearby streams israther modest but will most likely accelerate in the near future. One way to preventan uncontrolled leakage of these elements from the deposit into the environmentwould be to install a filter with an effective adsorbent that after saturation could easilybe regenerated and reused. The filter could not only be used to reduce the impact ofmetal leakage to the environment but also to reclaim valuable elements like nickel,vanadium, uranium and molybdenum. Unfortunately such a filter does not existtoday, but there are a wide range of minerals that have high adsorbing capacities andcould serve as filter components in a mineral barrier system. The adsorbingproperties of some natural minerals with respect to selected metals that are abundantin the Kvarntorp deposit are studied in this project. These minerals are bentoniteclay, (burnt clay), unburnt shale (stybb), burnt shale (rödfyr), apatite, peat andbark. In the experiments each sorbent was blended with artificial groundwater and acertain amount of metal stock solution. Samples were taken at five different pH.The results show that the two shale-products stand out from the othersand have the best adsorbing qualities for nickel, copper and zinc. At a pH over 7between 96 and 99% of the metal ions were removed from the solution.Unburned shale especially shows remarkably good results for vanadiumthroughout the tested pH range of 3,4-7,7 between 98 and 99% of the vanadium ionswere removed from the solution. Unburned shale performs best of the testedadsorbents and could probably be used as an adsorbent in a geological barrier butmore research is needed.

Els Processos Avançats d'Oxidació (PAOs) són tècniques de degradació química basades en la producció in situ del potent reactiu radical hidroxil. L'acoblament entre PAOs i sistemes biològics pel tractament d'aigua contaminada amb compostos biorecalcitrants és una alternativa útil als mètodes de gestió convencionals. El principal benefici d'aquests tractaments acoblats és la minimització del pretractament químic fins a generar intermedis més biodegradables. Subseqüentment, un tractament convencional d'aigües residuals, basat en la activitat de microorganismes, es pot utilitzar per eliminar completament la matèria orgànica del medi.
Aquest tesi desenvolupa una estratègia d'acoblament entre sistemes químics i biològics per tractar herbicides específics com exemple de contaminants tòxics i no biodegradables produïts per l'home.
Advanced Oxidation Processes (AOPs) are chemical degradation techniques based on the in situ production of the powerful reactive hydroxyl radical. The coupling between AOPs and biological systems for the treatment of water polluted with biorecalcitrant compounds is a useful alternative to conventional management methods. The main benefit of these coupled treatments is the minimization of the chemical pretreatment to generate more biodegradable by-products. Subsequently, a conventional wastewater treatment, based on the activity of microorganisms, can be used to completely remove organic matter from solution.
This thesis deals with the development of a chemical and biological coupling strategy to treat some specific herbicides as examples of toxic and non biodegradable anthropogenic pollutants.

The purpose of this study was to investigate whether water protection areas with nearby shooting ranges could be polluted by lead from ammunition or not. The goal was to make a risk assessment of the hazard for human health and the environment. The risk assessment leads to a classification of the shooting ranges. The work of the inventory was done according to the method developed by the Swedish Environmental Protection Agency, called “Methodology for Inventory of Polluted Areas”. The report contains two types of studies: one literature study and one practical study where interviews were conducted along with a visit to one of the shooting ranges. The results show that one shooting range was considered to be of high risk to the environment because of the high activity that accumulated several tons of lead and the shooting range’s nearness to a water treatment plant. The other two shooting ranges were smaller and not too close to a drinking water source. Therefore the risks were moderate. Conclusions drawn from this report is that water protection areas within nearby shooting ranges are exposed to potential pollution from lead, but the risks aren’t immediate. Probably will time play an important role to prevent lead spreading to the ground water. Because of its attributes, lead has low mobility under normal conditions.  The vertical transport in the ground is considered slow and it could take hundreds of years before it reaches ground water.

A biofilm is any group of microorganisms in which cells stick to each other and adhere to a surface by excreting a matrix of extracellular polymeric substances (EPS). The chemoautotrophic nitrifying bacteria hardly form biofilms due to their extremely low growth rate; however, biofilm formation of nitrifying bacteria trends to attach in carrier by extracellular polysaccharides that facilitate mutual adhesion, the forming biofilm is also beneficial in nitrogen removal in biological filter systems, especially in aquaculture water treatment systems. The microbial activity within bio-carrier is a key factor in the performance of biofilm reactor. Selection the nitrifier bacteria that biofilm formation and immobilization on the carrier for application in ammonium polluted water treatment technologies, especially in aquaculture is our research objective. Therefore, in this study, ten and six strains of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) respectively were isolated from six different aquaculture water samples collected from Quang Ninh and Soc Trang. Basing on their high nitrification activity and biofilm forming capacity, six bacterial strains have been selected to take photo by scanning electron microscope (SEM) and carry out in 2 – liter tanks with and without carriers. As the results, the system with carriers (30% of total volume) increased nitrogen compounds elimination efficiency from 1.2 times to 2 times in comparison with the system without carrier. Two representatives of ammonia oxidizing bacterial group (B1.1; G2-1.2) were classification based on characteristics and they were classified as Nitrosomonas sp. and Nitrosococcus sp
Màng sinh học được hình thành từ vi sinh vật nhờ các tế bào tiết ra các chất cao phân tử ngoại bào (EPS) và dính vào nhau đồng thời được gắn lên một bề mặt vật thể lỏng hoặc rắn. Vi khuẩn nitrate hóa tự dưỡng có thể tạo ra màng sinh học nhưng khá khó khăn do tỷ lệ sinh trưởng rất chậm của chúng. Tuy nhiên vi khuẩn nitrate hóa tạo màng sinh học thường có xu thế bám lên giá thể nhờ sự gắn kết của các polisaccarit ngoại bào. Sự hình thành màng sinh học cũng là lợi thế để loại bỏ các hợp chất nitơ trong các hệ thống lọc sinh học, đặc biệt là trong các hệ thống xử lý nước nuôi trồng thủy sản. Hoạt tính vi sinh vật cùng với giá thể sinh học là một yếu tố quan trọng để thực hiện trong các bể phản ứng màng sinh học. Trong nghiên cứu này, mục tiêu của chúng tôi là lựa chọn được các vi khuẩn nitrate hóa có khả năng tạo màng sinh học và cố định chúng lên giá thể để ứng dụng trong các công nghệ xử lý nước bị ô nhiễm ammonia đặc biệt là trong nuôi trồng thủy sản. Kết quả cho thấy, từ sáu mẫu nước nuôi trồng thủy sản khác nhau từ Quảng Ninh và Sóc Trăng, 10 chủng vi khuẩn oxy hóa ammonia (AOB) và 6 chủng vi khuẩn oxy hóa nitrite (NOB) đã được phân lập. Dựa vào hoạt tính nitrate hóa và khả năng tạo màng sinh học của các chủng vi khuẩn phân lập được 6 chủng điển hình đã được lựa chọn để chụp ảnh kính hiển vi điện tử quét và được ứng dụng trong hai bể sinh học với dung tích 2 lít có chứa và không chứa chất mang (giá thể). Sau 7 ngày, hệ thống sinh học chứa giá thể (chiếm 30% thể tích) có hiệu suất loại bỏ các hợp chất nitơ tăng hơn từ 1,2 đến 2 lần so với bể sinh học không chứa chất mang. Hai đại diện của nhóm vi khuẩn oxy hóa ammonia (B-1.1 và G2-1.2) đã được phân loại sơ bộ dựa vào một số đặc điểm sinh học và chúng đã được xác định thuộc chi Nitrosomonas và chi Nitrosococcus

The aim of this experimental work has been the application of a new polluted waters treatment technology for the selection of a bacterial population capable of bioremediating a synthetic groundwater polluted by four different chlorinated compounds. The innovative technology applied in this study was the biological treatment system known as MSBR (Membrane Sequencing Bioreactor), which consists of a Sequencing Batch Reactor (SBR) coupled to a membrane module for the filtration of the biological sludge that degrades the chlorinated compounds present in the polluted water fed to the system. The synthetic groundwater used in this experimentation contained four chlorinated compounds: 1,2-dichloroethane, 1,2-dichlorobenzene, 2-chlorophenol and trichloroethylene. During the development of the research, the chlorinated compounds were fed either alone on in different mixtures in order to identify possible effects of each substrate on the degradability of the others. Some operational parameters were varied in order to check the possibility of implementing the system at a larger scale. The MSBR system equipped in this study was effective in the acclimation of a sludge to hardly biodegradable xenobiotic compounds, and the degradation rates achieved were comparable to other similar studies performed, even if in this experimentation, differing from all the others found in literature, good removal rates were achieved for the degradation of the substrates when they were fed in mixtures.

