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1
Gralheira, Daniel José Rossa. "Tyrosinase-based phenol remediation". Master's thesis, Faculdade de Ciências e Tecnologia, 2012. http://hdl.handle.net/10362/8951.
Testo completoAbstract (sommario):
Dissertation for the obtention of the Master Degree in BiotechnologyNanobiotechnology is an emerging area full of potentialities to explore and reshape instituted knowledge. In this work, the main goal was to design and test biological remediation systems (a total of three) taking advantage of nanotechnology features, as a step towards future progress of sense-and-shoot combined systems. This task involved the development of active bionanoconjugates (BNC) with two different tyrosinases (Agaricus bisporus - AbT, and Tricoderma reesei - TrT) to be implemented in three suggested phenol remediation systems. AuNP-MUA (gold nanoparticles capped with11-mercapto-1-undecanoic acid) 1:5000 colloid was shown to be stable up to 100 mM ionic strength (sodium cloride) and able to form active BNCs with AbT. TrT:AuNP ratio for BNC formation is recommended as 100, supported by zeta potential and agarose gel mobility experimental data which, in turn, atone with the proposed theoretical estimation. The incubation of 100 ppm phenol with BNC-MUA-AbT for 60 minutes achieved 50% substrate conversion (the efficiency of the systems were also investigated using ultravioletvisible spectrophotometry (UV-Vis) complemented by standard addition method and solid-phase microextraction - gas chromatography (SPME-GC)).
2
Heckel, Kyle Christopher. "PETROLEUM CONTAMINATED AQUIFER REMEDIATION". Thesis, The University of Arizona, 2009. http://hdl.handle.net/10150/192479.
Testo completo
3
Onwubuya, Kenechukwu Maurice. "Sustainable remediation : designing a decision support tool for the selection of 'gentle' remediation approaches". Thesis, University of Brighton, 2013. https://research.brighton.ac.uk/en/studentTheses/b50521c6-cd0e-4f39-93db-9f4e73ae5e3f.
Testo completoAbstract (sommario):
A range of tools have been proposed to support decision making in contaminated land remediation (collectively referred to as Decision Support Tools or DSTs). From a European perspective it is clear, however, that there are considerable national differences in the decision support process, and more generally in the extent to which this process supports the se lection of less invasive, alternative and potentially more sustainable remediation options such as phytoremediation, in situ immobilisation etc. (referred to here as "gentle" remediation technologies or options). This thesis critically reviews available DSTs in terms of their fitness for purpose for the application of "gentle" remediation technologies, using published literature and data from two stakeholder surveys: the first from a European perspective (completed in the European Union ERANET SNOWMAN project SUMATECS (Sustainable Management of Trace Element Contaminated Sites)) (sample size of 130) and the second focused on contaminated land consultants and managers in the UK (sample size of 71). In general stakeholder feedback from both surveys indicates a lack of knowledge of currently available DSTs and the requirement for a simple OST using a tiered approach that can be integrated into an existing national framework. Based on this stakeholder feedback, a novel OST has been developed that will interface with an existing national framework and which will act as a guide to selection of "gentle" remediation approaches. This DST is a literature based tool that will direct users to collated information on successful practical pilot/field scale studies on " gentle remediation approaches and ensures that the elements or sustainability are considered during selection. The proposed approach is validated against data from three large-scale remediation projects, involving both gentle and more invasive remediation methods, in the UK, France and Belgium.
4
Butler, R. M. "Remediation of bromate contaminated groundwater". Thesis, Cranfield University, 2005. http://dspace.lib.cranfield.ac.uk/handle/1826/3533.
Testo completoAbstract (sommario):
Bromate (BrO3") is a by-product formed at concentrations of 0.4 - 60 µg L'' during potable water ozonation. Following World Health Organisation designation as a 'possible human' carcinogen, a 10 pg L" drinking water limit was introduced in England and Wales. Discovery of bromate contamination within a UK aquifer highlighted a knowledge gap, addressed by this project, relating to environmental behaviour and groundwater remediation. Following selection of an anion analysis strategy utilising Ion Chromatography (IC), bromate behaviour in wastewater was investigated as contaminated groundwater ingress to treatment processes was deemed possible. Respiration of wastewater biomass was unaffected by spiking of < 200 mg Ul bromate or bromide, with pilot-scale process dosing trials (S 100 mg L') using a Membrane Bioreactor (MBR) also exhibiting little negative effect following biomass acclimation. Bromate reduction to bromide was observed in a continuous-flow suspended growth chemostat bioreactor at retention times of 20 - 80 hours. A biological mechanism was confirmed in this system, with reduction mediated by indigenous groundwater bacteria following glucose addition. Bromate reduction rates were initially low (5 27.8 pg U' hr 1), but acclimation increased rates to > 1000 pg L" hr t. An alteration in microbial composition was noted over this period, from a denitrifying 'co-metabolic' culture to predomination of 'high-rate' specific bromate degraders. Operational parameters including pH, temperature, carbon source, influent bromate and glucose, and retention times were investigated, with all parameters apart from pH shown to affect bromate reduction rates. For example increased bromate influent enhanced reduction rate, although potentially toxic effects were noted with an influent > 75 - 80 mg L"'. Batch studies suggested glucose was rapidly fermented (< 48 hours) by the microbial consortium. Nitrate was also rapidly removed (< 4 hours), with sulphate reduction only following removal of bromate. A fixed-film pilot-scale bioreactor system, seeded with biomass from the chemostat culture, reduced > 90% of a 1.1 mg L"1 bromate influent within unspiked contaminated groundwater. Plating studies were successful in producing a range of isolates from the mixed chemostat culture. Overall the project demonstrated, for the first time, continuous remediation of bromate groundwater contamination within a bioreactor system.
5
Crow, Matthew. "Environmental remediation and semiconductor photocatalysis". Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=12837.
Testo completo
6
Grilli, Selene <1969>. "Fermentative processes for environmental remediation". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5142/1/Grilli_Selene_tesi.pdf.
Testo completoAbstract (sommario):
The growing interest in environmental protection has led to the development of emerging biotechnologies for environmental remediation also introducing the biorefinery concept.
This work mainly aimed to evaluate the applicability of innovative biotechnologies for environmental remediation and bioenergy production, throught fermentative processes.
The investigated biotechnologies for waste and wastewater treatment and for the valorisation of specific feedstocks and energy recovery, were mainly focused on four research lines.
1. Biotechnology for textile wastewater treatment and water reuse that involving anaerobic and aerobic processes in combination with membrane technologies. Combinations of different treatments were also implemented for water reuse in a textile company.
2. Biotechnology for the treatment of solid waste and leachate in landfill and for biogas production. Landfill operated as Bioreactor with recirculation of the generated leachate was proposed for organic matter biostabilisation and for ammonia removal from leachate by favouring the Anammox process.
3. An innovative two-stage anaerobic process for effective codigestion of waste from the dairy industry, as cheese whey and dairy manure, was studied by combining conventional fermentative processes with a simplified system design for enhancing biomethanisation.
4) The valorisation of the glycerol waste as surplus by-product of the biodiesel industry was investigated via microbial conversion to value-added chemicals, as 1,3-propanediol. The investigated fermentative processes have been successfully implemented and reached high yields of the produced bio-chemical.
