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Shao, Mingfei. "Autotrophic denitrification in nitrate-induced marine sediment remediation." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B44139226.
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Xu, Jing. "Laboratory scale electrochemical remediation of phenanthrene in sediment." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497444.
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As a consequence of the link of polycyclic aromatic hydrocarbons (PAHs) to adverse health effects in the human population, efforts should be made to reduce or even eliminate them wherever possible. The limited pore water and contaminant movement in tight soils poses problems for traditional soil cleansing processes, which makes remediation of sediments contaminated with persistent PAH one of the more intractable environmental problems. Iimovative, new techniques are required for cleaning up PAHs contaminated sediment. In recent years, the application of electrochemistry to environmental pollution treatment has been thoroughly investigated and electrochemical remediation is shown to be more suitable to the removal of organic pollutants from low-permeability soils and sediments, but problems with removing PAHs still exist because of their low aqueous solubility and high preferential sorption to soils and sediment. The promising results from the complete destruction of PAHs from wastewater permit to consideration of the electrochemical technology as an alternative to PAH contaminated sediment.
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Shao, Mingfei, and 邵明非. "Autotrophic denitrification in nitrate-induced marine sediment remediation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B44139226.
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He, Ziqi. "Sonochemical remediation of Mercury from contaminated sediments." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1155666284.
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Para, Eric George. "Coastal Sediment and Fish Biosolids Remediation Using a Microbial Fuel Cell." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/ParaEG2006.pdf.
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Foltz, John Richard. "Impacts of contaminated sediment remediation on early life stages of rainbow trout." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/J_Foltz_113009.pdf.
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Thesis (M.S. in engineering)--Washington State University, December 2009.Title from PDF title page (viewed on Feb. 4, 2010). "College of Engineering and Architecture." Includes bibliographical references (p. 50-55).
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Acharya, Lok. "Chemical and physical characteristics of Mahoning River sediment before and after fungal bioremediation /." Connect to resource online, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1211558693.
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Dejan, Krčmar. "Uticaj promene fizičko-hemijskih uslova i odabranih tretmana na mobilnost metala u sistemu sediment/voda." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2010. http://dx.doi.org/10.2298/NS20101008KRCMAR.
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U radu je ispitana distribucija metala u sistemu sediment/voda na najugroženijim vodotocima uAP Vojvodini. Na osnovu dobivenih podataka urađena je procena rizika na osnovu analizeporne vode, kiselog volatilnog sulfida i simultano ekstrahovanih metala i sekvencijalneekstrakcione procedure. Procena mobilnosti metala u sistemu sediment/voda određena jepromenom fizičko-hemijskih uslova u realnom sistemu (vodotok) i u laboratorijskim uslovima.Ispitana je efikasnost in-situ (aeracijom sistema sediment/voda) i ex-situ remedijacijesedimenta metodama termičkog tretmana i solidifikacije/stabilizacije.Rezultati su ukazali da u svakom vodotoku i zaštićenoj zoni postoji lokacija u kojoj je sedimentbarem po jednom metalu klasifikovan (holandski sistem klasifikacije sedimenata) kao zagađen(klasa 3) ili izuzetno zagađen sediment (klasa 4). Generalno, kvalitet sedimenta manjihvodotoka (Krivaja, Nadela, Kudoš, Veliki Bački kanal i Begej) je lošiji u odnosu na ostaleispitivane vodotoke.Procena dostupnosti metala u sedimentu Velikog Bačkog kanala ukazala je da na svakomispitivanom profilu postoji minimum jedan metal i jedna metoda koja definiše sediment kaovisoko rizičan. Takođe je zaključeno da je sediment na delu od 2+000 do 4+900 km zagađeniji,jer postoji veći broj metala i metoda koji ga definišu kao visoko rizičnim. Ovako dobijenirezultati ukazuju da nije dovoljan jednostavan i samo jedan pristup u oceni kvaliteta sedimentai proceni rizika koji metali mogu da ispolje u akvatičnom ekosistemu.Ukazano je da pomeranje sedimenta (npr. otvaranja ustave), dovodi do promene fizičkohemijskihuslova u sistemu sediment/voda, resuspenzije i transporta sedimenta. Usled ovihpromena povećava se dostupnost metala i dolazi do povećanja njihove koncentracije u vodenojfazi čime se znatno povećava rizik i mogućnost ispoljavanja negativnih efekata na akvatičniekosistem.U slučaju resuspenzije sedimenta u sistemu sediment/voda pronađena je zavisnost izmeđukoncentracije metala u suspendovanim materijama i vodi od sadržaja određenih frakcija ususpendovanim materijama (sadržaj organskih materija i frakcije do 63 μm).Remedijacione tehnike često su ekonomski neprihvatljive zbog velike zapremine zagađenogsedimenta. Ukazano je da primena in-situ aeracije, omogućava smanjenje količine sedimenta(čime se smanjuju troškovi eventualno naknadnog tretmana sedimenta), a da je tretmansolidifikacije/stabilizacije sedimenta sa glinom i termičke remedijacije zadovoljavjući saaspekta izluživanja metala. Dobijeni rezultati izvedenih testova izluživanja ukazali su namoguću primenu ovih tretmana u pogledu rešavanja problema sedimenta koji je zagađenmetalima, bilo u pogledu sigurnog odlaganja na deponiju ili u smislu njegove upotrebe kaododatka pri proizvodnji građevinskog materijala (opeke), osnove za puteve, uređenje obale(nasipa) itd. Na taj način mogu se znatno umanjiti troškovi izmuljivanja i manipulacijekontaminiranog sedimenta, a sama remedijacija učiniti mnogo prihvatljivijomThis work investigates the distribution of metals in the sediment / water systems of the most endangered rivers in Vojvodina. Utilizing the data obtained, risk assessments are carried out based on analysis of pore water, acidic volatile sulphides and simultaneously extracted metals and sequential extraction procedure. The assessment of metal mobility in the sediment / water system is determined by the changing physical and chemical conditions in real systems (waterways) and under laboratory conditions. The effectiveness of in-situ (aeration of sediment / water) and ex-situ remediation of sediment by thermal treatment methods and solidification / stabilization are investigated. The results show that in each waterbody and protected area, certain locations have sediment which for at least one metal, is classified (by the Dutch system of sediment classification ) as polluted (class 3) or highly polluted (class 4). In general, the quality of sediment in smaller rivers (Krivaja, Nadela, Kudoš, Veliki Bački canal and Begej) is inferior to the other rivers studied. Assessment of the metals availability in the sediments of the Veliki Bački canal indicates that in each profile examined, at least one metal and one method defines the sediment as very hazardous. It is also shown that the sediment at the section from 2 +000 to 4 +900 km is the most polluted, with a number of metals and methods that define it as a high risk. The results indicate that it is inadequate to have a simple singular approach to sediment quality assessment and the assessment of the risks posed by metals detected in aquatic ecosystems. This work shows that sediment movement (e.g. from opening a sluice gate) leads to changes in the physical-chemical conditions of the sediment / water system, with resuspension and sediment transport. These changes increase metals availability and increase their concentrations in the aqueous phase, significantly increasing the posed risk and the possibility of adverse effects on aquatic ecosystems. In the case of sediment resuspension in the sediment / water system, a relationship was found between the concentration of metals in suspended matter and the concentration in the water for certain fractions of suspended matter (organic matter content and the fraction up to 63 μm). Remediation techniques are often not economically viable due to the large volume of contaminated sediments involved. It is shown that the implementation of in-situ aeration reduces the amount of sediment (which reduces the costs of subsequent sediment treatment), and that solidification / stabilization treatment with clay and thermal remediation results in satisfactory remediation with respect to metals leaching. Leaching test results show the potential of these treatments to solve the problem of sediments which are contaminated with metals, either in terms of safe disposal in landfill or in terms of its use as a supplement in the production of building materials (brick), as road foundation, or for river bank reinforcement (dams), etc.. Thus, the costs of dredging and manipulating contaminated sediments can be significantly reduced, making remediation itself much more applicable.
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au, jchen1232005@yahoo com, and Juan Chen. "Sediment remediation as a technique for restoring eutrophic wetlands and controlling nuisance Chironomidae." Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050817.102759.
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Eutrophication is a global problem affecting many inland and estuarine waters. Many wetlands on the Swan Coast Plain, in Western Australia, have undergone increasing nutrient enrichment since European settlement of the region in the 1850s. Problems such as algal blooms and nuisance swarms of non-biting midges (Diptera; Chironomidae) are the consequence of nutrient enrichment in many of these wetlands. The restoration of these degraded wetlands, especially with respect to reducing nutrient enrichment, requires a range of comprehensive and effective techniques including catchment management, diversion or treatment of surface inputs and treatment of enriched sediments. Nitrogen and phosphorus, especially phosphorus, are not the only factors controlling algal biomass in water bodies, but they are the only elements that can be removed efficiently and economically.
Internal P cycling from wetland sediments can initiate and sustain eutrophication and related algal blooms and nuisance midge problems even after external sources are diverted or reduced. The aim of this study was to identify an effective material to reduce sediment phosphorus release and thereby the phosphorus concentration of the water column. It was also important to determine the impact of the selected amendment material on phytoplankton and larval midge (chironomid) communities.
A range of experiments at increasing scales, from bench-top, to microcosm to outdoor mesocosm experiments were designed to test three hypotheses:
1) Materials which have a high P sorption capacity, over a wide range of P solution concentrations, and low P release rate, are potentially suitable agents to reduce P in wetlands with enriched sediments by inactivating sediment P;
2) A reduction in the abundance of cyanobacteria caused by increasing the N:P ratio of an aquatic ecosystem results in a reduction in the density of nuisance species of Chironomidae.
3) Successful amendment of enriched sediments reduces P in the water column thereby reducing the total phytoplankton biomass and the related density of nuisance species of Chironomidae.
The adsorption and desorption experiments were carried out under a range of pH values and P concentrations, with a number of materials including fly ash, red mud, precipitated calcium carbonate, crushed limestone and lime to determine the maximum adsorption capacity and affinity of these materials. A rang of P concentrations (0-1000 µg/L) simulated the P concentration of the water column in a range of wetlands of differing trophic status. Poor fits to the Langmuir equation occurred with both red mud and fly ash due to their high P content. A good fit occurred with lime, with a high P removal rate (90%-96%) over the same range. Fly ash and red mud were eliminated from further investigation due to the possibility that they might release phosphorus rather than absorb when P concentrations in surrounding environment were less than 300 µg/L or 200 µg/L respectively (concentrations which can occur in eutrophic systems).
Among the three lime-based, redox-insensitive materials tested in the second mesocosm experiments, precipitated calcium carbonate (PCC) possessed the highest maximum adsorption capacity and lowest desorption rate under a range of pH values (6.2, 7.2 and 10) and P concentrations (0-12 000 µg/L), followed by crushed limestone and lime. The different maximum absorption capacities of the three materials appears to be mainly attributed to their particle size (surface area).
Lime was chosen as the amendment material for further investigation because it was the only one of the three available in sufficient quantities within the timeframe of this study.
Microcosm experiments showed that lime was effective in reducing sediment P release from intact sediment cores, and the ratio of TN:TP in the treatment cores increased over time compared to the control cores (in which TN: TP decreased slightly).
In the first mesocosm experiment a significantly higher density of larval midges was found in the treatments than in the controls. The treatments were aimed to increase N:P ratio in the systems to reduce cyanobacteria and, subsequently, larval midge densities. However even though cyanobacteria were eliminated from the treatments, the nitrogen addition appeared to result in higher phytoplankton biomass overall, which fuelled an increase in larval midge densities.