Carbon tetrachloride (CT) and chloroform (CF) are chlorinated methanes (CMs) which have been released to the environment for decades owing to scarce waste management. Since they are dense non-aqueous phase liquids (DNAPLs), CMs migrate downwards and reach groundwater constituting a contamination source. Thus, this pollution requires a thoughtful monitoring and treatment since CT and CF are toxic and predicted to be carcinogenic substances (IARC, 2017). Although CT and CF are considered quite persistent in aquifers, they undergo abiotic and biotic natural attenuation. This degradation occurs mainly through reductive pathways under anoxic conditions, but CF oxidative microbial cometabolism could be also plausible (Cappelletti et al., 2012; Penny et al., 2010). Hence, CMs transformation processes are expected under field conditions. Òdena field site (Barcelona, Spain) is polluted by CMs among other volatile organic compounds (VOCs) due to industrial activity during the 70s and 80s. Chlorinated ethenes (CEs) degradation was detected in the fractured aquifer by carbon isotope (δ13C) enrichment over time (Palau et al., 2014b). CF alkaline hydrolysis (AH) was also revealed by δ13C monitoring in the interception trenches filled with construction wastes (pH ~12) built in the unsaturated zone after 2005 source removal, whereas the cause of CT δ13C enrichment over time in these trenches remains unknown (Torrentó et al., 2014). Induced reactions bear potential to overcome the challenges derived from the slow degradation rates of CMs natural attenuation. Biostimulation, zero valent iron permeable reactive barriers (Fe(0)-PRB) or those made of other reducing agents are receiving increasing attention as alternative remediation strategies. However, in situ chemical oxidation (ISCO) and alkaline hydrolysis are techniques of interest only for CF as a result of the high oxidation state of carbon in CT. Compound specific isotopic analysis (CSIA) is a useful tool to evaluate the efficiency of both CMs natural attenuation and induced strategies in the field. CSIA not only verifies that the concentration decrease is due to reactive processes (instead of dispersion or dilution) but also permits quantification. Moreover, dual isotope plots in which shifts in isotope values of one element are plotted against those of a second element, allow distinction between different CMs reaction mechanisms by means of specific slopes (Λ). Thus, laboratory CMs degradation experiments under controlled conditions are required to gain understanding of the expected isotopic changes in the field and to evaluate whether it is feasible to quantitatively detect degradation. Although relatively new, Cl-CSIA for CEs and chlorinated ethanes has been gradually incorporated in the last 6 years in combination with consolidated C-CSIA. However, Cl-CSIA was only used in few laboratory experiments for CF and the method was not validated for any CMs prior to this thesis. The main aims of this thesis have been to better understand CMs natural attenuation together with potential CMs remediation strategies to improve the assessment of CMs fate in Òdena site and, by extension, in other polluted sites all over the world. These goals were addressed primarily by C-CSIA and Cl-CSIA, among other techniques. Prior to their use in laboratory or field samples, Cl-CSIA method has been developed and evaluated for CT and CF by both, gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and by gas chromatography-quadrupole mass spectrometry (GC-qMS validated in an interlaboratory comparison) through an international collaboration (Helmholtz Zentrum München and Université de Neuchâtel) during different thesis stays. Three relevant abiotic CF transformation mechanisms were studied in batch experiments: oxidation by heat-activated persulfate (abbreviated as PS); AH and reductive dechlorination by Fe(0), obtaining similar Λ values for PS and AH (17±2, 13.0±0.8) which are distinguishable from reductive dechlorination (8±2). CT and CF degradation by Fe(0) and Fe-bearing minerals (pyrite (Py, FeS2) and magnetite (Mag, Fe3O4) in the presence of FeCl2 were carried out in laboratory experiments at pH 7 and 12 simulating groundwater in the saturated zone and in alkaline interception trenches in the unsaturated zone of Òdena site, respectively. CF hydrogenolysis to dichloromethane (DCM) by milli-sized Fe(0) was characterized at both pHs, whereas CF degradation by Fe- bearing minerals was only identified at pH 12. In this case, AH was hypothesized since no VOCs by-products were detected except for DCM only with Py, evidencing CF hydrogenolysis. CT degradation by both Fe(0) and Fe-bearing minerals was confirmed at pH 12, whereas at pH 7, CT degradation was only obtained by nano-sized Fe(0) and Py. pH did not affect Λ values of CT and CF degradation by Fe(0) nor CT degradation by Py. CT thiolytic reduction to carbon disulphide (CS2) occurred in parallel to CT hydrogenolysis in experiments with Py at both pH values, showing different Λ values to net CT hydrogenolysis by Fe(0), but similar Λ values to CT reduction by Mag at pH 12. These differences provide good chances to detect these pathways in the field. Additionally, CT and CF microcosm experiments were performed separately for each compound by using slurry from one of the most polluted wells in Òdena site (S3). Biotically- mediated CT hydrogenolysis was confirmed in the microscoms. Biostimulation with vitamin B12 catalyzed CT biodegradation and stimulates CF biodegradation, the latter not observed without B12. For both target compounds, no relevant accumulation of other chlorinated compounds neither CS2 was detected with B12. CT experiments with B12 might be linked to a major activity of Pseudomonas stutzeri able to reduce CT to CO2. Acidovorax, Ancylobacter and Pseudomonas were the most metabolically active genera observed in the experiments, whereas commonly found organo-halide respiring bacteria, Dehalobacter and Desulfitobacterium, were below 0.1% of relative abundance. The Λ of CF biodegradation by B12 (7±1) was similar to that reported for CF reductive dechlorination by Fe(0) (hydrogenolysis plus reductive elimination) (8±2). Λ of CT biodegradation without B12 showed no difference to CT hydrogenolysis by Fe(0) which indicates the same pathway. Furthermore, Λ of CT degradation was statistically different despite their 95% of confidence interval (CI) with and without B12 (5±1 vs. 6.1±0.5, respectively), indicating possible influence of other reduction processes different from CT hydrogenolysis. δ13C enrichment of CEs, once CMs were completely degraded by B12-catalyzed biotic reactions, confirmed CMs inhibition of CEs degradation. The obtained laboratory data improved the knowledge on CMs degradation processes and established the basis applicable in multi-contaminant polluted sites like Òdena. A long-term monitoring to study 2005 source’s removal effects on groundwater CMs has been performed from 2002 to 2014. Through by-products and C-CSIA monitoring, CMs transformation processes over time have been confirmed. The source’s removal was inefficient since active CMs leaching was proved in the outskirts of the dismantled wastewater pipe and in the wastewater tank. Nevertheless, by-products and Λ studies disclosed CT and CF reduction processes precisely in those areas. In contrast, in former disposal pit source, where removal was more efficient, isotopic values unveiled a migration of the focus downstream as well as an influence of hydrolysed CF coming from the alkaline trench and/or CF oxidation processes in the saturated zone of this area. To sum up, this thesis has provided progress in Cl-CSIA methodology for CMs and new compelling C and Cl-isotope laboratory data related with CT and CF degradation processes. These data combined with other microbial and geochemical tools have allowed the discrimination of CMs degradation processes at field scale and are promising for monitoring the efficiency of remediation strategies in other polluted sites. The routine use of Cl-CSIA analyses are worthwhile for further research together with well-stablished C-CSIA. Moreover, the up-scale application and evaluation of studied CMs remediation techniques such as biostimulation by economical B12 sources in combination or not with Fe(0) or Fe-bearing minerals (which implies mining wastes revalorization) are challenges ahead.
El tetracloruro de carbono (CT) y el cloroformo (CF) son compuestos orgánicos que pertenecen al grupo de los metanos clorados (CMs) los cuales han sido vertidos descontroladamente al medio ambiente durante décadas debido a la escasa gestión y tratamiento de residuos. Puesto que son disolventes más densos que el agua, una vez vertidos, estos contaminantes migran en profundidad hasta las aguas subterráneas creando frecuentes fuentes de contaminación ambiental que, por su persistencia, constituyen un riesgo para la salud pública. Por lo tanto, este tipo de contaminación requiere de un seguimiento exhaustivo, así como de hallar tratamientos específicos debido a que el CT y el CF son consideradas substancias tóxicas y carcinogénicas (IARC, 2017). Aunque el CT y el CF son persistentes en acuíferos, estos compuestos experimentan atenuación natural tanto biótica como abiótica. Los CMs se degradan principalmente a través de mecanismos de reducción bajo condiciones anóxicas, aunque la oxidación microbiana del CF por cometabolismo también es un proceso de degradación potencial (Cappelletti et al., 2012; Penny et al., 2010). Por consiguiente, se esperan procesos de transformación de los CMs en emplazamientos contaminados. El enclave contaminado de Òdena (Barcelona) se encuentra afectado tanto por CMs como por otros compuestos orgánicos volátiles (VOCs, por sus siglas en inglés) debido a actividad industrial en los años 70 y 80. La degradación de etenos clorados (CEs por sus siglas en inglés) en este acuífero fracturado fue detectada ya que se observó un enriquecimiento isotópico del carbono (δ13C) a lo largo del tiempo (Palau et al., 2014b). La presencia de hidrólisis alcalina (AH, por sus siglas en inglés) del CF fue también revelada mediante el seguimiento de la δ13C del CF en las rasas de intercepción de agua de lluvia creadas con residuos de la construcción (pH~12) en la zona no saturada, una vez que se extrajeron las fuentes de contaminación en 2005. Sin embargo, aún se desconoce el motivo del enriquecimiento de la δ13C del CT a lo largo del tiempo en estas rasas (Torrentó et al., 2014). Para mejorar las limitaciones de los potenciales procesos de atenuación natural de los CMs y hacerlos más eficientes, se pueden usar diferentes técnicas de remediación inducida. La bioestimulación y el uso barreras reactivas permeables de Fe(0) o construidas con otros agentes reductores son de creciente interés. La oxidación química in situ (ISCO) y la AH son técnicas de remediación abiótica pertinentes únicamente para el CF, debido al alto estado de oxidación del carbono en el CT. El análisis isotópico de compuesto específico (CSIA por sus siglas en inglés) es una herramienta muy útil para evaluar la eficiencia tanto de la atenuación natural de los CMs como la de las estrategias de remediación aplicadas en emplazamientos contaminados. El método de CSIA no solo verifica, mediante el seguimiento de la composición isotópica a lo largo del tiempo, que la disminución de la concentración de los CMs sea debida a procesos reactivos (vs. otros no destructivos, como por ejemplo la dispersión o la dilución), sino que también permite la cuantificación del alcance de la degradación del contaminante. Asimismo, los gráficos binarios de isótopos, en los que los cambios isotópicos de un elemento se grafican respecto al de un segundo elemento de la molécula estudiada, permiten la discriminación entre diferentes vías de degradación de los CMs, a través de la obtención de pendientes específicas de cada mecanismo (Λ). Para aplicar el CSIA con tales fines, deben realizarse previamente experimentos de laboratorio bajo condiciones controladas para estudiar las reacciones de degradación de los CMs. De este modo es posible evaluar de forma fiable los cambios isotópicos esperados en el campo y, por lo tanto, conocer si se puede detectar de forma cuantitativa la degradación, así como también, estudiar la viabilidad de los potenciales tratamientos. El CSIA del carbono (C-CSIA) está ampliamente consolidado para el análisis de VOCs. El CSIA del Cl (Cl-CSIA) ha sido extensamente usado en los últimos años para los CEs y los etanos clorados. Sin embargo, el Cl-CSIA solamente ha sido aplicado en algún experimento para el CF y no ha sido utilizado previamente para el CT. Por consiguiente, el método de Cl-CSIA no había sido evaluado ni validado pormenorizadamente para ningún CMs antes de la presente tesis. Los principales objetivos de esta tesis son la adquisición de un mejor conocimiento de los procesos de atenuación natural de los CMs a través de experimentos de laboratorio, así como también de las potenciales estrategias de remediación de éstos, con el fin de aplicar dichos avances en emplazamientos tales como el de Òdena. El C-CSIA y el Cl-CSIA han sido las herramientas de seguimiento principales de los estudios realizados, aunque se han utilizado otras técnicas geoquímicas y microbiólogas dando un carácter pluridisciplinar a la tesis. Previamente al uso del método de Cl-CSIA en los CMs de las muestras de laboratorio y campo, se ha desarrollado y validado el método para el CT y CF con un cromatógrafo de gases acoplado a un espectrómetro de relación isotópica (GC-IRMS) y con un cromatógrafo de gases acoplado a un espectrómetro de masas cuadrupolo (GC-qMS, siendo la metodología para este último comparada en un interlaboratorio). Este desarrollo se ha llevado a cabo en colaboración con grupos de investigación internacionales (Helmholtz Zentrum Müenchen y Université de Neuchâtel) durante las tres estancias del doctorado. Han sido estudiados tres mecanismos diferentes de transformación abiótica del CF en experimentos batch: oxidación por persulfato activado térmicamente (abreviado como PS); AH y decloración reductiva del CF con Fe(0). Se han obtenido valores similares de Λ del CF para PS y AH (17±2 y 13.0±0.8, respectivamente) que se pueden distinguir de la decloración reductiva (8±2). Se han realizado experimentos de degradación de CT y CF con Fe(0) y minerales de hierro (pirita (Py, FeS2) y magnetita (Mag, Fe3O4)), estos últimos con la presencia de FeCl2 a pH 7 y pH 12, simulando el agua subterránea de la zona saturada y la de las rasas de intercepción alcalinas de la zona no saturada de Òdena, respectivamente. Se detectó hidrogenólisis del CF a diclorometano (DCM) mediante Fe(0) de tamaño milimétrico para ambos valores de pH, mientras que la degradación del CF por minerales de hierro solo fue identificada a pH 12. En este último caso, se hipotetiza la existencia de AH ya que no se detectan VOCs como productos, salvo cierta acumulación de DCM con Py, lo que evidenciaría hidrogenólisis solo en el experimento con Py. La degradación del CT, mediante Fe(0) o minerales de hierro, ha sido confirmada a pH 12. Sin embargo, a pH 7 la degradación del CT solo ha sido confirmada con Fe(0) nanométrico y Py. Se ha observado la existenia paralela de reducción tiolítica del CT a CS2 e hidrogenólisis del CT a CF en ambos valores de pH, dando lugar ambos procesos a un valor de Λ diferente al obtenido para la hidrogenólisis neta del CT con Fe(0) y similar al de la reducción del CT con Mag a pH 12. De esta manera, se evidencia el potencial para detectar y diferenciar estos procesos en el campo mediante gráficos binarios de isótopos C-Cl. Así mismo, se deduce que el pH no afecta al valor de Λ de la degradación del CT ni del CF mediada por el Fe(0), ni a la degradación del CT por acción de la Py o del Fe(0). Adicionalmente, se han realizado experimentos de microcosmos con CT y CF, separadamente, con lodo del fondo de uno de los pozos más contaminados de Òdena (S3). Se ha confirmado una biodegradación natural de CT siguiendo la vía de hidrogenólisis a CF. La bioestimulación con vitamina B12 ha catalizado la degradación de CT y estimulado la biodegradación del CF, siendo la última inexistente sin la presencia de B12. Para ambos compuestos, no se detecta una acumulación de compuestos clorados ni de CS2 en los tratamientos con B12. La ausencia de acumulación de CF con la adicción de B12 durante la degradación de CT puede estar relacionada con una mayor actividad de la especie Pseudomonas stutzeri detectada más activa en esos tratamientos y capaz de reducir el CT a CO2. Los géneros más metabólicamente activos en los tratamientos del microcosmos son Acidovorax, Ancylobacter and Pseudomonas son, mientras que bacterias ampliamente conocidas como decloradoras (como Dehalobacter y Desulfitobacterium), se encuentran por debajo de un 0.1% de abundancia relativa. El valor de Λ para la biodegradación del CF (solo detectada con la adicción de B12, 7±1) es similar al registrado para la decloración reductiva del CF con Fe(0) (8±2), el cual incluye hidrogenólisis y eliminación reductiva. El valor de Λ de la biodegradación del CT sin la vitamina B12 y el de la hidrogenólisis neta del CT por Fe(0) no muestran diferencia estadística, lo cual confirma la misma vía para ambos experimentos. También cabe destacar que los valores de Λ de la degradación del CT con y sin B12 son estadísticamente diferentes (5±1 vs. 6.1±0.5), respectivamente, a pesar de su similitud a juzgar por su intervalo de confianza del 95%. Este hecho indicaría una posible influencia de otros procesos de reducción del CT diferentes a la hidrogenólisis cuando la vitamina B12 está presente. Por último, añadir que este estudio de microcosmos revela un enriquecimiento en 13C de los CEs, una vez los CMs son totalmente degradados mediante reacciones bióticas catalizadas por la B12, lo cual confirma la inhibición que ejercen los CMs en la degradación de los CEs. Considerando todo lo anteriormente mencionado, el conjunto de datos obtenido en los experimentos sienta las bases para un mejor conocimiento de la atenuación natural e inducida de los CMs aplicable a nivel práctico en acuíferos contaminados por múltiples contaminantes como el citado de Òdena. De esta forma, ha sido llevado a cabo un estudio a largo plazo (del 2002 al 2014) del efecto de la remoción de las fuentes de contaminación de CMs en 2005 en las aguas subterráneas del emplazamiento monitorizado de Òdena. A través del seguimiento de la concentración de los CMs y sus productos de degradación, así como del C-CSIA de los CMs, se han sido confirmado procesos de transformación de estos contaminantes a lo largo del tiempo. La remoción de las fuentes de contaminación se considera ineficiente dado que se han detectado procesos de lixiviado de CMs tanto en la zona no saturada alrededor del conducto de transporte de aguas residuales que fue desmantelado, como también entorno al tanque de almacenamiento subterráneo. No obstante, los productos de degradación y el estudio de los valores de Λ han evidenciado procesos de reducción del CT y del CF en ambas áreas. Por otro lado, en la zona donde se realizaron vertidos al aire libre sí se ha detectado una remoción eficiente de la fuente de contaminación y los valores isotópicos han revelado una migración del foco aguas abajo, así como también, cierta influencia de CF afectado por AH en las zanjas de intercepción y/o por procesos de oxidación del CF en la zona saturada de esta área. Para concluir, subrayar que esta tesis proporciona avances en la metodología de Cl- CSIA de los CMs, así como nuevos datos isotópicos de carbono y cloro para caracterizar procesos de degradación del CT y del CF. Estos datos combinados con otras técnicas geoquímicas y microbiológicas permiten discriminar y evaluar de forma pluridisciplinar procesos de atenuación natural en emplazamientos contaminados, así como realizar un asesoramiento y seguimiento de la eficiencia de las potenciales técnicas de remediación de CMs aquí descritas por parte de consultorías ambientales y administraciones. El uso rutinario del método de Cl- CSIA en los CMs es prometedor para futuras investigaciones y proyectos de remediación, paralelamente al ya consolidado C-CSIA. La implementación y evaluación de las técnicas de remediación de CMs a escala de campo, como la bioestimulación a través de fuentes económicas de B12, en combinación o no con el uso de Fe(0) o minerales de hierro a través de la puesta en valor de residuos mineros, son desafíos a corto plazo.