The studied biotechnological systems proved to be feasible for environmental remediation and bioenergy and chemicals production.
7
Grilli, Selene <1969>. "Fermentative processes for environmental remediation". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5142/.
Testo completoAbstract (sommario):
The growing interest in environmental protection has led to the development of emerging biotechnologies for environmental remediation also introducing the biorefinery concept.
This work mainly aimed to evaluate the applicability of innovative biotechnologies for environmental remediation and bioenergy production, throught fermentative processes.
The investigated biotechnologies for waste and wastewater treatment and for the valorisation of specific feedstocks and energy recovery, were mainly focused on four research lines.
1. Biotechnology for textile wastewater treatment and water reuse that involving anaerobic and aerobic processes in combination with membrane technologies. Combinations of different treatments were also implemented for water reuse in a textile company.
2. Biotechnology for the treatment of solid waste and leachate in landfill and for biogas production. Landfill operated as Bioreactor with recirculation of the generated leachate was proposed for organic matter biostabilisation and for ammonia removal from leachate by favouring the Anammox process.
3. An innovative two-stage anaerobic process for effective codigestion of waste from the dairy industry, as cheese whey and dairy manure, was studied by combining conventional fermentative processes with a simplified system design for enhancing biomethanisation.
4) The valorisation of the glycerol waste as surplus by-product of the biodiesel industry was investigated via microbial conversion to value-added chemicals, as 1,3-propanediol. The investigated fermentative processes have been successfully implemented and reached high yields of the produced bio-chemical.
The studied biotechnological systems proved to be feasible for environmental remediation and bioenergy and chemicals production.
8
Sanderson, Patrick M. Miller Cass T. "Development and application of analytical methods to evaluate DNAPL remediation using a brine based remediation technology". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,667.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Environmental Science and Engineering, School of Public Health." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.
9
Duncan, Elizabeth Gunn. "Arsenic remediation using nanocrystalline titanium dioxide". Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=53330.
Testo completo
10
Croft, Richard G. "Remediation techniques for gas plant contamination". Thesis, Imperial College London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521955.
Testo completo
11
Mitrani, Helen. "Liquefaction remediation techniques for existing buildings". Thesis, University of Cambridge, 2006. https://www.repository.cam.ac.uk/handle/1810/252017.
Testo completo
12
Mewett, John University of Ballarat. "Electrokinetic remediation of arsenic contaminated soils". University of Ballarat, 2005. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/12797.
Testo completoAbstract (sommario):
"Arsenic is a common soil contaminant in Australia and worldwide. There is a need to find safe, effective and economic methods to deal with this problem. The soils used in this research were collected from central Victoria. They were contaminated with arsenic by historic gold mining activity or by past sheep dipping practices. This research investigated ten different leaching agents for their effects on three different arsenic contaminated soils. [...] Electrokinetic experiments were conducted on three arsenic contaminated soils. [...] The arsenic in these soils appears to be relatively stable and immobile under oxidising conditions. The soils had a high iron content which assists in the stabilisation of arsenic. This is beneficial with respect to the environmental impact of the arsenic contamination, however, it remains an obstacle to low cost electrokinetic remediation."Masters of Applied Science
13
Eftekhari, Farzad. "Foam-surfactant technology in soil remediation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0018/MQ54314.pdf.
Testo completo
14
Tejowulan, Raden Sri. "Remediation of trace metal contaminated soils". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0030/NQ64679.pdf.
Testo completo
15
Chan, M. S. M. "Photocatalytic remediation of organics in groundwater". Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597429.
Testo completoAbstract (sommario):
The aim of this research is to investigate the remediation of Methyl Tertiary Butyl Ether (MTBE) and other organics in groundwater by applying photocatalysis as an in-situ process. Photocatalytic degradations of MTBE and some other organics pollutants were proved to be possible. Experimental results suggest that photocatalytic degradation is accurately described by first order kinetics. The efficiency of photocatalytic degradation was expressed as the rate constant or the quantum yield. It was found that complete photocatalytic degradation of MTBE was only possible under aerobic conditions. Intermediates, such as Tertiary Butyl Formate (TBF) and acetone were found in oxygen-limiting photocatalytic degradation of MTBE. It was experimentally deduced that the rate constant of photocatalytic degradation was linearly proportional to the light irradiance and illuminated catalyst surface and inversely proportional to the reactor volume. The quantum yields of photocatalytic degradation of 100 mg/L MTBE solution in the five reactors were measured as 0.23% to 0.71%. The equilibrium adsorption of MTBE on TiO2 was found to be a linear isotherm. Flow experiments were conducted by circulating MTBE solution between one of the designed reactors and a reservoir. It was found that the reduction of pollutant was a function of the circulation rate, reactor volume and the batch rate constant of photocatalytic degradation in the reactor. Some soil experiments were conducted using one of the designed reactors, which was an underground reactor and some corresponding modelling was done to simulate the transport of MTBE under different flow regimes. It was found that pumping and regional flow facilitated the exchange of water between the reactor and the surrounding soil.
16
Mansfield, Rachel. "The evaluation of land remediation methods". Thesis, Nottingham Trent University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401471.
Testo completo
17
Spracklin, Katherine Helen. "The remediation of industrially contaminated soil". Thesis, University of Newcastle Upon Tyne, 1992. http://hdl.handle.net/10443/656.
Testo completoAbstract (sommario):
The remediation of two contaminated soils in the Tyne and Wear Metropolitan district was examined. These were a sediment dredged from the river bed at Dunston Coal Staiths on the River Tyne (downstream from Derwenthaugh coke work site) and coke work-contaminated soil from the Derwenthaugh site, Blaydon, Nr. Newcastle-upon-Tyne. The river Tyne dredgings were of a very fine material (70% silt; 24% clay) with high water retention capacity. Levels of (EDTA available) Zn (490mg/kg), total Cd (7.5mg/kg) and total Pb (510mg/kg) were above the Department of Environment's (1987) threshold values for soil contaminants. Barley (Hordeuin vulgare L. cv Kym) sown in the drcdgings in ten outdoor plots (Irn x 0.5m), grew very poorly (yield = 2.4g dry wt. /plant, compared with that on an uncontaminatedc. ontrol soil (7.4g dry wt./ plant). The barley exhibited all the classic signs of metal phytotoxicity despite the addition of fcrtiliscr and organic waste (straw and spent mushroom compost). When lime was added to raise the pH of the dredgings in the plots to over pH 7.1, the growth rate and the yield of barley improved significantly (yield = 6.8g dry wt. /plant). Levels of available Zn, Cd, Pb and Cu in the limed dredgings were now lower than in the unlimed dredgings. Copper and zinc levels in leaves of barley raised on the limed material were lower than levels in barley grown on unlimed dredgings. There was no significant difference in yield or growth rate between the different plots of dredgings in which organic supplementation parameters were varied. In conclusion, pH was the dominant factor in the remediation of the heavy metal phytotoxicity in the dredged material. Gas chromatography/mass spectrophotometry analysis showed the principal contaminants of the coke works soil to be organic. The soil was heavily contaminated with coal tars (19.0%) consisting of a complex mixture of aliphatic, polycyclic and aromatic compounds including phenols (160mg/kg). Viable counts of the soil microflora, on selective media, showed the presence of bacteria capable of degrading phenol and several of its alkylated homologues and thiocyanate, which was converted to ammonia and used as aN source. The coke works soil was treated on a laboratory scale using microbially based clean-up methods. Soil was incubated in glass jars under laboratory conditions. Nu trients (yeast extract) and microbial biomass (a mixed culture, previously isolated and enriched by growth on cresol and thiocyanate, but capable of oxidising a wide range of alkylated phenols), were inoculated into the contaminated soil. The addition of such biomass (106 organisms /g soil) led to a marked improvement in the rate of phenolic degradation in the soil (26% loss in'22 weeks, compared with 9% in the untreated control. ). Degradation rates decreased after 14 days but a repeated application of biomass (106 organisms/g soil) caused further phenolic loss (47% total loss). Cresol (100mg/kg) subsequently added to the bacterial ly-amended soil disappeared within 7 days, showing that the biomass amendment was still biochemically very active. These findings demonstrate the importance and the effectiveness of two different treatment methods in the rcmediation of contaminated soil.
