共查询到19条相似文献,搜索用时 500 毫秒
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含油工业废水的净化及回收利用 总被引:2,自引:1,他引:2
丹东输油分公司采用凤眼莲微生物净化含油工业废水,为了使凤眼莲水生物在预处理过程中发挥其净化水质的最佳功效,使原来的三级隔油处理变成了七级隔油处理。通过七级隔油池预处理后的含油工业废水,再经过放入凤眼莲水生物的氧化塘净化处理后,第一级氧化塘水质清澈、透明见底,第三级、第四级氧化塘内已自然生长出鱼类,微生物种类增加。于2001年放入淡水鱼试验,至今长势良好。同时通过合理调控微生物的密度、生长环境以及采用防止二次污染等措施,目前已全年连续净化含油工业废水,实施工业净化水回收再利用,实现了含油工业废水零排放。 相似文献
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河道治理工程重在改善河道的水质,以恢复河流生态系统。本文以北京市大兴区天堂河河道治理工程为例,介绍了河道治理工程环境影响评价中的水质改善预测分析,首先分析生态需水量和供氧量是否满足河流生态需水要求,后又利用地面水环评助手软件预测了河流水质,预测分析了天堂河水质目标的可达性,旨在为以后的河道治理类工程环境影响评价提供参考。 相似文献
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长庆石油勘探局生物技术处理废(污)水的工艺中存在着如下问题:活性污泥法处理水的水质不稳定;接触氧化法缓冲池较小,氧化塘法处理污水效率低,出水水质达不到要求。为解决上述问题,提出各项整改措施。经过整改后,装置运行率、处理达标率都会有很大提高。 相似文献
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利用二维模型求解太湖水质CODMn的研究 总被引:1,自引:0,他引:1
在二维黎曼近似解模型的基础上建立了太湖水质预测模型,并运用该模型对太湖的水质指标CODMn了模拟。模拟的结果跟太湖各监测站的测量值相接近,表明该模型能较好的运用于太湖的水质预测。 相似文献
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城市生活垃圾卫生填埋场渗滤液水量水质的确定 总被引:13,自引:2,他引:11
本文论述了3种渗滤液水量预测法,推荐采用Q=CIA×10-3公式;介绍了确定渗滤液水质的方法;根据国内外渗滤液水质实测值,分析了水质特点,认为我国渗滤液浓渡呈增加趋势。 相似文献
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C. W. Fetter 《Journal of the American Water Resources Association》1974,10(4):779-789
ABSTRACT: The South Fork of Long Island, New York is an area which relies entirely on ground water for water supply. Most of the water which is pumped is artifically recharged, without treatment, via cesspools. The natural quality of the ground water is very high. Some areas show increasing nitrate in the ground water. This comes from both cesspools and agricultural fertilizer. Saline water intrusion is a potential problem in coastal areas. High ammonia in surface ponds may result in eutrophication. 相似文献
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Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to a number of water quality problems including high nutrient, chemical contaminant, and bacterial levels. This study examined the interaction between land use and coastal pond water quality in a South Carolina residential subdivision pond. Eutrophic levels of chlorophyll and phosphorus were present in all seasons. Harmful cyanobacterial blooms were prevalent during the summer months. Microcystin toxin and fecal coliform bacteria levels were measured that exceeded health and safety standards. Low concentrations of herbicides (atrazine and 2,4-D) were also detected during summer months. Drainage from the stormwater pond may transport contaminants into the adjacent tidal creek and estuary. A survey of residents within the pond's watershed indicated poor pet waste management and frequent use of fertilizers and pesticides as possible contamination sources. Educational and outreach activities were provided to community members to create an awareness of the water quality conditions in the pond. Pond management strategies were then recommended, and selected mitigation actions were implemented. Water quality problems identified in this study have been observed in other coastal stormwater ponds of varying size and salinity, leading this project to serve as a potential model for coastal stormwater pond management. 相似文献
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INTEGRATING DIFFUSEINONPOINT POLLUTION CONTROL AND WATER BODY RESTORATION INTO WATERSHED MANAGEMENT1
Vladimir Novotny 《Journal of the American Water Resources Association》1999,35(4):717-727
ABSTRACT: The objective of water quality/watershed management is attainment of water quality goals specified by the Clean Water Act. The Total Maximal Daily Load (TMDL) planning process is a tool to set up watershed management. However, TMDL methodologies and concepts have several problems, including determination of Loading Capacity for only low flow critical periods that preclude consideration of wet weather sources in water quality management. Research is needed to develop watershed pollutant loading and receiving waters Loading Capacity models that will link wet and dry weather pollution loads to the probability of the exceedence of water quality standards. The long term impact of traditional Best Management Practices as well as ponds and wetlands, must be reassessed to consider long term accumulation of conservative toxic compounds. Socioeconomic research should focus on providing information on economic and social feasibility of implementation of additional controls in water quality limited watersheds. 相似文献
