固城湖水环境污染状况与来源分析

对2001~2011年固城湖水环境污染状况评价与时空变化特征分析的基础上,探讨了固城湖的特征污染物及污染来源。结果表明,固城湖水质污染的主要超标因子为TN和TP;总体水质呈现先恶化再改善的趋势,污染由拦河网水域向小湖区水域扩散;固城湖湖体水质基本上劣于水环境功能区划要求;固城湖特征污染物为COD+M n、NH4-N、TN、TP、BOD 5;富营养化程度不断加重,之后又有所改善;氮磷污染的主要来源是水产养殖污染。     

Confronting limitations: new solutions required for urban water management in Kunming City

Despite continuous investment and various efforts to control pollution, urban water environments are worsening in large parts of the developing world. In order to reveal potential constraints and limitations of current practices of urban water management and to stimulate proactive intervention, we conducted a material flow analysis of the urban water system in Kunming City. The results demonstrate that the current efficiency of wastewater treatment is only around 25% and the emission of total phosphorous from the city into its receiving water, Dianchi Lake, is more than 25 times higher than its estimated tolerance. With regard to the crisis of water quantity and quality, the goal of a sustainable urban water environment cannot be attained with the current problem-solving approach in the region due to the technical limitations of the conventional urban drainage and treatment systems. A set of strategies is therefore proposed. The urban drainage system in Zurich is used as a reference for a potential best-available technology for conventional urban water management (BAT) scenario in terms of its low combined frequency of sewer overflow.     

MEAD: an interdisciplinary study of the marine effects of atmospheric deposition in the Kattegat

This paper summarises the results of the EU funded MEAD project, an interdisciplinary study of the effects of atmospheric nitrogen deposition on the Kattegat Sea between Denmark and Sweden. The study considers emissions of reactive nitrogen gases, their transport, transformations, deposition and effects on algal growth together with management options to reduce these effects. We conclude that atmospheric deposition is an important source of fixed nitrogen to the region particularly in summer, when nitrogen is the limiting nutrient for phytoplankton growth, and contributes to the overall eutrophication pressures in this region. However, we also conclude that it is unlikely that atmospheric deposition can, on its own, induce algal blooms in this region. A reduction of atmospheric nitrogen loads to this region will require strategies to reduce emissions of ammonia from local agriculture and Europe wide reductions in nitrous oxide emissions.     

Eutrophication of Buttermilk Bay,a cape cod coastal embayment: Concentrations of nutrients and watershed nutrient budgets

Nutrient concentrations in Buttermilk Bay, a coastal embayment on the northern end of Buzzards Bay, MA, are higher in the nearshore where salinities are lower. This pattern suggests that freshwater sources may contribute significantly to nutrient inputs into Buttermilk Bay. To evaluate the relative importance of the various sources we estimated inputs of nutrients by each major source into the watershed and into the bay itself. Septic systems contributed about 40% of the nitrogen and phosphorus entering the watershed, with precipitation and fertilizer use adding the remainder. Groundwater transported over 85% of the nitrogen and 75% of the phosphorus entering the bay. Most nutrients entering the watershed failed to reach the bay; uptake by forests, soils, denitrification, and adsorption intercepted two-thirds of the nitrogen and nine-tenths of the phosphorus that entered the watershed. The nutrients that did reach the bay most likely originated from subsoil injections into groundwater by septic tanks, plus some leaching of fertilizers.Buttermilk Bay water has relatively low nutrient concentrations, probably because of uptake of nutrients by macrophytes and because of relatively rapid tidal flushing. Annual budgets of nutrients entering the watershed showed a low nitrogen-to-phosphorus ratio of 6, but passage of nutrients through the watershed raised N/P to 23, probably because of adsorption of PO₄ during transit. The N/P ratio of water that leaves the watershed and presumably enters the bay is probably high enough to maintain active growth of nitrogenlimited coastal producers. There is a seasonal shift in N/P in the water column of Buttermilk Bay. N/P exceeded the 161 Redfield ratio during midwinter; the remainder of the year N/P fell below 161. This suggests that annual budgets do not provide sufficiently detailed data with which to interpret nutrient-limitation of producers. Further, some idea of water turnover is also needed to evaluate impact of loading rates. Urbanization of watersheds seems to increase loadings to nearshore environments, and to shift the nutrient loadings delivered to coastal waters to relatively high N-to-P ratios, potentially stimulating growth of nitrogen-limited primary producers.     

基于人工神经网络的巢湖富营养化分时分区评价

应用人工神经网络方法,以温度、高锰酸盐指数、总磷、总氮作为评价参数,对巢湖湖区12个点位的营养状态进行了分时段评价,一共评价了2000年至2003年四个年度的各月份的营养状态。因为湖泊的营养状态水平是变化的,不同区域、不同时段营养状态水平是不同的,因此采用分区分时评价更能全面客观地反映巢湖的营养状态水平及其变化特征。     

湖泊富营养化评价的Euclid贴近度评价法──兼与《湖泊营养状态的Hamming贴近度评价法》作者商榷

针对湖泊富营养状态Ｈａｍｍｉｎｇ贴近度评价模型存在的“阈值漂移”问题,重新构造了评价参数隶属函数,提出了一种湖泊营养状态Ｅｕｃｌｉｄ贴近度评价模型,经过对全国２３个湖泊富营养状态的实例分析,证明这种评价模型结构合理,评价过程简单,模型通用性好。     

长江中下游地区地下水中铅元素的背景特征及其形成

根据调查结果，研究了长江中下游地区地下水铅元素的背景特征及其分布规律，并分析了地下水的含水介质成分，氧化还原环境，径流条件及酸碱度对铅元素的分布的影响。     

白龟山水库富营养化与热污染研究（Ⅰ）

对平原浅水型大型水库的富营养化特征和水平作了深入研究,特别对标志富营养化的浮游藻类、浮游动物及底栖动物等作了模拟试验和现场验证,对加速白龟山水库富营养化的诱导因素作了详细探讨。     

中国主要湖泊营养氮沉降临界负荷的研究

水体营养氮沉降临界负荷是不致使水体产生富营养化的最高氮沉降量。文中探讨了一种依据湖泊氮质量平衡原理计算营养氮沉降临界负荷的方法。用该方法计算表明 ,我国主要湖泊的营养氮沉降临界负荷比较低 ,大部分小于 1keq· hm- 1 · a- 1 ,部分已为目前的氮沉降量或者两者相当接近 ,意味着只接受氮沉降也能导致这些湖泊产生富营养化。但实际统计结果表明 ,氮沉降在导致受工农业生产和生活影响很大的城市和郊区湖泊的水质富营养化的所有氮污染源中所占比例较低 ,而其它来源的氮输入如河道入湖、工业生活废水和农田径流等才是导致富营养化的最主要因素 ,它们的量已远远超过了这些水体可随最高允许氮负荷。因此 ,对控制这些湖泊的水质富营养化而言 ,控制氮沉降并不是目前最紧迫的任务 ,而其它人为污染源的控制才是最急需的。但氮沉降临界负荷在湖泊富营养化的中长远控制中仍具有十分重要的意义。     

污水生物除磷研究进展

水体富营养化是世界性难题,其中磷通常是主要限制因子.生物除磷工艺简单,污泥产量少,可节约能源,运行费用也较低,便于操作和磷的回收.在介绍水体中磷的来源、污染特点及其造成危害的基础上,着重综述了国内外生物除磷的研究进展,并对生物除磷存在的问题和发展趋势提出了一些看法.