18
Calì, Eleonora. "Nanoparticle technology in radionuclide-waste remediation". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/64906.
Testo completoAbstract (sommario):
The rapid development of the nuclear industry and the associated production of waste has created a large demand for the design of materials aimed at the removal of metal ions and radionuclides from the environment and for their safe and efficient disposal. Treatment of waste waters from reprocessing or storage of nuclear fuel requires highly selective sequestering materials with characteristics of high capacity and facile separation from water, whilst decommissioning of nuclear installations requires highly sensitive detection methods. The development of magnetic nanoparticles for separation technologies in liquid systems is wide-spread and already in use in medical testing. Generally, the method relies on the nanoparticles exhibition of superparamagnetic behaviour (i.e. external magnetic field-induced magnetisation of the suspension, with redispersion of the nanoparticles at the removal of the field). In this work, the challenge of translating this methodology, via surface functionalisation, for developing nano-sorbent structures to be used in radionuclide remediation from liquid streams, and to use superparamagnetic behaviour for waste form speciation and separation is addressed. Specifically, in this thesis superparamagnetic iron oxide nanoparticles, in the form of magnetite (Fe3O4), were designed as magnetic-adsorbents for uranium in water. Through surface activation with a phosphate-based ligand, magnetite nanoparticles with high uranium adsorption capacity and selectivity were obtained, with characteristics of extremely rapid uptake and sequestration from low concentration solutions. The former feature is crucial if the nanoparticles are to be applied for sequestering and storage purposes, whilst the latter opens the possibility for their sensing application to ascertain presence of uranium in even low amounts. Selectivity of the functionalised nanoparticles towards uranium against other cation species (Mg(II), Ca(II), Sr(II)) is observed. Desorption studies show a strong “irreversible” interaction between the functionalised nanoparticles and uranium, with no release of uranium detected after 14 months of contact with water. The possibility of tuning the nanoparticles’ magnetic properties by the synthesis of different-sized Fe3O4 nanoparticles and/or by developing an inert coating strategy is also shown. This feature would offer the potential of separation of nanoparticles targeting different waste-stream components after a single adsorption step from water. The optimum characteristics commonly exhibited by nanosized materials, such as increased surface area, high number of sorption sites given by a high yield in surface functionalisation, and the nanomagnetic properties, are observed to be crucial for the extremely efficient sequestration of uranium from water. The coating of the same nanoparticles by a silica shell was also exploited for potential applications in infrastructure projects: i.e. sealing of cracks present in deteriorating cementitious barriers for radionuclide containment. Silica coated-Fe3O4 nanoparticles were effectively produced and shown to undergo controlled gelation in NaCl solution.
19
Hedbavna, Petra. "Bioelectrochemically-enhanced remediation of contaminated groundwater". Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/13560/.
Testo completo
20
Thill, Patrick. "Hybrid remediation strategies for industrial effluents". Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:f2259720-1b37-49a0-97b1-da7c385e8245.
Testo completoAbstract (sommario):
Many industrial effluents are toxic, difficult to treat and contain potentially valuable resources. Current treatment methods are expensive and unsustainable. Bioprocessing is a promising alternative, but poses multiple challenges due to the chemically complex nature and high variability of different industrial effluents. As a result, it benefits from being combined with advanced oxidation processes. In this study, the potential benefit of coupling bioprocessing with nanoscale zero-valent iron and electron beam treatment was examined. Both processes have shown great promise individually in environmental applications but have not previously been applied in a hybrid system. This triple combination proved to be an effective approach when tested against two recalcitrant metalworking fluids, a textile dyeing effluent and a distillery wastewater. Strategies to remediate the different industrial effluents included a selection of key performance indicators and their amalgamation into a novel remediation index to assess treatment effectiveness. The different treatments were optimised both individually and in combination. Hybrid sequential e-beam, bioprocessing and nanoscale zero-valent iron treatment followed by bioprocessing synergistically detoxified both metalworking fluids and reduced their chemical oxygen demand (COD) by 92.8 ± 1.4 % and 68.4 ± 1.6 % respectively. E-beam pre-treatment of the met- alworking fluids enabled high-COD bioprocessing at the expense of residence time. Hybrid treatment also remediated the textile dyeing wastewater achieving a 99.4 ± 0.4 % reduction in colour, a 54.6 ± 6.1 % reduction in COD, a 89.0 ± 3.5 % reduction in sulphate and a 67.7 ± 4.2 % reduction in total nitrogen. E-beam treatment also enabled the recovery of copper from a distillery wastewater, whilst proving to have significant potential for the disinfection of industrial effluents post-bioprocessing. Overall process economics, footprint and sustainability were evaluated on a lab-scale and estimated for an industrial-scale implementation. The scope for improvements in the hybrid treatment system is discussed and suggests that future implementations of novel hybrid processes could provide tailor-made solutions for sustainable in situ treatment of a wide range of industrial effluents.
21
Donaldson-Selby, Claudia. "The use of poetry in remediation". Master's thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/21154.
Testo completoAbstract (sommario):
This dissertation presents an evaluation of a new method of teaching reading by means of a handbook for teachers and a workbook for children who have not learnt reading after being taught by the traditional methods in the classroom. The method uses poetry, mainly in doggerel and limerick form, assembled into a sequential and meaningful reading/spelling programme which, together with reference to phonics workbooks and reading books, trains the beginner reader up to the level of reading literacy. Research on the literature available shows that poetry has not yet been used as a total remedial programme. The efficacy of the need for remediation is examined, and remediation methods analysed for what they should include. Other avenues of remediation are explored, such as the gross and fine motor and perceptual schools of thought, and the language and auditory orientation to remediation, into which the Poetry Method neatly fits. Psychological theories - such as the behaviourist operative reward systems and the ideas of phenomenologists such as Rogers - that total healing can come about through renewed motivation and growth in self-esteem, are shown to be included in the Poetry Method.
22
Sayed, Shakeela. "Remediation of water using modified chitosan". Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/6361.
