Dissertations / Theses on the topic 'Salt – Environmental aspects'
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Shaw, Gregory Alan. "Rehabilitation of the Orange River Mouth Salt Marsh : seed, wind and sediment characteristics." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/603.
Full textSauer, Robert Eugene Jr. "Development and use of saltmarsh mesocosms in studies of sedimentary mercury transformation." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/19608.
Full textSibley, Samuel D. Jr. "The Impact of Salt Marsh Hydrogeology on Dissolved Uranium." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7262.
Full textMudumbi, John-Baptist Nzukizi. "Perfluorooctane sulfonate and perfluorooctanoate contamination of riparian wetlands of the Eerste, Diep and Salt Rivers." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/2017.
Full textPerfluorinated compounds (PFCs), in particular perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) have been found in aquatic environments throughout the world. Recent studies have reported that owing to their bioaccumulative nature, PFCs may also be present in various water sources, resulting in human and wild-life exposure. Although, these PFCs usually occur at low concentration levels, their presence in the environment has nevertheless been a concern in both developed and developing countries, since water remains an important natural resource for most living species. Water and sediment from rivers are one of the matrices in which PFC contamination is studied, since rivers receive water from various sources. However, limited studies have been conducted in South Africa on PFC contamination of river water and sediments. Although PFCs are sometimes unintentionally released into the environment, the concentration and type of PFCs that contaminate water sources vary among countries and depend on the types of industry releasing them into the environment, suggesting that PFC contamination patterns can be expected to differ from country to country, with PFOA and PFOS being the predominant perfluorinated contaminants. The aim of this study was therefore to determine the concentration of PFOS and PFOA in riparian wetlands of the Western Cape, focusing on the Eerste, Diep and Salt rivers, which are the primary rivers in the largest catchment areas of the Western Cape, South Africa.
Wartena, Ryan Craig. "Generation of sodium oxide and discharge of carbon by the electrolysis of multi-component molten salt systems : a recycle process for kraft pulping chemicals." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/10281.
Full textRaffel, Ann Eileen. "Methyl Halide Production by Calcareous Periphyton Mats from the Florida Everglades." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1524.
Full textForsyth, Donald Scott. "Determination of organolead salts in biological tissue." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=73971.
Full textYang, Jeongwoo. "Fate and effect of alkyl benzyl dimethyl ammonium chloride in mixed aerobic and nitrifying cultures." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19871.
Full textCommittee Chair: Spyros G. Pavlostathis; Committee Member: Ching-Hua Huang; Committee Member: John A. Pierson.
Silva, Ana Claudia Ribeiro Cardoso da. "Aspectos jurídicos do marco regulatório do pré-sal sob a luz da política nacional sobre mudança do clima." Universidade Católica de Santos, 2014. http://biblioteca.unisantos.br:8181/handle/tede/2281.
Full textMade available in DSpace on 2016-04-12T14:32:54Z (GMT). No. of bitstreams: 1 Ana Claudia Ribeiro Cardoso da Silva.pdf: 2526727 bytes, checksum: 671c8fba2162cafddef2b61b34bbb0a5 (MD5) Previous issue date: 2014-04-24
The present dissertation had with main objective to analyse the regulatory framework of the pre ¿salt the light of national policy on climate change, identifying whether there are points of confronting between the two legal frameworks. Therefore, it was necessary to demonstrate the evolution of environmental law in the world and in Brazil, as well as the institutionalization of climate protection policy in Brazil, their policies and objectives. In the oil industry sector, evaluate the influence of owning countries and oil producers in the Brazilian energy matrix, the legal changes that have altered the ownership of natural resources throughout history, the change of legislation for oil exploration in the pre -salt field in 2010, and the current scenario of oil exploration in the polygon. In order to achieve the proposed goal, there was a brief overview on the scientific aspects of climate change and the voluntary commitments made by Brazil, in an effort to reduce gas emissions between 36,1 % to 38,9 % by 2020. It was found that oil is a finite resource and that, according to the theory of Peak Oil and the current target for oil exploration in the pre-salt, there are two possible future scenarios with different consequences to Brazil. It was understood that the country published two legislations, one of climate protection and other oil exploration in the pre-salt, which does not establish a dialogue and demonstrate a route of confront between the policies. Still, proposals were searched for confronting of the two scenarios mentioned above.