In the second mesocosm experiment, the addition of lime to enriched sediments resulted in a reduction in P in the water column. This reduction was accompanied by a reduction in total phytoplankton biomass, the absence of cyanobacteria, and a less abundant and more species - diverse chironomid fauna in the treatment mesocosms.
Sediment P fractionation undertaken for both the microcosm and mesocosm experiments showed that most of the phosphorus adsorbed by lime was in the labile fraction (NH3Cl extractable P and NaOH extractable P). Phosphorus in the HCl extractable fraction was also found to be higher in the treatments due to the presence of inert mineral P in the lime than the formation of new hydroxyapatite from adsorbed P.
The two mesocosm experiments suggested that larval midges were non-selective feeders, responding to total phytoplankton biomass, rather than the presence of cyanobacteria. Dissolved oxygen and predation also influenced larval midge densities.
In summary, although lime appeared to be a useful material for reducing P release from enriched sediments under controlled laboratory conditions, the effect under field conditions was not as definitive. Further work is required to more fully determine the conditions under which sediment remediation may be used as a means of controlling sediment P release and associated high densities of larval chironomids.
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Chen, Juan. "Sediment remediation as a technique for restoring eutrophic wetlands and controlling nuisance Chironomidae." Chen, Juan (2003) Sediment remediation as a technique for restoring eutrophic wetlands and controlling nuisance Chironomidae. PhD thesis, Murdoch University, 2003. http://researchrepository.murdoch.edu.au/651/.
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Eutrophication is a global problem affecting many inland and estuarine waters. Many wetlands on the Swan Coast Plain, in Western Australia, have undergone increasing nutrient enrichment since European settlement of the region in the 1850's. Problems such as algal blooms and nuisance swarms of non-biting midges (Diptera; Chironomidae) are the consequence of nutrient enrichment in many of these wetlands. The restoration of these degraded wetlands, especially with respect to reducing nutrient enrichment, requires a range of comprehensive and effective techniques including catchment management, diversion or treatment of surface inputs and treatment of enriched sediments. Nitrogen and phosphorus, especially phosphorus, are not the only factors controlling algal biomass in water bodies, but they are the only elements that can be removed efficiently and economically.
Internal P cycling from wetland sediments can initiate and sustain eutrophication and related algal blooms and nuisance midge problems even after external sources are diverted or reduced. The aim of this study was to identify an effective material to reduce sediment phosphorus release and thereby the phosphorus concentration of the water column. It was also important to determine the impact of the selected amendment material on phytoplankton and larval midge (chironomid) communities.
A range of experiments at increasing scales, from bench-top, to microcosm to outdoor mesocosm experiments were designed to test three hypotheses:
1) Materials which have a high P sorption capacity, over a wide range of P solution concentrations, and low P release rate, are potentially suitable agents to reduce P in wetlands with enriched sediments by inactivating sediment P;
2) A reduction in the abundance of cyanobacteria caused by increasing the N:P ratio of an aquatic ecosystem results in a reduction in the density of nuisance species of Chironomidae.
3) Successful amendment of enriched sediments reduces P in the water column thereby reducing the total phytoplankton biomass and the related density of nuisance species of Chironomidae.
The adsorption and desorption experiments were carried out under a range of pH values and P concentrations, with a number of materials including fly ash, red mud, precipitated calcium carbonate, crushed limestone and lime to determine the maximum adsorption capacity and affinity of these materials. A rang of P concentrations (0-1000 mcg/L) simulated the P concentration of the water column in a range of wetlands of differing trophic status. Poor fits to the Langmuir equation occurred with both red mud and fly ash due to their high P content. A good fit occurred with lime, with a high P removal rate (90%-96%) over the same range. Fly ash and red mud were eliminated from further investigation due to the possibility that they might release phosphorus rather than absorb when P concentrations in surrounding environment were less than 300 mcg/L or 200 mcg/L respectively (concentrations which can occur in eutrophic systems).
Among the three lime-based, redox-insensitive materials tested in the second mesocosm experiments, precipitated calcium carbonate (PCC) possessed the highest maximum adsorption capacity and lowest desorption rate under a range of pH values (6.2, 7.2 and 10) and P concentrations (0-12 000 mcg/L), followed by crushed limestone and lime. The different maximum absorption capacities of the three materials appears to be mainly attributed to their particle size (surface area).
Lime was chosen as the amendment material for further investigation because it was the only one of the three available in sufficient quantities within the timeframe of this study.
Microcosm experiments showed that lime was effective in reducing sediment P release from intact sediment cores, and the ratio of TN:TP in the treatment cores increased over time compared to the control cores (in which TN: TP decreased slightly).
In the first mesocosm experiment a significantly higher density of larval midges was found in the treatments than in the controls. The treatments were aimed to increase N:P ratio in the systems to reduce cyanobacteria and, subsequently, larval midge densities. However even though cyanobacteria were eliminated from the treatments, the nitrogen addition appeared to result in higher phytoplankton biomass overall, which fuelled an increase in larval midge densities.
In the second mesocosm experiment, the addition of lime to enriched sediments resulted in a reduction in P in the water column. This reduction was accompanied by a reduction in total phytoplankton biomass, the absence of cyanobacteria, and a less abundant and more species - diverse chironomid fauna in the treatment mesocosms.
Sediment P fractionation undertaken for both the microcosm and mesocosm experiments showed that most of the phosphorus adsorbed by lime was in the labile fraction (NH3Cl extractable P and NaOH extractable P). Phosphorus in the HCl extractable fraction was also found to be higher in the treatments due to the presence of inert mineral P in the lime than the formation of new hydroxyapatite from adsorbed P.
The two mesocosm experiments suggested that larval midges were non-selective feeders, responding to total phytoplankton biomass, rather than the presence of cyanobacteria. Dissolved oxygen and predation also influenced larval midge densities.
In summary, although lime appeared to be a useful material for reducing P release from enriched sediments under controlled laboratory conditions, the effect under field conditions was not as definitive. Further work is required to more fully determine the conditions under which sediment remediation may be used as a means of controlling sediment P release and associated high densities of larval chironomids.
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Chen, Juan. "Sediment remediation as a technique for restoring eutrophic wetlands and controlling nuisance Chironomidae /." Access via Murdoch University Digital Theses Project, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050817.102759.
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Royle, Anna. "Characterisation and remediation of a canal sediment contaminated with heavy metals and organic pollutants." Thesis, Liverpool John Moores University, 2005. http://researchonline.ljmu.ac.uk/5790/.
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Sun, Mei. "Experimental evaluation of electrode‐based technologies for in situ sediment remediation and industrial brine treatment." Research Showcase @ CMU, 2012. http://repository.cmu.edu/dissertations/142.
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This thesis evaluated the feasibility and performance of electrode‐based technologies for managing environmental contaminants. Specifically, research presented here focuses on the use of electrodes for in situ sediment remediation, and for the selective removal of bromide from brines produced in hydraulic fracturing.
Sediment capping is an in situ remediation strategy to contain contaminants. Compared to traditional sand and sorbent‐amended caps, reactive caps capable of transforming contaminants may improve the remediation efficiency. However, few materials that can provide long‐term contaminant degradation are available for use in sediment caps. An electrode‐based reactive cap using carbon electrodes as the reactive capping material is proposed in this study to stimulate abiotic and biotic contaminant degradation in situ. A thorough understanding of factors affecting cap performance is essential to apply such reactive caps in the field. The primary objectives of study presented here for reactive sediment capping are to demonstrate the ability of an electrode‐based reactive cap to degrade sediment contaminants, to identify factors affecting contaminant degradation, and to investigate the impact of powered electrodes on contaminant biodegradation.
Preliminary results in this study demonstrated a laboratory scale simulated sand cap containing carbon electrodes connected to a DC power supply induced and maintained redox gradient in Anacostia River sediment for more than 100 days. Hydrogen and oxygen were produced by water electrolysis at the electrode surfaces and may serve as electron donor and acceptor for potential contaminant degradation. The hydrogen production rate was proportional to the applied voltage between 2.5 and 5 V, and not greatly affected by pH or the presence of metal cations. Increasing ionic strength and addition of natural organic matter promoted hydrogen production.
Complete nitrobenzene (NB) degradation was achieved in batch reactors with graphite electrodes. NB was stoichiomtrically reduced to aniline (AN) at the cathode with nitrosobenzene (NSB) as an intermediate, followed by rapid oxidization of AN at the anode. The reduction rate of NB and NSB were enhanced by increasing the applied voltage between the electrodes from 2V to 3.5V, but diminishing returns were observed above 3.5 V. NB and NSB reduction rate constants were faster at lower initial NB concentrations. Humic acid and simulated Anacostia River sediment porewater both affected the degradation rate, but only to a limited extent (~factor of 3).
The effect of powered electrodes on contaminant biodegradation rates was investigated in sediment slurry using 2,4‐dichlorophenol (DCP) as a probe compound. DCP was reductively transformed to 4‐chlorophenol in sediment slurry with powered or unpowered electrodes. Graphite felt electrodes did not change DCP removal rates in nutrient‐amended sediment slurry and carbon paper electrodes decreased DCP removal rate in unamended sediment slurry. The observed negative effect of powered electrodes on DCP biodegradation rate may be caused by hydrogen production and increase of sediment pH near the cathode, since an increase of either hydrogen concentration or pH was found to depress the dechlorination rate in unamended sediment slurries without electrodes.
Another application of electrode‐based contaminant removal technology evaluated in this study is selective bromide removal from mining brine produced in hydraulic fracturing of shale gas. Such brine (referred as “flowback” and “produced” water) has raised a number of environmental and human health issues. An important health concern associated with the brine is its high bromide concentration (~1g/L). If the brine is discharged to receiving waters that serve as drinking water sources, the bromide in it can lead to the formation of carcinogenic brominated disinfection byproducts (DBPs) during water treatment. However, the co‐existence of other ions in the mining brine, especially chloride as high as 30‐200 g/L, makes selective bromide removal technically challenging.
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Bosiljcic, Gregory Roy. "Bioaugmentation using Pleurotus ostreatus to Remediate Polycyclic Aromatic Hydrocarbons (PAH) Contaminated River Sediment." Youngstown State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1220405240.
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Ljiljana, Rajić. "Unapređivanje elektrokinetičke remedijacije sedimenta zagađenog teškim metalima." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2010. http://dx.doi.org/10.2298/NS20101028RAJIC.