The prevention of outbreaks of waterborne diseases remains a major challenge to public health service providers globally. One of the major obstacles in this effort is the unavailability of on-line and real-time methods for rapid monitoring of faecal pollution to facilitate early warning of contamination of drinking water. The main objective of this study was to develop a β-glucuronidase (GUD)-based method that could be used for the on-line and real-time monitoring of microbial water quality. GUD is a marker enzyme for the faecal indicator bacteria Escherichia coli. This enzyme breaks down the synthetic substrate p-nitrophenyl-β-D-glucuronide (PNPG) to D-glucuronic acid and p-nitrophenol (PNP), which turns yellow under alkaline pH. The enzymatically produced PNP was used to detect GUD activity. In situ GUD assays were performed using running and stagnant water samples from the Bloukrans River, Grahamstown, South Africa. The physico-chemical properties of environmental GUD were determined, after which a liquid bioprobe and a microbial biosensor modified with Moraxella 1A species for the detection of the enzyme activity were developed. In order to determine the reliability and sensitivity of these methods, regression analyses for each method versus E. coli colony forming units (CFU) were performed. The storage stabilities of the bioprobe and biosensor were also investigated. The physico-chemical properties of in situ GUD were different from those of its commercially available counterpart. The temperature optimum for the former was between 35 and 40 °C while for the latter it was 45 °C. Commercial (reference) GUD had a pH optimum of 8.0 while the environmental counterpart exhibited a broad pH optimum of between pH 5.0 and 8.0. The liquid bioprobe had a limit of detection (LOD) of GUD activity equivalent to 2 CFU/100 ml and a detection time of 24 h. The method was less labour intensive and costly than the culturing method. The liquid bioprobe was stable for at least four weeks at room temperature (20 ± 2 °C). The biosensor was prepared by modifying a glassy carbon electrode with PNP degrading Moraxella 1A cells. The biosensor was 100 times more sensitive and rapid (5-20 min) than the spectrophotometric method (24 h), and was also able to detect GUD activity of viable but non-culturable cells. Thus it was more sensitive than the culturing method. Furthermore, the biosensor was selective and costeffective. The possibility of using a Pseudomonas putida JS444 biosensor was also investigated, but it was not as sensitive and selective as the Moraxella 1A biosensor. The Moraxella biosensor, therefore, offered the best option for on-line and real-time microbial water quality monitoring in South African river waters and drinking water supplies.