Testo completoAbstract (sommario):
Includes bibliographical references.Water treatment has been an area of increasing concern over the last decade. This interest is due to exponential increase in demand of already limited water sources. Therefore the treatment of wastewater for re-use is a topic of great interest. The treatment applied depends on the source and quality of the water. Common water treatment options include filtration, flocculation, coagulation, lime softening, reverse osmosis and clarification to name a few. In addition, water should also be treated for the presence of harmful micro-organisms which is normally done using chlorine-based disinfection. Water purification filters which purify water by removal of impurities and micro-organisms are in great demand. Therefore the aim of this study was to develop ion exchange polymers and antimicrobial filters using ‘green’ materials.
23
Gorr, Matthew W. "Arsenic Remediation Using Constructed Treatment Wetlands". University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1301943769.
Testo completo
24
Mewett, John. "Electrokinetic remediation of arsenic contaminated soils". Thesis, University of Ballarat, 2005. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/68354.
Testo completoAbstract (sommario):
"Arsenic is a common soil contaminant in Australia and worldwide. There is a need to find safe, effective and economic methods to deal with this problem. The soils used in this research were collected from central Victoria. They were contaminated with arsenic by historic gold mining activity or by past sheep dipping practices. This research investigated ten different leaching agents for their effects on three different arsenic contaminated soils. [...] Electrokinetic experiments were conducted on three arsenic contaminated soils. [...] The arsenic in these soils appears to be relatively stable and immobile under oxidising conditions. The soils had a high iron content which assists in the stabilisation of arsenic. This is beneficial with respect to the environmental impact of the arsenic contamination, however, it remains an obstacle to low cost electrokinetic remediation."Masters of Applied Science
25
Mewett, John. "Electrokinetic remediation of arsenic contaminated soils". University of Ballarat, 2005. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/14633.
Testo completoAbstract (sommario):
"Arsenic is a common soil contaminant in Australia and worldwide. There is a need to find safe, effective and economic methods to deal with this problem. The soils used in this research were collected from central Victoria. They were contaminated with arsenic by historic gold mining activity or by past sheep dipping practices. This research investigated ten different leaching agents for their effects on three different arsenic contaminated soils. [...] Electrokinetic experiments were conducted on three arsenic contaminated soils. [...] The arsenic in these soils appears to be relatively stable and immobile under oxidising conditions. The soils had a high iron content which assists in the stabilisation of arsenic. This is beneficial with respect to the environmental impact of the arsenic contamination, however, it remains an obstacle to low cost electrokinetic remediation."Masters of Applied Science
26
Niarchos, Georgios. "Electrodialytic Remediation of PFAS-Contaminated Soil". Thesis, KTH, Vatten- och miljöteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-239878.
Testo completoAbstract (sommario):
Per- and polyfluoroalkyl substances (PFASs) are a group of anthropogenic aliphatic compounds, widelyknown for their environmental persistence and toxicity to living beings. While they are ubiquitous in theenvironment, interest has been focused on contaminated soil, which can act as a primary recipient andsource of groundwater contamination. Electrokinetic technology is based on the movement of ionsunder the effect of an electric field. This could be a promising remediation solution, since PFASs areusually present in their anionic form. The contaminants can then be concentrated towards the anode,thus reducing a plume’s volume and possibly extracting the substances from soil. The preliminary aimof the present study was to evaluate the potential of using electrodialysis for the remediation of PFAScontaminatedsoil for the first time. Experiments were run with natural contaminated soil samples,originating from a fire-fighting training site at Arlanda Airport, and at Kallinge, Sweden, as well as inartificially spikedsoil. Electrodes were placed in electrolyte-filled chambers and separated by the soilwith ion-exchange membranes for pH-control. In total, five experiments were conducted. Two differentsetups were tested, a typical 3-compartment EKR cell and a 2-compartment setup, to allow for pHincrease and facilitate PFAS desorption. Two different current densities were tested; 0.19 mA cm-2 and0.38 mA cm-2. After twenty-one days, soil was cut in ten parts lengthwise and triplicate samples wereanalysed for PFAS concentrations, with HPLC-MS/MS. Sixteen out of the twenty-six screened PFASswere detected above MDL in the natural soil samples. The majority of the detected PFASs showed apositive trend of electromigration towards the anode, under both current densities, with only longerchainedcompounds (c>8) being immobile. This can be attributed to the stronger sorption potential oflong-chained PFAS molecules, as has been reported in previous sorption studies. Mass balancedistribution for a high current density (0.38 mA cm-2) experiment revealed that 73.2% of Σ26PFAS wasconcentrated towards the anode, with 59% at the soil closer to the anode, 5.7% at the anion exchangemembrane and 8.5% at the anolyte. It also showed higher mobility for short-chained molecules (c≤6),as they were the only compounds to be extracted from soil and be concentrated in the anolyte. Highercurrent densities were not directly correlated with higher electromigration rates, as to the lack of massbalance data for the low current density experiments. Regardless, electrodialysis could be a viable optionfor PFAS soil remediation and further research to encourage the understanding of the migrationmechanism, as well as combination with other treatment methods is encouraged.Per- och polyfluoralkylsubstanser (PFAS) är en grupp av antropogena alifatiska föreningar, allmäntkända för sin miljöpåverkan och toxicitet för levande varelser. Medan de är allestädes närvarande imiljön har intresset varit inriktat på förorenad mark, som kan fungera som primär mottagare och källatill grundvattenförorening. Elektrokinetisk teknik är baserad på jonernas rörelse under effekten av ettelektriskt fält. Detta kan vara en lovande lösningsmedel, eftersom PFAS är vanligtvis närvarande i sinanjoniska form. Föroreningarna kan sedan koncentreras mot anoden, vilket reducerar en plums volymoch eventuellt extraherar ämnena från jorden. Det preliminära målet med den föreliggande studien varatt utvärdera potentialen att använda elektrodialys för sanering av PFAS-förorenad jord för förstagången. Experimenten kördes med naturliga förorenade jordprover, härrörande från enbrandbekämpningsplats vid Arlanda flygplats, och i Kallinge, Sverige, samt i konstgjort spikedsol.Elektroder placerades i elektrolytfyllda kamrar och separerades av jorden med jonbytesmembran förpH-kontroll. Totalt genomfördes fem experiment. Två olika inställningar testades, en typisk 3-facksEKR-cell och en 2-facksinställning, vilket möjliggör pH-ökning och underlättar PFAS-desorption. Tvåolika strömtätheter testades; 0,19 mA cm-2 och 0,38 mA cm-2. Efter tjugo dagar skärs jorden i tio delari längdriktningen och trippelprover analyserades för PFAS-koncentrationer, med HPLC-MS / MS.Sexton av de tjugosex screenade PFAS: erna detekterades över MDL i de naturliga markproverna.Majoriteten av de upptäckta PFAS-värdena visade en positiv trend av elektromigration mot anodenunder båda strömtätheten, varvid endast längre kedjiga föreningar (c> 8) var immobila. Detta kanhänföras till den starkare sorptionspotentialen hos långkedjiga PFAS-molekyler, vilket har rapporteratsi tidigare sorptionsstudier. Massbalansfördelning för ett experiment med hög strömtäthet (0,38 mA cm-2) visade att 73,2% av Σ26PFAS koncentrerades mot anoden, med 59% vid jorden närmare anoden, 5,7%vid anjonbytarmembranet och 8,5% vid anolyten. Det visade också högre rörlighet för kortkedjigamolekyler (c≤6), eftersom de var de enda föreningarna som skulle extraheras från jord och koncentrerasi anolyten. Högre strömtätheter var inte direkt korrelerade med högre elektromigrationshastigheter,avseende bristen på massbalansdata för experimenten med låg strömtäthet. Oavsett elektrodialys kandet vara ett lönsamt alternativ för PFAS-markrening och ytterligare forskning för att uppmuntraförståelsen för migrationsmekanismen, liksom kombinationen med andra behandlingsmetoder främjas.