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Od primenjenih elektrokinetičkih tehnika:konvencionalna, elektrodijalitička (uz primenu CEM), zatim tretmanuz izmenu polariteta na elektrodama, primena pomeranja anode kakatodi, bipolarnih elektroda kao i povećane dužine katodnog prostora,na uzorku Ni zagađenog kaolina (model matriks) najveću efikasnostuklanjanja Ni pokazale su primena pomeranja anode ka katodi (51%odnosno 82% bez uračunavanja katodnog regiona kaolina) i primenabipolarnih elektroda uz povećani katodni prostor (45%).Primenom bipolarnih elektroda uz povećan katodni prostor kaounapređene EK tehnike prečišćavanja sedimenta sa visokim ANCpostignute su efikasnosti od 44% za uklanjanje Ni odnosno 36%,42% i 43% za uklanjanje Ni, Cd i Pb u smeši, redom. Ove efikasnostisu približno dvostruko veće u odnosu na efikasnosti konvencionalnihtretmana, a uviđa se neznatni uticaj prisustva Cd i Pb na efikasnostuklanjanja Ni. Procena rizika na osnovu različitih kriterijuma utvrdilaje da je sediment zagađen Ni nakon tretmana siguran za okolinu.Sediment zagađen Ni, Cd i Pb je prema sadržaju Ni i Pb siguran pookolinu, ali se poređenjem različitih kriterijuma procene rizika koji sukorišćeni u toku rada dobijaju informacije koje se u manjoj ili većojmeri potvrđuju što ukazuje na neophodnost postojanja jedinstvenih isveobuhvatnih kriterijuma procene rizika. Navedeno potvrđuje da jeprimena bipolarnih elektroda uz povećan katodni prostor efikasnatehnika prečišćavanja sedimenta koji je zagađen Ni i Pb prikoncentracijama koje su navedene u radu.Primenom pomeranja anode ka katodi uz povećan katodniprostor kao unapređene EK tehnike prečišćavanja sedimenta saniskim ANC postignute su efikasnosti od 25% za uklanjanje Niodnosno 17%, 24% i 62% za uklanjanje Ni, Cd i Pb u smeši, redom.Ove efikasnosti su približne za Ni odnosno dvostruko i trostruko većeza Cd i Pb, redom u odnosu na efikasnosti konvencionalnih tretmana.Može se utvrditi da je efikasnost unapređenog procesa značajnopovećana, ali poređenjem krajnih koncentracija metala u sedimentunakon tretmana sa kriterijumima procene rizika, utvrđeno je da jedinoprema sadržaju Pb sediment se može smatrati sigurnim po akvatičnusredinu dok prema sadržaju ostalih metala spada u visoko rizičnuklasu (>50%).As the result of applying electrokinetic techniques: conventional, electrodialytic, treatment with electrode polarity exchange, moving anode, using bipolar electrodes and increased cathodic compartment length, on Ni contaminated kaolin (model matrix) the most efficient were moving anode technique (51% or 82% without calculating the cathode region of kaolin) and using bipolar electrodes and increased cathodic compartment length (45%). Using bipolar electrodes and increased cathodic compartment length as enhanced EK technique for remediation of sediment with high ANC resulted in 44% of Ni removal and 36%, 42% i 43% for removal of Ni, Cd and Pb, respectively. This technique nearly doubled efficiency after conventional treatment and there is slight influence of Cd and Pb on Ni removal. Risk assessment based on different criteria determine that Ni contaminated sediment is safe for the environment after EK treatment. According to Dutch standards it is classified as Class 1/2. Ni, Cd and Pb contaminated sediment is safe for the environment according to Ni and Pb content after EK treatment according to Dutch standards but comparing the risk assessment arise from different criteria in some cases it do not provide the same information. This indicates that it is of great importance to develop unique risk assessment criteria. According to the results using bipolar electrodes and increased cathodic compartment is efficient EK remediation technique of Ni and Pb contaminated sediment at the concentrations used for these investigations. Using the moving anode technique and increased cathodic compartment length as enhanced EK technique for remediation of sediment with low ANC resulted in 25% of Ni removal and 17%, 24% and 62% for removal of Ni, Cd and Pb, respectively. It can be concluded that efficiencies after enhanced technique compare to conventional treatments are significantly increased but the final metal concentrations (except Pb) in sediment after treatment according to risk assessment criteria are highly hazardous for the environment (>50%).
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Pantzare, Nathalie. "Biochar-based thin-layer capping of contaminated sediment in Burefjärden, northern Sweden : Assessment of biochar mixed into four structural materials for preventing release of trace elements from sediment to water." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-87235.
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Coastal areas around the world have been recognized as largely impacted by anthropogenic activities resulting in pollution of marine sediments. In Sweden, surveys conducted along the coastline of the Bothnian Bay have identified a total area of about 29 km2 as fiber rich sediments. In the Bureå sea area near Skellefteå vicinity, Västerbotten county, elevated levels of mercury (Hg), methyl-Hg, arsenic (As), copper (Cu), lead (Pb), cadmium (Cd), zinc (Zn) and polycyclic aromatic hydrocarbons (PAH) have been classified and believed to be mainly affected by emissions from a pulp and paper industry formerly active on a nearby headland. Contaminants in sediments are of concern as continuous dispersion can adversely affect the benthic community. To isolate contaminants and reduce their bioavailability, in-situ thin-layer capping using an active material is one suitable approach. This type of remediation method, using biochar mixed with bentonite clay will be implemented on a pilot scale in the sea area outside of Bureå in the spring of 2021. However, bentonite is a relatively expensive material yielding a need to further develop the selection of capping materials suitable to aid in the deposition of biochar in an active thin-layer cap. In this thesis, biochar-based thin layer caps mixed with bentonite clay, rock dust of two grain sizes and a concrete-based slurry was evaluated on their physicochemical properties and efficiency for preventing release of trace elements from sediment to the overlying water. This was conducted by a laboratory column experiment where four set ups were performed: (1) no capping for sediment control, (2) only capping material for material control, (3) sediment mixed with biochar and (4) sediment capped with each material mixed with biochar. Three times during an 8-week test period, 60 mL of the overlying water in the columns was extracted and sent for trace element analysis. The experimental set up revealed that the capping layers effectively prevent release of trace elements trough the sediment to the overlying water. The concrete slurry showed suitable settling properties and negligible loss of biochar in the set-up of the columns. Also, the biochar+concrete slurry thin-layer cap displayed the highest efficiency for preventing and/or delaying release of As, P, Cu, Fe, Mn and SO4.
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Pabba, Sowmya. "Effects of Cyclodextrin on Extraction and Fungal Remediation of Polycyclic Aromatic Hydrocarbon-contaminated Mahoning River Sediment." Connect to resource online, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1220027268.
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Samuelsson, Göran S. "In situ remediation of contaminated sediments using thin-layer capping : efficiency in contaminant retention and ecological implications." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-94845.
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Hydrophobic organic contaminants (HOCs) often reside in sediments sorbed to particles, most tightly to particles with high content of organic carbon. If persistent, such pollutants can accumulate in the sediment for many years and constitute a contamination risk for sediment-living organisms and organisms at higher trophic levels, including humans. Since traditional remediation techniques are associated with complications (e.g. release of contaminants during dredging operations, disturbance of benthic faunal communities), or constraints (handling of large amounts of contaminated sediment and water, limitations due to depth and size of the area, high costs), there is a need for new alternative methods. In situ remediation through thin-layer capping (a few centimeter cover) with a sorbing material such as activated carbon (AC) has been proposed as an alternative remediation method. Compared to traditional remediation techniques, AC amendment in a thin layer means less material handling and lower costs and is assumed to be less disruptive to benthic communities. The objectives of this thesis were to investigate the ecological effects from thin layer capping as well as the efficiency in contaminant retention. Thin layer capping amended with AC proved to reduce availability of HOCs to the tested organisms, the gastropod Nassarius nitidus (Paper II), the clam Abra nitida (Paper III) and to polychaete worms (Paper II and III). The remediation technique also decreased the sediment-to-water fluxes of the contaminants (Paper II and III). However, AC amended thin-layer capping was also found to cause negative biological effects. In laboratory studies with only a few species the negative effects were minor, or difficult to discern with the endpoints used (Paper II and III). In a larger multi-species mesocosm (boxcore) study, on the other hand, the negative effects were more prominent (Paper I) and in a large scale field study the benthic community was found to be profoundly disturbed by the AC amendment, with the effects persisting or even worsening ca one year (14 months) post amendment (Paper IV).At the time of the doctoral defence the following papers were unpublished and had a status as follows: Paper 3: Manuscript; Paper 4: Manuscript.
Carbocap
Opticap
Thinc
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Römer, Dirk. "Grundlagenuntersuchungen zur elektrochemischen Remediation von schwermetallkontaminierten Boden- /Sediment- Wassersystemen am Beispiel von Uran, Chrom, Arsen und Chlorbenzen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1109837957299-09232.
Full textAbstract:
In den 80-iger Jahren war die DDR hinter den USA und Kanada der drittgrößte Uranproduzent mit einer Jahresproduktion von ca. 200.000 Tonnen. Die Gewinnung erfolgte durch konventionellen Bergbau, durch in- situ- oder offene Haufenlagerung. Die Urangewinnung auf dem Territorium der ehemaligen DDR wurde nach der Wiedervereinigung eingestellt und mit der Sanierung der Altstandorte begonnen. Nach Einstellung des Uranabbaus muss die Wasserhaltung solange betrieben werden, bis eine kontrollierte Flutung der Bergbauschächte erfolgen kann. Die dabei anfallenden Grubenwässer werden je nach Schadstoffkonzentration direkt in den Vorfluter abgeleitet oder in geeigneten Aufbereitungsanlagen meist durch Flockung und Adsorption behandelt. Dieses praktisch oft angewandte Grubenwasserreinigungsverfahren bezüglich Uran und den auftretenden Begleitelementen Chrom und Arsen hat den entscheidenden Nachteil, dass die anfallenden schwermetallhaltigen Fällschlämme auf Deponien verbracht werden müssen. Durch Niederschlagsereignisse oder ansteigendes Grundwasser besteht die Gefahr, dass die Deponien wieder ausgelaugt werden und somit eine erneute Mobilisierung von Schwermetallen in die Umwelt erfolgt. Die Sanierung kontaminierter Gebiete, insbesondere Sedimente, Sondermüll-deponien, Standorte ehemaliger Galvanikbetriebe, Betriebsflächen chemischer Industriestandorte, Rieselfelder oder Orte der Klärschlammaufbereitung erfordern neue Herangehensweisen an das gegenwärtig hochaktuelle Problem der Rehabilitation. Es wurde deshalb u.a. im Rahmen dieser Arbeit ein Konzept auf Grundlage der elektrochemischen Umsetzung im "verdünnten" elektrochemischen Festbettreaktor entwickelt, das es gestattet, die mobilen Schwermetallspezies im Boden bzw. Deponiekörper in immobile Schwermetallverbindungen umzuwandeln. Damit kann die Nachsorge und Sicherung solcher Deponiekörper bezüglich einer Remobilisierung wesentlich kostengünstiger gestaltet werden. Ausgehend von diesem Konzept sollen Möglichkeiten, Einsatzbedingungen und -grenzen der Immobilisierung von Schwermetallen am Beispiel von Uran(VI), Chrom(VI), Arsen(III) und chlorierten Kohlenwasserstoffe aufgezeigt werden. Elektrochemische Verfahren zur Sanierung kontaminierter Böden, Schlämme und Sedimente befinden sich international in einer dynamischen Forschungs- und Entwicklungsphase. Sie sind einzeln und in Verfahrenskombinationen einsetzbar und werden, bei verantwortungsvoller Handhabung, in absehbarer Zeit auch als zertifizierte Verfahren in Deutschland in bestimmten Sanierungsvorhaben ihre Leistungsfähigkeit beweisen. Gegenwärtig befinden sie sich in Deutschland noch im Stadium der Forschung und Entwicklung, während international (z.B. USA, Niederlande) schon kommerzielle Anwendungen angeboten werden. Zur objektiven Beurteilung ihrer Leistungsfähigkeit und Einsatzgrenzen bedarf es spezieller Grundkenntnisse. Elektrochemische Remediationsverfahren können als ergänzende, in Einzelfällen auch als alternative Verfahren zur Sediment- und Bodensanierung angesehen werden. Sie haben dann eine Chance auf Einsatz, wenn vor Ort (in- situ) saniert werden soll. Von ihrem Prinzip her, sind sie preiswerter als Bodenaushub und Verbrennung. Das Sanierungsziel besteht in einer möglichst vollständigen Konzentrierung oder Umsetzung der Wasserschadstoffe an der Feststoffmatrix.
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Arévalo, Eduardo [Verfasser]. "Approach for an integrated assessment and optimisation of waste water treatment and sediment remediation processes / Eduardo Arévalo." Aachen : Shaker, 2006. http://d-nb.info/1166514994/34.
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Römer, Dirk. "Grundlagenuntersuchungen zur elektrochemischen Remediation von schwermetallkontaminierten Boden- /Sediment- Wassersystemen am Beispiel von Uran, Chrom, Arsen und Chlorbenzen." Doctoral thesis, Technische Universität Dresden, 2003. https://tud.qucosa.de/id/qucosa%3A23840.