This thesis presents concentration and speciation data for Cu, Zn, Cd, and Al in eight highland rivers and streams in the Røros area, central Norway. About 16 sampling campaigns were performed before, during and after floods during spring and autumn of 1997. Due to rain- and snowmelt-induced flushout from weathered mine tailings, the flood episodes were expected to produce high concentrations of metals in the local rivers. The examined river sites represent highly different degrees of pollution, height above sea level, annual discharge, pH, etc., and the project is aimed towards producing general information about the temporal variations of the metal chemistry and parameters important for the metal chemistry in this and similar regions. Dissolved species of the metals were fractionated by dialysis in situ, colloidal species by filtration, and total (more precisely; soluble in 0.1 M HNO₃) concentrations were determined directly after acidification. Ca concentration, pH, river discharge, water temperature, and to a lesser extent precipitation and TOC were also monitored. In addition Cu and Zn/Cd metallothioneins were studied in kidney, liver and gills in trout (salmo trutta) populations in two of the rivers characterized by completely different metal concentration fingerprints.

The results showed that Cu and Al, and possibly Zn and Cd as well, were practically completely in particulate or colloidal form at pH values of 7 and above. At pH levels one or a few pH units lower, the trace metals shifted to occur almost completely dissolved. The pH range at which the change from colloidal/particulate to dissolved species occurred, depended on the metal concerned and the TOC in the water. High TOC concentrations (> 8) seemed to accompany low fractions of dissolved metals, probably because the metals adsorbed on high molecular weight organic compounds or organic coatings on inorganic particles. At TOC concentrations lower than 8 mg/L, a 50 % dissolved fraction was estimated at pH ~7.2 and ~5.8 for Cu and Al respectively, whereas for Cd and Zn, a 50 % dissolved fraction was estimated at pH 7.7. The latter is a pH slightly higher than the highest value observed in the present investigation. Higher TOC concentrations (>8 mg/L) increased metal adsorption and made adsorption start up to one pH unit lower than in low TOC waters (<8 mg/L).

Total metal concentrations were generally elevated during flood conditions in the pH neutral rivers, whereas pH was significantly lowered. In spite of the low pH, the dissolved fractions of Zn, Cd, and Al decreased during flood periods, probably due to enhanced particle concentrations. Thus flood conditions apparantly brought metals into a less acute toxic state. However pH may have influenced metal toxicity in other ways as well; e.g. the free metal ion activity in the dissolved fraction could have increased during flood due to the decreased pH. But even if that was the case, metal toxicity would not necessarily be higher since H⁺ competes with free metal ions for uptake sites on biological membranes.

Alkalinity and Ca reduce negative effects of metals, and both were low during flood conditions. This is obviously unfortunate for aquatic organisms. Generally however, total metal concentration peaks occurred at the beginning of rising floods, followed by a very low pH, alkalinity, and Ca concentration a few weeks later and the spring discharge maximum a few weeks after that. Thus Ca²⁺ and pH had not yet reached their spring minimum, that is; the most unfavorable condition to protect organisms against metals, at the metal concentration maximum.

The snowcap covering River Orva accumulated and contained huge amounts of Cu, and may have substantially increased the Cu concentration in the river during snowmelt. This also impacts reaches of the large river Glåma which receives water from Orva. It is suggested that the hydroelectric power plant Kuråsfossen in Glåma should regulate river runoff in a different manner in order to smooth out metal concentration peaks.

Gill concentrations of Cu metallothionein (MT) in Rugla and Cd/Zn MT in Naustebekken were appreciably elevated during run-off episodes. The Cu MT and Cd/Zn MT concentrations in gills and kidneys were high enough to account for all or almost all Cu and Cd but only for a minor fraction of the Zn present in these organs. For Zn this indicates that other detoxifying mechanisms may be more important than MT.

The ultimate objective of this work was to develop a real-time method for detecting and monitoring β-D-galactosidase as a suitable indicator of the potential presence of total coliform bacteria in water environments. Preliminary comparison of the chromogenic substrate, chlorophenol red β-D-galactopyranoside and the fluorogenic substrate, MuGAL, revealed unreliable results with the fluorogenic technique due to interference from compounds commonly found in environmental water samples. Thus, the chromogenic assay was further explored. Hydrolysis of the chromogenic substrate chlorophenol red β-D-galactopyranoside by β-D-galactosidase to yield chlorophenol red was the basis of this assay. Fundamental studies with chlorophenol red β-Dgalactopyranoside showed that β-D-galactosidase occurs extracellularly and in low concentrations in the polluted water environment. A direct correlation between enzyme activity and an increase in environmental water sample volume, as well as enzyme activity with total coliform colony forming unit counts were observed. Spectrophotometric detection was achieved within a maximum period of 24 h with a limit of detection level of 1 colony forming unit 100 ml[superscript -1]. This enzyme also exhibited physical and kinetic properties different from those of the pure commercially available β-D-galactosidase. Cell permeabilisation was not required for releasing enzymes into the extracellular environment. PEG 20 000 offered the best option for concentrating β-D-galactosidase. The source of β-D-galactosidase in the polluted environmental water samples was confirmed as Escherichia coli through SDS-PAGE, tryptic mapping and MALDI-TOF, thus justifying the further use of this method for detecting and/or monitoring total coliforms. Several compounds and metal ions commonly found in environmental water samples (as well as those used in water treatment processes) did have an effect on β-D-galactosidase. All the divalent cations except Mg [superscript 2+], at the concentrations studied, inhibited the relative activity of β-D-galactosidase in both commercial β-D-galactosidase and environmental samples. Immobilisation of chlorophenol red β-D-galactopyranoside onto a solid support material for the development of a strip bioprobe was unsuccessful, even though the nylon support material yielded some positive results. A monthly (seasonal) variation in β-Dgalactosidase activity from the environmental water samples was observed, with the highest activity coinciding with the highest monthly temperatures. Electro-oxidative detection and/or monitoring of chlorophenol red was possible. Chlorophenol red detection was linear over a wide range of concentrations (0.001-0.01 μg ml[superscript -1]). Interference by chlorophenol red β-D-galactopyranoside in the reduction window affected analysis. A range of phthalocyanine metal complexes were studied in an attempt to reduce fouling and/or increase the sensitivity of the biosensor. The selected phthalocyanine metal complexes were generally sensitive to changes in pH with a reduction in sensitivity from acidic pH to alkaline pH. The tetrasulphonated phthalocyanine metal complex of copper was, however, more stable with a minimum change of sensitivity. The phthalocyanine metal complexes were generally stable to changes in temperature. While only two consecutive scans were possible with the unmodified glassy carbon electrode, 77 consecutive scans were performed successfully with the CuPc-modified glassy carbon electrode. Among the phthalocyanine metal complexes studied, the CuPc-modified glassy carbon electrode therefore provided excellent results for the development of a biosensor. The CuPc modified-glassy carbon electrode detected 1 colony forming unit 100 ml[superscript -1] in 15 minutes, while the plain unmodified glassy carbon electrode required 6 hours to detect the equivalent number of colony forming units. CoPc, ZnPc and CuTSPc required 2, 2.25 and 1.75 h, respectively, to detect the same numbers of colony forming units. The CuPcmodified glassy carbon electrode detected 40 colony forming units 100 ml[superscript -1] instantly. In general, a direct correlation between colony forming units and current generated in the sensor was observed (R2=0.92). A higher correlation coefficient of 0.99 for 0-30 coliform colony forming units 100 ml[superscript -1] was determined. Current was detected in some water samples which did not show any colony forming units on the media, probably due to the phenomenon of viable but non-culturable bacteria, which is the major disadvantage encountered in the use of media for detecting indicator microorganisms. This novel biosensor therefore presents a very robust and sensitive technique for the detection and/or monitoring of coliform bacterial activity in water.

