太湖地区地表水氮污染源的评论

The nitrogen （N） pollution status of the 12 most important rivers in Changshu, Taihu Lake region was investigated. Water samples were collected from depths of 0.5-1.0 m with the aid of the global positioning system （GPS）. The seasonal variations in the concentrations of different N components in the rivers were measured. Using tension-free monolith lysimeters and ^15N-labeled fertilizer, field experiments were carried out in this region to determine variations of iSN abundance of NO3^- in the leachate during the rice and wheat growing seasons, respectively. Results showed that the main source of N pollution of surface waters in the Taihu Lake region was not the N fertilizer applied in the farmland but the urban domestic sewage and rural human and animal excreta directly discharged into the water bodies without treatment. Atmospheric dry and wet N deposition was another evident source of N pollutant of the surface waters. In conclusion, it would not be correct to attribute the N applied to farmlands as the source of N pollution of the surface waters in this region.     

Water Environmental Issue in Three Gorges Reservoir Area and Its Protective Countermeasures

By single-factor-index evaluation on water of earth＇s surface, the result shows that the water-quality keep Ⅲ grade on the whole in Yang-tze River, Jia-ling River and Wu River of the Three Gorges reservoir, it occurs no obviously deteriorated tendency in 2005. But some sub-grade rivers are polluted badly, cross-section amount of water-quality Ⅰ, Ⅱ ,Ⅲ only has 64 percent, their water-quality is bad. It is clear that the gap between the water environmental state and the object of keeping water- quality Ⅱin the Three Gorges reservoir is very big. This paper thoroughly analyses the problems and causes of the water environment, points out that the main factors resulting in the water pollution in recent years include the industrial sewage, solid wastes, soil and water loss, domestic rubbish and agricultural non-point source pollution, and finally puts forward the countermeasures for protecting of the water environment in the Three Gorges Reservoir.     

作物种植导致的非点源污染: 全球性、地域性以及民族性的问题

China is now the world's largest producer and user of industrial fertilizers and manures. Consequently China plays a substantial role in global N cycle dynamics and in man's disruption of the nitrogen cycle though there are still significant uncertainties about the size and importance of emission and leaching rates. A major cause of China's global role is the overuse of nitrogen fertilizers, which is most serious with intensive vegetable production where application rates can be up to 50% greater than crop needs, but is also a problem with wheat, rice and maize.China's overuse of nitrogen fertiliser over the past 10-20 years has resulted in non-point source (NPS) pollution from crop production becoming a major cause of water pollution, and the situation is projected to get worse. In contrast, water pollution from point sources such as intensive livestock production and urban or industrial development is being brought more under control. The consequences for air pollution are equally serious. Emissions of nitrous oxide from fertilizers and manures may be so large that China could be responsible for 25-30% of global emissions of this damaging greenhouse gas and of the global warming resulting from it. The main national and local issues relate particularly to low fertilizer use efficiency and the losses of ammonia and NOx that lead to acid precipitation, and leaching and run-off losses that result in high nitrate levels in groundwater and eutrophication of rivers and lakes. The reasons why farmers overuse nitrogen fertilizer are complex and not fully understood. They involve agro-climate differences between provinces and counties, farming systems and farm income structures. Although there is a wide range of institutional and technological improvements that can greatly reduce this overuse rapid progress in reducing NPS is unlikely.     

Non-Point Pollution from Crop Production： Global,Regional and National Issues

China is now the world＇s largest producer and user of industrial fertilizers and manures. Consequently China plays a substantial role in global N cycle dynamics and in man＇s disruption of the nitrogen cycle though there are still significant uncertainties about the size and importance of emission and leaching rates. A major cause of China＇s global role is the overuse of nitrogen fertilizers, which is most serious with intensive vegetable production where application rates can be up to 50% greater than crop needs, but is also a problem with wheat, rice and maize. China＇s overuse of nitrogen fertiliser over the past 10-20 years has resulted in non-point source （NPS） pollution from crop production becoming a major cause of water pollution, and the situation is projected to get worse. In contrast, water pollution from point sources such as intensive livestock production and urban or industrial development is being brought more under control. The consequences for air pollution are equally serious. Emissions of nitrous oxide from fertilizers and manures may be so large that China could be responsible for 25-30% of global emissions of this damaging greenhouse gas and of the global warming resulting from it. The main national and local issues relate particularly to low fertilizer use efficiency and the losses of ammonia and NOx that lead to acid precipitation, and leaching and run-off losses that result in high nitrate levels in groundwater and eutrophication of rivers and lakes. The reasons why farmers overuse nitrogen fertilizer are complex and not fully understood. They involve agro-climate differences between provinces and counties, farming systems and farm income structures. Although there is a wide range of institutional and technological improvements that can greatly reduce this overuse rapid progress in reducing NPS is unlikely.     

