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1
Rowe, Owen Francis. "A study of the geochemical and microbial interactions in acidic environments and their potential application for the bioremediation of acid mine drainage." Thesis, Bangor University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446531.
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Mudashiru, Liadi K. "Electrochemical determination of dissolved and particulate iron in mine-waters." Thesis, University of Newcastle Upon Tyne, 2009. http://hdl.handle.net/10443/1136.
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A voltammetric procedure for the determination of dissolved and colloidal iron in mine-waters has been developed. Whilst mine-waters are of course enriched in iron. we are remarkably ignorant of the physical state and chemical speciation of the iron. This is a problem since the physical and chemical state of iron is central to understanding a range of processes relevant to mine-water geochemistry and remediation. Examples include hydrolysis of dissolved Fe (III) to release protons. the adsorption of trace metals onto iron colloids and the bioavailability of iron within wetlands designed to remediate acidic waters. In this work, we have developed differential pulse voltammetry (DPV) as a rapid and robust method of determining the concentration of truly dissolved and colloidal iron in 0.45 J.lm filtered waters from a series of mine-water discharges and remediation sites in NE, England. Mine-water samples were collected from CoSTaR sites: these are abandoned mine sites in the UK, designated by the UK Coal Authority for remediation research and routine monitoring of water quality. The sites comprise of six full-scale bioreactors receiving a wide range of mine-waters with pH ranging from 3 to 5 and concentrations of < 0.45 Jlm iron between 30 and 800 mg L-1 across the sites. Monthly samples were collected over the period March 2006 to April 2007. The samples were analysed directly using differential pulse voltammetry (DPV) at gold electrode. The results show that our analysis provides data for total dissolved iron of comparable analytical quality to the established mine-water analysis techniques based on inductively couple plasma spectroscopy (ICP-OES). The good agreement between the iron concentrations measured in acidified samples electrochemically and by ICPOES validates the accuracy of DPV as an analytical method for iron. Colloidal and particulate iron was also determined since DPV measures only dissolved iron. particulate (>0.45 Jlm) and/or colloidal «0.45 Jlm) iron can then be estimated as the difference between the voltammetric responses of natural samples and samples in which the solid phase iron has been dissolved by the addition of He!. v The percentage dissolved iron ranged from 60-90% (in most cases) in unfiltered samples, while the percentage of colloidal iron varied widely across the sites; from 25-45% in unfiltered samples and 50-75% and 38-85% for dissolved and colloidal iron in the 0.45 Jim filtered samples. The ratio of Fe (II) to Fe (III) in the dissolved fraction was detennined usmg ultramicroelectrodes (UME) method. Iron ratio varied widely for the three sites studied. However, in general, the ratio is 1: 1 for the surface influent waters. 1:3 for the sub-surface waters (underground water-Shilbottle site) and 3: 1 for most of the effluent samples. Results suggest that in general, the influent waters are more oxidised and the effluent more reduced. Finally, characterisation of solid phase iron was done usmg a wide range of spectroscopic techniques. Atomic Force Microscopy (AFM) shows that iron colloids range from nm to Jim for lower pH mine waters; at higher pH, particles mainly aggregates on the Jim to mm scale. FT-IR, XRD, TEM and EDX show that the most common colloidal phase is poorly crystalline Fe oxyhydroxides, however certain unusual crystalline phases, e.g., Schwertmannite were found.
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Mohd, Kusin Faradiella. "Coupled hydraulic and geochemical performance assessment of passive mine water treatments in the UK." Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1291.
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Current design practice for aerobic wetlands treating net-alkaline mine water in UK applications of passive treatment is based on zero-order kinetics for pollutant removal; the commonly used area-adjusted removal formula. Lagoons are designed to allow 48 hours of estimated retention time. However, there is significant variation in performance between systems. Neither of these approaches takes account of the hydraulic factors that may influence treatment performance. Therefore, this study aimed to improve understanding of both hydraulic and geochemical factors that govern contaminant behaviour, such that future design of treatment systems is able to optimise treatment efficiency and make performance more predictable, and improve performance over the long-term. Assessment of the hydraulic behaviour (flow pattern) of the treatment systems was accomplished by means of tracer tests. The tracer tests and simultaneous sampling of mine water were undertaken at eight UK Coal Authority mine water treatment systems (lagoons and wetlands) within Northern England (main study areas) and part of southern Scotland. Analyses of mine water samples were also undertaken in the laboratory alongside the field tests for assessment of geochemical processes controlling iron removal in the lagoons and wetlands studied. Analyses of the tracer test results were performed using a residence time distribution (RTD) analysis to account for the different shapes of tracer breakthrough curves observed. There appear to be multiple influences that possibly affect the RTDs in lagoons and wetlands e.g. vegetation and seasonal variation (growing or non-growing season), system age, flow and geometry (length-to-width ratio and depth). The RTD analysis shows that lagoons generally have a more dispersed flow pattern, associated with a more pronounced short-circuiting effects and a long tail compared to wetlands. A modelling approach using a tanks- in-series (TIS) model was adopted to precisely analyse and characterise the RTDs, in an effort to account for the different flow patterns across the treatment systems. Generally, lagoon RTDs are characterised by a greater flow dispersion compared to wetlands (i.e. higher dispersion number, D and lower number of TIS, n). Consequently, the hydraulic efficiency, e for lagoons is much lower than wetlands (mean of 0.20 for lagoons compared to 0.66 for wetlands). This is attributed primarily to a much lower volumetric efficiency, ev in lagoons, meaning that a greater proportion of the total volume of the lagoon system is not being involved in the flow of water through them, with implications for design to optimise performance. In contrast, in wetlands a greater volumetric efficiency is evident, and there is therefore a longer relative mean residence time for retention and attenuation of iron. On the evidence of field data, in lagoon systems the iron removal processes are primarily controlled by ferrous iron oxidation, whilst in wetlands the removal is controlled by iron settlement. The time- and concentration-dependence of iron removal (oxidation and / or settlement rate) has also been investigated in the laboratory alongside the field data. The rates are faster in lagoons compared to wetlands due to higher concentration of iron available for the processes. General trends showed that efficient treatment performance for iron removal corresponds with greater system hydraulic efficiency in wetlands compared to lagoon systems. The greater hydraulic efficiency in wetlands was mainly attributed to a grea ter volumetric efficiency in the wetland systems. In contrast, shorter relative mean residence time was found in lagoons, thus a lower retention time for iron attenuation and lower removal efficiency as a consequence. For lagoon systems, performance can be optimised by ensuring greater volumetric efficiency (hence residence time), which can be achieved with a large length-to-width ratio system (up to a ratio of 4.7), but also a greater depth (up to 3.0 m), though only if systems are regularly maintained (dredged). For wetlands, the use of the area-adjusted removal rate formula appears to work well for the design of aerobic wetlands, despite the observed concentration-dependence of iron removal processes. However, use of first-order removal formula (TIS basis) would be a more appropriate approach to the design of mine water treatment systems since it takes account of the flow pattern effect on pollutant removal processes, in addition to the first-order kinetics (concentration-dependence) for iron removal. Regular sludge removal (yearly) is recommended in lagoons to provide longer residence time because lagoon depth and volume tends to rapidly decrease over time due to build up of ochre and debris (7- 49% depth reduction per year). Thinning of reeds is recommended whenever apparent channelisation would otherwise dominate the flow pattern, and therefore limit the capacity for adsorption and settlement of precipitated iron hydroxide.