Nitrate pollution is a widespread problem that affects water bodies in many regions of the world, undermining water quality and therefore its safe use. Despite the application of improved management practices, nitrate pollution seems to increase, particularly in groundwater. The Nitrate Vulnerable Zone (NVZ) designation in Europe, for instance, has increased from 35.5% of the EU-15 territory at the end of 1999 to 44% at the end of 2003, and the Commission’s report for the period 2004-2007 revealed that 15% of groundwater monitoring stations in the EU-27 territory showed nitrate levels above the limit of 50 mg of nitrates per liter. Some trends towards nitrate attenuation are observed, but at least 33% of water bodies will clearly fail in achieving the 2015 goals set by the Water Framework Directive. Several efforts have been addressed to either reduce nitrogen inputs or to decrease its already accumulated levels, particularly by designing nitrate-removal technologies aimed at recovering drinking-water standards. This PhD thesis, hence, focuses on the optimization of an already existing technology for nitrate­removal: enhanced in situ biodenitrification (EISB), which is now regaining attention due to its economic and environmental benefits and its potential for scale-up and design of case­specific solutions. EISB is an engineered application of microbial heterotrophic denitrification aimed at in situ nitrate removal from groundwater. Aimed at stimulating facultative denitrifiers, EISB is based on the injection of a C source into the aquifer. Microbial denitrification is then enhanced in a designated area of the aquifer, creating a biologically active zone (often referred as biowall) which removes nitrate from the naturally-flowing groundwater. Among the different factors that affect the technical feasibility of EISB, the type and quantity of the injected C source is a key issue, particularly due to its influence upon the microbial processes that determine the treatment performance. The understanding of the subsurface geology and hydrogeology is also an issue of concern, particularly if highly heterogeneous media, such as fractured aquifers, are meant to be remediated. Aimed at achieving our research goal, several EISB experiments were developed at different scales -batch, flow-through column and pilot scale-and involving different geological media -granular and fractured-. Combined chemical, microbial and isotope monitoring tools where applied to gain a better insight on the denitrification process and thus improve technology design and optimization. The first set of batch-scale experiments focused on testing the viability of in situ heterotrophic denitrification and determining the most suitable biostimulants for a case­specific scenario in the Osona region, a Catalan NVZ showing historic nitrate pollution up to 200 mg/L. Native microbiota was stimulated and nitrate reduction was effectively achieved by addition of a carbon source (ethanol or glucose) as well as a phosphorous source (disodium hydrogen phosphate). Transient nitrite accumulation was observed, especially when using glucose as the C source. The N and O isotope fractionation was determined to be -13.0‰ and -17.1‰ for eN and -8.9‰ and -15.1‰ for eO in ethanol and glucose-amended experiments respectively, resulting in eN/eO values of 1.46 (ethanol-amended experiment), and 1.13 (glucose-amended). Organic carbon (OC) consumption in batch­scale experiments, expressed as .C/.NO3 -, varied slightly depending on the type of C source used: 1.6 mmolOC/mmolNO3 -for ethanol and 2.2 for the glucose, similarly to stoichiometric values associated with nitrate respiration (0.83 and 1.25 mmolOC/mmolNO3 ­respectively). When deriving stoichiometric reactions that accounted not only for the amount of electron donor used for nitrate respiration but also for cell synthesis, the following values were determined: 1.9 and 2.0 mmolOC/mmolNO3 -for ethanol and glucose­induced biodenitrification respectively. These values were used for the numerical modeling of batch-scale experiments, aimed at quantifying microbial kinetics by applying the modified Monod expression. The (geochemical) numerical model also indicated a different effect of mineral precipitation on ethanol or glucose-induced denitrification, an effect that is linked to a different alkalinity production. Such effect could be taken into account when designing and/or optimizing EISB systems, particularly as a way to control geochemical clogging. A pilot-scale application was then performed at the site, aimed at assessing the viability of EISB in a fractured aquifer. Ethanol was now used as the main C source, and based on lab­scale results, P was also added. Again, transient nitrite accumulation was detected, and evidences for incomplete denitrification and coexistence of other respiration processes (such as iron or sulfate reduction) and autotrophic denitrification were observed. Sulfate isotope characterization proved that autotrophic denitrification linked to sulfide oxidation could be occurring along with heterotrophic denitrification, while sulfate­reduction couldn’t be verified. Overall, results suggested that stimulated heterotrophic denitrification could be applied as a remedial alternative in a fractured media and despite the complexity of the formation. However, a deep understanding of the system is required and efforts must be addressed to control microbial population and stability as a key issue to avoid the decrease of groundwater quality due to incomplete denitrification or secondary respiratory processes. Different engineering approaches such as feeding or pumping strategies could help improving the system performance. Aimed at testing the impact of such engineering approaches upon resulting water quality, a second study-case was studied, now in an alluvial media. . A flow-through experiment was built to simulate an EISB system and assess the influence of different C addition strategies upon the denitrification process. Heterotrophic denitrification was stimulated by the periodic addition of a C source (ethanol), and 4 different addition strategies were evaluated, being the first-one a weekly injection, and the others a daily injection with decreasing amounts of C. Enhanced denitrification was stimulated following the first C addition, easily achieving drinking water standards for both nitrate and nitrite. Water quality in terms of remaining C, denitrification intermediates and other anaerobic respiration products varied during the experimental time. Ethanol, for instance, showed a cyclic behavior during the weekly feeding strategy while it was completely depleted when injected daily. A quasi steady­state nitrate outflow, similar to ethanol’s, was obtained in daily injection scenarios, with nitrate levels ranging from non-detected values and up to 10 mg/L, and nitrite’s remaining undetected. No dissimilatory nitrate reduction to ammonium was ever detected and some secondary microbial respiration processes, mainly manganese reduction, were suspected to occur temporarily. Overall, results showed that biodenitrification could be successfully achieved by a daily addition of a C source slightly higher than the stoichiometric value, diminishing the accumulation of non-desired products and the biofilm growth and still obtaining the required denitrification results. Reducing the C/N ratio enables us to reduce treatment costs while achieving a better water quality in terms of remaining C and residual microflora, and potentially reducing the biofouling effect due to the increase of endogenous respiration. Endogenous activity –that provides internal C for denitrification-may become important when low C/N values are used, keep denitrification temporarily ongoing and reducing the biofilm growth, but may affect the biodenitrification performance at longer operation times. Such aspects should be further evaluated using modeling and/or experimental tools. Furthermore, results suggested that not only the feeding strategy but also the biofilm life-time have a direct effect on microbial population structure and hence on the biodenitrification performance, reducing the accumulation of nitrite over time. The obtained eN/eO fractionation values for the flow-through experiment (1.01) fell within the low-end of previously reported data (varying from 0.9 to 2.3), an effect that may be linked to faster microbial kinetics in enhanced vs. natural biodenitrification. Similar low values were observed in our previous batch-scale experiments as well as in other work conducted in our lab. Concerning ethanol’s fractionation, on the other side, a two-trend behavior was observed, probably indicating a change in the dominating C­consuming population. Interestingly, the second trend suggests an inverse fractionation of the C source that got depleted while being consumed.
Esta tesis se destina a la evaluación de la viabilidad técnica de la biodesnitrificación in situ de aguas subterráneas contaminadas por nitratos, con el objetivo de optimizar las estrategias de bioestimulación y mejorar los resultados del proceso microbiano. El proyecto evalúa la aplicación de la tecnología en dos entornos geológicos distintos: un medio fracturado de baja porosidad y un aluvial arenoso. Se desarrollan ensayos a tres escalas distintas: batch, columna de laboratorio de flujo continuo y piloto. El seguimiento y estudio del proceso se desarrolla mediante la combinación de herramientas de análisis químico y microbiológico y la aplicación de isótopos estables del nitrato, el sulfato y el C.

Le travail rapporté porte sur la biodégradation des composés aromatiques volatils (benzène, toluène, xylènes) en solution aqueuse. La principale question abordée est la quantification et le contrôle des transferts gaz-liquide de soluté. Il a été démontré que la séparation de la biomasse d'un liquide doit être effectuée avec une attention particulière et un protocole basé sur la centrifugation de la suspension est proposé. Une nouvelle technique pour la détermination expérimentale du coefficient d'activité à dilution infinie, également basée sur des expériences de centrifugation est présentée. Le travail principal au niveau microbien révèle que les pertes de soluté par stripping gazeux ne peuvent pas être évitées même avec l'utilisation d'un système biphasique liquide-liquide. Une approche anaérobie mettant en oeuvre une bactérie effectuant la respiration des nitrates a montré que cette technique pouvait présenter un grand intérêt lorsqu'elle est utilisée avec un milieu hétérogène.

Plastic deposition in hydrological systems is a pervasive problem at all geographic scales from loci of pollution to global ocean circulation. Much attention has been devoted to plastic deposition in marine contexts, but little is known about inputs of plastics into local hydrological systems, such as streams. Any attempt to prevent plastic litter must confront people’s behaviors, so archaeological concepts are used to distinguish between various cultural inputs (e.g., littering) and non-cultural forces (e.g., stream transport) that affect litter patterns on the landscape. Litter surveys along Hickory Creek in Denton, TX, are used to assess these factors.

Este trabajo plantea el estudio del concepto del medio ambiente y de los principios que lo informan desde el gasto público. El marco teórico es el Derecho financiero constitucional y el Derecho de los gastos públicos. Se analiza ampliamente la concepción de la protección del medio ambiente como necesidad pública y los instrumentos jurídicos para satisfacer esta necesidad.
La posibilidad de configurar el medio ambiente como necesidad pública obliga al análisis de la compleja función otorgada al Estado en cuanto obligado a intervenir en la protección y conservación del medio ambiente, que presenta el problema, no tan sólo de tener que adoptar una gran diversidad de medidas de protección en función del elemento a proteger, sino también un elevado coste. Por ello el trabajo se centra en los instrumentos financieros y económicos para la protección del medio ambiente en nuestro país, haciendo hincapié en la problemática de las subvenciones e incentivos fiscales aplicados al medio ambiente.
This work deals with the concept of environment and its legal principles from the perspective of public expenditure. Constitutional Financial Law and the Law of Public Expenditure provide the theoretical framework of the study. The analysis focuses on the conception of environmental protection as a public need, and on the legal instruments to fulfil such need.
Understanding the environment as a public need requires a proper analysis of the State's complex functions. In particular, State intervention in activities of environmental protection and conservation arises problems not only related with the adoption of a wide diversity of protection measures according to the intended element to be protected, but also with the high cost of protection. Therefore, the study focuses on the financial and economic instruments for environmental protection used in our country, and specifically it deals with the use of subsidies and tax incentives for environmental purposes.