27
Merker, Marissa C. "Persulfate transport in two low-permeability soils". Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Summer2010/M_Merker_061610.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in civil engineering)--Washington State University, August 2010.Title from PDF title page (viewed on July 23, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 15-17).
28
García, Molina Verónica. "Wet oxidation processes for water pollution remediation". Doctoral thesis, Universitat de Barcelona, 2006. http://hdl.handle.net/10803/1526.
Testo completoAbstract (sommario):
The main objective of this work was to test the efficiency of wet oxidation processes when treating several types of aqueous wastes. On one side its performance for the abatement of chloro-organic aromatic toxic pollutants, such as 4-chlorophenol and 2,4-dichlorophenol has been studied. On the other hand, wastewater from pulp and paper mills, which has been reported to be an indirect source of entry of chlorophenols in the aquatic environment, has been investigated. More in detail, it has been taken as feed stream for the wet oxidation unit in order to investigate whether this type of waste streams can be treated by this technology or not. Regarding Chlorophenols, special attention was drawn to the degradation of 4-chlorophenol by means of wet oxidation and wet peroxide oxidation. This aromatic compound was taken into investigation due to its harmful properties against the environment and due to its wide presence in the environment. Once it was clear that it could be degraded by these technologies, a research focused on the influence of the operating conditions in the result of the oxidation was carried out. The influence on the wet peroxide oxidation and wet oxidation reactions of the following parameters, initial concentration of the pollutant, temperature and amount of oxidizing agent (oxygen or hydrogen peroxide depending on the process) has been taken under study.
The identification and quantification of the intermediate compounds involved in the wet oxidation of 4-chlorophenol, together with a suggested mechanistic pathway, allowed the obtaining of a kinetic model, which appeared to be a useful tool for the prediction of these compounds throughout the reactions. The evolution of the free chlorine released to the solution from the degraded chlorophenol was also a useful tool when determining the kinetic pathway of the reaction.
Another objective of the work comprised the investigation of the variations of the biodegradability of the samples during the process. The knowledge of evolution of this parameter during the wet oxidation was thought to be of major importance, since high biodegradability enhancements allow the combination of a wet oxidation unit with a biological post-treatment, which is an effective and inexpensive technology to couple the oxidation.
The establishment of a comparison between wet oxidation and the wet peroxide oxidation for the removal of 4-chlorophenol was investigated as well.
Concerning wastewaters from pulp and paper mills, debarking and termo-mechanical pulp process wastewater have been treated by wet oxidation. Both waters were concentrated before oxidation in order to favor the economy of the process. Debarking wastewater was concentrated by evaporation and pulp process water by nanofiltration. The influence of the operating conditions, such as temperature and partial pressure of oxygen, on the results achieved at the end of the wet oxidation were studied and evaluated in order to find the optimum working conditions for each type of wastewater. Special attention was drawn to the evolution of Lipophilic Wood Extractive Compounds throughout the reactions. In addition, kinetic models suggested in the literature were tested to find a suitable one, which allowed the prediction of for instance, the organic load, over the duration of the reactions.
Due to the fact that wet oxidation is more economically viable when the initial waste stream is highly concentrated, a final chapter dedicated to a emerging technique, i.e., membrane technology has been included in this thesis. An investigation regarding the parameters affecting its performance, as well as the general aspects of the process has been conducted.
29
González, Olmos Rafael. "Thermodynamics and remediation techniques for fuel oxygenates". Doctoral thesis, Universitat Rovira i Virgili, 2008. http://hdl.handle.net/10803/8567.
Testo completoAbstract (sommario):
In the last years, due to an increasing concern about the possible harmful effects of the gas emissions of the continuous gasoline use, their compositions have changed considerably. The lead additives ban and the aromatic compounds content limitation has caused the worldwide expansion of the use of fuel oxygenates. These compounds are mainly molecules with an atom of oxygen inside its structure. Usually they are ethers or alcohols. The most used worldwide is methyl tert-butyl ether (MTBE) followed by ethyl tert-butyl ether (ETBE). These compounds because of their physical and chemical properties have become persistent and recalcitrant pollutants in the groundwaters of the entire world.Due to the problem generate by the contamination of water resources is important to go deeper in the knowledge of the behaviour of fuel oxygenates in the environment in order to obtain tools that let us model and study their environmental dispersion and remediation. This doctoral thesis offers an important thermodynamical study of these compounds and analyzes different remediation techniques.
The work is structured in four chapter well differentiated. The first one consists of an introduction to the problem, the current situation of thermodynamical information and the existent techniques for the water treatment.
The second chapter is focused on obtaining and improving the thermodynamical information. It is studied how temperature affect to the interactions of fuel oxygenates with different gasoline compounds such us BTEX (benzene, toluene, ethylbenzene and xylenes), alcans or degradation products like tert-butyl alcohol. In this chapter is included new thermodynamical information in terms of physical properties (density and speed of sound), vapor-liquid equilibria and liquid-liquid equilibria (as water solubility). As a result have been characterized 25 binary systems and their pure compounds in terms of physical property, 3 vapor liquid equilibria and finally the study of water solubility of the ethers most used in gasoline blending as temperature function.The third chapter is focused from a technological point of view. Here it is studied thermodynamically, different conventional remediation techniques fort he MTBE and ETBE like the adsorption onto activated carbon and batch air stripping. It is observed that the temperature increases the efficiency in both processes and that ETBE is easier treated. On the other hand, it has been analyzed the use of new solvents, in this case ionic liquids, in order to dehydrate fuel oxygenates obtaining satisfactory results. Finally, studies of advanced oxidation processes have been carried out using Fe-zeolites as catalyst. The use of these materials let oxidize MTBE and their most problematic degradation products, like tert-butyl alcohol and tert-butyl formate at environmental conditions and neutral pH in reasonable times.Finally in the fourth and last chapter are summarized the conclusions obtained during the development of this work and the research directions to follow in the future.