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Mighanetara, Krongkaew. "Impact of metal mining on the water quality in the Tamar catchment." Thesis, University of Plymouth, 2008. http://hdl.handle.net/10026.1/824.
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This study discusses the effects of past mining activities on sediment and water quality in streams and rivers in the Tamar catchment. High trace element concentrations, both in water and sediments, were observed in streams and rivers draining areas associated with abandoned mine sites. Maximum concentrations were observed in the Gunnislake/Calstock mining district, where intense metalliferous mining took place during the 19th century. Mine waste from abandoned mine sites in this area contained up to 6.3% arsenopyrite, 5.8% pyrite, 0.3% chalcopyrite and 24% scorodite. As a result, high concentrations of trace elements of up to 180000 mg kg‾¹ As, 6500 mg kg‾¹ Cu were determined in these wastes. Sequential extraction of the mine waste revealed that in most cases, the oxidisable fraction accounted for large proportions of mobile species, followed by the reducible fraction. The exchangeable fraction was relatively low, except for Cu in samples from fine grained waste heaps, in which significant amounts of secondary minerals, such as Fe oxides/oxyhydroxides and Fe-As-O minerals were observed, suggesting trace elements had the tendency to be retained and recycled within the fine grained waste heaps. The Fe oxides/oxyhydroxides can contain up to 12% As and Fe-As-O minerals can contain up to 25% As and 6% Cu, indicating that the As and Cu associated with Fe oxide phases represent their reducible fraction. The coarse grained waste heaps, with higher permeability and low cohesion characteristics, had a higher potential to produce acid leachate and were more susceptible to erosion than the fine grained waste heaps. Contaminants from abandoned mine sites entered aquatic systems within the catchment, as shown by the high concentrations of trace elements (up to 25000 mg kg‾¹ As, 28000 mg kg‾¹ ' Cu, 32000 mg kg‾¹ Mn, 9200 mg kg‾¹ Pb and 2700 mg kg‾¹ Zn) observed in sediments in water channels draining these mine sites. Some streams and adits draining abandoned mine sites carried acidic waters with pH values frequently below pH 4. Dissolved concentrations up to 560 μg L‾¹ As, 7600 μg L‾¹ Cu, 3800 μg L‾¹ Fe, 5700 μg L‾¹ Mn, 170 pg L‾¹ Pb and 2500 μg L‾¹ Zn, and particulate concentrations up to 1600 μg UI As, 7900 μg L‾¹ Fe, 290 pg U' Ni, 11 pg U' Pb and 91 μg L-¹ Zn were observed in channels draining abandoned mine sites. In total, the annual flux of trace elements from 25 studied streams and adits input ca. 13,000 kg Fe, 4300 kg Mn, 4200 kg Cu, 3600 kg Zn, 1400 kg As, 400 kg Ni, 350 kg Co, 43 kg Pb, and 6.6 kg Cd into the Tamar estuary. Seven important point sources of metals to the River Tamar were identified. The mass balance calculation revealed that over 50% of trace elements were not accounted for by the studied point sources, suggesting an importance of diffuse sources. The inputs of solid and dissolved contaminants from the intensive mining district affect the water and sediment quality of the Tamar estuary, an important ecosystem in southwest England. This work has provided important information on the relative importance of point and diffuse sources, ‾which is essential in the formulation of effective catchment management strategies
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Hubbard, Christopher George. "Acid mine drainage generation and transport processes in the Tinto River, SW Spain." Thesis, University of Reading, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440101.
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Crowley, O. A. "Stable carbon isotopes as a tool to investigate parameters affecting natural attenuation of chlorinated hydrocarbons." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411099.
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Khor, Jen Nee. "Oxidation of pesticides in photocatalytic reactors." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403398.
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Buckby, Tracy. "Processes of persistent metal contamination in the RiÌo Tinto, south west Spain." Thesis, University of Reading, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428101.
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Cutting, Jamie Paul. "Geochemical controls on trace metal behaviour in acid mine drainage." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446257.
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Fogg, Paul. "Fate and behaviour of pesticides in biobeds." Thesis, Cranfield University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405625.
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Grachev, Viatcheslav. "Selective recognition of herbicides : calix[4]arene derivatives and imprinted polymers for the education of chlorophenoxy acids." Thesis, University of Surrey, 2005. http://epubs.surrey.ac.uk/844364/.