La production de plastique est en augmentation continue pour répondre à la forte demande mondiale. Cette production massive est la source d'importantes quantités de plastiques que l'on retrouve dans les milieux aquatiques. Parmi ces plastiques, les microplastiques (MP) (particules microscopiques d’une taille < 5 mm) se retrouvent dans l’eau, les sédiments et sont susceptibles d’être ingérés par divers organismes marins. Cette thèse se focalise sur (1) l’évaluation des sources et des apports de microplastiques au milieu aquatique et de leur présence dans les organismes, et (2) de tester la faisabilité d’utiliser des organismes vivants pour la surveillance de la pollution de l’environnement par les microplastiques. Deux zones côtières affectées par des pressions anthropogéniques ont été étudiées : Le Havre et le littoral libanais. Dans le premier cas, le rôle d’une station de traitement des eaux usées (STEP) et d’une décharge côtière dans l’introduction des microplastiques dans l’environnement a été étudié. Les MPs ont d’abord été analysés dans l'influent, la boue et l’effluent de la STEP. Leur devenir a été suivi selon un gradient de distance de la STEP au niveau de trois matrices : eau de surface, sédiments et moules sauvages (Mytilus spp.). Les MPs ont été trouvés au niveau de toutes les matrices avec une concentration qui diminue en s’éloignant de l’effluent. Des taux de microplastiques élevés (plus élevés que ceux trouvés à côté de la STEP) ont été observés à proximité de la décharge côtière, suggérant son rôle important comme voie d’entrée des MPs dans les eaux côtières. Le long de la côte libanaise, nous avons évalué pour la première fois la pollution par les MPs dans l'eau de mer, les sédiments et dans deux espèces marines importantes en terme de consommation humaine (un poisson pélagique: Engraulis encrasicolus et un bivalve: Spondylus spinosus). Les résultats ont montré différents patterns de concentration des MPs dans les matrices analysées. La présence de MPs dans les organismes était élevée (83.4% et 86.3% dans les anchois et les huîtres, respectivement). Ces résultats ont mis en évidence la pollution élevée liée aux MPs au niveau du bassin Levantin par rapport aux autres régions de la Méditerranée occidentale. De plus, les résultats obtenus indiquent une contribution potentielle des décharges côtières à cette pollution. Le plus souvent, les études sur les microplastiques impliquent l'échantillonnage d’organismes indigènes. Au cours de cette thèse, nous avons testé la faisabilité d'utiliser des organismes transplantés (encagement) pour évaluer la pollution par les microplastiques dans l'environnement marin côtier. Nous avons mis au point des expériences d'encagement avec des juvéniles de flets, Platichthys flesus, en estuaires et des moules bleues, Mytilus edulis, en zone côtière. Pour chaque espèce, l'abondance et les caractéristiques (forme, taille, couleur et type de polymères) des MPs ingérés par les individus encagés ont été comparées avec les MPs ingérés par des individus sauvages capturés sur le même site et avec ceux trouvés dans leur environnement (eaux de surface et sédiments). Nos résultats suggèrent que la technique d'encagement d'organismes peut constituer un outil prometteur pour la biosurveillance des MPs la rendant plus fiable et permettant une étude précise des effets biologiques des MPs sur une période d'exposition prédéterminée
Plastic fabrication is increasing worldwide in response to daily human demands. This mass production is linked to the immense plastic marine litter found all around the world: each synthetic material is meant to find its way back into the aquatic systems. Anthropogenic pressure and the immense human population, the lack of appropriate plastic treatment process and the growing industrial activities advocate their presence in the aquatic environments. These plastics are then found in the form of microplastics (microscopic particle with a size < 5 mm) observed in the water, in the sediments and are prone to be ingested by various marine organisms along the trophic chain. This thesis focuses on (1) assessing microplastics sources and input into the aquatic environment and their occurrence in biota, and (2) to test the feasibility of using transplanted organisms (caging) for monitoring microplastics pollution in the marine coastal environment. Two coastal areas highly impacted by anthropogenic pressures were studied: Le Havre in France and the Lebanese coast. For the former, the role of a municipal wastewater treatment plant (WWTP) effluent and an abandoned coastal landfill as pathways for microplastics (MPs) input into the marine environment was assessed. MPs were first analyzed in raw sewage influent, sludge and effluent samples, and their fate was studied along a distance gradient from the WWTP in three matrices: surface water, sediments and wild mussels (Mytilus spp). MPs were found in all matrices with a decreasing abundance from the effluent. Strong MPs abundances (higher than those found near the WWTP effluent) were observed in the vicinity of the coastal landfill suggesting its importance as a MPs entry route into the marine coastal environment. Whereas for the Lebanese coast, we evaluated for the first time the MPs pollution in the seawater, sediments and two important seafood species (one pelagic fish: Engraulis encrasicolus and one bivalve: Spondylus spinosus). Results showed different patterns of MPs concentration in the analyzed matrices. The occurrence of MPs in the biota was high (83.4% and 86.3% in anchovies and spiny oysters, respectively). These results highlighted the high MPs pollution found in the Levantine Basin in comparison to other Western Mediterranean regions. In addition, the obtained results indicate the potential contribution of coastal landfills to this pollution. Most often microplastics studies involve collection of organisms’ samples from natural populations. In this thesis, we tested the feasibility of using transplanted organisms (caging) for monitoring microplastics’ pollution in the marine coastal environment. We developed caging experiments with juvenile European Flounder, Platichthys flesus, in estuarine nursery grounds and blue mussels, Mytilus edulis, in coastal marine environment. For each species, the abundance and characteristics (shape, size, color and type of polymers) of MPs ingested by caged individuals are compared with those ingested by wild individuals collected at the same site and with those found in their surrounding environment (surface water and sediments). Our results suggest that transplanted organisms (caging) may be a promising tool for MPs biomonitoring making monitoring more reliable with an accurate assessment of the biological effects of MPs over a predetermined exposure period

Microorganisms have the potential to remove heavy metals from polluted waters and effluents and may be used in clean-up processes. Microbial associations were enriched for and adapted to grow in nutrient solutions containing various concentrations of different metals. As immobilised cells are known to be more stable and more efficient in metal uptake than are corresponding planktonic or free-living cells the attachment of the microbial associations was investigated using a model stream and it was found that biofilm development was better on rough surfaces such as ground glass and polystyrene than on smooth surfaces such as unetched glass plates and glass beads. When comparing metal uptake by planktonic and attached microorganisms, attached populations were found to have a greater metal-uptake capacity. The uptake of individual metals from various metal combinations was tested with various proportions of pregrown metal-adapted microbial populations as inoculum and it was found that a particular metal was taken up more readily by microbial associations which had previously been exposed to that metal. Lead (Pb2+) appeared to be taken up more readily than copper (Cu2+) or cadmium (Cd2+) while Cd2+ was more actively removed than Cu2+ from solution. pH also affected metal uptake and the optimum range for Cu2+ uptake by the Cu2+ -adapted microbial association was found to be between 5.8 and 7.0. Dead microbial biomass was investigated and found to have efficient metal uptake capacity. Living mycelium from an isolated Aspergillus species showed poor uptake of Cu2+ initially, but when this fungus was pregrown and subsequently killed by moist heat treatment the non-living mycelium was efficient in removal of Pb2+ and Cu2+ ions. The optimum mycelial biomass concentration for metal uptake was also determined. The mechanism of metal uptake by this Aspergillus species was determined, using electron microscopy and EDX techniques, to be metabolism-independent biosorption onto the hyphal surface. Thus the microbial associations and fungal cultures used in this study were shown to have the potential for use in the removal of heavy metals from polluted waters.
Thesis (Ph.D.)-University of Natal, Pietermartizburg, 1995.

碩士
國立高雄第一科技大學
環境與安全衛生工程所
92
Constructed wetland system is a water purification process ecological engineering technology, which is quite economical and potential. For finding out the feasibility of the polluted river and campus sewage re-purified with constructed wetland, this study utilizes lab-scale constructed wetland system, and uses river water and the original sewage of the east campus sewage treatment plant as the object of study. This study employs four forms of lab-scale constructed wetland systems, each of which is with uniform size: 0.6m in height, 0.55m in width, and 0.72m in length, and all of them are placed outdoors to simulate the method of operation constructed wetland. In the medium area is the gravel, which is used as the medium for the growing of the plants, and some reeds. The way of influent water is in parallel, it makes use of wriggle pump to control the flow rate of the polluted river (trough A) and campus sewage (trough B), and then the sewages get into experimental pattern trough. The main study purpose is compare the difference of the water quality of effluent water which was through the purification of constructed wetland system and current river quality, so that we can confer and evaluate the feasibility of reuse retrieve effluent water which was through the purification of constructed wetland system. At the same time, I proceed with the test of constructed wetland system control, and analyze the variation of water quality after the waterpower conditions tests of different stages. After utilizing constructed wetland system of two different molds (FWS and SSF) and different waste water source (polluted river and campus sewage), we can compare the effects and advantages or drawbacks of the two. On the whole, subsurface flow constructed wetland works better on handling polluted river and campus sewage. The handling effects of the second stage is the best of all as its flow rate is 8ml/min, and waterpower retention period in FWS system is 7.08days, in SSF system is 4.71days.

