富营养化湖泊治理研究综述

湖泊富营养化是指湖泊生产力水平逐步由较低的贫营养状态向较高的富营养状态转变的现象。控制营养盐输入是湖泊治理的关键,但对于削减外源污染物,是控磷还是控氮,学术界一直存在争议。一是认为磷是藻类生长的主要限制因子,只需控磷。二是认为氮也是藻类主要生长限制因子,必须控氮。针对我国湖泊生态系统中氮磷含量具有显著的时空异质性特点,藻类生长过程中的限制因子可能随季节发生变化,因此建议富营养化湖泊治理在控磷的同时也要控氮,并且要加强外源和内源污染控制。     

巢湖流域湿地环境质量问题及其生态重建对策

本文通过对环巢湖流域湿地的现状调查,发现巢湖及其流域存在着水质污染、富营养化、农药残留入湖、毁林开荒、水土流失、防浪林丧失、崩岸严重、湖水封闭、水生生态环境恶化等诸多问题。提出除结合工程治理措施外,应大力营造水源涵养林、低丘冈地水土保持林、巢湖平原圩区防护林、建设环湖园林生态隔离带等生物防治措施,意在为巢湖流域水环境综合治理提供科技支撑。     

江苏太湖流域水污染综合治理考察报告

通过对环太湖流域湿地的调查,从控制污染源头、种植水生植物、生态清淤、放养鲢鱼、设施过滤清除蓝藻等方面,总结太湖湿地治理的成功经验,试图为我省巢湖流域水环境综合治理提供一定的借鉴与技术参考。     

浮床栽培绿叶蔬菜对富营养化水体的净化效果

用生菜和苋菜作为泡沫板浮床栽培材料,研究了其生长状况及对富营养化水体的净化效果。结果表明,生菜和苋菜在富营养化水体中可以正常生长。生菜28d内对富营养化水体中的TN、NH4＋-N、NO3--N、TP、PO43--P的去除率分别达到69.83%、85.41%、59.57%、76.58%和82.16%,苋菜28 d内对TN、NH4＋-N、NO3--N、TP、PO43--P的去除率分别为74.91%、89.58%、54.60%、78.53%和84.71%。生菜和苋菜能显著改善富营养化水体的水质,并且没有产生亚硝酸盐及重金属富集,符合食用标准。     

Numerical modeling of nutrient transport to assess the agricultural impact on the trophic state of reservoirs

A trophic state increase relates to surface water bodies nutrient enrichment, due to the chemical products used such as fertilizers in agriculture and residues from cattle raising activities. This research consists of nutrient transport numerical modeling to analyze the Betancí reservoir trophic state in Colombia; Water samples were collected to analyze total nitrogen, total phosphorus, ammonia, nitrates, nitrites, phosphates, chlorophyll-a, dissolved oxygen, BOD, COD, suspended solids, and water transparency. The water quality model MOHID Studio was implemented and after its calibration, scenarios of increase and decrease of nutrients and inflows to the reservoir through its main tributaries were simulated to reproduce the agricultural activity changes in the basin and the effects that would have on the reservoir's trophic state dynamics; Therefore, the Carlson Trophic Status Index was calculated for each case. The results show that variations in total nitrogen concentration and increased inflows present short-term consequences on the reservoir's trophic state. Increasing the incoming total nitrogen concentrations by 100% causes the reservoir to change from a light eutrophic to a hypereutrophic state. The results of this research provide a starting tool to water resources integrated management in reservoirs.     

Vulnerability to eutrophication of a semi-annual life history: A lesson learnt from an extinct eelgrass (Zostera marina) population

A semi-annual eelgrass (Zostera marina L.) population became extinct in 2004. It had flourished for many decades at Terschelling in the western Wadden Sea, one of the most eutrophied locations where seagrass growth has been recorded. Semi-annual populations survive the winter season by seed (annual), and by incidental plant survival (semi-annual). We compared seed bank dynamics and fate of plants between this impacted site and a reference site in the winter of 1990-1991. Seed bank density at Terschelling was extremely low (5-35 seeds m⁻²) in comparison to the reference site (>60 seeds m⁻²) and also in comparison to seed bank densities of (semi-)annual eelgrass populations in other parts of the world. Plant survival during winter was nil. Nevertheless, the population more than doubled its area in 1991, implying maximum germination and seedling survival rates. However, from 1992 onwards the decline set in and continued - while the nutrient levels decreased. To establish the cause of the low seed bank density, we conducted a transplantation experiment in 2004 to study the relationship between seed production and macro-algal cover. The transplantation experiment showed a negative relationship between the survival of seed producing shoots and suffocation by macro-algae, which is associated with light limitation and unfavourable biogeochemical conditions. The plants died before they had started to produce seeds. Thus, it is likely that macro-algal cover was responsible for the low seed bank density found in Terschelling in 1990-1991. Both the recorded low seed bank density and absence of incidental plant survival during winter were related to eutrophication. These parameters must have been a severe bottleneck in the life history of the extinct population at the impacted site, particularly as Z. marina seed banks are transient. Therefore we deduce that this population had survived at the edge of collapse, and became extinct after a small, haphazard environmental change. We argue that its resilience during these years must have been due to (i) maximum germination and seedling survival rates and (ii) spatial spreading of risks: parts of the population may have survived at locally macro-algae-free spots from where the area could be recolonised. As a consequence, the timing of the collapse was unpredictable and did not synchronise with the eutrophication process. The lesson learnt for conservation is to recognise that eutrophication may be a cause for seagrass population collapse and its eventual extinction, even years after nutrient levels stabilised, or even decreased.     

人工湖泊滴水湖水质演变趋势及富营养化分析

对上海临港新城滴水湖自建成以来的水质指标进行为期6年的监测.结果表明,湖区自2004年蓄水以来,水体盐度已由3逐渐下降到2010年的1左右;N/P也呈现逐年下降的趋势,其中磷是滴水湖的营养限制元素;湖区总体水质基本维持在地表水Ⅳ～Ⅴ类,影响水质的主要污染物为CODMn 、Tp、TN和BOD.对湖区富营养化分析的结果表明,其富营养化程度变化趋势与水体中叶绿素a含量的变化基本一致,TP是影响其叶绿素a含量和水体富营养化程度的主要指标,且在夏秋季节容易出现富营养化指数上升的现象.     

杭州西湖总氮、总磷周年变化与水体富营养化研究

２００６年１０月～２００７年９月,对西湖５个主要湖区的８个样点水体的温度、溶解氧、ｐＨ、透明度、悬浮物、总氮、总磷、叶绿素ａ浓度等理化因子和藻类生物量进行测定和分析,讨论总氮、总磷与优势种藻类、藻类总量的平均浓度的关系。结果表明,总氮年平均值２．６３ｍｇ／Ｌ,变化范围０．１７～７．８８ｍｇ／Ｌ;总磷年平均值为０．０８７ｍｇ／Ｌ, １０月最高,为０．１８７ｍｇ／Ｌ;叶绿素年平均值为２４．４９μｇ／Ｌ,最大值和最小值分别出现在２００７年７月（５０．５９μｇ／Ｌ）与２月（１．０９μｇ／Ｌ）。优势种藻类及藻类总量的平均浓度与总氮呈极显著负相关（Ｐ＜０．０１）,与总磷呈显著正相关（Ｐ＜０．０５）,总磷为西湖藻类增殖的主要限制因子。作为一个内源性污染的浅水富营养化湖泊,西湖的治理需要控制人为因素对水体的影响,减少底泥营养盐的再释放,尤其是降低可溶性磷酸盐的释放,从而抑制藻类的过量繁殖。