检索结果-内蒙古大学图书馆

MINIMIZING CONTAMINATION HAZARDS TO WATERBIRDS USING AGRICULTURAL DRAINAGE EVAPORATION PONDS

environmental MANAGEMENT 1991年第6期15卷 785-795页

作者： BRADFORD, DF SMITH, LA DREZNER, DS SHOEMAKER, JD 1. Environmental Science and Engineering Program School of Public Health University of California 90024 Los Angeles California USA

In much of the San Joaquin Valley, California, USA. inadequate drainage of applied irrigation water and accumulating salts in the soil have necessitated the installation of subsurface tile drainage systems to preserve crop productivity. At present, these subsurface drainage waters are disposed of by means of evaporation ponds or discharges into the San Joaquin River. Unfortunately, most of these agricultural drainage waters contain high concentrations of salts and naturally occurring trace elements, such as selenium, and recent evidence indicates that substantial numbers of waterbirds are exposed to contamination by selenium in the evaporation ponds. In order to avoid, minimize, or mitigate the adverse impacts on wildlife using the ponds, alternative pond management methods must be identified and evaluated for implementation. A number of methods have the potential to be cost-effective in significantly reducing the contamination hazard to birds using agricultural evaporation ponds. Twenty general methods were evaluated in this study, and four methods are recommended for implementation: remove levee vegetation. remove windbreaks, deepen the ponds, and haze birds. A number of other methods are recommended for further consideration because they appear to have good prospects for reducing the contamination hazard: steepen interior levee slopes, apply herbicides and insecticides, place netting on pond shorelines, and provide freshwater habitat adjacent to evaporation ponds. It may be necessary to use a combination of methods to effectively control selenium contamination of aquatic birds because it is unlikely that a single affordable pond management method will be able to entirely eliminate the contamination hazard.

关键词： AGRICULTURAL PONDS BIRDS EVAPORATION PONDS SELENIUM SELENIUM CONTAMINATION SHOREBIRDS SUBSURFACE DRAINAGE WATERFOWL

来源：评论

学校读者我要写书评

暂无评论

FIELD SAMPLING OF RESIDUAL AVIATION GASOLINE IN SANDY SOIL

引用

GROUND WATER MONITORING AND REMEDIATION 1991年第2期11卷 107-120页

作者： OSTENDORF, DW LEACH, LE HINLEIN, ES XIE, YF 1 David W. Ostendorf is an associate professor in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department University of Massachusetts Amherst MA 01003). His research interests include unconfined aquifer contamination hazardous waste site remediation and analytical modeling of problems in environmental fluid mechanics. Dr. Ostendorf is a registered professional engineer in Massachusetts and a member of the American Geophysical Union American Society of Civil Engineers Soil Science Society of America Water Pollution Control Federation and Association of Environmental Engineering Professors as well as the National Water Well Association.2 Lowell E. Leach is an environmental engineer with the Robert S. Kerr Environmental Research Laboratory of the U.S. Environmental Protection Agency (RS Kerr Environmental Research Laboratory U.S. EPA P.O. Box 1198 Ada OK74820). Leach received his B.S. ingeological engineering at the University of Oklahoma in 1959 and has been a registered professional engineer in Oklahoma since 1966. With 29 years of experience in field applications of geological engineering he is responsible for developing methodology for sampling ground water and subsurface materials for the Robert S. Kerr Environmental Research Laboratory.3 Erich S. Hinlein is a research assistant in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department University of Massachusetts Amherst MA 01003). His research interests include ground water pollution hazardous waste site investigation and transport processes in unconfined aquifers. Hinlein graduated with a B.S. in electrical and computer engineering from the University of Massachusetts at Amherst in May 1985 and entered the Environmental Engineering Master's Degree Program in January 1989.4 Yuefeng Xie is a postdoctoral research associate in the Environmental Engineering Program of the Civil E