碩士
淡江大學
水資源及環境工程學系
84
This study uses the combination of chemical coagulation and Fenton'sProcess to treat polluted raw waters. Because it is inefficient to usechemical coagulation to remove the low-molecular-weight organic compounds(e.g. pesticide, phenol) , and Fenton's reagent has dual functions ofpreoxidation and coagulation, we consider using conventional coagulation withFenton's reagent to remove the low-molecular- weight organic compounds. Thisstudy is conducted to evaluate the reduction of DOC and THMFP under variou sconditions of pH, iron salts dosages, hydrogen peroxide dosages and processcombination. Finally, we will discuss the relationship among THMFP, DOC andUV254. The effect of pH on THMFP reduction by Fenton's reagent and coagulationrange 3.0-4.0 and 4.0-5.0. It is effective and economical if we use theprocess combination to treat the polluted raw waters at pH 5.0. At this range(pH 5.0), hydrogen peroxide can't enhance the effect of ferric (Fe3+=4mg/L)coagulation, but it can preoxidize phenol. Relatively , hydrogen peroxide canenhance the effect of ferrous (Fe2+=4mg/L) coagulation and preoxidation. Whenthe combination of chemical coagulation and Fenton's process is in use, coagulant, ferrous, and hydrogen peroxide are combined in the rapid-mix basin,and the equipment cost and the effect are better than those isolated process.Compare Fenton's Process with chemical coagulation, when 4mg/L ferrous iscombined with 2mg/L hydrogen peroxide, each mg of iron salts can remove0.404mg DOC, 0.0799mg THMFP, and 0. 138mg phenol; when there are 2mg/Lferrous, 2mg/L ferric, and 2mg/L hydrogen peroxide, each mg of iron salts canremove 0.771mg DOC, 0.1055mg THMFP, and 0.140mg phenol. This shows that thecombination of chemical coagulation and Fenton's Process is better thanFenton's Process. Besides ferric, when alum is combined in use with Fenton'sProcess, the same effect still exists, which shows that the combination ofchemical coagulation and Fenton' s Process can not only remove organic, andreduce THMFP, but also p reoxidize phenol effectively. As to THMFP and DOC,the relative coefficients (R) of raw water, synthetic water, and polluted rawwater are 0.834, 0.983, and 0.907, which show that there is good relationshipbetween THMFP and DOC. Because organic matter in raw water and synthetic wateris simpler, the relative coefficients between THMFP and UV254 are 0.828 and0.934. As to polluted raw water because effect of notably ferrous iron,nitrate, nitrite, and bromide, the relative coefficient is just 0.214, which shows that UV254 is inadequate as surrogate when interference is occurred insample.

碩士
明新科技大學
營建工程與管理研究所
97
The wetlands have rich ecological resources in the nature, if people appropriate to operation ,which will offers people a place of leisure and education, the wetlands also hold a chance to use solar energy、wind、land、plant and animal etc that have been used to improve water quality of natural mechanism；it’s so important to get more better that water -purified function in the situation. In this study,I will use Touchien River wetland park inHSIN-CHU Country as a case study.To use three different types of flow rate,and probing into purpose and difference of the polluted water was clarified.seting the flow rate is 8000m3/day、6000m3/day and 4000m3/day.The results showed that,when the flow rate is 4000m3/day,the whole removal efficiency is the most best, the polluted water retention period(HRT) is 4.8days,the average consistency in SS is 74.1mg/L,the average consistency in effluent is 13.5mg/L,and the removal rate is 81.8%;the average consistency in BOD5 is 5.85mg/L,the average consistency in effluent is 3.79 mg/L,and the removal rate is 35.21%;the average consistency in COD is 37.4mg/L,the average consistency in effluent is 26.6mg/L,and the removal rate is 28.9%;the average consistency in NH4-N is 9.33mg/l,the average consistency in effluent is 6.51mg/l,and the removal rate is 30.22%.

碩士
國立成功大學
環境工程研究所
82
The Feng-San Water Treatment Plant (abbreviated by FSWTP aft erward,which is the major public water supplier for the Great Ka ohsiung area,draws it raw water directly from the nearby Feng- San Reservoir.The current water treatment processes include prec hlorination,coagulation(with alum),sedimentation, filtration,and disinfection processes.The reservoir is off-line which stores su rface water pumped from the Tungkang River.It is also supplement ed by groundwater pumped from under the bed of Kaoping River.Owi ng to upstream discharge of farming industrial,and domestic wast es,the water of Tungkang River is heavily polluted,with high amm onia-nitrogen and organics,it is affected by salt-water intrusio n.Therefore,the NH3-N,NPDOC,and bromide concentration of the res ervoir water,which is also the influent to the FSWTP,depend on the proportion of water pumped from Tungkang River and from grou ndwater source.Because of high ammonia-nitrogen concentration,th chemical dosage for prechlorination can be higher than 30 mg/L, especially during dry season.As chlorine could also react with organics to form chlorinated organics,it is the big concern of the general public. In order to upgrade the existing water treatment processes ,some preliminary tests were conducted in the laboratory,then a pilot plant was established inside the FSWTP. It consisted of the following units:packed bed nitrification column with coke medium ,flash mixing chamber,flocculator, sedimentation tank,sand filter ,ozone contact column,GAC adsorption column,and chlorine contact column.The flow rate for each unit is in the range of 4.8-12 m3/ day.In addition to the conventional water quality parameters,the organic surrogate parameter such as:NPDOC,THMFP,HAAFP and AOXFP were also measured.The instantaneous values of THM,HAA,and AOX of the treated water from the pilot plant were also compared wit h those obtained from the FSWTP.

碩士
中原大學
土木工程研究所
89
Recently , the industrial and urban waste water has increased dramatically in Taiwan , but there is no exclusive sewage systems in most area . As a result , most of these waste water is directed through existing irrigation systems . Irrigation water quality always receives strong attention by the related authority , and heavy finds have imposed on illegal waste water discharge , but illegal discharge is not stop . The basic problem is that there is no separate system for irrigation and sewage water . This research is to study the problem aroused by using the same system for irrigation and sewage water , based on the current related laws and standard operating procedures for water quality management . Then a new operating procedure is set up to prevent the pollution from irrigation water , and whether improvement is needed . Two improvement methods are proposed based on whether the irrigation water is polluted directly or indirectly . In order to make the improvement more feasible , two rules , ” Cost Benefit Ratio ” and “ Decission-weighting Analysis ” are applied . Finally , seriously polluted Taoyuan Huang Qian Stream basin is taken as an example . Its current pollution situation , improvement and economic benefit are discussed.

碩士
國立成功大學
環境工程研究所
82
The water supply source of Kang-Shan Water Purification Plant is Akong-Dian Reservior. The high concentration of ammonia(2mg/ L) in this surface water caused about 3mg/L of BODn,higher than BODc (2mg/L)caused by total organic carbon(TOC 4.6-13.2mg/L), indicated that biodegradable organic constituent having lower oxygen demand than nitrogen compound. The KSWPP had built up four biofilter for the biooxidation of ammonia as pretreatment. Using coarse coke as filter media for keeping more biomass on the porous media. Bench- scale experiments were conducted as a prestudy. The results indi- cated that NH4+-N of 2-5mg/L could be reduced to 0.1 mg/L. During two months of batch acclimation in the full scale of biofilters , about 10mg/L NH4 was fed to enhance the growth of biofilm, while nitrification complete within 12 hours.After two months adaption, various microbial morphology made up population of biofilms. Bio- mass of coke ranged 0.44 -0.99 gVSS/m2 and specific oxygen uptake rate (SOUR) of 5mg/L NH4 degraded by the existed nitrifier ranged from 4.83-7.62mgO2/gVSS-hr.Semicontinuous operation(3-6hr/day) of the biofilter was performed in the last three months . Biomass of the coke was grown up from 4.80 to 9.87 gVSS/m2 , 60% of ammonia- nitrogen removal efficiency could achieve. Breakpoint chlorination was reduced from 30 mg/L to 10 mg/L after nitrification. However, shock loading of high ammonia- nitrogen would turndown the perfor- mance of biofilter . It showed that the amount of biomass was not enough. The rapid built-up of headloss led to increase the frequ- ency of backwash operation.It is necessary to clean up the under- drain of the biofilter and the pipeline. Furthermore , triplicate tests of overall oxygen transfer coefficient(average KLa=1.5 hr-1) of the biofilter showed that aeration efficiency was lower than that of coarse bubble diffuser tank (KLa=10hr-1). Aeration system of this biofilter has to be improved for energy saving.

In the present project work our plan was to make an attempt to remove heavy metal ions (Pb ions in our case) from polluted water using low cost materials. Eggshell composed of mostly calcium carbonate is a waste natural product available abundantly. Since Ca ions have large affinity towards heavy metal ions, eggshell could be used for said purpose. We prepared artificially Pb-polluted water by adding Pb(NO3)2 in pure water and processed eggshell was used successfully to absorb lead from the solution used as the precursor impurity . Our aim was also to use simple and easily available instruments to detect the absorption of Pb ions from the impure water. The eggshell used was calcined at three different temperatures 3000C, 5000C and 9500C, respectively. The samples were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy and chemical test.The XRD spectra of 5000C and 9500C processed samples after Pb absorption from water indicate the presence of lead in different compositional forms (mostly PbO and PbCO3). The UV-VIS and FTIR spectra were studied to characterize the samples. Finally chemical test was done for confirming the absence of Pb salt in the filtered solution (water).