Full textAbstract:
In den 80-iger Jahren war die DDR hinter den USA und Kanada der drittgrößte Uranproduzent mit einer Jahresproduktion von ca. 200.000 Tonnen. Die Gewinnung erfolgte durch konventionellen Bergbau, durch in- situ- oder offene Haufenlagerung. Die Urangewinnung auf dem Territorium der ehemaligen DDR wurde nach der Wiedervereinigung eingestellt und mit der Sanierung der Altstandorte begonnen. Nach Einstellung des Uranabbaus muss die Wasserhaltung solange betrieben werden, bis eine kontrollierte Flutung der Bergbauschächte erfolgen kann. Die dabei anfallenden Grubenwässer werden je nach Schadstoffkonzentration direkt in den Vorfluter abgeleitet oder in geeigneten Aufbereitungsanlagen meist durch Flockung und Adsorption behandelt. Dieses praktisch oft angewandte Grubenwasserreinigungsverfahren bezüglich Uran und den auftretenden Begleitelementen Chrom und Arsen hat den entscheidenden Nachteil, dass die anfallenden schwermetallhaltigen Fällschlämme auf Deponien verbracht werden müssen. Durch Niederschlagsereignisse oder ansteigendes Grundwasser besteht die Gefahr, dass die Deponien wieder ausgelaugt werden und somit eine erneute Mobilisierung von Schwermetallen in die Umwelt erfolgt. Die Sanierung kontaminierter Gebiete, insbesondere Sedimente, Sondermüll-deponien, Standorte ehemaliger Galvanikbetriebe, Betriebsflächen chemischer Industriestandorte, Rieselfelder oder Orte der Klärschlammaufbereitung erfordern neue Herangehensweisen an das gegenwärtig hochaktuelle Problem der Rehabilitation. Es wurde deshalb u.a. im Rahmen dieser Arbeit ein Konzept auf Grundlage der elektrochemischen Umsetzung im "verdünnten" elektrochemischen Festbettreaktor entwickelt, das es gestattet, die mobilen Schwermetallspezies im Boden bzw. Deponiekörper in immobile Schwermetallverbindungen umzuwandeln. Damit kann die Nachsorge und Sicherung solcher Deponiekörper bezüglich einer Remobilisierung wesentlich kostengünstiger gestaltet werden. Ausgehend von diesem Konzept sollen Möglichkeiten, Einsatzbedingungen und -grenzen der Immobilisierung von Schwermetallen am Beispiel von Uran(VI), Chrom(VI), Arsen(III) und chlorierten Kohlenwasserstoffe aufgezeigt werden. Elektrochemische Verfahren zur Sanierung kontaminierter Böden, Schlämme und Sedimente befinden sich international in einer dynamischen Forschungs- und Entwicklungsphase. Sie sind einzeln und in Verfahrenskombinationen einsetzbar und werden, bei verantwortungsvoller Handhabung, in absehbarer Zeit auch als zertifizierte Verfahren in Deutschland in bestimmten Sanierungsvorhaben ihre Leistungsfähigkeit beweisen. Gegenwärtig befinden sie sich in Deutschland noch im Stadium der Forschung und Entwicklung, während international (z.B. USA, Niederlande) schon kommerzielle Anwendungen angeboten werden. Zur objektiven Beurteilung ihrer Leistungsfähigkeit und Einsatzgrenzen bedarf es spezieller Grundkenntnisse. Elektrochemische Remediationsverfahren können als ergänzende, in Einzelfällen auch als alternative Verfahren zur Sediment- und Bodensanierung angesehen werden. Sie haben dann eine Chance auf Einsatz, wenn vor Ort (in- situ) saniert werden soll. Von ihrem Prinzip her, sind sie preiswerter als Bodenaushub und Verbrennung. Das Sanierungsziel besteht in einer möglichst vollständigen Konzentrierung oder Umsetzung der Wasserschadstoffe an der Feststoffmatrix.
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Nataša, Varga. "Uticaj unapređenih tretmana elektrokinetičke remedijacije na mobilnost i uklanjanje metala u sedimentu." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2017. https://www.cris.uns.ac.rs/record.jsf?recordId=104799&source=NDLTD&language=en.
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U radu je: 1. Određena efikasnost elektrokinetičkih tretmana (konvencionalni tretman, tretman sa izmenom polariteta, tretman sa dve anode i heksagonalni dvodimenzionalni elektrokinetički tretman) koji izuzimaju dodatak agenasa u tretirani sediment, za uklanjanje metala; 2. Ispitan je uticaj diskontinuiteta napajanja strujom (tokom noći), kao i uticaj oscilacija jačine električne energije pri primeni solarnih panela na efikasnost tretmana; 3. Ispitan je uticaj geohemije sedimenta, fizičko-hemijskih promena u sistemu i karakteristika prisutnog zagađenja (oblici pojavljivanja metala, koncentracije) na efikasnost elektrokinetičkog procesa. 4. Izvršena je procena rizika u sistemu sediment/voda pre, tokom i nakon tretmana; 5. Primenjen je matematički model na dobijene rezultate. Na osnovu određene efikasnosti i procene rizika tretmana elektrokinetičke remedijacije na realan problem Velikog Bačkog kanala zaključeno je, da je najbolja opcija dvoanodni tretman u kome se primenjuju solarne panele (e9). Dobijeni rezultati tretmana ukazuju da diskontinuiteti napajanja strujom (tokom noći), kao i uticaj oscilacija jačine električne energije pri primeni solarnih panela nemaju značajnog uticaja na efikasnost procesa. Što se tiče, geohemije sedimenta, pokazalo se da ona ima snažan uticaj i da upravo ona određuje fizičko-hemijske promene koje se događaju u sedimentu tokom sprovođenja tretmana elektrokinetičke remedijacije. Ključ uspeha ovih tretmana sedimenta jeste i zadržavanje metala u frakcijama (karbonatna i reducibilna) koje lakše migriraju. Primenom matematičkog modela zaključeno je da se mogu predvideti promene koncentracija metala bez sprovođenja eksperimenata, što je od krucijalnog značaja za buduća istraživanja.This work includes: 1. An investigation into efficiency of various electrokinetic treatments (a conventional treatment, and treatments with changing polarity, two anodes and two-dimensional hexagonal electrodes) without the addition of agents to the treated sediment, for the removal of metals; 2. An investigation of the influence of discontinuous (off during the night) and oscillating power supplies on the application of solar panels and their effect on the efficacy of the treatment; 3. A study on the influence of sediment geochemistry, physico-chemical changes in the system and the characteristics of the pollution present (metals speciation and concentration) on the efficiency of the electrokinetic process; 4. A risk assessment of the sediment/water system before, during and after the treatment; 5. Mathematical modelling of the results obtained. Based on the risk assessment and the efficiency of the electrokinetic treatments in the Veliki Backa canal sediment, it was concluded that the best remediation option was a two anode treatment using solar panels (e9). The investigation into the influence of treatments using discontinuous (off during the night) and oscillating power supplies showed they did not have a significant impact on the efficiency of the process. Sediment geochemistry was shown to have a strong influence, determining the physical and chemical changes that occur in the sediment during the implementation of the electrokinetic remediation. The key to success for these treatments is the retention of metals in the fractions (carbonate and reducible) which more easily migrate. It is concluded that the mathematical model can be applied to successfully predict thechanges in the concentration of metals without experimentation, which is of crucial importance for future studies.
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Raulinaitis, Mindaugas. "Effects of Hydromechanical Lake Remediation on Distribution of Metals and Metalloids in Bottom Sediments." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20121227_090648-54420.
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Although hydromechanical lake remediation projects have been carried out over several decades, there still is a lack of evidence about the changes in environmental status after such projects, while scientific literature regarding redistribution of metals and metalloids caused by hydromechanical bottom sediment removal is especially scarce both in Lithuania and in other countries. Research of the dissertation consisted not only of extensive geochemical field work and laboratory analysis, but also methods of mathematical statistics and spatial interpolation. Results of the research and their analysis allowed to conclude that hydromechanical lake remediation results in changes of the contents of metals and metalloids of interest and their spatial redistribution in lake bottom sediments, which are specific to each metal and metalloid, thus cumulative indicators should be used to assess overall changes in sediment quality of remediated lakes. Calculation and statistical analysis of on of such indicators - total sediment contamination index (Zd) and surface interpolation of its values allowed to evaluate statistical significance of changes in contamination degree of the newly formed surface sediment layer and to assess cumulative spatial redistribution of metals and metalloids caused by hydromechanical lake remediation. Data provided in the dissertation is especially significant in preparation and design of future sediment removal projects and in determining their feasibility.Nors hidromechaninio ežerų valymo darbai vykdomi jau daugelį metų, iki šiol nėra aišku, kaip pasikeičia ežero aplinkosauginė būklė po jo išvalymo, o Lietuvos ir kitų šalių mokslinėje literatūroje informacijos apie valymo sąlygotus metalų ir metaloidų pasiskirstymo dugno nuosėdose pokyčius yra stebėtinai mažai. Disertacijos tyrime buvo taikoma kompleksinė šių pokyčių vertinimo sistema, pasitelkiant ne tik išsamius geocheminius lauko ir laboratorinius tyrimus, bet ir matematinę statistinę analizę bei erdvinę duomenų prognozę ir interpoliaciją. Tyrimų ir analizės rezultatai parodė, kad hidromechaninis ežero valymas sąlygoja nagrinėjamų metalų ir metaloidų kiekių pokyčius ir jų persiskirstymą dugno nuosėdose, kuris yra savitas atskiriems cheminiams elementams, todėl siekiant nustatyti valymo darbų įtaką būtina naudoti indikatorius, leidžiančius įvertinti bendro, kumuliacinio nuosėdų užterštumo lygio pokyčius visų nagrinėjamų elementų atžvilgiu. Vieno iš tokių indikatorių – suminio užterštumo rodiklio Zd verčių statistinė analizė ir erdvinė interpoliacija leido ne tik nustatyti statistiškai patikimą hidromechaninio ežero valymo įtakotą metalų ir metaloidų pokyčių reikšmingumą naujai susiformavusiame paviršiniame dugno nuosėdų sluoksnyje, bet ir pademonstruoti erdvinį šių elementų perskirstymą dugno paviršiaus plote. Disertacijoje pateikiama informacija yra ypač aktuali vertinant Lietuvos ežerų būklę, planuojant ežerų dugno nuosėdų šalinimo darbus ir nustatant jų tikslingumą.
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Nataša, Slijepčević. "Potencijal primene stabilisanog i „zelenom“ sintezom produkovanog nano gvožđa (0) za remedijaciju sedimenta kontaminiranog metalima." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2020. https://www.cris.uns.ac.rs/record.jsf?recordId=114875&source=NDLTD&language=en.
