湖泊富营养化模型的研究进展

湖泊的富营养化是全球普遍关注的环境问题之一.湖泊的富营养化模型是防治、修复和治理湖泊富营养化的重要决策工具.按研究的侧重点不同,将湖泊富营养化模型分为简单回归模型、水质模型、生态模型和生态-水动力水质模型,并分别回顾了四类模型的研究进展.最后指出湖泊富营养化模型的发展趋势,强调不确定理论、3S技术、耦合模型是今后湖泊富营养化模型研究的重点,应在此基础上建立通用的模拟、预测、评价和优化模型,为湖泊富营养化管理提供科学依据.     

湖泊富营养化模型的研究进展

湖泊的富营养化是全球普遍关注的环境问题之一.湖泊的富营养化模型是防治、修复和治理湖泊富营养化的重要决策工具.按研究的侧重点不同,将湖泊富营养化模型分为简单回归模型、水质模型、生态模型和生态-水动力水质模型,并分别回顾了四类模型的研究进展.最后指出湖泊富营养化模型的发展趋势,强调不确定理论、3S技术、耦合模型是今后湖泊富营养化模型研究的重点,应在此基础上建立通用的模拟、预测、评价和优化模型,为湖泊富营养化管理提供科学依据.     

基于最大流原理的草型与藻型湖泊富营养化驱动因子识别

湖泊生态系统是一个十分复杂的动力学系统,Chl-a、TN、TP、COD和SD在影响湖泊生态结构的同时也被湖泊生态动力所影响,即这些因子可能在其中扮演着因和果的双重角色。本文在对现有湖泊富营养化研究工作总结与分析的基础上,为湖泊生态系统建立符合动力学原理的基于最大流原理的新模型,弱化单一的因果关系,把湖泊生态系统当作一个动态的整体来分析。选取了抚仙湖连续5年(2005—2009)以及滇池草海连续10年(1999—2008)的水质监测数据进行分析,通过比较原始数据与设置的对照组数据的模拟结果,发现藻型湖泊更容易受到化学类的营养物质驱动,而对于营养不过剩的草型湖泊,则更倾向于受到物理因子透明度的驱动。     

底泥营养盐的释磷对富营养化湖泊的影响

富营养化是中国湖泊的重大环境问题。当湖泊的污染外源受到控制以后，由于沉积物（底泥）中营养盐内负荷的存在和释放，湖泊仍然可以发生富营养化。底泥营养盐就成为湖泊富营养化的主导因子，特别是溶解态的磷会逐步释放，成为水体富营养化的主导因子。沉积物中磷的循环在一定程度上决定着富营养化的进程，对水体磷含量有深刻的影响。结合国内外研究动态，对底泥磷形态、磷释放与水体水质的关系作了概述，并对底泥磷释放的研究方向以及控制湖泊富营养化发表了一些见解。     

沉积物疏浚技术在富营养化湖泊修复中的应用

沉积物疏浚是削减富营养化湖泊内源负荷的最为直接和有效的手段.分析了沉积物疏浚的效果和可能引起的风险;从外源污染、作业区域和深度、沉水植物3个方面探讨了影响沉积物疏浚效果的关键因素.最后指出,富营养化湖泊沉积物疏浚的重要原则是截断外源污染、划分作业区域、合理控制挖掘深度、创造适宜生境、恢复沉水植物、重构生态系统等.     

第一次全国湖泊环境保护学术讨论会在杭州举行

“第一次湖泊环境保护学术讨论会”于1982年10月15日至20日在杭州举行.这次会议是受中国科学环境委员会的委托,由中国科学院南京地理所和杭州市环境科学研究所筹备召开的.从事湖泊环境监测、教学、科研单位、及湖泊环境主管部门的代表82人参加了会议.会议共收到论文和报告55篇,内容涉及湖泊环境监测和评价方法、湖泊水质富营养化、农药和重金属污染、湖泊生态系统、水利工程对湖泊环境影     

第一届湖泊环境科学学术讨论会在杭州召开

第一届湖泊环境科学学术讨论会于1982年10月15日至20日在杭州举行。会议受中科院环委会委托,由中科院南京地理所和杭州市环科所筹备召开。我国从事湖泊环境监测、教学、科研单位的代表82人参加了会议。收到的论文和报告内容较为广泛,有湖泊环境监测及其评价、水质富营养化、农药和重金属污染及湖泊生态系统、水利工程对湖泊环境的影响、还有水质标准和规划与湖     

基于Vague集的集对分析在湖泊富营养化评价中的应用

针对湖泊富营养化评价的不确定型多属性决策问题,提出了Vague集的集对分析模型,详细介绍了集对分析和Vague集的基本理论、Vague集的表示方法和Vague集相似度的同异反状态关系.建立了湖泊富营养化评价指标体系,引入了超标权重确定各湖泊指标权重,再依据待评湖泊关于等级i特征的Vague集和理想Vague集的相似度构成特征值法确定评价等级,并应用该模型对我国9个湖泊的富营养化程度进行了评价,该方法的评价结果与实际情况基本相符,为湖泊的治理和保护提供了科学依据.     