Two complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured field extrusion of core barrels into pint-size Mason jars, while the second consisted of laboratory partitioning of intact stainless steel core sleeves. The barrel extrusion procedure involved jar headspace sampling in a nitrogen-filled glove box, which delineated the 0.7m thick residually contaminated interval for subsequent core sleeve withdrawal from adjacent boreholes. Soil samples removed from the Mason jars (in the field) and sleeve segments (in the laboratory) were subjected to methylene chloride extraction and gas chromatographic analysis to compare their aviation gasoline content. The barrel extrusion sampling method yielded a vertical profile with 0.10m resolution over an essentially continuous 5.0m interval from the ground surface to the water table. The sleeve segment alternative yielded a more resolved 0.03m vertical profile over a shorter 0.8m interval through the capillary fringe. The two methods delivered precise estimates of the vertically integrated mass of aviation gasoline at a given horizontal location, and a consistent view of the vertical profile as well. In the latter regard, a 0.2m thick lens of maximum contamination was found in the center of the capillary fringe, where moisture filled all voids smaller than the mean pore size. The maximum peak was resolved by the core sleeve data, but was partially obscured by the barrel extrusion observations, so that replicate barrels or a half-pint Mason jar size should be considered for data supporting vertical transport analyses in the absence of sleeve partitions.

关键词：

来源：评论

学校读者我要写书评

暂无评论

ASSESSING AND MANAGING environmental RISK

引用

environmental PROGRESS 1991年第2期10卷 M2-M2页

作者： LOEHR, RC H. M. Alharthy Centennial Chair and Professor Environmental and Water Resources Engineering Program The University of Texas at Austin and Chairman Science Advisory Board U.S. Environmental Protection Agency

来源：评论

学校读者我要写书评

暂无评论

A METHOD FOR ASSESSING RESIDUAL NAPL BASED ON ORGANIC-CHEMICAL CONCENTRATIONS IN SOIL SAMPLES

引用

GROUND WATER MONITORING AND REMEDIATION 1991年第2期11卷 128-136页

作者： FEENSTRA, S MACKAY, DM CHERRY, JA Stan Feenstra is a hydrogeochemist and president of Applied Groundwater Research Ltd. in Mississauga Ontario He received a B.Sc. in earth sciences and an M.Sc. in hydrogeology from the University of Waterloo in 1978 and 1980 respectively and was designated a Certified Ground Water Professional by AGWSE in 1989. Since 1980 he has been a ground water consultant with Golder Associates in Mississauga Ontario and Zenon Environmental in Burlington Ontario and founded Applied Groundwater Research Ltd. in 1987. Feenstra specializes in the hydrogeochemical evaluation of ground water contamination at waste disposal facilities and chemical spill sites. He is currently a Ph.D. candidate in hydrogeology and research associate in the Waterloo Centre for Ground Water Research at the University of Waterloo (Waterloo Ontario N2L 3G1) and is involved in research related to the behavior of dense organic solvents in ground water. Douglas M. Mackay is an adjunct professor at the Waterloo Centre for Groundwater Research at the University of Waterloo Waterloo Ontario (N2L3G1). Dr. Mackay received a B.S. in engineering and M.S. and Ph.D. in civil engineering from Stanford University in 1970 1973 and 1981 respectively. From 1986 to 1990 he was a faculty member of the Environmental Science and Engineering Program of the UCLA School of Public Health. His research focuses on field studies of transport and fate of organic chemicals in ground water various scale studies of decontamination of soil and ground water and ground water monitoring technologies. John A. Cherry is a professor at the Waterloo Centre for Groundwater Research at the University of Waterloo Waterloo Ontario (N2L 3G1). He received his B.S. in geological engineering from the University of Saskatchewan in 1962. He received his M.S. from the University of California at Berkeley in 1964 and his Ph.D. from the Department of Geology at the University of Illinois in 1966. His research interests include the field study and modeling of contaminants in ground wat

Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost-effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non-aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. The presence of NAPL pools may be evident as a floating or sinking phase in monitoring wells. The residual NAPL contamination may be identified in soil samples if residual contents are high and contaminated zones in the soil cores are thick. However, visual identification may not be effective if residual contents ar elow or if the NAPL residual is distributed heterogeneously in the samples. The chemical analysis of soil samples provides a measure of the total chemical concentration in the soil but cannot determine directly whether NAPL is present in the samples. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or > 10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil

关键词：

来源：评论

学校读者我要写书评

暂无评论

METHANOGENIC TRANSFORMATION OF AROMATIC-HYDROCARBONS AND PHENOLS IN GROUNDWATER AQUIFERS

引用

GEOMICROBIOLOGY JOURNAL 1990年第3-4期8卷 167-200页

作者： GRBICGALIC, D Environmental Engineering and Science Program Department of Civil Engineering Stanford University Stanford CA 94305-4020 United States

Fermentative and methanogenic bacteria have been found repeatedly as important members of microbial flora in anoxic zones of the subsurface-in pristine as well as in contaminated groundwater aquifers. These bacteria, which together with obligate proton reducers form complex methanogenic communities, are significant as decomposers of organic matter under conditions of exogenous electron acceptor depletion. Their metabolic activity has been demonstrated in laboratory microcosms derived from aquifer material, and also in the subsurface in situ. Methanogenic communities have been shown to transform numerous organic pollutants, or even to completely degrade these compounds with the production of carbon dioxide and methane. Depending on the chemical structure of the pollutant, such a compound can be used as an electron donor and a carbon/energy source for fermentative microorganisms (which is typically the case with highly reduced compounds);alternatively, a highly oxidized pollutant can be used as a potential electron acceptor or electron sink. This review addresses fermentative/methanogenic degradation of chlorinated and nonchlorinated aromatic hydrocarbons and phenols by subsurface microorganisms;for comparison, it briefly relates also other types of anaerobic transformations (under sulfate-reducing, iron-reducing, and denitrifying conditions). Furthermore, it outlines transformation pathways, those that are proposed as well as those that are already partially proved, for aromatic hydrocarbons and phenols under fermentative/methanogenic conditions;finally, it discusses the relevance of these processes to bioremediation of contaminated groundwater aquifers.

关键词： ANAEROBIC HABITATS AROMATIC HYDROCARBONS BIOREMEDIATION CHLOROBENZENES CHLOROPHENOLS GROUNDWATER AQUIFERS INTERSPECIES TRANSFER OF HYDROGEN AND INTERMEDIATES METHANOGENIC COMMUNITIES PHENOLS

来源：评论

学校读者我要写书评

暂无评论

RESPONSES OF PERIPHYTON TO CHANGES IN CURRENT VELOCITY, SUSPENDED SEDIMENT AND PHOSPHORUS CONCENTRATION

引用

FRESHWATER BIOLOGY 1990年第2期24卷 215-232页

作者： HORNER, RR WELCH, EB SEELEY, MR JACOBY, JM Environmental Engineering and Science Program Department of Civil Engineering University of Washington. Seattle Washington U.S.A

1. Research was performed in laboratory streams to evaluate periphytic biomass accrual, export, and community composition over a range of limiting nutrient (phosphorus) concentrations with variable velocity, and suspended sediment addition, in comparison to constant velocity and no suspended sediment. In fixed-velocity treatments, velocity increase to 60 cm s-1 significantly enhanced biomass accrual, but further increase resulted in substantial biomass reduction. Average biomass loss rates did not change significantly over a velocity range of 10-80 cms-1. Diatoms were favoured at relatively high velocities and low phosphorus concentrations, whereas the blue-green Phormidium tended to dominate at higher SRP concentrations and the green Mougeotia seemed to prefer lower velocities. 2. Sudden increases in velocity raised instantaneous loss rates by an order of magnitude or more, but these high rates persisted only briefly. As a result, marked biomass reductions were not apparent a day after the velocity change. Dominance change from filamentous green or blue-green to diatoms immediately after the increase was reversed within 2 days. Loss rate increases due to solids addition were much smaller than those accompanying velocity increase, but simultaneous velocity elevation and solids addition produced instantaneous loss rates approximately double those with velocity increase alone. 3. The experiments demonstrated that an elevation in velocity, above that to which algae were accustomed, led to increased loss rates and temporarily reduced biomass. However, recolonization and growth after biomass reduction were apparently rapid. Substantial export of periphyton following solids addition required erosion of the protective boundary layer accompanied by a velocity increase. These results are applicable to understanding the response of lotic periphytic algae to elevated, turbid storm discharges and similar runoff or high-flow events. 4. Areal uptake rates of P by algae growing in