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In this day and age there is a growing concern about the increasing number of dangerous chemicals in Agriculture. Obsolete pesticides and their metabolites represent a major threat to the environment. These compounds are highly persistent, toxic and tend to accumulate within the human body. While considerable efforts have been made to abolish stockpiles of these hazardous chemicals, the removal of their residues from soil and water sources remains problematic. Therefore, the main aim of this research project is to provide the basis for the development of a simple, cost-effective and environmentally friendly technology for the removal of obsolete pesticides from water and soil. The fundamental concept was based on Supramolecular Chemistry, which implies non-covalent interactions between "host" and "guest". Although such interactions have formed the basis of numerous fundamental studies, their application within the environmental field has yet to be assessed. Introductory physicochemical analyses of the pollutants and prospective receptors in various media such as solubility, speciation in different organic solvents as well as partition and distribution in binary organic solvent/water systems were carried out. Design of the "host" was based on the calix[4]arene framework since it provided a convenient route for chemical transformations and possesses cavities of complementary size to the guest species. The receptor was chemically converted, using synthetic resource-saving techniques that provide the best outcome, to improve its ability to remove obsolete pesticides from water and soil. In connection with the preliminary studies and the synthetic activities, extensive 1H NMR, X-ray, UV and electrochemical evaluations of interactions between a wide variety of obsolete pesticides and the receptors were carried out. As a result, the receptors were proved to interact selectively with chlorinated phenyl- and phenoxyacetic acids and their metabolites. This was followed by a detailed determination of the stability of supramolecular complexes as well as the thermodynamic parameters associated with the complexation process. Finally, aqueous samples of pollutants were subjected to extraction by the most prospective receptors. At this stage, some macrocycles were anchored to a polymeric backbone or naturally occurring materials. As such, both liquid-liquid (LLE) and solid-liquid (SLE) extraction techniques were tested and proved to be effective tools for water remediation.
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Butler, R. M. "Remediation of bromate contaminated groundwater." Thesis, Cranfield University, 2005. http://dspace.lib.cranfield.ac.uk/handle/1826/3533.
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Bromate (BrO3") is a by-product formed at concentrations of 0.4 - 60 µg L'' during potable water ozonation. Following World Health Organisation designation as a 'possible human' carcinogen, a 10 pg L" drinking water limit was introduced in England and Wales. Discovery of bromate contamination within a UK aquifer highlighted a knowledge gap, addressed by this project, relating to environmental behaviour and groundwater remediation. Following selection of an anion analysis strategy utilising Ion Chromatography (IC), bromate behaviour in wastewater was investigated as contaminated groundwater ingress to treatment processes was deemed possible. Respiration of wastewater biomass was unaffected by spiking of < 200 mg Ul bromate or bromide, with pilot-scale process dosing trials (S 100 mg L') using a Membrane Bioreactor (MBR) also exhibiting little negative effect following biomass acclimation. Bromate reduction to bromide was observed in a continuous-flow suspended growth chemostat bioreactor at retention times of 20 - 80 hours. A biological mechanism was confirmed in this system, with reduction mediated by indigenous groundwater bacteria following glucose addition. Bromate reduction rates were initially low (5 27.8 pg U' hr 1), but acclimation increased rates to > 1000 pg L" hr t. An alteration in microbial composition was noted over this period, from a denitrifying 'co-metabolic' culture to predomination of 'high-rate' specific bromate degraders. Operational parameters including pH, temperature, carbon source, influent bromate and glucose, and retention times were investigated, with all parameters apart from pH shown to affect bromate reduction rates. For example increased bromate influent enhanced reduction rate, although potentially toxic effects were noted with an influent > 75 - 80 mg L"'. Batch studies suggested glucose was rapidly fermented (< 48 hours) by the microbial consortium. Nitrate was also rapidly removed (< 4 hours), with sulphate reduction only following removal of bromate. A fixed-film pilot-scale bioreactor system, seeded with biomass from the chemostat culture, reduced > 90% of a 1.1 mg L"1 bromate influent within unspiked contaminated groundwater. Plating studies were successful in producing a range of isolates from the mixed chemostat culture. Overall the project demonstrated, for the first time, continuous remediation of bromate groundwater contamination within a bioreactor system.
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Літинська, Марта Ігорівна. "Видалення сполук арсену та гуматів з водного середовища." Doctoral thesis, Київ, 2021. https://ela.kpi.ua/handle/123456789/40411.
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Дисертаційна робота присвячена розробці та науковому обгрунтуванню методу для ефективного видалення сполук арсену різних ступенів окиснення та гуматів з природних вод.
В дисертації теоретично (на основі літературних даних та розрахунків) та експериментально (в результаті сорбційних досліджень) обгрунтовано вибір сполук феруму, як основного сорбуючого компоненту для видалення сполук арсену з водного середовища. Різними способами (гетерогенне осадження, гомогенне осадження, гідротермальний метод) синтезовано ряд ферумвмісних сорбційних матеріалів, серед яких порошкові, зернисті на основі активованого вугілля та суспензійні сорбенти.
Визначено, що використання комбінації «дрібнодисперсний ферум(ІІІ) оксигідроксид/мембрана» дозволяє вилучати сполуки арсену з модельних та підземних вод до санітарних вимог за вихідних концентрацій арсену 500-16733 мкг/дм3 та відділяти відпрацьований дрібнодисперсний ферумвмісний сорбент від води і захищає мембрани від засмічування.
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Currie, Martin James. "Enhancement of particle removal in water treatment by pre-ozonation :." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412314.
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Phoochinda, Wisakha. "An appraisal into techniques of algal removal." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406363.
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Amornraksa, Suksun. "Development of magnetic floc technology for water treatment." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405033.
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Kerwick, Mark Ian. "An evaluation of alternative technologies for drinking water disinfection." Thesis, University of Surrey, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.594172.