底泥磷形态及分布特征对水体富营养化的影响

富营养化是当今中国浅水湖泊面临的重大污染问题。结合国内外的报道,通过大量湖泊水库的实地调查,对各种磷形态的性质和分布特征及转移规律作了深入研究,介绍了水体底泥中磷的物理化学性质、磷的存在形式与转化、磷的分布特征、磷在不同粒径底泥下的含量及转移趋势,为探明水体富营养化提供科学而有力的依据。最后指出了其对湖泊富营养化的影响,并对控制湖泊富营养化提出了见解。     

湖水源热泵系统尾水排放对湖泊富营养化进程的影响研究

以重庆市开县人民医院湖水源热泵工程为例,通过对该工程运行期间尾水受纳湖泊水域水温、氮、磷和浮游植物的长期监测,研究了湖水源热泵系统尾水对湖泊富营养化进程的影响。结果表明,夏季系统的长期运行导致了排放口附近水域水温的升高;当系统温排水水温在30℃以下时,温排水造成的温升使得排放口附近氮、磷含量升高,蓝、绿藻数量大幅增加,加速了湖泊的富营养化进程;当温排水水温达到33℃以上时,过高的温度会抑制藻类的生长。冷排水使湖泊排放口近水域浮游植物总量降低,且硅藻占总藻的比例增大,冷排水同时抑制了蓝藻和其他一些藻类的生长,对湖泊富营养化有一定缓解作用。但另一方面,由于温差较小,且冷排水的扰动作用加速了湖泊沉积物中营养盐的释放,因而冷排水对湖泊富营养化进程又有一定促进作用。     

Eutrophication of freshwater and coastal marine ecosystems a global problem

GOAL, SCOPE AND BACKGROUND: Humans now strongly influence almost every major aquatic ecosystem, and their activities have dramatically altered the fluxes of growth-limiting nutrients from the landscape to receiving waters. Unfortunately, these nutrient inputs have had profound negative effects upon the quality of surface waters worldwide. This review examines how eutrophication influences the biomass and species composition of algae in both freshwater and costal marine systems. MAIN FEATURES: An overview of recent advances in algae-related eutrophication research is presented. In freshwater systems, a summary is presented for lakes and reservoirs; streams and rivers; and wetlands. A brief summary is also presented for estuarine and coastal marine ecosystems. RESULTS: Eutrophication causes predictable increases in the biomass of algae in lakes and reservoirs; streams and rivers; wetlands; and coastal marine ecosystems. As in lakes, the response of suspended algae in large rivers to changes in nutrient loading may be hysteretic in some cases. The inhibitory effects of high concentrations of inorganic suspended solids on algal growth, which can be very evident in many reservoirs receiving high inputs of suspended soils, also potentially may occur in turbid rivers. Consistent and predictable eutrophication-caused increases in cyanobacterial dominance of phytoplankton have been reported worldwide for natural lakes, and similar trends are reported here both for phytoplankton in turbid reservoirs, and for suspended algae in a large river CONCLUSIONS: A remarkable unity is evident in the global response of algal biomass to nitrogen and phosphorus availability in lakes and reservoirs; wetlands; streams and rivers; and coastal marine waters. The species composition of algal communities inhabiting the water column appears to respond similarly to nutrient loading, whether in lakes, reservoirs, or rivers. As is true of freshwater ecosystems, the recent literature suggests that coastal marine ecosystems will respond positively to nutrient loading control efforts. RECOMMENDATIONS AND OUTLOOK: Our understanding of freshwater eutrophication and its effects on algal-related water quality is strong and is advancing rapidly. However, our understanding of the effects of eutrophication on estuarine and coastal marine ecosystems is much more limited, and this gap represents an important future research need. Although coastal systems can be hydrologically complex, the biomass of marine phytoplankton nonetheless appears to respond sensitively and predictably to changes in the external supplies of nitrogen and phosphorus. These responses suggest that efforts to manage nutrient inputs to the seas will result in significant improvements in coastal zone water quality. Additional new efforts should be made to develop models that quantitatively link ecosystem-level responses to nutrient loading in both freshwater and marine systems.     