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Ekološki problem svetskih razmera predstavlja zagađenost sedimenta teškim metalima, usled negativnih ekoloških efekata metala na životnu sredinu. Mnoge zemlje i regioni, kao i naša zemlja suočavaju se sa ovom problematikom, koja je vrlo rasprostranjena usled sve brže urbanizacije i industrijalizacije, a sa sve većom nebrigom usled ispuštanja otpadnih voda bez prethodnog prečišćavanja u vodotokove. Prilikom promene uslova vodenog ekosistema, može doći do izluživanja metala i štetnih efekata na životnu sredinu kao i na zdravlje ljudi. Stoga je remedijacija sedimenata zagađenih metalima ključna aktivnost u okviru procesa potpune sanacije vodenog ekosistema, a ekonomične, efikasne i ekološki prihvatljive tehnike remedijacije su hitno potrebne i rado primenljive u tretmanu na velikoj skali. Pre primene remedijacione tehnike na velikoj skali, neophodna su ispitivanja pri laboratorijskim uslovima i pilot skali. Na kraju svakog uspešnog laboratorijskog ispitivanja nalaze se pilot istraživanja. Pomoću njih se dobija p ravi odgovor u smislu izbora optimalne tehnologije imajući u vidu investicione i operativne troškove,postignuti rezultat i krajnje ciljeve u pogledu upravljanja postrojenjem i otpadom. U ovom radu ispitan je potencijal primene stabilisanog i zelenom sinte zom produkovanog nano Fe(0) zaremedijaciju sedimenta zagađenog teškim metalima. Kao remedijaciona tehnika odabrana je stabilizacija/solidifikacija, koja podrazumeva dodavanje agenasa za imobilizaciju metala u sedimentu sprečavajući time potencijalni rizik od izluživanja metala u životnu sredinu. Konvencionalni materijali poput letećeg pepela, cementa, gline se već odavno koriste u ovu svrhu. Kako u današnje vreme raste potražnja za novim, lako dostupnim agensima za stabilizacijusedimenta, došlo se na ideju o primeni nanomaterijala na bazi gvožđa, tj. nano Fe(0) stabilisanog nativnom glinom i produkovanog redukcijom pomoću organskih molekula prirodno prisutnih u ekstraktu lišća hrasta i crnog duda. Nanomaterijali su sintetisani i karakterisani različitim metodama i tehnikama. U nastavaku, u cilju efikasnosti njihove primene za stabilizaciju sedimenta, sprovedeni su ekstrakcioni i dinamički laboratorijski testovi izluživanja. Odabrane su smeše sedimenta i nanomaterijala koje su pokazale najbolju efikasnost tr etmana. Nakon toga se ispitivanje nastavilo na pilot skali, gde se pratilo ponašanje nanomaterijala u zavisnosti od konvencionalnih materijala koji su već u literaturi dokumentovani kao efikasni imobilizacioni agensi. Dodatna potvrda uspešnosti tretmana data je analizom i karakterizacijom s/s smeša nakon pilot ispitivanja Na osnovu dobijenih rezultata proces se uspešno pokazao pri laboratorijskim uslovima, a takođe i prilikom pilot tretmana, odnosno nakon pilot tretmana nije došlo do povećanih koncentracija izluživanja metala iz s/s smeša, kao ni degradacije smeša nakon procesa ovlaživanja tokom šest meseci. Na osnovu toga, ovako tertirani sediment se može bezbedno odlagati na deponije, ili pak iskoristiti za „kontrolisanu“ upotrebu, izgradnju puteva,kamenoloma, pomoćnih objekata i slično. Rezultati su doprineli u cilju trajnijeg rešavanja pitanja odlaganja zagađenog (izmuljenog) rečnog sedimenta, pri čemu se u procesu stabilizacije/solidifikacije dobijaju proizvodi sa dodatom vrednošću neumanjenog kvaliteta .Nanomaterijali sintetisani u ovom radu na bazi ekstrakta lišća biljaka doprinose kako očuvanju životne sredine, tako i ekonomičnosti primene remedijacione tehnike. Zahvaljujući velikoj specifičnoj površini, malim dimenzijama čestica i velikom kapacitetu za imobilizaciju teškihmetala predstavljaju efikasnu alternativu komercijalno dostupnim materijalima, što ih čini veoma atraktivnim i obećavajućim u budućnosti pri tretmanu rečnog sedimenta zagađenog teškim metalima.The pollution of sediment by heavy metals represents a large environmental problem allover the world. A lot of countries in the region as well as our country deal with this problem, which is widespread because of the fast urbanization and industrialization. There is more and more carelessness about wastewater discharge into water flows without previous purification. When the conditions of the aquatic ecosystem change, metal leaching and harmful effects on the environment and human health can occur. Therefore, remediation of metal-contaminated sediments is crucial activity in the process of the complete ecosystem remediation. Cost effective, efficient and environmentally friendly remediation techniques are urgently needed and readily applicable in large-scale treatment. Before applying remediation techniques on the largescale, both laboratory and pilot tests are necessary. There are pilot studies at the end of each successful laboratory test. Those studies provide the right answer in terms of choosing the optimal technology, taking into account the investment and operating costs, the achieved resultand the ultimate goals in terms of plant and waste management. In this study, the applicationpotential of stabilized and green - synthesized nano Fe(0) for the remediation of heavy metal -contaminated sediment was investigated. Stabilization / solidification technique was chosen as remediation technique which involves the addition of metal immobilizing agents in the sediment thus preventing the potential risk of metal leaching into the environment. Conventional materials such as fly ash, cement and clay have long been used for this purpose. Nowadays there is need for new, easily accessible agents for the sediment stabilization. Therefore it came up with the idea of using iron-based nanomaterials, ie. nano Fe(0) stabilized by native cla y and produced by reduction using organic molecules naturally present in oak and black mulberry leaf extract. Nanomaterials have been synthesized and characterized by different methods and techniques. In order to be effective in their application for sediment stabilization, extraction and dynamic laboratory leaching tests were performed. Mixtures of sediment and nanomaterials were selected that showed the best treatment efficiency. After that, the examination was continued on a pilot scale, where the behavior of nanomaterials was monitored, depending on conventional materials which have already been documented in the literature as effective immobilizing agents.Additional confirmation of treatment success was given by analysis and characterization of s / s mixtures after pilot testing. According to obtained results, the process was successfully demonstrated under laboratory conditions, and also during the pilot treatment. After the pilot treatment there were no increased concentrations of metal leaching from s/s mixtures, nor mixture degradation after the wetting process for six months. Based on that, the sediment treated in this way can be safely disposed of in landfills, or used for "controlled" use, construction ofroads, quarries, auxiliary facilities and etc. The results have contributed to the goal of a more permanent solution to the issue of disposal of polluted (slugged) river sediment, whereby in the process of stabilization/solidification, products with added value of undiminished quality are obtained. The nanomaterials synthesized in this paper on the basis of plant leaf extract contribute to both the preservation of the environment and the economy of remediation techniques. Thanks to their large specific surface area, small particle size and large ca pacity for immobilization of heavy metals, they represent an effective alternative to commercially available materials. It makes them very attractive and promising in the future in the treatment of river sediment contaminated with heavy metals.
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Simon, Matthew Larson. "Sediment and Interstitial Water Toxicity to Freshwater Mussels and the Ecotoxicological Recovery of Remediated Acid Mine Drainage Streams." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/34883.
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The river drainages originating in the Cumberland region of Virginia, Tennessee and Kentucky are home to some of the last surviving and most diverse assemblages of native freshwater mussels. This region of the country also has historically and continues to be a major source of coal for the United States. Numerous experiments were carried out in an attempt to determine what ecotoxicological effects these activities have had on mussels as well as what has been done to correct some of the most severe cases of environmental pollution due to historical coal mining operations. Analysis of interstitial water (IW), sediment and in situ toxicity testing and chemical analyses showed that the most likely cause for mussel declines was elevated metal concentrations (Al, Cu, Fe, Pb) found in IW. Ecotoxicological assessments of the two streams (Black and Ely Creeks) most impacted by acid mine drainage (AMD) in the state of Virginia were carried out to determine their potential for future degradation of the Powell River watershed into which they drain. The Powell River is a major system still inhabited by native mussels. Sophisticated wetland systems built at Ely Creek have significantly improved the ecological health of Ely Creek, decreasing the pollution into the Powell River. Reclamation and wetland construction at Black Creek have had a positive impact but active coal mining and un-remediated AMD are still negatively affecting this system. After the watershed has been fully reclaimed the discharge from Black Creek will likely be improved.Master of Science
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Himmelheber, David Whims. "In situ capping of contaminated sediments." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/28128.
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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.Committee Co-Chair: Joseph B. Hughes; Committee Co-Chair: Kurt D. Pennell; Committee Member: Danny D. Reible; Committee Member: Frank E. Loeffler; Committee Member: Jim C. Spain; Committee Member: Martial Taillefert; Committee Member: Terry W. Sturm.
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Bedu-Mensah, Henry. "Influence of Water Quality and Sediment Transport on Biological Recovery Downstream of Lime Doser Systems." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1430922920.
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Miljana, Prica. "Efekti primene različitih postupaka remedijacije na imobilizaciju teških metala u sedimentu." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2009. https://www.cris.uns.ac.rs/record.jsf?recordId=73282&source=NDLTD&language=en.