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A methodology has been developed and used to evaluate the alternatives to chlorination for primary and residual drinking water disinfection. From the evaluation process it was concluded that at present none of the altemalives could viably replace chlorination for both primary and residual disinfection. The study did however highlight the potential of electrochemical disinfection technologies to provide primary and residual disinfection in the future by the generation of a range of oxidants including chlorine species. Hence, three electrochemical technologies (a mixed oxidant generator, a direct electrolyser with carbon aerogel electrodes, and a direct electrolyser called Zappi ™ )were chosen to assess their potential as an alternative to conventional chlorination for primary and residual disinfection. The disinfection efficiencies of the three devices were assessed. Anolyte produced from the mixed oxidant generator was compared directly with hypochlorite at equal doses. Anolyte was shown be more effective against E. coli, reducing the E. coli count by >6 logs and to have the same potential for trihalomethane formation in slow sand filtered water, generating 30).μg/L when dosed at lmg/L for 24 hours. The carbon aerogel and Zappi™ direct electrolysers were shown to disinfect E. coli in a range of electrolytes and water matrices. Total measurable E. coli log reductions were achieved in both devices using a chloride electrolyte. Significantly, both devices were effective against E. coli in sulphate electrolytes without the generation of chlorine, with 3 and 4 log reductions respectively. The carbon aerogel device was also shown to be effective in a good quality sewage effluent matrix and tap water reducing E. coli by >4 logs. Whilst, the Zappi was shown to reduce E. coli by >2 logs in slow sand filtered water. Phosphate was shown to significantly reduce disinfection in both direct devices. The effectiveness of the direct electrolysers was shown to be variable against other micro-organisms. The Zappi™ device was effective against the virus, bacteriophage MS2 in a sulphate electrolyte, with a >5 log inactivation after 30 minutes. Whilst, the carbon aerogel device achieved a > 1 Jog reduction of Enterovirus after 40 minutes in tap water and a 2 log reduction of Cryptosporidium oocysts in tap water. It should be noted that the reduction in Cryplosporidium could be attributable to removal via filtering rather than inactivation by oxidant attack. Possible mechanisms for electrochemical disinfection were investigated of these oxidant generation was shown t~ be responsible for disinfection_ Determination of the oxidant species generated proved to be problematic. The presence of chlorine and the high voltages used in all three devices made it difficult to isolate specific oxidants. The bactericidal properties of two poly-viologens were assessed 10 determine their potential for mediating oxidant generation for drinking water disinfection. The poly-viologens were shown to reduce the E. coli count by 6 logs. However, the results were inconclusive due to the variability between poly-viologen batches. These studies do however infer that poly-viologens may still have a future use as oxidant mediators in disinfection devices.
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Lau, Sze Chun Gary. "Physical characteristics of flocs in water treatment processes." Thesis, University College London (University of London), 2005. http://discovery.ucl.ac.uk/1444945/.
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Aluminium sulphate, calcium nitrate, and two cationic polymers have been used to coagulate and flocculate dilute kaolin and latex suspensions (< 100 mg/1) in a stirred vessel. The effects of the different destabilising agents on the resulting floes have been monitored using a simple continuous optical technique based on turbidity fluctuations and the behaviour of these floes under shear conditions and the possibility of subsequent floe re-formation have been investigated. The results showed vast differences in behaviour regarding to floe breakage and re formation between the systems. For a low molecular weight, high charge polymer (A) and calcium nitrate, floe breakage was almost completely reversible. However, for aluminium sulphate, limited floe re-formation was observed on restoring previous shear conditions after breakage. For a high molecular weight polymer (B), limited floe breakage was observed. Moreover, a new automated monitoring technique based on cake and vacuum filtration has been developed to assess the filterability of floes. The technique is reliable and provides reproducible results. The results showed that polymer A was more effective in enhancing filterability than polymer B for both kaolin and latex suspensions. However, polymers do not have a significant influence on the filterability of floes if the primary particles involved have high sphericity.
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Lamont, Yvonne. "The effects of UV-rich light pulses on pathogenic microorganisms in liquids." Thesis, University of Strathclyde, 2005. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21595.
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The work presented in this thesis is concerned with investigating the use of UV-rich light pulses for the inactivation of problematic microorganisms. UV radiation is an effective means of disinfecting surfaces and liquids and of reducing contamination in air. The germicidal effects are primarily due to the UV-C region of the electromagnetic spectrum, which interferes with the nuclear core of a microorganism resulting in a loss of ability to replicate and initiate infection. When UV radiation is delivered as pulses of light however, the results are even more appealing, with higher levels of microbial inactivation achieved in much shorter timescales. Drinking water and wastewater disinfection is normally provided by the use of chemicals such as chlorine. These are disadvantaged by the production of harmful chemical by-products and the resistance of certain types of microorganism to chemical treatment. The main aim of this investigation was therefore to look at the role of pulsed UV-rich light for inactivating a range of microorganisms suspended in liquid media and to determine how successful the treatment process would be as an alternative disinfection method. The results show that pulsed UV-rich light treatment is extremely effective against many types of bacteria, virus and Cryptosporidium. It was also demonstrated that the sensitivities of microorganisms to UV radiation can vary significantly depending on the cell-wall structure, growth phase, strains and nucroorgarusm specIes. Studies were also undertaken to identify electrical and biological parameters that may influence the inactivation success. It was found that high operating voltages and low pulse repetition frequencies give desirable levels of inactivation Other important factors investigated were sample depth, volume and reflection. Finally, the possible limitations to pulsed UV-rich light treatment were investigated. It was found that the success of the treatment is primarily determined by the transmittance of UV pulses through a sample. As expected, transmittance depends upon microorganism size and population. The major limitation of UV treatment is the ability of microorganisms to reactivate following exposure to visible light (photoreactivation). Studies showed photoreactivation to occur following pulsed UV-rich light treatment, only when the microorganisms do not receive sufficient UV treatment or if they are exposed to high intensities of visible light.
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Panagoulopoulos, Alexios. "Comparative performance of potassium ferrate in wastewater and water treatment." Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/830/.
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Jarvis, Peter. "The impact of natural organic matter on floc structure." Thesis, Cranfield University, 2004. http://dspace.lib.cranfield.ac.uk/handle/1826/4559.
