Visualising the equilibrium distribution and mobility of organic contaminants in soil using the chemical partitioning space

2011 ◽  
Vol 13 (6) ◽  
pp. 1569 ◽  
Author(s):  
Fiona Wong ◽  
Frank Wania
1998 ◽  
Vol 25 (6) ◽  
pp. 1091-1095
Author(s):  
Jian Peng

Exchange of synthetic organic contaminants across the air-water interface is a significant process affecting the fate of the contaminants released into the environment. Benzene, toluene, trichloroethylene, and tetrachloroethylene were selected as typical contaminants in this study. The equilibrium distribution of the selected volatile organic compounds between air and water was simulated in the laboratory at the University of Saskatchewan. A gas chromatograph headspace auto sampler system was used to analyze the chemical concentrations. The effect of salinity on the equilibrium distribution of selected organic contaminants between water and air was studied. Concentrations of sodium chloride from 100 to 1000 mol/m3 were used to simulate various levels of salinity in water at a temperature of 20°C. Typical seawater was simulated with 3.5% sodium chloride and tested at temperatures from 15°C to 45°C. A modified van't Hoff expression was developed by incorporating a salting-out coefficient to predict the effect of temperature and salinity on the equilibrium distribution. The parameters of the modified van't Hoff model were determined by using the experimental results for selected organic contaminants.Key words: water pollution, volatile organic contaminants, distribution, salinity.


1998 ◽  
Author(s):  
Robert Long, Jr. ◽  
Fred Rigby ◽  
Lawrence Grimes

1993 ◽  
Author(s):  
LaDonna M. Bishop ◽  
Colleen E. Rostad ◽  
Wilfred E. Pereira ◽  
Thomas J. Leiker
Keyword(s):  

Author(s):  
G. Samburskii ◽  
O. Ustinova ◽  
Svetlana, Leont’eva

Распространенным технологическим приемом удаления из воды грубодисперсных примесей, находящихся во взвешенном состоянии, а также коллоидных органических загрязнений, присутствующих в растворенном виде, является процесс коагуляции. Эффективными коагулянтами для систем с водной дисперсионной средой являются соли поливалентных металлов. Цель работы заключалась в создании нового государственного стандарта, предназначенного для обеспечения единообразной оценки качества коагулянтов. Рассмотрена область применения коагулянтов в процессе водоподготовки и проведен их сравнительный анализ. Показана необходимость унификации в области процессов контроля качества коагулянтов. Сформулированы общие требования к контролю качества полиоксихлорида алюминия. Представлен разработанный и утвержденный новый национальный стандарт ГОСТ Р 58580-2019 Полиоксихлорид алюминия. Технические условия , который учитывает требования санитарного законодательства, технического регулирования, безопасности процессов производства и транспортировки полиоксихлорида алюминия.Coagulation process has been a widespread process technology for removing coarse suspended impurities from water, as well as colloidal organic contaminants present in dissolved form. Polyvalent metal salts are effective coagulants for the systems with aqueous disperse medium. The purpose of the work was developing a new state standard to provide for a uniform assessment of the quality of coagulants. The scope of coagulants in the process of water treatment is considered and their comparative analysis is carried out. The general requirements to the control of polyaluminium chloride quality are formulated. The developed and approved new national standard GOST R 58580-2019 Polyaluminium chloride. Technical conditions is presented that takes into account the requirements of sanitary legislation, technical regulation, safety of the processes of production and transportation of polyaluminium chloride.


1987 ◽  
Vol 22 (1) ◽  
pp. 49-64 ◽  
Author(s):  
J.F. Devlin ◽  
W.A. Gorman

Abstract The Gloucester Landfill is located near Ottawa, Ontario, on a northeast trending ridge of Quaternary age. The ridge comprises outwash sediments which make up two aquifer systems. A confined system exists next to bedrock, and is overlain by a silty-clayey stratum (the confining layer) which is, in turn, overlain by an unconfined aquifer system. Two independent volatile organic plumes have previously been identified at the landfill: the southeast plume, which has penetrated the confined aquifer system, and the northeast plume which is migrating in the unconfined aquifer. The distribution of volatile organic contaminants at the northeast plume site appears to be a function of two factors: (1) heterogeneities in the aquifer sediments are causing the channeling of contaminants through a narrow path; (2) the low fraction of organic carbon in the unconfined aquifer sediments at the northeast site is resulting in little retardation of the contaminants there, relative to those at the southeast site. Acetate was the only volatile fatty acid detected in the leachate. It was measurable only in areas where the volatile organic contamination was significant. Although methane was detected in the contaminated sediments, suggesting that microbial activity was present, the high concentration of acetate (>1000 ppm) which was detected down-gradient from the source area indicates that any biodegradation which is occurring is proceeding at a very slow rate.


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