关键词：

来源：评论

学校读者我要写书评

暂无评论

BINATIONAL MANAGEMENT OF HAZARDOUS-WASTE - THE MAQUILADORA INDUSTRY AT THE UNITED-STATES MEXICO BORDER

引用

environmental MANAGEMENT 1990年第4期14卷 441-450页

作者： PERRY, DM SANCHEZ, R GLAZE, WH MAZARI, M 1. Environmental Science and Engineering Program School of Public Health University of California 90024-1772 Los Angeles California USA

Foreign-owned industry in the form of assembly plants, termed maquiladora, has become very important in Mexico to the extent that it represents the second largest source of foreign exchange and is a valuable source for employment and regional development. The economic prosperity gained from the rapid growth of the maquiladora industry has been accomapanied by increased environmental and human health risks associated with generation of hazardous waste. Diversification of industry has resulted in the predomination of those sectors that likely use hazardous substances. The Mexicali-Calexico border region was selected to demonstrate the potential for environmental and health risks associated with the generation of hazardous waste. Estimates for the generation of hazardous waste were obtained from 34 maquiladora plants in Mexicali, represented by the electronic and electronic equipment and parts, mechanical and transportation equipment, and toys and sporting equipment sectors. Repeated detection of volatile organic compounds in the New River at the US-Mexico border suggests that hazardous waste from the printed circuit board industry in Mexicali is not being disposed of in a proper manner. Potential adverse health effects, such as carcinogenic and mutagenic responses associated with the detected volatiles, are discussed. US and Mexico national legislation and the Binational environmental Agreement were examined for their adequacy to ensure proper management of hazardous waste generated by the maquiladora industry. environmental policy options are presented that focus on: (1) increased environmental accountability of US parent companies for their maquiladora assembly plants in Mexico;and (2) more integration between US Customs and border states with the US environmental Protection Agency to improve the binational management of hazardous waste generated by the maquiladora industry.

关键词： Hazardous waste Maquiladora industry environmental policy US-Mexico border

来源：评论

学校读者我要写书评

暂无评论

MAGNETIC SURVEYING FOR BURIED METALLIC OBJECTS

引用

GROUND WATER MONITORING AND REMEDIATION 1990年第3期10卷 204-211页

作者： BARROWS, L ROCCHIO, JE Larry Barrows received his M.S. and Ph.D. degrees in geophysics from the Colorado School of Mines in 1973 and 1978 respectively. He has worked as a systems engineer on Skylab remote-sensing experiments and as an exploration geophysicist in frontier areas of Alaska. Since 1979 he has specialized in geophysical surveying for ground water and hazardous waste site investigations first as the project geophysicist on a radioactive waste disposal program and then as a research scientist for the U.S. EPA. In 1988 he joined Earth Science and Engineering Inc. and LaCoste and Romberg Gravity Meters Inc. (4807 Spicewood Springs Rd. Bldg. 2 Austin TX 78759). Current projects include using microgravity to detect solution conduits in karst terrains and using seismicgroundroll to determine near-surface shear moduli. Judith E. Rocchio is the future air resource specialist on the Stanislaus National Forest (1977 Greenley Rd. Sonora CA 95370). She will obtain the position upon completion of her M.A. degree in air resource management at Colorado State University Department of Natural Resources (1990). She was with Lockheed Engineering Management Services Co. Las Vegas Nevada prior to attending CSU where she was involved in several environmental monitoring programs and coauthored the paper with Dr. Barrows. From 1981 to 1986 Rocchio was a project geologist for Gower Oil Co. and Consolidation Coal Co. Denver Colorado. She received her B.S. in geology (1981) from the University of Nevada Las Vegas.