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The removal of natural organic matter (NOM) at water treatment works (WTW) is essential in order to prevent toxic compounds forming during subsequent disinfection. Coagulation and flocculation processes remain the most common way of removing NOM. The properties of the resulting flocs that form are fundamental to the efficient removal of organic material. Periods of elevated NOM loads at WTW can lead to operational problems as a result of the deterioration in floc structural quality. Assessment of floc physical characteristics can therefore be a crucial tool in order to determine and predict solid-liquid removal performance at WTW. Here the growth, size, breakage, strength, re-growth, fractal dimension and settling velocity were measured for flocs formed from a NOM rich water source. NOM floc structural characteristics were measured and evaluated over a one year period in order to monitor the seasonal variation in floc structure. The results showed that a significant improvement in floc size and strength was seen during autumn and summer months. It was subsequently shown that as the organic fraction in the floc increases the floc size, settling velocity and fractal dimension all decrease. A model was proposed showing how these changes were dependent upon the adsorption of NOM onto primary particle surfaces. A range of different chemical coagulant treatment options were applied for NOM removal and the resulting floc structure compared. Considering both floc structure and optimum NOM removal the treatment systems were of the following order (best to worst): MIEX® + Fe > Fe > Fe + polymer > Al > polyDADMAC. NOM floc re-growth was shown to be limited for all the treatment systems investigated. The practical implications of the results were: (1) The requirement for careful coagulant dosing or order to achieve optimum floc characteristics. (2) The use of a pre-treatment anionic ion-exchange stage prior to coagulation. (3) A comparison of alum and ferric based coagulants suggested the ferric coagulants gave better floc structure and improved NOM removal rates.
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Berry, Alice L. "The effects of shear and mixing on a continuously-fed stirred tank reactor for aerobic, biological wastewater treatment." Thesis, Cranfield University, 2002. http://dspace.lib.cranfield.ac.uk/handle/1826/7984.
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Treatment of domestic wastewater in a 9 L well defined conventional biotechnology type reactor was investigated over a range of stirrer speeds (8.3 to 16.7 s-1) and retention times (8 to 12 h). Parameters of reactor oxygen transfer coefficient and shear were found to be close to conditions used for pure cell culture in industrial applications rather than typical wastewater treatment conditions. The major treatment effects measured were carbonaceous load removal and nitrification. Carbonaceous load removal was found to be highest at low stirrer speeds with short retention times. Ammonia removal was greatest at stirrer speeds of 15 s-1 with 12 h retention time. Most of the ammonia was converted to nitrite, this agreed with reports in the literature of temperature; retention time and free ammonia inhibition promoting nitrite build up. Specific nitrification rates of up to 35 mg(N)g-1h-1 (at 15 s-1 10 h retention time) were achieved in the reactor, found to be close to those observed in pure culture experiments. An inverse correlation was observed between ammonia and CBOD5 removal. The temperature increased with stirrer speed and also had a strong effect in the nitrification rate. The interaction between temperature and stirrer speed was investigated using a control unstirred reactor and multiple linear regression technique. It was found that while the temperature and stirring were correlated, separate effects could be discerned. The stirrer effects were further investigated by varying the impeller type. Tip speeds were matched to the disk turbine for a low and a high shear impeller. The lower shear LE20 impeller gave promising results that required a much lower power input to achieve the treatment. Finally an anoxic reactor was added to denitrify the stirred tank effluent. It was found to successfully denitrify when sufficient nitrite and nitrate were supplied by the stirred tank. The combination of a stirred nitrifying tank followed by a denitrifying stage could make be an attractive alternative wastewater treatment method providing the stirred tank power requirements can be reduced.
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Al-Anezi, Khalid M. "Parameters affecting the solubility of carbon dioxidein saline water : anti-scalants, anti-foam agents and atomic force microscopy." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445692.
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Meynet, Paola. "Bactericidal activity of TiOâ‚‚ photoanodes." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430342.
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Steele, Andrew Michael. "The catalytic ozonation of industrial wastewaters." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428198.
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Tyldesley, Kathryn Victoria. "The effects of wastewater treatment processes on the oestrogenic and anti-androgenic activity of UK wastewater treatment works effluent." Thesis, University of Exeter, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441795.
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Jonkergouw, Philip M. R. "Simulating chlorine decay in water distribution systems." Thesis, University of Exeter, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441805.
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Robinson, Philip Mark. "A quantitative investigation into the factors affecting the flocculation of bacteria (Escherichia coli) with cationic polyacrylamide." Thesis, Teesside University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410864.
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Kim, Cheol Gyu. "The evaluation of modified clays as a coagulant for water and wastewater treatment." Thesis, University of Surrey, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435215.
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Zhang, Yanping. "Occurrence and removal of endocrine disrupting chemicals from aquatic environment by adsorption and photodegradation." Thesis, University of Sussex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426305.
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Tran, Tien Khoi. "Evaluation of potassium ferrate as a coagulant in water and wastewater treatment." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9642.
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Ferrate is believed to have a dual role in water treatment, both as oxidant and coagulant. Few studies have considered the coagulation effect in detail, mainly because of the difficulty of separating the oxidation and coagulation effects. This study aims to evaluate the coagulation performance of ferrate together with its oxidation effect in water and wastewater treatment processes, as it has not been studied thoroughly in previous work. The study involves laboratory-based experiments that investigate the coagulation reaction dynamically via a PDA instrument, between ferrate and a suspension of kaolin powder, and humic acid solution at different doses and pH values, and comparing the observation with the use of ferric chloride. The PDA output gives a comparative measure of the rate of floc growth and the magnitude of floc formation. The results of the tests with kaolin suspension show some similarities and significant differences in the pattern of behaviour between ferrate and ferric chloride. Ferrate demonstrated very similar coagulation characteristics to ferric chloride with regard to the influence of pH and Fe dose. However, the magnitude of floc formation with ferrate was always inferior to that with ferric chloride. The rate of floc growth with ferrate was slower and sometimes less extensive than that with ferric chloride in most cases. It was discovered that the reason for the inferior performance of ferrate was the slow formation of Fe(III) species at neutral to high pH owing to the low degradation rate of ferrate in aqueous solution at these pH values. The interaction between HA and ferrate was extensively investigated in comparison to ferric chloride in this study. The results reveal that ferrate achieved comparable or better floc formation to ferric chloride over a much broader Fe dose range. However, the degree of organics removal (DOC) was lower than ferric chloride (~5%). The results obtained from model waters containing HA were consistent with those for samples of a natural upland coloured water. Ferrate oxidation appears to increase the hydrophilic and electronegative nature of the HA leading to an extended region of charge neutralization and a consequent slightly lower HA removal compared to ferric chloride.