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Chen‐Wuing Liu Kao‐Hong Lin Shiau‐Zon Chen Chen‐Shin Jang 《Journal of the American Water Resources Association》2003,39(4):817-827
ABSTRACT: This study analyzes possible causes of shallow ground water salinization in the coastal area of Yun‐Lin. The local hydro‐geologic setting is determined from geological drilling data and sea floor topography. Three possible causes (sea water intrusion, salt water percolation through wells, and infiltration of salty water from fish ponds) are evaluated. Chloride concentration is used as an index to measure ground water salinization. Sea water intrusion is modeled by the advective/dispersive equation, and salt water infiltration from wells and fish ponds is calculated by estimating the amount of water percolated. The determined local hydrogeologic setting suggests that the shallow aquifer may be connected to the sea water, resulting in salt water intrusion as a large amount of shallow ground water is withdrawn. The percent contributions of sea water intrusion, percolation through wells, and infiltration of water from fish ponds, to the salinization of the shallow aquifer at Ko‐Hu in the Yun‐Lin coastal area are approximately 27 percent, less than 1 percent and 73 percent, respectively. The results suggest that the vertical infiltration of salt water from fish ponds is the major cause of shallow ground water salinization in the coastal area of Yun‐Lin. 相似文献
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ABSTRACT: The main factor in the location of medieval Cracow was drainage. In the 700-year history of the City, there were numerous changes in water conditions, particularly in channel network, runoff, ground water level, and ice phenomena. The most dangerous threat to surface water and ground water in Cracow in the last decades has been from industrial and municipal sewage. Currently there are no rivers that meet Drinking Water Quality standards in Cracow. The quality of the ground water has declined because of infiltration of contaminated river water, water from sewage disposal ponds, and pollution from the atmosphere and soil. Cracow does not have enough waste water plants to meet its needs. Most municipal and industrial sewage has not been treated or has been treated only partially. Because of considerable contamination of surface and ground waters in Cracow, more than half of the city's fresh water is pumped about 50 kilometers from a reservoir on the Raba River. A Polish government declaration of April 4, 1989, recognized Cracow as an area of particular protection, and directed that a number of actions be undertaken for the protection of environmental quality. 相似文献
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Ronald A. Chadderton 《Journal of the American Water Resources Association》1979,15(4):1159-1167
ABSTRACT: Three methods of modeling acid mine drainage effects are discussed. A net alkalinity routing model is the simplest of these, but can be potentially misleading. It typically overestimates the effect of acid sources on pH by neglecting carbon dioxide transfer to the atmosphere. Inclusion of a simple carbon dioxide transfer function can substantially reduce errors in stream quality prediction. A plug flow reaeration equation, coupled with mass balancing at mixing points in a stream network provides modeling results comparable to those of more complex computerized solutions of chemical equilibrium equations. None of the models accounts for carbonate dissolution or oxidation and hydrolysis of ferrous iron. 相似文献
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Ruochuan Gu Frederick N. Luck Heinz G. Stefan 《Journal of the American Water Resources Association》1996,32(4):831-844