A presente dissertação teve como objetivo principal analisar o marco regulatório do pré-sal sob a luz da política nacional sobre mudança do clima, identificando se existem pontos de colidência entre os dois marcos legais. Para tanto, foi preciso demonstrar a evolução do direito ambiental do mundo e no Brasil, assim como a institucionalização da política de proteção ao clima no Brasil, suas diretrizes e objetivos. No setor da indústria petrolífera, foi necessário avaliar a influência dos países possuidores e produtores de petróleo na matriz energética brasileira, as mudanças legais que alteraram a propriedade dos recursos naturais ao longo da história, a mudança da legislação do petróleo para a exploração no campo do pré-sal em 2010, e o atual cenário de exploração de petróleo no polígono do pré-sal. De modo a cumprir o objetivo proposto, realizou-se uma breve abordagem sobre os aspectos científicos das mudanças climáticas publicadas pelo IPCC e os compromissos voluntários assumidos pelo Brasil, no sentido de reduzir suas emissões de GEE entre 36,1% a 38,9%, até 2020. Constatou-se que o petróleo é um recurso finito e que, de acordo com a teoria do Peak Oil e a atual meta de exploração de petróleo no pré-sal, existem dois possíveis cenários futuros com consequências distintas paras o Brasil. Entendeu-se que o país editou duas legislações: uma de proteção ao clima e outra de regulamentação da exploração de petróleo no pré-sal, que que não estabelecem um diálogo e demonstram uma rota de confronto entre as políticas. Ainda, buscou-se propostas para o enfrentamento dos dois cenários mencionados acima.
Tezel, Ulas. "Fate and effect of quaternary ammonium compounds in biological systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28229.
Full textCommittee Chair: Pavlostathis, Spyros G.; Committee Member: Huang, Ching-Hua; Committee Member: Hughes, Joseph B.; Committee Member: Sobecky, Patricia A.; Committee Member: Spain, Jim C.
Owojori, Olugbenga J. (Olugbenga John). "Influence of clay content and salinity on the bioavailability and toxicity of metals (copper and zinc) to soil organisms." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1484.
Full textENGLISH ABSTRACT: Metal pollution is a problem of increasing global concern. It could arise from industrial activities, as well as pesticide use in agriculture, among other sources. For adequate protection of the soil ecosystem from metal toxicity, the bioavailability of metals must be properly evaluated. A plethora of soil factors affect the bioavailability of metals to soil organisms. These include pH, clay and organic matter contents, salinity among others. While much is known about the influence of some of these parameters, little is known on how clay content and salinity modify the bioavailability of metals to soil organisms. This study investigated the influence of clay content and salinity on partitioning, uptake and toxicity of two essential metals (Cu and Zn) to the earthworm Eisenia fetida in separate laboratory trials. Partitioning of the metals was evaluated with 0.01 M CaCl2, DTPA (di-ethylene-triamine-penta acetic acid), and nitric acid extractions. The metal content of worms was determined by acid digestion, while growth, cocoon production, and mortality were used as endpoints showing toxicity to metals and/or salinity. To test the validity of some of the laboratory results, a field study was undertaken, using the earthworm Aporrectodea caliginosa. Further, the study assessed the effect of salinity, using a battery of laboratory tests (acute, chronic and avoidance tests) with natural and/or artificial soils on four species of organisms (a collembolan Folsomia candida, a potworm Enchytraeus doerjesi and two earthworm species E. fetida and A. caliginosa), representing different feeding patterns and ecological roles in soil. Results showed that with increased clay content, there was increased availability of Cu in the substrate, and increased toxicity to E. fetida as shown by data for mortality and growth. The situation with Zn was less significant at sub-lethal concentrations but much so at lethal concentrations. DTPA and CaCl2 extracted metals revealed changes in partitioning of Cu and Zn with changes in clay content, but this trend was not always consistent. Both DTPA and CaCl2 revealed increased availability of Zn in substrates with increased salinity. Salinity had an additive to synergistic effect with Zn in toxicity to E. fetida. When combined with Cu, salinity also increased the availability of Cu as shown by CaCl2 extracted fraction, and had additive effect on toxicity of Cu to the earthworm. The field study did not succeed in in iv confirming the results of the laboratory study due to confounding role of flooding after heavy rainfall and subsequent leaching of salts and Cu. The results of the experiment on acute and chronic toxicity tests for NaCl on E. fetida showed LC50 of 5436 mg/kg NaCl and EC50 for growth and cocoon production of 4985 and 2020 mg/kg NaCl. These values showed that earthworms might be negatively affected in many soils containing fairly moderate concentrations of salts. Similarly, A. caliginosa could not survive in natural soil containing relatively low salt concentrations (EC = 1.62 dS/m) while reproduction was severely affected at lower EC value of 0.52 dS/m. F. candida and E. doerjesi could survive in the highest salinity soil (EC = 1.62 dS/m) used in this study but their reproduction was severely affected from 1.03 dS/m. Overall, it appears that of all the taxa used, earthworm species were the most sensitive to saline stress and could proof useful in determining ‘safe levels’ of salt in contaminated soils. The results of the avoidance test showed that A. caliginosa avoided both natural and artificial saline soil containing concentrations lower than those avoided by E. fetida. The conclusion is that the influence of clay content and salinity on the bioavailability of Cu and Zn depends largely on the metal in question, but generally speaking, bioavailability and toxicity of the metals were reduced with increased clay content while the opposite was true for salinity. If the species used in this study can be seen as fairly representative of a wide range of soil organisms, the conclusion is that salinisation of soil will be detrimental to most soil organisms at relatively low saline concentrations. Given the role of beneficial soil organisms in several soil processes which in turn contribute to soil fertility and sustainable use of land, it is recommended that any farming practices that may lead to an increase in salt content of agricultural soils should be discouraged.