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Predmet izučavanja ove disertacije, osim poređenja različitih metoda procene rizika na osnovu karakterizacije kvaliteta sedimenta vodotokova Vojvodine, bilo je i ispitivanje mogućnosti imobilizacije teških metalau sedimentu primenom različitih remedijacionih tehnika kao i određivanje njihove efikasnosti (npr. solidifikacija/stabilizacija silikatnim materijalima, portland cementom, kalcijum-oksidom itd.) u zavisnosti od brojnih faktora. Osim pseudo-ukupnog sadržaja metala određene su i specifičnije frakcije metala sa posebnimosvrtom na određivanje potencijalno biodostupnih frakcija.Rezultati su ukazali da je naosnovu holandskih preporuka sediment pojedinih vodotokova Vojvodine (Begej, DTD-kanal,Nadela, Sava-Šabac) zagađen metalima (klasa 4) i da je neohodno izmuljivanje i remedijacija. Prema USEPA i kanadskim preporukama, neki uzorci su potencijalno toksični, ali nije zabeležena akutna toksičnost za test vrste u pornoj vodi. Za neke uzorke, i pored visoke pseudo-ukupne koncentracije (klasa 4), nije potvrđena potencijalna toksičnost na osnovu odnosa kiselog volatilnog sulfida i simultano ekstrahovanih metala. Dok se ne primene skuplje metode remedijacije i tretmana sedimenta, najbolje rešenje je izolovano skladištenje na specijalnim deponijama. Naredni koraci bi trebali da budu usresređeni na kontrolu i sprečavanje zagađenja kako bi se obezbedilo da revitalizacija ovih vodotoka ima trajni pozitivan uticaj na životnu sredinu i nesmetanu i bezbednu plovidbu, kao i na primenu određenih remedijacionih metoda. Poređenje rezultata koji su dobijeni različitim procenama kvaliteta sedimenta pokazalo je da ponekad nije dovoljan jedan pristup i da je potrebno je uključiti metode procene biodostupnosti, biotestove i aspekt radioaktivnosti. U uzorku sedimenta koji je korišćen za ispitivanje efikasnosti remedijacionih tretmana, pokazano je da cink, nikal i olovo imaju visok rizik po okolinu, jer seprocenat metala u izmenljivoj i karbonatnoj fazi kretao od 40.1 do 45.2%. Cr i Cd imaju umeren rizik, dok je bakar prisutan u ovim frakcijama u koncentraciji koja predviđa nizak rizik (5.3%). Ovo je u skladu i sa rezultatima analize porne vode i simultano ekstrahovanih metala i kiselog volatilnog sulfida.Istraživanje prikazano u radu je dalo odgovor na pitanje da li remedijacija može uspešno da ukloni zagađenje, u smislu imobilizacije metala u stanje kada oni više neće biti opasnost po okolinu. Svi primenjeni tretmani doveli su dosmanjenja procenta kumulativno izluženih metala iz S/S smeša, ali nijedna smeša tretiranog sedimenta i ispitivanih imobilizacionih agenasa ne pripada grupi inertnog otpada ukoliko se kumulativne izlužene koncentracije metala porede sa koncentracijama koje za otpad propisuje Evropska Unija (2003/33/EC). Ukoliko nam je cilj dobijanje nehazardnog otpada onda moramo primeniti u tretmanu sedimenta kontaminiranog metalima najmanje 30% imobilizaconih agenasa (cementa, kalcijum-oksida). Najveća efikasnost u imobilizaciji metala postignuta je korišćenjem cementa i kalcijum-oksida u smeši (30% cementa i 10% kalcijum-oksida) i primenom termičkog tretmana na višoj temperaturi (11000C) sa glinom (20% gline) što je zaključeno na osnovu koeficijenata difuzije i indeksa izlužljivosti. Dominantan mehanizam izluživanjametala iz ovih smeša je difuzija.This work is concerned with the comparison of the different methods of metal risk assessment in sediments based on examination of the qualityof water courses in Vojvodina. Besides, it deals with the possibility of applying remediation treatments of contaminated sediment and with the efficiency of the different methods, that is the techniques, for immobilization of sediment heavy metals by applying S/S and thermal treatments. A dominant mechanism is proposed for the process of leaching ofthe metals from treated mixtures.Comparison of the results obtained by the different methods of sediment quality assessment showed that in some cases one approach to solving this problem is not sufficient. Metal concentrations in particular sediment samples (the Begej, the DTD Canal, the Nadela, the Sava at Šabac) indicate the presence of contamination, the analyzed samples being of Class 4. According to the Dutch regulations, a sedimentof Class 4 is of unacceptable quality and requires urgent intervention in the sense of sediment dredging, disposal into special depots, and, if possible, remediation. For some samples, despite a high pseudo-total concentration (Class 4), no potential toxicity was confirmed onthe basis of the ratioof the acidic volatile sulfide and simultaneously extracted metals. The results showed that, apart from chemical analyses, biological tests are also necessary, but also sequential extraction analysis, which can more clearly define the way of metal binding to the particular sediment fractions, to allow a more reliable prediction of metal mobility, potential toxicity and bioavailability. In the analysis of sediment quality it is also necessary toinclude the aspect of radioactivity, as it has been shown that the results of this analysis can, not only confirm some of the results of the other analyses, but also indicate the sediment age, origin of contamination and potential toxicity.The subsequent steps should be directed to the control and prevention of contamination, in order to ensure that the water course reviatalization has a lasting positive effect on the environment, an unimpared and safe navigation and application of remediation methods.In the sediment sample (Class 4) that was usedfor the examination of the efficiency of it appeared that zinc, nickel and lead exhibit a high risk, as the percentages of these metals in the exchangeable and carbonate phases were in the range from 40.1 to 45.2%. On the other hand, chromium and cadmium exhibited a moderaterisk, whereas copperin these fractions was present at the levels corresponding to a low risk (5.3%). This is alsoin agreement with the results of pore water analysis and simultaneously extracted metals and acid volatile sulphide examinations.The investigations presented in this work provided an answer to the question whetehr the remediation can successfully remove the contamination in the sense of the immobilization of metals in a state that will not be harmful tothe environment. All the treatments applied yielded a decrease of the percentage of cumulatively leached metals from the S/S mixtures, but none of the mixtures of treated sediments with the tested immobilization agents belongs to the group of inert materials if the cumulative leached concentrations are compared with the concntrations for the wastes given by the EU legislation (2003/33/EC). Ifthe goal is to obtain a non-hazardous material it is necessary to treat the contaminatedsediment with at least 30% of the immobilizing agent (cement or calcium oxide). Based on the diffusion coefficients and leachability index, the highest immobilization efficiency was achieved using a mixture of cement and calcium oxide (30% of cement and 10% of CaO) and by applying thermal treatment at a higher temperature (11000C) with clay (20%). A dominant mechanism of leaching metals from these mixtures is diffusion.
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Acharya, Lok P. "Chemical and Physical Characteristics of Mahoning River Sediment Before and After Fungal Bioremediation." Youngstown State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1211558693.
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Mothersill, Carol L. "Impact of sediment accumulation and biofilm growth on the operation of submerged aerobic biological filters for the remediation of urban stormwater runoff." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq22366.pdf.
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Beenk, Elliott E. "Smooth cord grass (Spartina alterniflora) response to simulated oil spills in sediment-water microcosms." Thesis, The University of Iowa, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1545453.
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Simulated oil spills were created in S. alterniflora sediment-water microcosms to determine the effects of applied crude oil on S. alterniflora during two 90-day studies. In the first experiment, oil dosage was varied at 0-250 mg crude oil/g wet soil to determine the lethal dosage level. In the second experiment, oil type, dosage, and soil type were varied to determine the effects of oil under multiple scales of resolution. A light, medium, and heavy crude oil at dosages ranging from 0-150 mg crude oil/g wet soil were used in addition to an oiled and non-oiled soil. Following the completion of the 90-day experiment, several key findings were observed: (1) The lethal dosage limit was reached at 250 mg crude oil/g wet soil during the first experiment but not the second, by design; (2) At initial dosages of 10 and 50 mg crude oil/g wet soil, the oiled soil (acclimated for 4 months) was more influential in decreasing cumulative biomass growth rates compared to oil applied at the oil-water interface; (3) At the heaviest dosages applied as a simulated oil slick, concentrations of 150 mg crude oil/g wet soil, evapotranspiration rates were negatively affected by the oil (significant at p=0.05 in a one-tailed t-test); (4) Light, heavy, and then medium crude oil showed the lowest biomass growths, in that order, indicating that light crude oil was the most toxic in these microcosm experiments with S. alterniflora; (5) The 10 mg oil/g wet soil out-performed the 0 mg oil/g wet soil in transpiration and biomass growth.
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Schleich, Katharine L. "Geochemical Modeling of Processes Affecting Water and Sediment Chemistry and their Relationship to Biological Recovery in an Acid Mine Drainage Remediated Stream." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1399477158.
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Korajkic, Asja. "Discrimination of Human and Non-Human Sources of Pollution in Gulf of Mexico Waters by Microbial Source Tracking Methods and the Investigation of the Influence of Environmental Factors on Escherichia coli Survival." Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3503.
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Water quality worldwide is assessed by enumeration of fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli, and enterococci) intended to act as surrogates for human enteric pathogens. In environmental waters, this predictive relationship is confounded by many possible sources of FIB with varying implications for human health. Many physico-chemical and biological factors influence the fate of enteric pathogens and FIB in aquatic habitats, but are poorly understood, thus limiting our understanding of the usefulness of FIB as fecal pollution indicators.
These studies explored the field application of a “toolbox” approach to microbial source tracking (MST) intended to discriminate between human and non-human fecal pollution: a) in a Florida estuary used for shellfishing and recreational activities and b) at public beaches before and after remediation of wastewater infrastructure. Lastly, the effects of environmental factors (sediments, protozoa, sunlight) on survival of culturable E. coli were investigated in freshwater and seawater mesocosms simulating environmental conditions.
Detection of a human- associated MST marker (the esp gene of Enterococcus faecium) at sites with suspected sewage contamination indicated that human fecal pollution is impacting water quality in Wakulla County, while Lagrangian drifters designed to follow current and tidal movement suggested that local hydrology plays an important role in bacterial transport and deposition pathways.
Elevated FIB concentrations and frequent detection of human-associated MST markers (esp and human polyomaviruses) identified human sewage pollution at a public beach, facilitating remediation efforts (sewage main repair, removal of portable/abandoned restrooms), followed by significant decreases in FIB concentrations and MST marker detection. These studies show that comprehensive microbial water quality assessment can reliably identify contamination sources, thereby improving pollution mitigation and restoring recreational water quality.
Protozoan predation, freshwater vs. seawater habitat and sediment vs. water column location affected the concentration of culturable E. coli in outdoor mesocosms. Sediments offered a refuge from predation where freshwater vs. seawater habitat was amore important determinant of survival. These findings provide important insight into the ecology of E. coli and their natural predators in aquatic habitats and underscore the inherent effect different habitats play in their survival.
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Enmark, Gustav. "Recipientundersökning av Ensjön : Bedömning av sulfidmalmgruvan Enåsens eventuella påverkan på sjöns vattenkvalitet." Thesis, Uppsala University, Department of Earth Sciences, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88821.
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Ensåsengruvan is a mine situated within Ljusdals municipality in central Sweden. Themine was in use from 1984 to 1991 and has since been undergoing a remediation program. Mine tailings from sulfide rich ore is a potential environmental hazard due to its tendency to cause acid waters and heavy metal leakage. Lake Ensjön is situated one kilometer from the mine area. Due to the hydrological conditions it was not expected to receive inflowing water from the mining area. A study done in 2005 showed high amounts of heavy metals in the lake.
In this study water and sediments was analyzed to confirm the results from the 2005 study. Water was sampled two times during summer 2006 from the lake and adjoining streams. Sediment samples were collected with a core sampler at ten different locations within the lake. The water and sediment samples were analyzed for heavy metal content. Sub-samples from different depths in the sediment core were extracted so that conclusions on the contamination history could be drawn. The sediments were dated trough Cs-137 analyses. The depth in the profile with the highest Cs-137 content can be dated to the time of the Chernobyl fallout (1986). After dating, relevant samples were analyzed for metal content.
The results show that Ensjön is contaminated by a local source. The surface sediments are high in copper, zinc, nickel and cadmium content. The content is high both compared to the samples from deeper in the sediment core and the surface sediments analyzed in the reference study done in 1980. The amounts of heavy metals are also high relative to the standards set by the Swedish Environmental Protection Agency. The water from the stream adjoining the lake from the mining area is high in content of the previously mentioned metals. The methods used, including sediment dating and metal analyses together with water analyses, has proven to be useful in investigating a suspected contamination from a point source.
It can be concluded that Lake Ensjön is contaminated with water from the mine waste. No other sources in the catchment area can be the source of the enriched amounts of heavy metals. Focus should in further work be put upon finding the exact source of leakage from the mining area.
Från Enåsengruvan i Ljusdals kommun utvanns ur sulfidmalm guld, silver och koppar under åren 1984 till 1991. Avfall från sulfidmalmsgruvor medför miljöproblem genom försurning och läckage av tungmetaller. Vanligtvis täcks avfallet med jordmassor eller vatten för att förhindra påverkan på naturen. De studier som genomfördes under prospekteringen visade på att Ensjön, som är belägen inom en kilometers avstånd från gruvområdet, inte skulle påverkas av gruvan men en provtagning under 2005 visade på höga halter av tungmetaller i sjön.
I denna studie har Ensjöns vattenkvalitet undersökts genom vatten och sedimentanalyser. Vattenprover i sjön och dess inlopp togs två gånger under sommaren 2006 och sedimentprover togs vid ett tillfälle på tio olika lokaler i sjön. En djupprofil av sedimenten analyserades för att föroreningshistoriken från innan gruvan togs i bruk till nutid skulle kunna kartläggas. För att datera sedimenten analyserades de med avseende på Cs-137. De högsta halterna av Cs-137 kan härledas till nedfallet från Tjernobylolyckan 1986. Efter datering valdes lämpliga prover ut för metallanalys.
Resultaten visar på förhöjda halter av koppar, zink, nickel och kadmium. Halterna i ytsedimenten är höga både jämfört med de halter som återfinns på större djup i sedimentprofilen, motsvarande avsättning innan gruvdriften och vad som uppmättes i referensstudien från 1980. Halterna är även höga relativt de jämförvärden som Naturvårdsverket satt upp. Vattenanalyserna visar på att vattnet i inflödet från gruvområdet innehåller höga halter av de tidigare nämnda metallerna. Metoden med Cs-137-datering och analys med avseende på metaller av sediment har visat sig fungera väl för kartläggning av en nutida förorening från en punktkälla. Tillsammans med kompletterande vattenprover ger det en bra bild av den rådande situationen.