碩士
嘉南藥理科技大學
環境工程衛生系碩士班
91
This study was using a constructed wetland (CW) system directly treating polluted river water from Erh-Ren River. The main goal of this research is a study of the kinetic behavior of the CW in removing ammonia nitrogen and orthophosphate in order to obtain related treatment models and parameters. The CW is built at the bank of Erh-Ren River, including a free water surface flow ( FWS) system and a subsurface flow (SSF) system from March 1997 to March 2003. During the research period, three strategies were used in order to study different operating (in series and parallel connection). Strategy 1: between March 1997 and January 1999 (in series); Strategy 2: between March 1999 and November 2000 (in series); Strategy 3: between November 2001 and January 2003 ( in parallel). Ammonia nitrogen removal efficiency in CW system is 63±25 %; FWS and SSF system is 80±19 % and 68±20 %, respectively. Orth phosphate in CW system is 55±21 %; FWS and SSF system is 62±24 % and 74±26 %, respectively. Strategy 3 have two different hydraulic loading rate. Between December 2001 and June 2002, the hydraulic loading rate was retained at 0.036 and 0.038 m3/m2/d (HRT=4day) in FWS and SSF system, respectively. Between August 2002 and Januar 2003, the hydraulic loading rate was retained at 0.072 and 0.075 m3/m2/d (HRT=2day) in FWS and SSF system, respectively. Ammonia nitrogen removal rate in SSF (0.10~0.60 g N/m2/d) batter than FWS (0.10~0.40 g N/m2/d) system; orthophosphate removal rate is similar in SSF (0.01~0.20 g P/ m2/d) and FWS system (0.01~0.20 g P/m2/d). The temperature correction factor ( θ) of ammonia nitrogen in CW, FWS and SSF system are 1.005, 1.091 and 0.875, respectively; The θ of orthophosphate in CW, FWS and SSF system are 0.946, 1. 074 and 1.040, respectively. Effect of the temperature on FWS was more than SSF system.

Many large and small rivers in Uttar Pradesh (India) pass through many cities and provide for the needs of their residents. However, the growing industrialization and urbanization in UP have resulted in a rapid deterioration of river conditions. River water quality is continuously declining, which has prompted numerous government agencies, NGOs, and researchers to conduct studies to address the issue. Some of the rivers, including Gomti, in UP, are among the most polluted rivers in India. The Gomti River routinely conveys pollutants from point and nonpoint sources throughout the river basin, including agriculture waste, sewage from households and offices, wastewater from industries, and other sources. Over the past few decades, the river Gomti has witnessed a surge in human activities, leading to a reduction in the flow of the river and a significant deterioration in its water quality. The objective of this study was to formulate a water quality management plan by assessing the existing condition and anticipated future state of water quality of the Gomti River, which flows through Lucknow, UP (India). The research was conducted to manage water quality in relation to assimilative capacity and climate change (effect of rising temperatures) by identifying, quantifying, and characterizing a subset of selected pollutants of river Gomti. This study is based on the physicochemical and biological monthly data from 2013-2017 for seven sampling stations collected from the Uttar Pradesh Pollution Control Board (UPPCB), Lucknow (UP), which monitors the water quality along the Gomti River in Lucknow. The data sets were further investigated using descriptive statistics and multivariate statistical techniques (PCA and CA). One way ANOVA was used to assess seasonal and spatial variation. The Gomti River's water quality was evaluated using four distinct water quality indices (Arithmetic WQI, CPI, SPI, and CPCB-WQI). The results were integrated with GIS to delineate several zones based on the severity of pollution. Four WQIs (Arithmetic WQI, CPI, SPI, and CPCB-WQI) for the river Gomti were forecasted using statistical modeling to help with future water quality conditions and identification of the most appropriate WQI through model performance indicators or metrics. The assimilative capacity of the river was evaluated using DO and BOD, and statistical modeling was used to predict assimilative capacity for future scenarios. IX The assessment of physical, chemical, and biological characteristics of the river water samples revealed significant parameter ranges exceeding the prescribed limits (BIS, 2012/WHO, 2011), including those for DO, BOD, COD, EC, TA, TC, and FC. It is abundantly apparent from these findings that the water is unsafe for human consumption. It was established that the entire river stretch was severely polluted, and pollution levels increased from upstream to downstream (S1 to S7), demonstrating the impact of Lucknow’s rapid industrialization and urbanization. One-way ANOVA analysis concluded all parameters increase from S1 to S7 except for pH and DO, which exhibit steady declines from S1 to S7. All parameters show temporal and spatial variation, although only a few parameters, including EC, TDS, Ca, Mg, and Cl, also show annual variation. The main principal components contributing to the decline in water quality throughout the study were pH, Cl, DO, BOD, COD, TC, and FC, with a total variance of 54.65% in the dataset. These elements reflected sewage contamination and organic pollutants from residential wastewater. To prioritize control efforts concerning different pollution sources, the PCA helped locate the study area's point and nonpoint sources of pollution., Cluster analysis of the river Gomti identified three distinct clusters representing areas with moderate (S1, S2, S3, and S4), high (S5 and S6), and very high (S7) levels of pollution. This categorization can reduce monitoring stations, with one per cluster, cutting river sampling costs in resource-limited countries like India. To help policymakers and stakeholders understand how various policy initiatives affect the water quality of a water body, WQIs simplify complex data. All of the water samples fell into category E (>100), which is unsuitable for drinking and fish culture except at S1, S2, and S3 during the monsoon season, which falls under category D (75- 100), according to the results of the Arithmetic WQIs. At all sampling sites, the SPI value indicated very poor (1-3) status and could only be used for irrigation. The CPI value was found in three categories: qualified (0.41-0.8), basically qualified (0.81-1.0), and polluted (1.01-2.0) at different locations and months. The mean values of CPCB WQI at S1 and S2 lie under the category medium to good, Class - B (50-63), S3 and S4 under the category bad, Class - C (38-50), S5, S6, and S7 under category bad to very bad, Class - D & E (<38). It was also noticed that the river Gomti water was found in all categories classified by CPCB-WQI for different sampling stations. Station S7 recorded the highest value for all estimated WQIs. Statistical analysis further X corroborated that the WQIs increased from S1 to S7. PCA investigation further confirms that anthropogenic activities primarily contribute to the deterioration of this region's water quality. As a result, it can be argued that apart from S1 and S2, WQIs are high at all sampling stations. Statistical modeling for the period of 10 years (2018-2027) based on calculated data of WQIs (Arithmetic WQI, SPI, CPI and CPCB-WQI) reveals similar results as the baseline period (2013-2017). In the case of all four projected WQIs, the maximum value was observed at station S7, followed by the minimum value at S1, and it rose from S1 to S7. RMSE, MAPE, MAE, MaxAPE, and MaxAE were employed as model performance indicators or metrics to track the model's effectiveness. SPI and CPI were determined to be the most appropriate WQIs out of the four based on model performance indicators or metrics values. Gomti River has an average daily flow of 1,500 MLD, rising to 55,000 MLD after rains and dropping to 500 MLD during the summer, resulting in a reduction of assimilative capacity. The minimum DO concentration at all sampling stations was below the reference limit (4 mg/l), while the maximum DO concentration was well above it. The sampling station S7 had a lower minimum and maximum DO concentration than the reference limit. According to the CPCB’s best-use criteria (IS 2296: 1992), river water at selected sampling stations was inappropriate for all purposes in respect of BOD. DO concentrations at S5, S6, and S7 are excessively low for the predicted period (2018- 2027). At S1, DO concentrations are higher than the reference limit for the predicted period, whereas at S2, S3, and S4, higher in the wet season and lower in the dry season. BOD exceeds the reference level (2 mg/l) at all sample locations over the predicted period. The water quality profile of BWQI for the four different climate change scenarios, RCP 4.5 (2040-2069), RCP 4.5 (2070-2099), RCP 8.5 (2040-2069), and RCP 8.5 (2070- 2099) are 38.79, 37.90, 37.75, and 34.83 respectively. It reveals that the BWQI is not significantly different from the previous scenario (2014-2017) as it lies in the bad (26- 50) category in the water quality classification; however, a slight decrease in BWQI is expected in the future under all scenarios. The selected WQIs have been studied through the GIS method. The maps of WQIs showed that 28 drains highly polluted the study area, discharging approximately 461.33 XI MLD wastewater. Therefore, the Gomti River water should not be used due to its high physicochemical and biological load. Prior treatment should be considered to meet water quality regulations, public expectations, environmental and public health concerns. Direct discharge of industrial and domestic wastewater into river through drains is the leading cause of the significantly polluted water quality. As a result, management alternatives are suggested to lessen pollution. A sufficient sewage treatment facility should be set up between S2 and S7. It is imperative to remove solid waste and to maintain adequate discharge at all times, particularly during the dry or non-monsoon seasons, to maintain its self-purification capacity.

碩士
國立成功大學
環境工程研究所
81
It is known that water sources in southern Taiwan have been seriously polluted by domestic sewage, industrial and agricul- ture wastewaters in recent years. The adverse effect is the increasing amounts of ammonia and organics in raw waters year by year. For effectively solving the afore-said problem, most water purification plants select prechlorination process which needs only a short peroid of reaction time. Nonetheless, pre- chlorination will generate carcinogenic chlorinated organic compounds and thus, a significant number of local people al- ready suspect safety of such kind of finished water. For tackling the afore-said problem, three sets of aerobic draft tube fluidized-bed bioreactor(abbreviated by DTFBBR)were constructed and set near Feng-San water purification plant to investigate their efficiencies for removing ammonia and orga- nics from the polluted raw water. After the field-test of DTFBBRs had been completed, one of them was transfered to the laboratory and was introduced with only ammonia-containing synthetic water.Then the effects of ammonia volumetric loading on both ammonia removal and the amount of biomass attached on- to granualar activated carbon(abbreviated by GAC)using DTFBBRs for treating the polluted raw water and ammonia-containing synthetic water were comparatively studied. During the entire test period,the influent NH-N and BOD concentrations of the polluted raw water were ranged from 1.43 to 4.62 mg/l and 3.9 to 8.2 mg/l,respectively; the influent NH-N concentration of the synthetic water was ca. 3.0 mg/l. Compressed air was con- tinuously introduced into DTFBBRs with aeration rate of 5 l/ min; three hundred grams of GAC was added into each DTFBBR.