AFRIKAANSE OPSOMMING: Metaalbesoedeling is ‘n probleem wat toenemende globale kommer veroorsaak. Dit kan ontstaan as gevolg van industriële aktiwiteite sowel as van plaagmiddelgebruik in die landbou en ander bronne.Ten einde die grondekostelsel genoegsaam te beskerm, moet die biobeskikbaarheid van metale ge-evalueer word. ‘n Verskeidenheid van grondfaktore be-invloed die biobeskikbaarheid van metale vir grondorganismes Hulle sluit onder andere in pH, klei, organiese inhoud en soutgehalte. Hoewel heelwat bekend is oor die rol van sommige van hierdie parameters, is min bekend oor hoe klei en soutgehalte die biobeskikbaarheid van metale vir grondorganismes kan modifieer. Hierdie studie het die invloed van kleiinhoud and soutgehalte op die verdeling/partisie, opname en toksisiteit van twee essensiële metale (Cu en Zn) vir die erdwurm Eisenia fetida in afsonderlike laboratoriumproewe ondersoek. Kompartementele verdeling van die metale is geevalueer deur middel van ekstraksie-metodes met 0.01 M CaCl2, DTPA (di-etileentriamien- penta asysnsuur), en salpertersuur ekstraksies. Die metaalinhoud van wurms is bepaal deur suurverterings en spektrofotometriese analises te doen terwyl groei, kokonproduksie en mortaliteit van organismes gebruik is as gevoeligheidseindpunte om toksisiteit van metale en soutgehalte aan te toon. Om die geldigheid van somige van die laboratoriumresultate te toets, is ‘n veldstudie ook onderneem met die erdwurm Aporrectodea caliginosa. Die effek van soutgehalte is verder ondersoek deur ‘n battery van laboratoriumtoetse met vier spesies (‘n kollembool Folsomia candida,’n potwurm Enchytraeus doerjesi en twee erdwurmspesies E. fetida en A. caliginosa), wat verskillende voedingspatrone verteenwoordig. Die resultate het getoon dat met toenmende klei-inhoud was daar ‘n toename in die beskikbaarheid van Cu vir opname vanuit die substraat, asook ‘n toename in toksisiteit vir E. fetida soos deur die gegewens vir mortaliteit en groei uitgewys. Die situasie met Zn was minder betekenisvol by subletale konsentrasies en selfs baie minder so by letale konsentrasies. DTPA en CaCl2 ge-ekstraheerde metale het veranderinge in die partisie/verdeling van Cu en Zn uitgewys met verandering in klei-inhoud, maar die tendens was nie altyd konstant nie. Beide DTPA en CaCl2 ekstraksie het toenemende beskikbaarheid van Zn in substrate uitgewys met toenemende soutinhoud. Soutinhoud het ‘n additiewe/toegevoegde tot sinergistiese vi toksisiteitseffek saam met Zn vir E. fetida. In kombinasie met Cu het soutgehalte ook die geskatte biobeskikbaarheid van Cu verhoog soos uitgewys deur die CaCl2, geekstraheerde fraksie, en het ‘n additiewe effek gehad op die toksisitiet van Cu vir die erdwurm. Die veldstudie kon nie die resultate van die laboratoriumstudie bevestig nie weens die belemmerende rol van vloede na swaar reënneerslae en daaropvolgende uitloging van soute en Cu. Die resultate van die eksperimentele ondersoek na die akute en chroniese effekte van NaCl op E. fetida het ‘n LC50 van 5436 mg/kg NaCl en EC50 vir groei en kokonproduksie van 4985 en 2020 mg/kg NaCl opgelewer. Hierdie waardes het aangetoon dat erdwurms moontlik negatief beinvloed kan word in baie gronde wat ‘n redelike gemiddelde konsentrasie van soute bevat. Soortgelyk kon A. caliginosa nie oorleef in natuurllike grond wat relatief lae soutkonsentrasies bevat het (EC=1.62 dS/m) nie terwyl voortplanting sterk ge-affekteer is by ‘n lae EC waarde van 0.52 dS/m. F. candida en E. doerjesi kon oorleef in die grond met die hoogste soutgehalte (EC= 1.62 dS/m) maar hulle voortplanting is ernstig geknou vanaf 1.03 dS/m. In geheel blyk dit dat van allle taksa wat gebruik is, erdwurms die sensitiefste was vir die stres wat deur soutgehalte veroorsaak is. Die kennis kan nuttig wees in die bepaling van “veilige vlakke” van sout in gekontamineerde gronde. Die resultate van die vermydingstoetse het getoon dat A. caliginosa beide natuurlike en kunsmatig versoute gronde vermy het by konsentrasies wat heelwat laer was as dié wat deur E. fetida vermy is Die gevolgtrekking is dat die invloed van klei en soutgehalte op die biobeskikbaarheid van Cu en Zn grootliks afhanklik is van die metale wat betrokke is en dat biobeskikbaarheid en toksisiteit normaalweg verminder het met verhoogde klei-inhoud, met die teenoorgestelde wat waar was in die geval van soutgehalte. Indien die spesies wat in die studie gebruik is beskou kan word as redelik verteenwoordigend van ‘n wye reeks van grondorganismes, is die gevolgtrekking dat versouting van gronde nadelig sal wees vir meeste grondorganismes, selfs by relatief lae soutkonsentrasies. In die lig van die rol wat nuttige grondorganismes speel in verskeie grondprosesse wat bydraend is tot grondvrugbaarheid en volhoubare gebruik van gronde, word dit aanbeveel dat enige boerderypraktyk wat mag lei tot verhoging van die soutinhoud van landbougronde ontmoedig moet word.