高速发展的东南沿海地区资源与环境质量变化与可持续发展调整战略

Problems in water-land resources and environmental quality increase with the fast economic development in the coastal region of southeastern China,This region has the highest density in population,industry and towns in China,and the large export-oriented economy makes itself a strategic importance while China enters into international markets.The problems facing to this region include arable land reduction,land degradation aggravation,high percentage of built-up land with high rate of expansion,expanded non-point pollution,deteriorated water quality,decreasing biodiversity,destroyed ecosystems,sever air pollution,frequently occurred acid rain,and multi-pollutants.The important reaarch fields in the near future should include a )influence of high-intensity exploitaion of resources on changes of environment quality and its feedback;b) influence processes ,key mechanisms and adjustment principles for degradation of water,land-,and air-resources and environmental quality;c)evolvement processes and nurturing theory of bioiversity and ecological resourcs;and d) spatio-temporal variaiton and human-induced effects on regional resources and environment quality .Strategies for sustainable development in the region are as follows:a) controlling to ensure basic cultivated land area;b) enforcing remediation of polluted water environment,and controlling non-point pollution;c) strengthening ecological construciton and ecological security;and d) controlling multi-pollution and preventing trace toxic pollutants.     

曹娥江流域河流污染特征对土地覆被的响应

This study addressed the relationship of river water pollution characteristics to land covers and human activities in the catchments in a complete river system named Cao-E River in eastern China.Based on the hydrogeochemical data collected monthly over a period of 3 years,cluster analysis(CA) and principal component analysis(PCA) were adopted to categorize the river reaches and reveal their pollution characteristics.According to the differences of water quality in the river reaches and land use patterns and average population densities in their catchments,the whole river system could be categorized into three groups of river reaches,i.e.,non-point sources pollution reaches(NPSPR),urban reaches(UR) and mixed sources pollution reaches(MSPR).In UR and MSPR,the water quality was mainly impacted by nutrient and organic pollution,while in NPSPR nutrient pollution was the main cause.The nitrate was the main nitrogen form in NPSPR and particulate phosphorus was the main phosphorus form in MSPR.There were no apparent trends for the variations of pollutant concentrations with increasing river flows in NPSPR and MSPR,while in UR the pollutant concentrations decreased with increasing river flows.Thus dry season was the critical period for water pollution control in UR.Therefore,catchment land covers and human activities had significant impact on river reach water pollution type,nutrient forms and water quality responses to hydrological conditions,which might be crucial for developing strategies to combat water pollution in watershed scale.     

人类活动对太湖地区地表水水质的影响

Taihu Lake region is one of the most industrialized areas in China, and the surface water is progressively susceptible to anthropogenic pollution. The physicochemical parameters of surface water quality were determined at 20 sampling sites in Taihu Lake region, China in spring, summer, autumn, and winter seasons of 2005-2006 to assess the effect of human activities on the surface water quality. Principal component analysis (PCA) and cluster analysis (CA) were used to identify characteristics of the water quality in the studied water bodies. PCA extracted the first three principal components (PCs), explaining 80.84% of the total variance of the raw data. Especially, PC1 (38.91%) was associated with NH₄-N, total N, soluble reactive phosphorus, and total P. PC2 (22.70%) was characterized by NO₃-N and temperature. PC3 (19.23%) was mainly associated with pH and dissolved organic carbon. CA showed that streams were influenced by urban residential subsistence and livestock farming contributed significantly to PC1 throughout the year. The streams influenced by farmland runoff contributed most to PC2 in spring and winter compared with other streams. PC3 was affected mainly by aquiculture in spring, rural residential subsistence in summer, and livestock farming in fall and winter seasons. Further analyses showed that farmlands contributed significantly to nitrogen pollution of Taihu Lake, while urban residential subsistence and livestock farming also polluted water quality of Taihu Lake in rainy season. The results would be helpful for the authorities to take sound actions for an effective management of water quality in Taihu Lake region.     