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Winward, Gideon Paul. "Disinfection of grey water." Thesis, Cranfield University, 2007. http://dspace.lib.cranfield.ac.uk/handle/1826/2894.
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The reuse of grey water, for applications such as toilet flushing and irrigation, represents a potential sustainable solution to water shortages experienced by regions worldwide. Although reused grey water is not intended for potable use, the potential for transmission of waterborne pathogens by aerosol inhalation, topical contact, or indirect ingestion is a key concern for grey water reuse. This thesis explores the pathogen content of grey water and investigates pathogen removal through treatment and disinfection processes. The impacts of organic and particulate material in grey water on the efficacy of disinfection processes are investigated in depth. Grey water can potentially harbour a range of pathogenic microorganisms, with opportunistic bacterial pathogens in grey water indicating a particular risk of grey water reuse for the vulnerable members of society. The disinfection of grey water is therefore critical prior to reuse. Particulate material in grey water limits the efficacy of disinfection by chlorine, ultraviolet light, and origanum essential oil, by shielding microorganisms from the applied disinfectant. Microbial resistance to the disinfectants was linked to the particle size distribution of the grey water, with increasing particle size offering greater protection to associated microorganisms. Additional organic material was shown to reduce the applied disinfectant but no impact on microorganism resistance to disinfection was observed when a constant disinfectant dose was maintained. Treatment of grey water, targeting the removal of large particulate material, improves the efficacy of grey water disinfection, allowing compliance with stringent microbiological standards for urban water reuse.
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Henderson, Rita Kay. "PosiDAF for algae removal." Thesis, Cranfield University, 2007. http://dspace.lib.cranfield.ac.uk/handle/1826/4472.
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During algac blooms, coagulation is frequently unsuccessful resulting in poor flotation duc to complex algal character. 11iis thesis cxplorcs tlic link between algal character and conventional treatment and the potential for developing morc appropriatc algac trcatmcnt tcclinologics. Specifically, dissolvcd air flotation (DAF) that has bccn adaptcd by dosing cationic clicmicals to the saturator to modiry bubbic surfaccs, such that it docs not rcly on coagulation, is invcstigatcd. 1'his proccss is tcrmcd PosiDAF. Analysis of dissolved algogcnic organic mattcr (AOM) extracted from problcmatic species enabled investigation of the impact of morphology and AOM on coagulation- flocculation-flotation. Both increasing surface area and charge density of algae systcrns, werc rclatcd to increasing coagulant dcmand. Application of the appropriate coagulant dcmand ensured removal of all thrcc components - cclls, AOM and coagulant. Maintaining the zcta potential bct-%vccn -10 mV and +2 mV ensured optimum rcmoval was obtained. PosiDAF trials were conducted by dosing chemicals that had previously been shown to alter bubble charge, including co3gulant, surfactant and polymer, to the saturator. Coagulants were unsuitable for use in PosiDAF as they did not remain at the bubble surface. Highly hydrophobic, cationic surfactants were observed to remove cells according to a theoretical model, such that removal improved with increasing bubbic: particic ratio and with cell size. The polymer, polyDADNIAC, achieved greater removal cfficiencies than those predicted theoretically, attributed to an increase in the swept volume of the bubble. However, polyDADMAC was sensitive to changes in AOM composition. A chemical that combines attributes of both surfactant and polyDADMAC may overcome the barriers to PosiDAF implementation.
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Sharp, Emma. "Natural organic matter coagulation." Thesis, Cranfield University, 2005. http://dspace.lib.cranfield.ac.uk/handle/1826/2224.
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The removal of natural organic matter (NOM) is one of the main challenges facing water utilities in both the UK and the US. As a consequence of changes in land management and an increased carbon loss from solids, a greater amount of accumulated organics is now being flushed into the aquatic environment during increased surface run-off events such as snowmelt or heavy rainfall. Furthermore, whilst traditional treatment with trivalent coagulants has proven a successful strategy in the past, operational problems are now being reported during periods of elevated organic levels in the water. These include the formation of fragile flocs, a greater particulate carryover onto downstream processes and increased disinfection by product (DBP) formation. Resin adsorption techniques were employed to fractionate the water samples into their hydrophobic and hydrophilic components. This, coupled with raw water monitoring, revealed that NOM composition and characteristics can vary, even if the total organic concentrations appear stable. In particular, hydrophobic NOM fractions contribute the majority of the charge compared to the hydrophilic fractions, and therefore exert a greater impact on coagulation conditions. Comparison across different source waters, seasons, at varying experimental scales and under varying coagulation conditions, revealed that zeta potential monitoring during coagulation takes into account the changing electrical property of the water, and in general, maintaining a value between -10
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Hu, Alan Yung-Chih. "Anaerobic in-tank membrane bioreactor for wastewater treatment." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414422.
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Duckhouse, H. L. "The effect of sonication at different frequencies on microbial disinfection using hypochlorite." Thesis, Coventry University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436296.
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Simm, Andrew Oliver. "The electrochemical detection of arsenic." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433323.
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Dennis, Mark. "Synthesis of calix[4]arenes and their use in sensors." Thesis, Bangor University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443648.
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Heidrich, Elizabeth Susan. "Evaluation of microbial electrolysis cells in the treatment of domestic wastewate." Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1469.
