富营养化水体中藻类生长限制因素的确定及其应用

在富化营养化的巢湖，围隔实验结果表明磷和其它营养元素不是水体藻类的生长限制因素、藻类生长的正磷酸盐阈值浓度为０．０１９ｍｇ／ｌ，它低于巢湖实际浓度。湖水的矿物性浊度很高，净生产力在一米水深以下呈现负值，数据表明学强在大数时间是藻类生长的限制因素。在巢湖治理过程中，需大幅降低流域内的磷负荷，使湖水平均溶解态总磷浓度从目前的０．０４９ｍｌ／ｌ降到０．０１９ｍｇ／ｌ以下。因此巢湖在治理和恢复是一个缓慢的     

周庄水体内源磷负荷释放规律及其稳定性研究

以周庄河道内源磷负荷为对象，通过实验室模拟，研究了上覆水pH值，溶解氧及环境温度对内源磷释放的影响。结果表明，pH值5．0-9．5，上覆水中的磷浓度随pH值的升高而增加；在不同溶解氧释放条件下，缺氧促进内源磷的释放，好氧抑制磷释放，其抑制能力和pH值相关。pH值7．0～9．5，好氧的抑制效果明显：在好氧的条件下。高的溶解氧会增加磷的释放；温度和上覆水中总磷平衡浓度的对数呈正线性关系。采用Golterman分类提取方法，对不同释放条件下各形态内源磷的稳定性进行了考察。     

辽宁大伙房水库水生生物特征及水质生态学评价

1961～ 2 0 0 0年对大伙房水库 6个站进行了不同季节浮游植物、底栖动物群落特征的生态调查和水化学分析。共发现藻类 8门 ,1 74种 ,底栖动物 3 4种 ,分析了水库水生生物种类组成 ,数量变化和生物演替。水质生态学评价结果表明 :大伙房水库属中富营养化 ,水体只受到轻度污染 ,水质等级为 2级。     

西昌邛海水质现状调查分析

四川西昌的邛海水体中浮游植物群体组成以硅藻、绿藻及鼓藻为主，据1986～1991年连续监测结果表明，邛海水质总体处于贫营养状况，仅局部有富营养性藻类出现。     

浅析环境因子对城市缓流水体底泥磷释放的影响

水体富营养是当今世界面临的一个严重环境问题.造成富营养化的限制因子主要是氮和磷,尤其是磷.对于大多数外源磷得到控制的水体来说,底泥磷的释放对长期维持藻类生长,促进水体富营养化的发展具有举足轻重的作用.但是,底泥对磷的释放与吸收是有条件的,它受到多种因素的影响.在此采用实验模拟的方法,考察温度、pH值、扰动、溶解氧、不同深度、覆盖等环境因子对底泥磷释放的影响,进行初步为城市缓流水体富营养化的防治及治理积累基础资料和信息.     

南宁市南湖富营养化防治对策及综合整治方案的研究

通过对南湖现状进行分析，确定南湖环境容量，在借鉴国内外城市湖泊治理的先进经验与技术的基础上，结合南湖具体情况提出南湖富营养化防治对策，经过经济技术优化，制定因地制宜而又切实有效的综合整治方案．     

Embedded reservoir and constructed wetland for drinking water source protection: Effects on nutrient removal and phytoplankton succession

An embedded reservoir that provides an efficient nutrient removal system protects drinking water.However,embedded reservoirs are rarely used in eutrophic shallow lakes because of their undetermined nutrient retention efficiency and unknown effects by the phytoplankton community.In this study,we aim to investigate the nutrient retention and algae succession in an embedded reservoir and adjacent wetland from April 2017 to September 2018 in the eastern part of Lake Taihu,China.More than 40% of total phosphorus(TP) and 45% of particulate phosphorous entering the reservoir were retained semiannually,and the highest TP removal efficiency was achieved in the reservoir during autumn with an average value of 53.3% ± 9.9%.The overall nitrogen retention efficiency(21.7% ± 37.8%) was lower than that of TP(41.8% ± 27.8%).Similar trends were obtained in the wetland area.An important pathway for phosphorus removal is through particulate matter retention.Our study revealed that nutrient retention mechanisms in the reservoir were primarily via macrophyte absorption,particulate substance sedimentation,and prolonged water residence time.Consequently,the phytoplankton biomass(Chl-a) in the reservoir decreased(from 48.0 to 25.2 μg/L) and water transparency improved,due to the decreased P level and transformation of the phytoplankton group into simple structures with good ecological status.Therefore,the combination of embedded reservoir and constructed wetland ecosystem can be used successfully to protect surface water.The results will be advantageous to groups seeking to preserve drinking water sources.     

Ecological knowledge and North Sea environmental policies

In an analysis of North Sea eutrophication science and policies, focusing on the period 1980–2005, it was investigated how scientific information was used in policy-making. The analysis focused on the central assumptions of the rational policy-making model, i.e. that scientific information can be used to formulate decisions, based upon objective scientific information (rational decision-making), and secondly, can support implementing these decisions (rational management). In general terms, the following was concluded:

• •More knowledge has increased rather than reduced uncertainty;
• •In order to handle the problem of dealing with complexity and uncertainty at the political level, a simplification of facts has occurred, in this case focusing on nutrients as the main cause of the problem, at the same time excluding other possible causes;
• •Both the limited scientific view (i.e. the nutrient view) and the exaggeration of the seriousness of the problem (impacts, scope) have been used as an authoritative basis for the justification of political decisions. Both were not supported by the majority of the scientific community;
• •New scientific knowledge, not in support of existing policies, has been excluded from the policy process;
• •The science–policy interface, mainly consisting of “civil-servant scientists”, that emerged and increased its influence over the period of investigation, has been the central element in the simplification and exclusion process.

The main lesson learned is that work at the interface of science and policy must be subject to democratic principles, i.e. be transparent and involving all parties with a stake in the issue under consideration.     

Integrating empirical and heuristic knowledge in a KBS to approach stream eutrophication

The nutrient enrichment of rivers and its consequences are among the most severe water quality problems in Europe, causing eutrophication and other problems. The decision-making processes involved in the management of these problems require extensive human expertise from people who deal directly with day-to-day stream problems, as well as empirical knowledge based on scientific research. This means that eutrophication is a complex problem, the optimal management of which requires an integrated and multidisciplinary approach. This approach can be taken using a Knowledge-Based System (KBS) built upon the concepts and methods of human reasoning. Accordingly, a KBS was developed within the STREAMES project. In this KBS most of the knowledge needed for managing eutrophication problems was organised and structured in the form of a decision tree (DT). The methodology specially developed to build this KBS, as well as the internal structure of the eutrophication decision tree, is presented here. The good DT obtained led to consider the KBS a suitable tool to support the management of eutrophication.     

Eutrophication assessment in Greek coastal waters

An attempt is made to assess eutrophication in Greek coastal waters, since the measurements made to date at a few stations do not suffice. In this paper, for more accurate seasonal variations in the nutrient contents, the water masses and their volumes are taken into account. The Pagassitikos Gulf is given as an example and compared to other polluted areas in the Aegean. The variations in the levels of nutrients are due to differences in the sources, as well as the morphology of the bottom and the circulation of waters.