Suaire, Rémi. "Dynamique de transfert des fondants routiers dans un bassin de rétention des eaux de ruissellement routières : vers une solution d’assainissement par phytoremédiation." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0116/document.
Full textDuring winter, deicing salts are spread on roads in order to preserve road safety for users. Under the influence of different parameters, these compounds are partly transferred to the environment, the rest of it being collected by the road runoff retention systems. However, road runoff retention ponds have not been designed for deicing salt treatment; they only play a role in the regulation of fluxes before their rejection into the environment. Furthermore, NaCl has a harmful impact on the environment, because of its toxicity to certain aquatic organisms and because it contributes to the increase of trace metal (TM) mobility, which are toxic as well. This shows the need for a specific treatment for these compounds. The objective of this research is to bring better understanding of deicing salt dynamics in a retention pond, but also to investigate the potential use of phytoremediation as a treatment solution for road runoff. A model retention pond was selected; it is located along a highway in Chenevières (Lorraine region, France). The first part of the work focused on the monitoring and the characterization of NaCl transfers in this pond. Water was weekly sampled for 3 years at the pond input and output and NaCl and TM concentrations were measured. Meteorological conditions and salt spreading data were monitored to appraise the salt fraction actually collected by the pond. Results showed that only 25 to 50 % of the spread salt is effectively collected. Moreover, results on NaCl dynamics proved that the pond only plays a role on transient storage and salt dilution before rejection into the environment. Moreover, measurements and analyses of sampled basin sediments and roadside soils were performed to assess speciation and TM mobility in this particular context. In this case, no significant effect of NaCl was recorded except for zinc (Zn); but major ions were mobilized. When it comes to treatments, conventional desalination technologies are too expensive and inappropriate in this context. Then, potentialities of phytodesalination were explored. Three halophyte plants were selected on the basis of specific criteria, allowing their use in road runoff context: Armeria maritima, Atriplex halimus and Atriplex hortensis L. Germination and growth experiments were run in various salinity conditions and in the presence/absence of Zn, in order to assess their tolerance to salt and Zn, as well as their accumulation abilities. These plants showed a high tolerance for NaCl in salinities in the range of those encountered in road runoff existing treatment systems at Chenevières. The three species accumulated significant amounts of NaCl and zinc in their aerial parts. The use of halophytes for phytodesalination of road runoff is a promising technique to address the issue of environmental impact of deicing salts
Ko, Lih-jong. "Factors influencing the atmospheric aerosol composition at two sites in western Oregon." Thesis, 1992. http://hdl.handle.net/1957/28977.
Full textGraduation date: 1993
Bell, Justin Robert William Civil & Environmental Engineering Faculty of Engineering UNSW. "Cyclic deposition of salt-laden dusts as an explanation of salinisation in a groundwater recharge zone Coleambally irrigation area Riverine plain NSW." 2007. http://handle.unsw.edu.au/1959.4/40549.
Full textHillwalker, Wendy E. "Selenium and trace metal accumulation in detrital-benthic food webs of lotic and lentic wetlands, Utah, USA." Thesis, 2004. http://hdl.handle.net/1957/29920.
Full textGraduation date: 2005
Martin, Katherine Clare. "Interactive effects of salinity and nutrients on mangrove physiology : implications for mangrove forest structure and function." Phd thesis, 2007. http://hdl.handle.net/1885/149911.
Full text