Då resultaten visar att Ensjöns vatten är påverkat av en punktkälla och alla andra källor kan uteslutas får det anses klarlagt att sjöns vatten är påverkat av dränagevatten från gruvområdet. Fortsatta studier bör fokusera på att klarlägga den exakta källan till läckaget från gruvområdet.
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Oliveira, Aline Fernandes de. "Influência da adição de nitrato de cálcio e de PhoslockTM no abatimento dos fluxos de nutrientes e metais na interface sedimento-coluna de água em um sistema lacustre eutrofizado." Universidade Federal de São Carlos, 2012. https://repositorio.ufscar.br/handle/ufscar/6528.
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Previous issue date: 2012-02-16Financiadora de Estudos e Projetos
This research project evaluated the changes in the fluxes of nutrients and metals at the sediment-water interface as a result of sediment treatment by the additions of PhoslockTM and calcium nitrate solution. The experiments were executed in situ using mesocosms that were assembled in the Ibirité Reservoir (MG). The calcium nitrate addition experiments showed nutrients flux abatement for Porthophosphate, ammoniacal-N and nitrate-N that were ≥ 90% whilst for the metals Fe and Mn the percentages reached 48 and 69%, respectively, as a result of sediment oxidation promoted by the intensification of denitrification rates. For the PhoslockTM addition the percentages of reduction in the fluxes across sediment-water interface was over 90% for P-orthophosphate and ammoniacal-N, 78% for nitrate-N and for the metals, Fe and Mn, 47 and 50%, respectively, as a result of the increased adsorption capacity of sediments due an excess of adsorbent material left on sediment surface.
Este projeto avaliou a capacidade de abatimento dos fluxos de metais e nutrientes na interface sedimento-coluna de água da represa de Ibirité (MG), comparando-se duas diferentes tecnologias de remediação de sistemas lacustres, a adição de PhoslockTM e de nitrato de cálcio. Os experimentos foram realizados in situ, com montagem de mesocosmos na citada represa. Os resultados referentes ao tratamento com injeção de nitrato de cálcio mostraram, em função da oxidação dos sedimentos promovida por esta tecnologia, um abatimento dos fluxos de nutrientes (P-ortofosfato, N-amoniacal, N-nitrato) iguais ou superiores a 90%, enquanto que para os metais Fe e Mn, as porcentagens de abatimento de fluxo alcançaram 48 e 69%, respectivamente. Para o tratamento dos sedimentos com a adição de PhoslockTM, devido ao aumento da capacidade de adsorção dos sedimentos promovida pelo excesso de material adsorvente depositado na superfície dos mesmos, as porcentagens de redução dos fluxos sedimento-água foram superiores a 90% para o P-ortofosfato e N-amoniacal, 78% para o N-nitrato, e para os metais (Fe e Mn), 47 e 50%, respectivamente.
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Janke, Helena. "Avaliação ecotoxicológica da adição de nitrato em sedimentos eutrofizados da Represa Ibirité (Betim MG): experimentos em microcosmos." Universidade Federal de São Carlos, 2009. https://repositorio.ufscar.br/handle/ufscar/1953.
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Previous issue date: 2009-05-15Universidade Federal de Sao Carlos
The objective of the present dissertation was to make a toxicity assessment of the application of calcium nitrate solution as a remediation procedure for sediments of a eutrophic aquatic ecosystem. The study was carried out using microcosms with superficial sediments and water from sediment-water interface of the Ibirité Reservoir located in the metropolitan area of Belo Horizonte (Minas Gerais, SE Brazil). The experiment lasted 135 days and the following treatment or incubation periods were applied: t=0, t=5, t=10, t=25, t=50, t=85 and t=135 days. In each period, one controlmicrocosm and three treatment-microcosms were disassembled and, chemically and ecotoxicologically analyzed. The organisms Ceriodaphnia silvestrii and Vibrio fischeri (Microtox® System) were used for the acute toxicity assessment of the water from sediment-water interface and the pore water of sediments, whereas the organism Chironomus xanthus was used for the toxicity assessment of bulk sediment. The toxicity tests were run in parallel with chemical analyzes of dissolved inorganic nitrogen species (nitrate, nitrate and ammonium), sulfate, and metals in the interface sediment-water and interstitial water samples. Acid volatile sulfide (AVS), simultaneously extracted metal (SEM) and potentially bioavailable metals were analyzed in bulk sediment. The overall results indicate that nitrate whose concentration reached 1,200 mg N-NO3 - L-1 in sediment pore water samples from treatment-microcosms is the most probable compound causing toxicity to the tests organisms. For Chironomus xanthus sediments were deleterious to the exposed organisms in all microcosm run, except in the period of t= 135 days. For the experimental conditions of this work, the application of calcium nitrate as a remediation procedure for sediments from Ibirité Reservoir indicated to be inadequate from the ecotoxicological pint of view.
O presente trabalho visou à avaliação da toxicidade da aplicação de solução de nitrato de cálcio, como procedimento de intervenção para remediação de sedimentos de um ambiente aquático eutrofizado. O estudo foi realizado através de microcosmos com sedimento e água de interface sedimento-água da Represa Ibirité, situada na região metropolitana de Belo Horizonte (Minas Gerais, Brasil). Os experimentos tiveram a duração total de 135 dias, divididos nos tempos de tratamento ou incubação de: t=0, t=5; t=10; t=25; t=50; t=85 e t=135 dias. Em cada tempo de tratamento foram analisados um microcosmo-controle e três microcosmostratamento. Os organismos Ceriodaphnia silvestrii e Vibrio fischeri (Sistema Microtox®) foram utilizados para avaliação da toxicidade aguda das águas de interface sedimento-água e intersticial dos sedimentos, enquanto o organismo Chironomus xanthus para avaliação do sedimento integral. Em paralelo aos testes de toxicidade foram realizadas análises químicas da série nitrogenada (nitrato, nitrito e amônia), sulfato, e metais nas amostras de água de interface sedimento-água e intersticial dos sedimentos, sulfetos volatilizáveis por acidificação (SVA), metais extraídos simultaneamente (MES) e metais potencialmente biodisponíveis nos sedimentos. Os resultados mostraram que o nitrato, chegando a concentração superior a 1.200 mg N-NO3 - L-1 nas amostras de água intersticial dos sedimentos dos microcosmos-tratamentos, foi considerado o causador mais provável da toxicidade das amostras dos microcosmos-tratamento para os organismos-teste empregados. Para o organismo Chironomus xanthus, os sedimentos em tratamento foram deletérios aos organismos expostos em todos os tempos de incubação, exceto no tempo t=135 dias. Estritamente do ponto de vista ecotoxicológico e para as condições experimentais deste trabalho, a aplicação do nitrato como forma de intervenção para remediação dos sedimentos da Represa Ibirité não se mostrou adequada.
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Wei, Zongsu. "CHARACTERIZING ULTRASONIC SYSTEMS FOR IMPROVED REMEDIATION OF CONTAMINATED SEDIMENTS." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437741516.
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Zhang, Qian. "Chemical Characterization of AMD Sediments: Possible Application to Arsenic Remediation." Ohio : Ohio University, 2008. http://www.ohiolink.edu/etd/view.cgi?ohiou1227347243.
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Pee, Gim-Yang. "Sonochemical Remediation Of Freshwater Sediments Contaminated With Polycyclic Aromatic Hydrocarbons." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1204595333.
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Milum, Kristen Marie. "In Situ Remediation of Heavy Metal Contaminated Sediments Using Emulsified Zero-Valent Metal Particles." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3305.
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Sediments can act as both a sink for pollutants and a source for aquatic contaminants. Natural and human disturbances of the sediments can release the contaminants to the overlying water where bottom dwelling, or benthic, organisms may be exposed through direct contact, ingestion of sediment particles, or uptake of dissolved contaminants present in the water. Dredging, the most common remediation technology for heavy metals, exacerbates this process. The in situ use of emulsified metal has been studied for its ability to pull heavy metals from aqueous solution and from saturated soils. It has proven successful in the laboratory with removal of lead, cadmium, copper, nickel, and uranium from aqueous solution and removal of lead and cadmium from saturated spiked soils. The use of zero-valent metal particles, particularly those of zero-valent iron (Fe0), as an in situ remediation technique, is currently undergoing evaluation. The basic mechanism for removal appears to be reduction of contaminant metals followed by the subsequent precipitation of their insoluble forms. This is accompanied by the oxidation of the zero-valent metal. In the case of iron, Fe0 undergoes oxidation to Fe2+ and then to the Fe3+ state. Particulate Fe0 has been shown to precipitate Cr6+ to Cr3+ and Pb2+ undergoes reduction to Pb0. Initially, zero-valent iron filings were used to reduce the metal contaminants, but it has been shown that smaller size iron particles, such as nano-scale iron, have higher initial reduction rates as well as a higher concentration of contaminant removal per mole of iron. Emulsion liquid membrane (ELM) technology has been employed as a remediation technique for the removal of metals from wastewater where extraction and stripping processes are performed in a single operation. The ELMs are made by forming an emulsion between two immiscible liquids, such as oil and water, and are often stabilized by a surfactant. We have attempted to demonstrate the application of the combination of these two technologies through the use of emulsified zero-valent metal (EZVM) to treat sediments with heavy metal contamination. Emulsions were prepared using vegetable oil, water, Span 85, and either nanoscale Fe, 1-3 [micro]m Fe, 4 [micro]m Mg, or a 20 wt % Fe-Mg mixture. The results presented in this study demonstrate that EZVM is a viable technique for in situ remediation of heavy metals in sediments. Laboratory scale studies have shown high levels of removal of lead and cadmium from solution using emulsified zero-valent iron. Additionally, the use of emulsified magnesium has shown the ability for high levels of removal of copper, cadmium, nickel, lead, and uranium from solution. A variety of solution matrices were also explored for a lead solution including seawater, the presence of complexing agents and humic acids. Small-scale laboratory studies have shown 65% removal of lead and 45% removal of cadmium from saturated, spiked soils. A bench scale test to demonstrate the applicability of this technique in the environment revealed similar results for the removal of lead.M.S.
Department of Chemistry
Arts and Sciences
Industrial Chemistry
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Josefsson, Sarah. "Fate and transport of POPs in the aquatic environment : with focus on contaminated sediments." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-42107.
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Persistent organic pollutants (POPs) are hydrophobic substances that readily sorb to organic matter in particles and colloids instead of being freely dissolved in the water phase. This sorption affects the bioavailability and environmental transport of the POPs. The major part of this thesis concerns the role of sediments as secondary sources of POPs. As the primary emissions decrease, contaminated sediments where POPs have accumulated can become the main source of contamination. If the contaminated sediment by time becomes covered with cleaner layers, the POPs are buried and no longer in contact with the aquatic environment. Experiments in this thesis showed, however, that new invading species can alter the sediment-water dynamics as a result of their bioturbation, i.e. mixing of sediment particles and pore-water. Marenzelleria spp., invading species in the Baltic Sea that burrow deeper than native species, were found to increase the remobilization of buried contaminants. The sediment-to-water flux was inversely related to the burial depth (2-10 cm) of the POP congeners (polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers) and also inversely related to the hydrophobicity of the congener. The flux was therefore most pronounced for less hydrophobic contaminants, which was linked to the bioirrigating behaviour of these species. Marenzelleria spp. also accumulated the buried POPs and increased concentrations in surface sediment. Contaminants previously considered buried at a ’safe’ depth can thus be remobilized as a result of the invasion of Marenzelleria spp. in the Baltic Sea. One method to decrease the remobilization of contaminants from sediments is ’capping’, i.e. a layer of clean material is placed as a cap on the sediment. By amending the cap with active materials, which sequester the POPs and decrease their availability, thinner layers can be used (’active capping’ or ’thin-layer capping’). Results from an experiment with thin-layer capping using different active materials (activated carbon (AC) and kraft lignin) showed that both the sediment-to-water flux and the bioaccumulation by benthic species of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), hexachlorobenzene (HCB) and octachlorostyrene (OCS) decreased with increased thickness of the cap layer (0.5-5 cm). Amendments with active materials further increased the cap efficiency. AC was more efficient than kraft lignin, and a 3 cm cap with 3.3% AC reduced the flux and bioaccumulation with ~90%. The reduction of the sediment-to-water flux was inversely related to the hydrophobicity of the POP, and reductions in the flux had similar magnitudes as reductions in the concentration in deep-burrowing polychaetes, demonstrating the importance of bioturbation for sediment-to-water transport. In a one-year study on the levels of PCDD/Fs, PCBs, and HCB in a coastal area of the Baltic Sea, the correlations between the POP levels and the levels of particles and organic carbon in the water were found to differ for POPs of different structure and hydrophobicity. The levels of PCDD/Fs decreased to one third in May, which could be related to the increased sedimentation, i.e. water-to-sediment transport, during spring bloom.