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。     

Lake eutrophication at the urban fringe,Seattle region,USA

Nutrient pollution and associated eutrophication of freshwaters threaten the ecological integrity and the services provided to humans by lakes. We examined how human residential development influenced the level of lake eutrophication in the Seattle, WA, USA, region. We surveyed 30 lakes and measured 3 indicators of eutrophication: concentrations of chlorophyll-a and phosphorus, and the proportion of algae that are inedible to zooplankton. We classified lakes based on the waste-treatment method for shoreline homes: septic, sewer, and undeveloped lakes. Septic lakes occurred along the urban-rural fringe while sewer lakes occurred near urban centers. Septic lakes were more eutrophic than sewer lakes and undeveloped lakes, as indicated by higher levels of phosphorus and chlorophyll-a. These results suggest that septic systems contribute to the high levels of eutrophication in lakes at the urban-rural fringe. Lakes at the urban-rural fringe represent an opportunity for proactive management of urban expansion to minimize lake eutrophication.     

采用热解技术将湖泊浮游藻类用于燃料生产

湖泊的富营养化问题已成为中国湖泊环境保护中最严重的问题之一.回收利用富营养化湖泊中的浮游藻类是减轻水体中氮、磷等营养负荷,治理湖泊环境污染的一项重要措施.通过热解技术可将藻类转化成焦炭、生物油和合成气等多种燃料形式,因而是回收利用湖泊浮游藻类的一个理想途径.同木质-纤维素类生物质相比,藻类作热解原料具有易预处理、易热解、易获得高产等优点,可以为社会提供大量优质的燃料.     

Eutrophication assessment and management methodology of multiple pollution sources of a landscape lake in North China

Landscape lakes in the city suffer high eutrophication risk because of their special characters and functions in the water circulation system. Using a landscape lake HMLA located in Tianjin City, North China, with a mixture of point source (PS) pollution and non-point source (NPS) pollution, we explored the methodology of Fluent and AQUATOX to simulate and predict the state of HMLA, and trophic index was used to assess the eutrophication state. Then, we use water compensation optimization and three scenarios to determine the optimal management methodology. Three scenarios include ecological restoration scenario, best management practices (BMPs) scenario, and a scenario combining both. Our results suggest that the maintenance of a healthy ecosystem with ecoremediation is necessary and the BMPs have a far-reaching effect on water reusing and NPS pollution control. This study has implications for eutrophication control and management under development for urbanization in China.     

System-level responses of lake ecosystems to chemical stresses using exergy and structural exergy as ecological indicators

This paper presents the system-level responses of experimental lake ecosystems to three chemical stresses (acidification, copper and pesticide contamination) using exergy and structural exergy as ecological indicators. The results indicate that the doses or toxicity of the three chemical stressors contributed to changes in both exergy and structural exergy. Remarkable changes in exergy and structural exergy occurred under acidic conditions and in the presence of Dursban, 24D-DMA, permethrin, bifenthrin, Carbaryl, TCP, PCP, trichlorethylene, benzene, and high doses of Cu, oil, and hexazinone. This seemed to indicate that the subject ecosystems were seriously contaminated by these chemical stressors. For low doses of Cu, oil, atrazine, HCBP, and hexazinone, exergy and structural exergy were either unchanged or only slightly changed, suggesting that the lake ecosystems were not significantly impacted by these chemical stressors. Discussion of the relationships between ecosystem-level changes and structural and functional changes in stressed lake ecosystems indicates that the above-mentioned ecosystem-level changes were in accordance with the changes in structure and function. The observed changes in exergy and structural exergy were also consistent with Odum's predictions of shortened food chains, reduced resource use efficiency, poor stability, low information, and high entropy in stressed aquatic ecosystems. The findings lead the authors to conclude that it is feasible for exergy and structural exergy to serve as ecological indicators when characterizing the system-level responses of experimental lake ecosystems to chemical stress. These results for experimental lake ecosystems would be extrapolated to actual lakes.     

Assessment of the sustainability of technology by means of a thermodynamically based life cycle analysis

Life cycle analysis is one of the tools in the assessment of the sustainability of technological options. It takes into account all effects on the ecosystem and the population which may endanger the possibilities of current and future generations. However, the main bottleneck in current LCA methodologies is the balancing of different effects, being all quantified on different scales. In this work, a methodology is proposed, which allows one to quantify different effects of the production, consumption and disposal of goods, and services on a single scale. The basis of the methodology is the second law of thermodynamics. All production, consumption and disposal processes affecting the ecosystem and the population, are quantified in terms of loss of exergy. The exergy content of a material is the maximum amount of energy which can be transformed into work at given environmental conditions. Next to the elaboration of the methodology, the new approach is illustrated by examples of the production of synthetic organic polymers, inorganic building insulation materials and different waste gas treatment options.