En els darrers anys, degut a una creixent preocupació sobre els possibles efectes nocius de les emissions de gasos procedents de l'ús continu de gasolines, la composició d'aquestes ha patit canvis importants. La prohibició dels additius amb plom així com la limitació de compostos aromàtics han donat lloc a una gran expansió arreu del món de l'ús del que es coneixen com additius oxigenats de la gasolina. Aquest compostos son principalment molècules que tenen dins la seva estructura almenys un àtom d'oxigen. Normalment acostumen a ser èters o alcohols. De tots els més utilitzats a nivell mundial son el metil tert butil èter (MTBE), seguit pel etil tert butil èter (ETBE). Aquests compostos degut a les seves propietats físiques i químiques han esdevingut uns contaminants persistents i recalcitrants de les aigues a tot el món.Degut a la problemàtica generada per la contaminació del recursos hídrics és important aprofundir en el coneixement del seu comportament en el medi ambient per tal de obtenir eines que permetin modelitzar i estudiar tant la seva dispersió com la seva remediació. La present tesi doctoral ofereix un estudi termodinàmic important d'aquest compostos i estudia diferents tècniques de remediació.
Aquest treball s'estructura en quatre capítols ben diferenciats. El primer d'ells consisteix en una introducció a la problemàtica, la situació actual de la informació física i química de la qual es disposa i de les tècniques existents per al tractament d'aigües contaminades.
El segon capítol està enfocat a obtenir i millorar la informació termodinàmica. S'estudia com la temperatura afecta a les interaccions dels additius oxigenats amb diferents constituents de les benzines com son els BTEX(benzè, toluè, etilbenzè i xilens), alcans o compostos de degradació dels oxigenats com pot ser el tert butil alcohol. En aquest capítol s'aporta nova informació termodinàmica prèviament no reportada en la literatura en termes de propietat físiques (densitat i velocitat de so), equilibri vapor líquid i equilibri líquid líquid (en forma de solubilitat en aigua). Com a resultat d'aquest capítol cal remarcar la caracterització de 25 sistemes binaris i els seus compostos purs en termes de propietat física, 3 equilibris binaris líquid vapor i finalment l'estudi de la solubilitat dels èters més utilitzats com additius oxigenats com a funció de la temperatura.El tercer capítol està enfocat des d'un punt de vista tecnològic. En aquest s'estudia termodinàmicament diferent tècniques convencionals per l'eliminació de MTBE i ETBE com son l'adsorció en carbó actiu i l'aireació. S'observa que l'increment de la temperatura augmenta l'eficiència en tot dos processos i que l'ETBE es més fàcilment eliminat. Per altra banda s'ha analitzat l'ús de nous solvents, com son els líquids iònics, per tal de deshidratar additius oxigenats obtenint-se resultats satisfactoris. Finalment s'han realitzat estudis d'oxidació avançada utilitzant zeolites amb contingut fèrric. L'ús d'aquest materials permet oxidar l'MTBE i els seus compostos de degradació més problemàtics, com son el tert butil alcohol i el tert butil formiat en condicions ambientals i pH neutres en temps raonables.Finalment en el quart i últim capítol es resumeixen les conclusions obtingudes durant aquest treball i es donen ressenyes a seguir en investigacions futures en aquest camp.
30
Pearson, Robert. "In situ remediation of atrazine contaminated groundwater". Thesis, Cranfield University, 2006. http://dspace.lib.cranfield.ac.uk/handle/1826/1430.
Testo completoAbstract (sommario):
The natural attenuation of groundwater pesticides by biological degradation, is widely accepted to occur at concentrations > 1 mg 1-1. However from observations of groundwater monitoring data it can be indicated that the occurrence of pesticides in groundwater is primarily at trace μg 1-1 concentrations, with 45 % of UK groundwater samples that failed the EC Drinking Water Directives PV of 0.1 μg 1-1 between 1995 – 2000, accounting for an average concentration of 64 μg 1-1. However, there are limited directed studies of in situ biological degradation of pesticides at μg concentrations. Therefore, this work was designed provided an insight as to whether any prevalent microbial adaptation can occur to degrade atrazine at μg 1-1 concentrations in groundwater. Laboratory batch studies were performed using a groundwater exposed to 0.2 μg 1-1 of the herbicide atrazine, for an excess of 10 years. Bacterial enrichment using a glucose minimal salts medium resulted in no biological degradation of atrazine, when amended at concentrations between 10 μg to 50 mg 1-1. Batch studies using the atrazine degrader Pseudomonas sp. Strain ADP as a positive control, indicated a capability to degrade atrazine within sterilised groundwater, at 50 mg 1-1 (0.92 mg 1-1 day-1) and 1 mg 1-1 (0.14 mg 1-1 day-1), but no degradation of atrazine at 100 or 10 μg 1-1. Therefore, biological degradation of trace μg 1-1 concentrations of atrazine by groundwater in situ bacteria does not readily occur. It is expected that changes in atrazine groundwater concentrations, are resulting purely from dilution, sorption or chemical degradation. Consequently, it cannot be assumed that microbial adaptation can occur to degrade atrazine at μg 1-1 concentrations in groundwaters even if in situ bioaugmentation methods are applied.
31
Abed, S. N. "Floating treatment wetlands for synthetic greywater remediation". Thesis, University of Salford, 2017. http://usir.salford.ac.uk/42227/.
Testo completoAbstract (sommario):
Aggravation of water scarcity, eutrophication and pollution, has led to treatment and/or recycling of the major fraction of domestic wastewater, which is grey wastewater, for non‒potable options. The major aim of this study was to evaluate the performance of FTWs for remediation of various pollutants from synthetic greywater. In the present study, a novel synthetic greywater composition has been proposed with respect to the composition of organics, nutrients, heavy metals and other trace elements. As an imitation of bio‒physiochemical treatment technology, mesocosm‒scale retention ponds were artificially retrofitted with floating reedbed Phragmites australis to introduce, what is known as, floating treatment wetlands (FTWs) for improving the removal efficiency of soluble contaminations from synthetic greywater (SGW) in such systems. As a corroboration to the phytoremediation, pelletised ochre (acid mine wastewater sludge) was added into those FTWs for its capacity to adsorb phosphorus and other trace elements. Mainly, four operational variables were designated for the experimental design set‒ups of the FTWs, namely: pollutant strength (high‒ (HC) and low‒ (LC) concentrations), contact time (2‒ and 7‒day), presence of P. australis and presence of cement‒ochre pellets. The findings revealed that dissolved (DO), and biochemical and chemical oxygen demands (BOD5 and COD) decreased significantly (p < 0.05) in all FTWs. The concentrations of NO3‒N were significantly (p < 0.05) higher, and of PO4‒P were significantly (p < 0.05) lower than those concentrations of inflow, however, there were no significant (p > 0.05) changes in NH4‒N concentration in FTWs using a combination of ochre pellets with floating P. australis. Presence of ochre pellets in combination with P. australis significantly (p < 0.05) decreased Al, B, Cd, Cr, Cu, Mg, Ni and Zn, while increasing Al, Ca, Fe and K contents in the outflow. Accumulation of all considered elements was significantly (p < 0.05) higher in P. australis of all treatment systems (T) than in control systems (C), except for sodium (Na) contents which had significantly (p < 0.05) lower accumulations. The statistical analysis showed that accumulated concentrations of all considered elements in ochre pellets after the end of the treatment experiment were significantly (p < 0.05) higher, except for Ca concentrations which were significantly (p < 0.05) lower, than those in ochre pellets before commencing the experiment.