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Edirveerasingam, Veronica. "Implications of vehicle emissions in Lake Tahoe soils and sediments." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3239872.
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Carvalho, Pedro Neves de. "Research on ex-situ remediation by Halimione portulacoides of contaminated estuarine sediments with butyltin compounds." Dissertação, Porto : [s.n.], 2008. http://catalogo.up.pt/F?func=find-b&local_base=FCB01&find_code=SYS&request=000098095.
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Carvalho, Pedro Neves de. "Research on ex-situ remediation by Halimione portulacoides of contaminated estuarine sediments with butyltin compounds." Master's thesis, Porto : [s.n.], 2008. http://hdl.handle.net/10216/64147.
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Shumba, Trust. "Removal of heavy metals from CRUD and slime dam material using soil washing and bioremediation." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1536.
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Zheng, Guanyu. "Bioremediation of organochlorine pesticides contaminated soil with microemulsions." HKBU Institutional Repository, 2011. http://repository.hkbu.edu.hk/etd_ra/1245.
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Appasamy, Danen. "Physical and geochemical characterisation of canal sediments in the Black Country, West Midlands." Thesis, University of Wolverhampton, 2011. http://hdl.handle.net/2436/230851.
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Potentially harmful elements (PHEs) have been researched in a wide variety of disciplines, including pedology, chemistry, pollution science and medicine. Within the scientific community, emphasis has usually been placed on the toxic elements, such as cadmium, chromium, lead and arsenic, but rarely has there been consideration of interactions between PHEs, the sediment matrix and processes occurring in the sediments. Dredging of canals is needed for navigability purposes and consequently testing of dredged sediments (to assess whether sediments are hazardous) and landfilling can be costly for British Waterways facing constantly changing regulations and reduction in government grants. PHE mobility and availability in canal sediments can be affected by oxygen availability, pH and Redox. Remediation is thus becoming a priority for British Waterways to limit their operational costs. Zeolites, a type of remediation tool, have been widely studied in the past 30 years due to their attractive properties, such as molecular-sieving, high cation exchange capacities and their affinity for PHEs. The pilot study to investigate the efficiency of the clinoptilolite showed that there was a concentration difference between PHEs adsorbed by the clinoptilolite and the PHE concentration lost from the sediments from three sites in the West Midlands. Thorough characterisation of the sediments was needed to understand the speciation of the PHEs and the secondary processes occurring in the sediments. The different components of the sediments were analysed using various analytical methods, such as X-Ray Fluorescence spectroscopy (XRF), particle size and X-ray Diffraction (XRD) for the solid-inorganic phase, Ion Chromatography (IC) and Inductively Coupled Plasma-Optical Emissions Spectroscopy (ICP-OES) for the liquid phase (pore water), Gas Chromatography-Mass Spectrometry (GC-MS) and organic loss on ignition for the organic phase, pH and Redox for the electrochemistry of the sediments and Scanning Electron Microscope with Energy Dispersive X-Ray analysis (SEM-EDX) for microscopy and imaging. The British Geological Survey (BGS) sequential extraction method was used to investigate the different phases in the sediments. pH remained near neutral for all three sites and Redox remained anoxic. Organic contents for all three sites were around 30% and contained most of the polycyclic aromatic hydrocarbons considered hazardous. Pore water showed only high concentrations of sulphates but low concentrations of PHEs, suggesting PHEs were not mobile. Sequential extraction confirmed the other results showing that PHEs were mainly associated with stable phases, such as iron and manganese oxides or sulphides. The results have been taken into consideration to design a new remediation strategy to maximise efficiency of the zeolite.
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Maxwell, Deborah. "REMEDIATION OF HEAVY METAL CONTAMINATION IN SEDIMENTS: APPLICATION OF IN SITU TREATMENT UTILIZING EMULSIFIED LIQUID MEMBRANE AN." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4329.
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Heavy metal contamination of soils, sediments and groundwater presents an ongoing source of hazardous and persistent environmental pollution. How best to remediate these contaminants is the impetus of continuing research efforts. Methods include containment, ex situ and in situ techniques. A successful in situ method utilizing a combination of emulsified liquid membranes, ELM, and zero-valent metal, ZVM, and bimetals has demonstrated impressive heavy metal reduction in 100 ppm solutions of Cd, Cu, Ni, Pb, Cr and U. This promising in situ method has been employed by the Industrial Chemistry Laboratory at the University of Central Florida and it has demonstrated considerable success in treating several environmental threats. Contaminated soils, surfaces, sediments and groundwater with offending agents such as trichloroethene, polychorobiphenyls and heavy metals have been treated utilizing emulsified liquid membrane systems containing zero-valent iron or bimetal particles. In vial studies, lead spiked sediments have shown repeatable 60% removal of lead after seven days of treatment. A persistent pattern emerged at ten days whereupon remediation levels began to drop. The current study was established to determine the reason for the decline at ten days and beyond. Questions addressed: Does the formation of an impeding oxide layer diminish the remediation capacity of the iron/magnesium system? Does the emulsion reach a maximum capacity to withdraw the contaminant? Do the soil components or the soil structure interfere with the access to the contaminant? This study has yielded insight into the reasons emulsified liquid membrane systems containing zero-valent metals achieved maximum lead removal at day seven, and thereafter begin to lose their effectiveness. A three part study was implemented to address and to answer the three questions pertaining to the consistent pattern of diminishing remediation levels exhibited at day ten and beyond. Initially, from Study I results it appeared that the formation of an impeding oxide layer on the bi-metal which was inside the emulsion droplet and which plated or precipitated with the lead was not occurring at day ten. Results indicated that the iron/magnesium was still capable of removing lead. Furthermore, from Study II results the emulsion dose injected appeared adequate to remove the lead, meaning that the emulsion had not reached its maximum capacity for remediation. The emulsion dose was not a limiting factor. Lastly, Study III results seemed to indicate that the drop in remediation after day seven pertained to the soil structure. There appeared to be some merit to the idea that with aging of the sediment, the lead was diffusing and migrating to some inaccessible interior sites within the sediment particles. Additionally, indications from day ten and day fourteen delineated that a second emulsion dose injection might restore lead removal levels to approach those first observed at day seven and consequently be a useful field application. In order to explore the effectiveness of injecting a second dose of emulsion, another vial study was implemented. The typical pattern of observing sixty percent maximum lead removal at day seven was observed. In separate groups, a second injection of emulsion was added at day five, and then for another vial series, a second dose was added at day seven. The second emulsion dose treatment for either day five or day seven did not yield any increases in percent lead removal. Another theory emerged after viewing micrographs of recovered iron/magnesium compared with fresh ball-milled bimetal. In addition, scanning electron microscopy appeared to confirm the explanation that the emulsified zero-valent metal system might be compromised after day seven. This would lead to exposure of the iron/magnesium to the air and the elements. Corrosion of the bimetal might be occurring. With time, release of the plated or precipitated lead back into the sediment mixture could follow. The results of Study I had led to the conclusion that an impeding oxide layer had not formed; however, this conclusion may have been premature because the recovered iron/magnesium was exposed to lead solution in the vial study. Perhaps if the recovered iron/magnesium was inserted back into an emulsion and injected into lead spiked sediments the percent lead removed might give a more accurate picture of the iron/magnesium's capability to continue performing remediation. Remediation of sediments contaminated with lead is a complicated task because of the complex nature of sediment components. Emulsified liquid membranes utilizing zero-valent bimetals has repeatedly demonstrated impressive results at day seven; however, this treatment method is not without its limitations. Optimal results appear to be gained at day seven after emulsion injection. The bimetal and plated or precipitated lead must be removed at that point; otherwise the effective remediation of the contaminant is progressively reversed.M.S.
Department of Chemistry
Sciences
Industrial Chemistry MS
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Hawkins, Caleb M. "The Recovery of an AMD-impacted Stream Treated by Steel Slag Leach Beds: A Case Study in the East Branch of Raccoon Creek, Ohio." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1429784673.
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Bailey, Kathryn Lafaye. "Assessing the Microbial Consequences of Remediation: Surrogate Microbial Screening and Native Metabolic Signatures in Tc(VII) Contaminated Sediments." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/3965.
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The chemical and physical processes controlling contaminant fate and transport in the vadose zone limit the options for application of many remedial technologies. Foam delivery technology (FDT) has been developed as a potential solution to overcome these limitations for remediating subsurface and deep vadose zone environments using reactive amendments. Although there are many advantages to utilizing FDT for treatment in the deep vadose zone, little information is available on how the addition of these surfactants and remedial amendments affect the indigenous microbial communities in the deep vadose zone as well as the impact of biological transformations of surfactant-based foams on remediation efforts. The purpose of this study was to develop a rapid method for assessment of microbial communities in contaminated subsurface environments. This research was divided into two phases: (1) assess the toxicity of proposed FDT components on a single bacterial species, Shewanella oneidensis MR-1; and (2) determine the effects of these components on a microbial community from the vadose zone.
In Phase I, S. oneidensis MR-1 was exposed to proposed FDT components to assess potential growth inhibition or stimulation caused by these chemicals. S. oneidensis MR-1 cultures were exposed to the surfactants sodium laureth sulfate (SLES), sodium dodecyl sulfate (SDS), cocamidopropyl betaine (CAPB), and NINOL 40-CO, and the remedial amendment, calcium polysulfide (CPS). Results from this phase revealed that the relative acute toxicity order for these compounds was SDS>>CPS>>NINOL40-CO>SLES≥CAPB. High concentrations of SDS were toxic to the growth of S. oneidensis MR-1 but low concentrations were stimulatory. This benchtop system provided a capability to assess adverse microbial-remediation responses and contributed to the development of in situ remedial chemistries before they are deployed in the field.
For Phase II, sediments from the BC Cribs and Trenches (BCCT) area of the Hanford Site, WA, were characterized before and after exposure to potential FDT components. First, the phylogenetic and metabolic diversity of sediment from the BCCT was assessed by sequencing the microbial community and measuring the metabolic activity. The sediment was also incubated with various concentrations of SDS, CAPB, and CPS. Phylogenetic analysis detected phylotypes from the Alpha-, Beta-, Delta-, and Gammaproteobacteria, and Actinobacteria. Unlike the S. oneidensis MR-1 studies conducted in Phase I, the surfactants and CPS stimulated the metabolic activity of the native microbial communities. The observed stimulation could be caused by sorption of the chemicals to the sediment particles, or utilization of the surfactants by the microbial communities. These findings emphasize the importance of monitoring microbial activity at remediation sites in order to determine short and long term efficacy of the treatment, compliance with regulatory mandates, and act as an early warning indicator of unintended changes to the subsurface.