四种不同方法在土壤重金属污染评价中的应用比较

Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality was assessed as class Ⅳ （moderately polluted） for each soil with single-factor index method, and was identified to be classes Ⅳ, Ⅲ （slightly polluted）, Ⅲ, and Ⅲ for soils A, B, C, and D, respectively, with the comprehensive index model. In comparison with the single-factor index method, the comprehensive index model concerned both dominant parameter and average contribution of all factors to the integrated environmental quality. Using the two fuzzy mathematical methods （single-factor deciding and weighted average models）, the environmental risks were determined to be classes Ⅳ, Ⅲ, Ⅱ （clean）, and Ⅱ for soils A, B, C, and D, respectively. However, divergence of the membership degree to each pollution class still occurred between the two methods. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment.     

乡镇企业废水的综合再利用计划和湿地战略: 实例研究

A waste water reuse engineering was designed and then operated in Hongshan,a small town in Zhejiang Province,China,in order to solve pollution and shortage of water resources due to the development of rural enterprises.The results showed that series-structure design and cycling model were two effective modes of saving water and decreasing pollutants into environment,and wetland strategy should be a component part of the integrated planning for waste water reuse of rural enterprises.This case study could provide a basis for the optimum utilization and pollution avoidance of water resources.     

辽宁省污灌区土壤重金属污染特征与生态风险评价

针对当前污灌区土壤污染研究中存在的问题,提出了一种模糊识别模型评价土壤综合环境质量,并对潜在生态风险指数法进行改进,用以计量重金属潜在生态风险。采用建立的方法对辽宁省污灌区土壤环境质量和重金属潜在生态风险进行了评价,结果显示:Cd是辽宁省污灌区首要重金属污染物,而Hg、Pb、Ni污染较为普遍;重金属的来源主要是灌溉污水和农田施肥;以工业废水为灌溉用水的灌区污染情况比以河水为灌溉用水的灌区污染严重;污灌区重金属元素污染程度大小依次为:Cd>Pb>Ni>Hg>Cu>Cr>As,而重金属潜在生态风险从大到小则依次为:Cd>Hg>Pb>Cu>Ni>As>Cr。总体来看,辽宁省污灌区存在一定程度的重金属污染,且具有较为明显的复合型污染特点,其潜在生态风险超出警戒水平,各灌区应根据各自污染特点和风险等级制定相应的污染防治对策。     

Phosphorus management for sustainable biosolids recycling in the United States

Land-based recycling of processed sewage sludge (biosolids) has traditionally been challenged by concerns over metals, organics, pathogens, odors, and public perception. Nutrient concerns, however, portend even greater challenges, and threaten land application programs in the US. Long-term application of biosolids results in accumulation of soil phosphorus (P) above concentrations needed for optimum crop yields. Water quality impairment associated with accelerated eutrophication is driving the US states to adopt policies and laws to reduce P losses to surface waters from agricultural land. Nearly all states have developed site assessment tools (P indices) to rank fields based on their vulnerability to P loss and to target remedial strategies. Biosolids have not been systematically addressed in most states and sustaining economical biosolids recycling programs will be difficult if policies fail to consider certain critical issues. Soil test P benchmarks should be based upon environmental P loss risk rather than crop response. Policies must recognize the role of mandated buffers in protecting surface water quality. Site indices must account for the sizable differences in P loss potential among biosolids types compared to mineral fertilizers and livestock manures. Finally, agronomic rate calculations must recognize different P fertilizer replacement values among biosolids products. Deployment of P management regulations for biosolids lacking scientifically defensible strategies in these areas will adversely affect land-based recycling. Sustainability requires additional research and intentional inclusion of biosolids in implementation of evolving P management policies.     

毕节喀斯特山区饮用水源地水环境污染分析及保护

在对毕节地区倒天河水库等13个饮用水源地水质进行评价的基础上,选择生活污水排放量等9个水环境因素作为分析变量,通过采用主成分分析,把水源地水环境影响因素概括为流域人口数量、流域农业土地利用强度、流域农业化学污染、流域自然条件4个主因素,其方差累积贡献率达86.093%。根据各主因素影响水体污染的强度差异和水体污染现状,将饮用水源地水环境划分为生活废水污染、水土流失污染和农药化肥污染3种类型,提出了相应的水环境保护措施。     