Field tests were conducted to determine representative total-intensity magnetic anomalies due to the presence of underground storage tanks and 55-gallon steel drums. Three different drums were suspended from a non-magnetic tripod and the underlying field surveyed with each drum in an upright and a flipped plus rotated orientation. At drum-to-sensor separations of 11 feet, the anomalies had peak values of around 50 gammas and half-widths about equal to the drum-to-sensor separation. Remanent and induced magnetizations were comparable; crushing one of the drums significantly reduced both. A profile over a single underground storage tank had a 1000-gamma anomaly, which was similar to the modeled anomaly due to an infinitely long cylinder horizontally magnetized perpendicular to its axis. A profile over two adjacent tanks had a smooth 350-gamma single-peak anomaly even though models of two tanks produced dual-peaked anomalies. Demagnetization could explain why crushing a drum reduced its induced magnetization and why two adjacent tanks produced a single-peak anomaly. A 40-acre abandoned landfill was surveyed on a 50- by 100-foot rectangular grid and along several detailed profiles. The observed field had broad positive and negative anomalies that were similar to modeled anomalies due to thickness variations in a layer of uniformly magnetized material. It was not comparable to the anomalies due to induced magnetization in multiple, randomly located, randomly sized, independent spheres, suggesting that demagnetization may have limited the effective susceptibility of the landfill material. A different 6-acre site survey conducted on a 10- by 10-foot grid was analyzed to determine the maximum station spacing and line separation that could have been used. Essentially, all of the anomalies at this site would have been resolved by a survey conducted on a 20- by 20-foot grid and the larger anomalies would have been detected by a 50- by 50-foot grid.

关键词：

来源：评论

学校读者我要写书评

暂无评论

OZONE DOSE-RESPONSE OF ESCHERICHIA-COLI IN ACTIVATED-SLUDGE EFFLUENT

引用

WATER RESEARCH 1989年第8期23卷 1017-1025页

作者： FINCH, GR SMITH, DW Environmental Engineering and Science Program Department of Civil Engineering University of Alberta Edmonton Alberta Canada T6G 2G7

The response of E. coli ATCC 11775 in activated sludge effluent to various doses of ozone and for various contact times was studied using batch and semi-batch reactors at bench-scale and pilot-scale under controlled environmental conditions. The results indicated that there was no significant effect associated with contact time or scale. Also, the empirical dose-response model form described by the U.S. environmental Protection Agency for sizing ozone wastewater disinfection systems was found to have lack-of-fit over the experimental region studied. The inadequacy of the model was confirmed at both scales. It was found that the bench-scale experiments provided a reasonable estimate of the required ozone dose to achieve a specified reduction of bacteria thereby potentially eliminating the need for costly pilot-scale feasibility studies in many cases.

关键词： ozone disinfection dose-response Escherichia coli faecal coliform water wastewater model

来源：评论

学校读者我要写书评

暂无评论

TIDES IN THE ENGLISH-CHANNEL AND SOUTHERN NORTH-SEA - A FREQUENCY-DOMAIN ANALYSIS USING MODEL TEA-NL

引用

ADVANCES IN WATER RESOURCES 1989年第4期12卷 166-183页

作者： BAPTISTA, AM WESTERINK, JJ TURNER, PJ Department of Environmental Science and Engineering Oregon Graduate Center 19600 NW Von Neumann Drive Beaverton OR 97006 USA Ocean Engineering Program Civil Engineering Department Texas A & M University College Station TX 77843 USA

The frequency-time finite element model TEA-NL is used to investigate tidal propagation and circulation in the English Channel and the southern North Sea, in the context of the Tidal Flow Forum benchmark. Quality of TEA-NL simulations, relative to both field data and simulations by other numerical models is discussed. Sensitivity analyses are performed with regard to the effect on accuracy of bottom friction, and the effect on computational cost of the strategy used to harmonically decompose and iterate non-linear loading terms in the shallow water equations.

关键词： Tides

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：