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Wastewater can be an energy source and not a problem. This study investigates whether rapidly emerging bioelectrochemical technologies can go beyond working in a laboratory under controlled temperatures with simple substrates and actually become a realistic option for a new generation of sustainable wastewater treatment plants. The actual amount of energy available in the wastewater is established using a new methodology. The energy is found to be considerably higher than the previous measurement, or estimates based on the chemical oxygen demand with a domestic wastewater sample containing 17.8 kJ/gCOD and a mixed wastewater containing 28.7 kJ/gCOD. With the energy content established the use of bioelectrochemical systems is examined comparing real wastewater to the ‘model’ substrate of acetate. The abundance of exoelectrogenic bacteria within the sample, and the acclimation of these systems is examined through the use of most probable number experiments. It is found that there may be as few as 10-20 exoelectrogens per 100 mL. The impact of temperature, substrate and inoculum source on performance and community structure is analysed using pyrosequencing. Substrate is found to have a critical role, with greater diversity in acetate fed systems than the wastewater fed ones, indicating that something other than complexity is driving diversity. Laboratory scale microbial electrolysis cells are operated in batch mode fail when fed wastewater, whilst acetate fed reactors continue working, the reasons for this are examined. However a pilot scale, continuous flow microbial electrolysis cell is built and tested at a domestic wastewater treatment facility. Contrary to the laboratory reactors, this continues to operate after 3 months, and has achieved 70% electrical energy recovery, and an average 30% COD removal. This study concludes that wastewater is a very complex but valuable resource, and that the biological systems required to extract this resource are equally complex. Through the work conducted here a greater understanding and confidence in the ability of these systems to treat wastewater sustainably has been gained.
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Lan, Bingyan. "Treatment of industrial cork boiling water by ozonation and advanced oxidation." Thesis, University of Nottingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493119.
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The high concentration of organics, their toxic nature and possibly low pH levels restrict the application of biological treatments or traditional physicochemical treatments to cork boiling water. Highly efficient wastewater treatment intended for the reduction of contaminants levels is therefore required if the liquor is to be reused in the boiling stage or to be purified to meet the public waste limits before disposal.
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Alataway, Abed. "Suitability of waste water for irrigation in Saudi Arabia : analysis of public perceptions and quantitative microbial risk assessment." Thesis, University of Newcastle Upon Tyne, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601759.
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Wastewater reuse for irrigated practice is un alternative solution in which food production can be improved especially in the arid-region where freshwater resources are often limited However; the potential public health risk associated with wastewater reuse remain a major concern. as well as public perceptions towards wasteater. This research was conducted in two main agricultural cities within the Saudi Arabia
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Setta, Feth-Allah. "Calcium carbonate and barium sulphate scale formation kinetics : a surface scale deposition kinetic model." Thesis, University of Leeds, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595798.
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Scale formation is one of the major flow assurance problems in the water treatment and in the oil and gas sectors. Calcium carbonate (CaCO3) is the most common scale encountered in industry. Barium sulphate (BaSO4) scale is the most difficult to deal with as it is highly insoluble and requires chemical and/or physical treatments. Scale build up results in reduced water flow through pipes and could lead to an entire shutdown of installations leading to important financial losses. Nowadays, the main ways to treat and prevent scale formation are periodic squeeze treatments and/or the continuous injection of scale inhibitors. The use of nitrogen and phosphorous compounds, such as polyphosphino carboxylic acid (PPCA), has already been shown to significantly decrease calcium carbonate scale formation. However, the discharge of such inorganic chemicals into the environment represents a real threat and green inhibitors (such as Polymaleic acid (PMA), Poly-Aspartate (PA) and Carboxymethyl-inulin (CMI) are an altemative. A simultaneous comparison of their inhibition effects on scale precipitation and deposition has been carried out in this study. Several different scale preCipitation prediction models have been developed. However, these models are based on thermodynamics and give, at most, a scale tendency to form. Scale Deposition rate equations or prediction of scale deposition have been largely ignored. Moreover, no attempts have been made to associate precipitation data in the bulk solution with deposition data on a solid surface. If a comparison is made with corrosion prediction where a time-based rate is given (in millimetres per year), then it can be seen that a scale kinetic deposition model would be more useful for the flow assurance and the integrity management. This study present a first attempt for a calcium carbonate and barium sulphate scale deposition kinetic model giving an amount of scale (quantity as a mass or thickness) on a stainless steel surface in function of the saturation index, the temperature, the pressure and flow regime
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Buaprathoom, Somporn. "Photonics based cryptosporidium detection systems." Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.580330.
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Cryptosporidium is a protozoan parasite causing cryptosporidiosis; a diarrheal disease of varying severity. The infection is transmitted by tiny spores called oocysts resistant to harsh environmental conditions and various disinfectants. Cryptosporidium infection and recovery from the illness is dependent on the body's immune system. It is important to be able to detect these parasites quickly to reduce the risk of infection. Multiple-angle light scattering systems have been developed for detecting cryptosporidium oocysts suspended in water. The proposed systems were set up with a single wavelength (red AlGaInP laser: 658.4 nm) and two wavelength (violet InGaN laser: 405.7 nm and red AlGalnP laser: 658.4 nm) sources. The single wavelength system was developed for measuring particle concentration and particle size and refractive index. It combined multiple-angle scattering detection, to collect angle- resolved scattered intensities from suspensions, and the partial least square regression method (PLS-R) to predict characterizing information of samples under investigation based on calibration models. The calibration models were composed from the calibration data generated from the experiments for particle concentration measurement and according to Mie theory with refraction and transmission corrections included for particles' size and refractive index measurements. The dual wavelength system was set up for particle identification by using relative wavelength scattered intensity as the identifying means. Measurement of particle concentration, size and refractive index by the single multiple angle light scattering system was validated using polystyrene spheres in aqueous suspensions. Applying the systems to cryptosporidium oocyst suspensions, the concentration measurement results had lowest errors from the references 9.5 % at concentration of 2.00x10600cysts/ml in mono-dispersion and 3.6 % at concentration of 7.50x105 oocysts/ml for cryptosporidium and mixed suspensions with polystyrene sphere suspensions. The measured cryptosporidium oocysts' size and refractive index were 4.37 ± 0.16!-Lm and 1.38 ± 0.05 which also had good agreement to the reference value (size: 4.38 ± 0.23 urn, refractive index: 1.37). The dual wavelength multiple-angle light scattering system collected the relative wavelength scattered intensities from suspensions of the cryptosporidium oocysts comparing to polystyrene spheres and E.coli. The relative wavelength multiple-angle scattered intensity of cryptosporidium oocysts suspension showed a characteristic scattering pattern and significantly different pattern from the polystyrene spheres and bacteria E.coli. The results presented in this research have demonstrated that the proposed multiple-angle light scattering systems have the capability to initially detect cryptosporidium oocysts in suspension. These systems could be further developed for online cryptosporidium detection by combination with pattern recognition techniques.