32
Bowles, Marc W. "The trench and gate groundwater remediation system". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0024/MQ31330.pdf.
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Harrington, Bethany S. "Artificial riffles as a stream remediation technique /". View online, 2008. http://repository.eiu.edu/theses/docs/32211131458636.pdf.
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34
清家, 伸康, e 新太 片山. "Monitoring and Remediation of Persistent Organic Pollutants". 日本農薬学会, 2007. http://hdl.handle.net/2237/10923.
Testo completo
35
Sulak, Jodi Lopez. "Radon remediation using fluid-based recovery systems". Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17061.
Testo completo
36
Shea, Charles Brian. "Optimal well location in contaminant plume remediation". Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/19465.
Testo completo
37
Tunison, Douglas Irvin. "Streamline simulation of surfactant enhanced aquifer remediation". Thesis, Monterey, California. Naval Postgraduate School, 1996. http://hdl.handle.net/10945/31159.
Testo completoAbstract (sommario):
Nonaqueous Phase Liquids (NAPLs) are a recognized source of groundwater contamination. Surfactant Enhanced Aquifer Remediation (SEAR) shows promise in increasing the efficiency and effectiveness over traditional 'pump and treat' NAPL remediation processes. Laboratory results are not always consistent with the effects observed in field applications because of the complex interactions that occur in the subsurface. Mathematical modeling is required to enable accurate prediction and understanding of SEAR.
38
Clinton, Thomas. "Electrokinetic stabilisation as a subsidence remediation technique". Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7852/.
Testo completoAbstract (sommario):
This study comprises a three part investigation into electrokinetic stabilisation (EKS): numerical modelling, laboratory trials and site trials. The numerical modelling was introduced to identify issues in the physical trials and assess proposed site trial solutions and associated configurations. The laboratory trials concentrated on electrode development and chemical stabiliser combinations in conjunction with known practical issues such as electrode polarisation and current intermittence effects. English China Clay batches combined with predetermined chemical stabiliser mixes were cured for up to 540 days and tested for standard engineering indexes and electrodes were tested for durability in liquids and under electrolysis. Optimum electrodes, determined through current transfer and durability results, along with optimum chemical combinations, determined through increase in undrained shear strength and reduction is linear shrinkage, were then combined to determine the effects on English China Clay under a mock strip footing for 30 days. It was shown that EKS has a negligible effect on the footing itself through either damage or level changes. The methodology was developed from the laboratory trials where the optimum electrode type, chemical combination and current intermittence times were developed, and applied to a site trial near Watford, UK. Four trials were conducted consisting of: a control; a vertical electrode set‐up, a vertical electrode set‐up using current intermittence and a raked electrode set‐up. All trials consisted of a 0.3x0.3x1.0m strip footing with treatment targeted at beneath the concrete. EKS was conducted for 56 days on a predominantly London Clay based made ground material with apparent resistivity measurements taken pre‐, peri‐ and posttreatment where apparent resistivity measurements showed the movement of the stabilising fluids over time. Site monitoring included voltage, current, air temperature and footing underside temperatures. Post treatment testing included standard engineering index testing, chemical analysis and SEM photography to determine the effects of the treatment regime. It was determined that the vertical electrode system showed most beneficial clay improvements through the laboratory testing and apparent resistivity results and as in the laboratory trials, negligible effect on the strip footings.
39
Loving, James Howard. "Enabling malware remediation in expanding home networks". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/108839.
Testo completoAbstract (sommario):
Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program, 2017.Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 79-91).
As the Internet of Things (IoT) grows, malware will increasingly threaten Internet security and stability. Many actors, from individuals installing antivirus on their personal computers to law enforcement conducting botnet takedowns, have some capability to prevent or remediate malware, but these strategies face technical and economic challenges. These challenges worsen as the IoT expands, due to the high number of IoT devices and other characteristics of the IoT. Fortunately, Internet Service Providers (ISPs) are positioned to effectively contribute to malware remediation efforts, through the detection and notification of compromise. However, Network Address Translation (NAT) and IPv6 Privacy Extensions prevent ISPs from identifying the specific compromised device. We refer to this lastmile extension of the IP traceback problem as the residential source identification problem. As the IoT grows, the problem worsens: IoT devices are less capable of self-remediation and expected to soon outnumber traditional devices, thus imposing a significant cost on customers to triangulate and remediate an infection. To address the residential source identification problem, I propose EDICT, an open-source software package for home routers that will enable consumers to identify a specific device, given retrospective notification of the malicious behavior, without compromising the consumer's privacy. EDICT does this by maintaining a mapping of IP flows to devices through a series of scalable Bloom filters, allowing EDICT to operate under the significant memory constraints of home routers. When a customer is informed of compromise, EDICT will query this connection log using a fuzzy check of the timestamp and source port, both provided by the ISP, iterated across a log of identified devices. EDICT will then provide the customer with user-friendly information on the infection's source, enabling remediation.As the Internet of Things (IoT) grows, malware will increasingly threaten Internet security and stability. Many actors, from individuals installing antivirus on their personal computers to law enforcement conducting botnet takedowns, have some capability to prevent or remediate malware, but these strategies face technical and economic challenges. These challenges worsen as the IoT expands, due to the high number of IoT devices and other characteristics of the IoT. Fortunately, Internet Service Providers (ISPs) are positioned to effectively contribute to malware remediation efforts, through the detection and notification of compromise. However, Network Address Translation (NAT) and IPv6 Privacy Extensions prevent ISPs from identifying the specific compromised device. We refer to this lastmile extension of the IP traceback problem as the residential source identification problem. As the IoT grows, the problem worsens: IoT devices are less capable of self-remediation and expected to soon outnumber traditional devices, thus imposing a significant cost on customers to triangulate and remediate an infection. To address the residential source identification problem, I propose EDICT, an open-source software package for home routers that will enable consumers to identify a specific device, given retrospective notification of the malicious behavior, without compromising the consumer's privacy. EDICT does this by maintaining a mapping of IP flows to devices through a series of scalable Bloom filters, allowing EDICT to operate under the significant memory constraints of home routers. When a customer is informed of compromise, EDICT will query this connection log using a fuzzy check of the timestamp and source port, both provided by the ISP, iterated across a log of identified devices. EDICT will then provide the customer with user-friendly information on the infection's source, enabling remediation.
by James Howard Loving.
S.M. in Technology and Policy
S.M.
40
Stern, Heather A. G. (Heather Ann Ganung). "Electrolytic remediation of chromated copper arsenate wastes". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35284.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references.
While chromated copper arsenate (CCA) has proven to be exceptionally effective in protecting wood from rot and infestation, its toxic nature has led to the problem of disposal of CCA-treated lumber and remediation of waters and soils contaminated by process wastes. The active ions in water-based CCA are hexavalent chromium, divalent copper, and pentavalent arsenic. The objective of this study was to develop the underlying engineering science for remediation of aqueous CCA wastes via electrolytic deposition of neutral arsenic, chromium, and copper in order to evaluate the technical feasibility of this process. The specific approach focused on electrochemical stability analysis of the metals; development and testing of a copper sulfate reference electrode (CSE); electrolytic deposition of arsenic, chromium, and copper from model aqueous CCA wastes; and characterization of the resulting deposits. The electrochemical stability analysis of the individual components, As, Cr, and Cu, in an aqueous system was used to determined the most thermodynamically stable forms of the metals as a function of pH and electrochemical potential. This analysis predicted that under the conditions of codeposition of all three metals, hydrogen and arsine would also be produced.