陕西省丹汉江流域面源污染现状及防治对策

面源污染是丹江口水库水质安全的主要威胁。为了探寻陕西省丹汉江流域面源污染的总量及其组成,采用统计调查、参数计算、对比分析的方法,对目前陕西省丹汉江流域主要面源污染物的入河量及其贡献率等方面进行了研究。结果表明,丹汉江流域CODcr、氨氮、总氮、总磷的年入河量分别为103 053,19 851,213 453和39 838t。生活污水及人粪尿是产生CODcr污染的最主要来源,水土流失是产生氮磷污染的最主要来源。面源污染物入河量与污染源的基数、污染物含量、污染物分散程度等因素有关。建议在治理面源污染过程中采取加大水土流失治理力度,开展新农村建设和推广生态清洁小流域治理模式等措施。     

基于模糊积分模型的农村生活污水处理模式综合评价方法

目前生活污水污染问题是农村人居环境和生态环境恶化的重要原因之一。该文对现有中国农村生活污水处理技术和工艺、典型工程处理效果和运行状况以及存在的问题进行调查和分析,从经济、技术、环境3个方面筛选评价指标,通过层次分析法与熵值法相结合的主客观综合赋权法确定各评价指标的权重,构建农村生活污水处理技术评价指标体系;采用分层模糊积分模型对15种现有农村生活污水处理技术模式进行综合评价和排序,最终筛选出三级塘生物生态强化处理技术、户用生态滤池、厌氧-(兼氧)-人工湿地、生物接触氧化-生态沟渠、一体化净化槽、厌氧-兼氧-好氧三级生物滤池、厌氧-土地处理、生态滤池-生态塘、厌氧-生物接触氧化-人工湿地、地埋式微动力氧化沟10种技术模式,推荐作为中国农村生活污水处理典型技术模式。该文对中国农村生活污水治理工程建设具有一定的参考价值。     

Coliforms,fecal coliforms,and fecal streptococci as indicators of water pollution

The presence and survival of coliforms, fecal coliforms, and fecal streptococci were studied in sewage treatment plants, heavily polluted rivers, a lake, and other drinking water sources. In all cases the fecal streptococci were generally more resistant to the natural water environment and to purification processes than the other indicator organisms and, at points distant from the original source of pollution were often the only indicators of the fecal nature of the pollution. In two of the systems studied the survival of the fecal streptococci paralleled the survival of enteric viruses better than the coliforms. The fecal streptococci may thus in certain cases provide a better estimate of the probable virus content in lightly contaminated water than the other two indicators.     

北京市南沙河流域的水污染及治理建议

北京市的南沙河水体已受到严重污染 ,流域内的 3 1处污染源 ,年排放污水总量 5 75 15万t。现有 16处污染源建设了污水处理设施 ,但处理后的污水基本不达标 ,其他 15处污染源的污水未经任何处理就直接排入河中。针对目前南沙河水体污染存在的问题 ,提出了综合治理的建议     

Review of Groundwater Pollution and Protection in Karst Areas

Karst groundwater (the water in a karst aquifer) is a major water resource in many regions of some countries. Water requirements for most of the settlements in the karstic regions are supplied from karst aquifers. Karst environments are also used for the disposal of liquid and solid domestic agricultural, and industrial wastes, which result in karst groundwater pollution. Karst aquifers have specific hydraulic and hydrogeologic characteristics that render them highly vulnerable to pollution from human activities. Karst groundwater becomes polluted more easily and in shorter time periods than water in non-karstic aquifers. Thus, protection measures are required to preserve the quality and quantity of karst groundwater that specifically consider the vulnerability of the karst environment. In order to preserve karst groundwater, the geological, hydrological and hydrogeological characteristics of the karst area must be investigated and information on polluting activities and sources must be collected. Then, a comprehensive protection and control system must be developed consisting of the following six components: (1) develop and implement a groundwater monitoring system, (2) establish critical protection zones, (3) develop proper land use strategies, (4) determine the reasonable development capacity of the karst aquifer, (5) control and eliminate when necessary sources of pollution, (6) increase public awareness of the value and vulnerability of karst aquifers.     

生态清洁小流域水生态环境监测指标体系初探

以生态清洁小流域为研究对象,构建了北京市生态清洁小流域水生态环境监测指标体系。该指标体系包括3个层次,第一层共包括土壤侵蚀强度、村庄生活污水处理率、河流生物完整性指数等17项指标;第二层包括水土流失与面源污染状况、点源污染状况、河流健康状况;第三层为顶层指标,通过对第一、二层指标进行综合分析,评价生态清洁小流域水生态环境质量状况。建立该指标体系以期能为广泛开展的生态清洁小流域建设提供基础数据和决策依据,能够对小流域生态系统的保护和恢复起到一定的指导作用。