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Bailey-Horne, Victoria Adele. "Development of tools and sampling strategies to assess the significance of dietary and environmental exposure to perfluorinated compounds in the UK." Thesis, University of York, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.556248.
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Novel separation, extraction and detection methods were developed to accurately measure concentrations of perfluorinated compounds (PFCs) in environmental/food matrices. Sampling strategies and the significance of UK environmental PFC exposure were assessed by quantitative analysis of wildlife liver samples in aquatic and terrestrial food chains. As diet is the main exposure route for related contaminants, UK human PFC exposure was estimated through dietary studies. When analysing for PFCs in food, weak anion exchange solid phase extraction (WAX- SPE) is used for extract cleanup and liquid chromatography mass spectrometry (LC- MSIMS) for the quantification. This method was used to analyse the majority of foods in this PhD dietary study. Analysing fatty foods (cheese, meat, liver or eggs) is problematic, therefore fluorous biphasic systems (FBS) were investigated to partition PFCs from organic into fluorous solvents. When this developed FBS was prefixed to the conventional SPE method, PFC concentrations could be determined for the diet study by LC-MSIMS without enhancement/suppression from the fatty matrix. Aquatic and terrestrial wildlife livers were analysed by both conventional PFC methods and new techniques. PFCs were extracted using methanol, cleaned up by WAX-SPE and analysed by time-of-flight mass-spectrometry (LC-TOF-MS) or LC-MS/MS. The results showed two outcomes. Firstly, PFOS is readily detected in UK environmental samples, even from isolated ecosystems (Outer Hebrides) with very low anthropogenic contribution. Secondly, concentrations are of concern, as they are higher than those in foods of the UK diet. The mink would appear to be consuming food containing PFOS, thus indicating a contaminated environment. A database of PFCs «260) was developed, providing a valuable reference source. It contains molecular structures, compound names, abbreviations, formulae, fluorous percentages, neutral exact masses and the anion monoisotopic masses [M-Hr. The database is exportable and directly searchable by the LC-TOF-MS peak identification software and was used to screen environmental and food samples.
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Ebdon, James Edward. "Identification of sources of faecal pollution in surface waters using a novel antibiotic resistance profiling technique." Thesis, University of Brighton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434881.
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The presence of faecal material in rivers and bathing waters can degrade water quality and impact on drinking water supply, fishing, aquaculture and recreational uses. In developing countries, infectious diseases related to the faecal contamination of water resources can constitute a major burden on human health. Determining the origin of contamination is not only imp0l1ant when assessing the degree of risk posed to public health, but also in deciding how best to target remediation measures. This study set out to develop and implement a low-cost antibiotic resistance analysis (ARA) method for determining the sources of environments. 2 ~ OC1 2006 aquatic SERV\CES ARA is a potentially useful method for distinguishing faecal ba~ri~ttOG~U1J'Cre r~1M has been used successfully to predict the origin of faecal contaminaQ n in rIver t tchments in the U.S.A. This phenotypic approach has cost benefits over genotypic approaches but existing protocols are time-consuming and manual data handling is open to human error. A simplified, low-cost approach to the ARA technique was developed that uses automated data recording combined with simple statistical analyses to compare bacteria of the genus Enterococcus from various faecal sources. In total, 3675 isolates were analysed for their sensitivity to a combination of antibiotic concentrations, creating a database of over 250,000 test reactions. Discriminant function analysis (DF A) revealed how many of the isolates were correctly grouped into each source category, on the basis of their antibiotic resistance patterns. When the database was split into ' municipal wastewater (MW) vs. livestock vs. wild bird' 73% the database isolates were correctly classified. This rate fell slightly to 68% when the database was split into 'MW vs. cattle and sheep vs. pigs vs. wild birds vs. dogs vs. poultry'. Isolates of porcine origin demonstrated the highest levels of resistance to the chosen antibiotic concentrations and the best rates of classification. Once the most discriminant antibiotics had been identified, it was possible to reduce the number of concentrations from 80 to just 31 . The most common sources of faecal pollution present in river water samples were livestock and wild birds. Whilst isolates classified as originating from municipal wastewaters were also detected, they were not found to be the dominant source. The data presented in this thesis also suggest that patterns of antibiotic resistance amongst bacterial populations differ with respect to geographical location. Future faecal source tracking studies using ARA may therefore require the assembly of catchment specific databases. However, antibiotic resistance patterns did appear to remain stable for at least 36 months. Most imp0l1antly, the ARA technique has demonstrated that it is capable of distinguishing the human and animal populations responsible for a faecal pollution incident, thereby allowing a more cost-effective and targeted approach to the remediation of impaired surface waters in the future.
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Hing, Lee Siang. "The effects of diesel oil on the growth of three species of marine phytoplankton." Thesis, Royal Holloway, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413549.
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Liu, Shuming. "Simulating the diffuse pollution of nitrate in an urban catchment." Thesis, University of the West of Scotland, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398330.
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Hanson, Peter Stanley. "Development of ELISA-based assays for some environmentally persistent antibiotics." Thesis, University of Sunderland, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405980.
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Asanga, Patricia Bi. "Rapid bioassays for effect-directed analysis of pesticides in water and sediments." Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443083.
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Bailey, Lucinda. "Microbial resistance to advanced water treatment processes." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403584.
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