(cont.) A robust and accurate CSE was designed, constructed, developed and used as a reference electrode for the electrolytic deposition experiments in this study. The potential of the CSE as a function of temperature over the range of 5 to 45 °C was measured and related to the normal hydrogen electrode potential (317 mV at 25°C, slope of 0.17 mV/°C). Electrolytic deposition was performed using working and reference electrodes specially designed and fabricated for this study. Despite the results of the electrochemical stability analysis, conditions were found experimentally where arsenic, chromium, and copper were deposited from model aqueous CCA type-C solutions over a range of concentrations without the formation of arsine or hydrogen. Three different types of deposits were observed. One type contained a ratio of metal concentrations similar to that of CCA type-C and is a good candidate for use in CCA remediation and recycling processes. This study indicated that CCA remediation via electrolytic deposition is probably feasible from an engineering perspective.
by Heather A.G. Stern.
Ph.D.
41
Luo, Yongshou. "Optimal monitoring and remediation of groundwater contamination". Case Western Reserve University School of Graduate Studies / OhioLINK, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=case1056479934.
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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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Singh, Rajesh. "Role of Microorganisms in Heavy Metal Remediation". Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1447974231.
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Bases, Jessica. "NMR Studies of an Organophosphate Remediation Catalyst". Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1478459171278326.
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Bellarby, Jessica. "Assessment of remediation strategies for recalcitrant pollutants". Thesis, University of Aberdeen, 2005. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU200404.
Testo completoAbstract (sommario):
Chlorinated aliphatic and aromatic hydrocarbons are major pollutants resulting from their widespread use. In this project, one contaminant from each major group, namely trichloroethene and benzene, were studied in a shallow and deep aquifer, respectively. The shallow aquifer contaminated with trichloroethene and other chlorinated aliphatic hydrocarbons was too toxic for microbial processes. Several remediation technologies were investigated in laboratory studies, which were sparging, charcoal adsorption and the injection of chemical oxidants (Fenton's reagent and potassium permanganate). Each of these technologies on its own was found not to be suitable for the present site. The deep anaerobic aquifer contaminated with benzene was considered for enhanced natural attenuation. Despite the lack of constraints for anaerobic benzene degraders, no clear evidence for their presence was found. This was partly explained by a small biomass and aquifer variation as benzene was degraded under field conditions at low rates. The low degradation rates could not be observed in laboratory experiments so that an aerobic enhancement option in the form of hydrogen peroxide and/or nitrate injection was further investigated. Only the addition of hydrogen peroxide was demonstrated to be successful in reducing benzene concentrations. A direct transfer of the treatment to the field was considered unlikely due to the highly reducing in situ conditions. It was concluded that (enhanced) natural attenuation was unviable for both sites. Alternative remediation technologies considered at the respective sites were also found unsuitable based on laboratory results and aquifer properties. The luminescence-based bacterial biosensors provided a valuable tool for the evaluation of contaminant toxicity/bioavailability and the suitability of possible remediation strategies.
46
Kostarelos, Konstantinos. "Surfactant enhanced aquifer remediation at neutral buoyancy /". Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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47
Lee, MyungHo. "Electrokinetic remediation of heavy metal contaminated soils". 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144895.
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Ward, William Jackson. "1,4-Dioxane Remediation Using a Constructed Wetland". Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195111.
Testo completoAbstract (sommario):
This research addressed the question whether a constructed wetland system with phytoremediation could successfully uptake 1,4-Dioxane in groundwater and secondary effluent. It further addressed whether open pond storage could successfully treat wetland discharge. The project was located at the University of Arizona's Constructed Ecosystems Research Facility (CERF) in Tucson, Arizona. This two-year field study was motivated by previous laboratory studies which demonstrated the capability of plants to remediate the recalcitrant contaminant 1,4-Dioxane.The study was conducted in two open steel tanks configured to simulate constructed wetlands. The efficacy of 1,4-Dioxane uptake by cottonwood trees was tested in a side-by-side comparison utilizing planted and unplanted tanks. The sub-surface hydraulic conditions were fully characterized by bromide tracer studies. Six experiments were conducted, in which tapwater or secondary effluent was spiked with 5.2 mg/L 1,4-Dioxane and fed to the planted and unplanted (control) tank. The tank discharges were retained in separate open ponds to test if open pond storage would reduce 1,4-Dioxane content. Additional side experiments were conducted to examine the role of volatilization and UV degradation. Comparison of 1,4-Dioxane mass discharge from the planted and the control tank demonstrated an 18-48 percent uptake by the cottonwood trees. Mass balance assessments showed 1,4-Dioxane uptake efficiency was positively correlated to cottonwood transpiration rates in the planted tank. The open pond 1,4-Dioxane measurements demonstrated a 64-85 percent reduction in 1,4-Dioxane concentration due to volatilization during the initial 120 hours pond lapse time. Elimination of 1,4-Dioxane from the ponds followed first order kinetics. Field and laboratory side experiments demonstrated the potential for UV photo degradation of 1-4-Dioxane.
49
Journell, Scot. "Site Remediation of Underground Storage Tank Contamination". Arizona-Nevada Academy of Science, 1990. http://hdl.handle.net/10150/296432.
Testo completoAbstract (sommario):
From the Proceedings of the 1990 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 21, 1990, Arizona State University, Tempe, ArizonaRemedial techniques for sub-surface soil and water contamination are dependent on the lateral and vertical extent of petroleum hydrocarbon contamination and the type of petroleum hydrocarbons which have been released into the sub-surface. Specific remedial technologies are required for diesel fuel and heavy oils compared to the more volatile gasoline compounds. Available remedial technologies for vadose zone contamination include excavation and treatment; soil vapor extraction and possible vapor burning; bioremediation; and chemical treatment. Remedial technologies for ground-water contamination include water recovery, contaminant volatilization, carbon adsorption, bioremediation and water reinjection. Specialized apparatuses are utilized when petroleum hydrocarbon product floating on the water table surface must be separated from the ground water. A number of hydrologic considerations must be evaluated prior to any remediation scenario. These considerations include geologic characterization of the sub-surface soil matrix, and aquifer.
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Amorós-Pérez, Ana. "TiO2 based photocatalysts for environmental remediation reactions". Doctoral thesis, Universidad de Alicante, 2019. http://hdl.handle.net/10045/92551.
Testo completoAbstract (sommario):
Esta tesis doctoral se ha centrado en la preparación de fotocatalizadores nanoestructurados basados en TiO2 modificados con metales de transición o carbón activado para su aplicación en reacciones de interés medioambiental, concretamente, en la eliminación de tres contaminantes: ácido acético y diurón, en fase acuosa, y propeno en fase gas. Se ha estudiado la influencia de las propiedades fisicoquímicas (porosidad, cristalinidad, composición química, propiedades electrónicas) de cada material en su actividad fotocatalítica.