ABSTRACT: The physical limnology of three modern wastewater stabilization ponds serving a small community in Minnesota was investigated over a 1-year period (July 1989 - October 1990). Water temperatures and associated meteorological parameters were recorded continuously; underwater light, dissolved oxygen, pH, and Secchi depth were measured intermittently (about weekly). Measurements of nutrients and planktonic species were made by other investigators. Water quality stratification dynamics were studied by analyzing variations of water temperature, dissolved oxygen, and pH distributions with time and over depth. Intermittent stratification and mixing of the shallow waste stabilization ponds (1–2 m deep) were documented and related to weather. The strong response of the ponds to seasonal and daily weather variations was observed. Three types of pond stratification conditions have been identified: (1) completely mixed during consecutive day and night, (2) stratified during the day and well-mixed during the night, and (3) continuously stratified during day and night. A diurnal cycle of stratification dynamics was first noticed in late April and persisted through summer and into fall. Differences in light attenuation and hence temperature stratification and DO distribution between pond 1 (primary), pond 2 (second primary) and pond 3 (secondary) in the wastewater treatment system were documented and related to different waste loading conditions. Temperature stratification affects chemical, microbial, and planktonic processes in the ponds. Results presented in this paper can be used to provide guidance for water quality sampling in monitoring of pond performance. Information on true mixing conditions is also needed to gain better understanding of important factors affecting pond operation, and for process simulations and reactor modeling of waste stabilization ponds. 相似文献
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The Environmental Impact of Shrimp Aquaculture: Causes, Effects, and Mitigating Alternatives 总被引:3,自引:0,他引:3
FEDERICO PÁEZ-OSUNA 《Environmental management》2001,28(1):131-140
Attracted by the demand for shrimp in the developed countries, shrimp aquaculture has expanded rapidly, mainly in the subtropical
and tropical lowlands of America and Asia. This work provides a global review and viewpoint on the environmental impacts of
shrimp aquaculture, considering the causes and effects of the siting and operation of shrimp ponds and abandonment of farm
facilities. Additionally, mitigating alternatives are discussed. To date, approximately 1–1.5 million ha of coastal lowlands
have been converted into shrimp ponds, comprising mainly salt flats, mangrove areas, marshes, and agricultural lands. The
impact of shrimp farming of most concern is the destruction of mangroves and salt marshes for pond construction. Compatibility
with other users, the presence of buffer zones, maintaining an acceptable balance between mangroves and shrimp pond area,
improved pond design, reduction of water exchange, and an improved residence time of water, size and capacity to assimilate
effluents of the water body, are examples of ways to mitigate the adverse effects. The use of mangroves and halophytes as
biofilters of shrimp pond effluents offers an attractive tool for reducing the impact in those regions where mangrove wetlands
and appropriate conditions for halophyte plantations exist. Healthy seed supply, good feed with the use of prophylactic agents
(including probiotics), good water quality, and lower stocking densities are examples of actions suggested to control disease
in shrimp farming. Finally, in the context of integrated management, research priorities are suggested. 相似文献
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Scott A. Wells John A. Gordon 《Journal of the American Water Resources Association》1982,18(4):661-670
ABSTRACT: In developing water quality models for lakes and reservoirs, the assumptions of one-dimensionality (i.e., water quality changes are significant only in one dimension – usually depth), as well as two-dimensionality (considering the length and depth of the water body), have been utilized to predict water quality. In both caws, the assumption of lateral homogeneity is made. A field study was undertaken to determine the change of water quality in the lateral dimension. The main study reservoir was Center Hill Lake in Middle Tennessee. Data were also obtained for Cherokee Lake in East Tennessee. Several water quality parameters (temperature, dissolved oxygen, pH, conductivity, and oxidation reduction potential) were analyzed over the length, breadth, and depth of these reservoirs from pre-stratification through post-stratification. The statistical and theoretical three-dimensional analysis showed the expected variation for each water quality parameter in each direction. The influence of the lateral dimension on water quality management and modeling was found to be negligible. 相似文献