Direct evidence of phosphorus outbreak release from sediment to overlying water in a large shallow lake caused by strong wind wave disturbance

Concentration variations of suspended solids (SS), total phosphorus (TP), dissolved total phosphorus (DTP), dissolved reactive phosphorus (SRP), and algae available phosphorus (AAP) in overlying water were observed during the coldest week in a year in Lake Taihu, a large shallow lake in China. Water samples at different water depths were collected with wind speeds of 8, 12, 0 and 0 m/s on 23, 24, 26 and 30 January 2004, respectively. On 23 January 2004, SS concentration increased to 258 mg/L with a wind speed of 8 m/s lasting for 1 h. SS concentration kept increasing and reached to 507 mg/L when the strong wind lasted for 24 h and the peak value of wind-speed reached to 12 m/s on 24 January 2004. On 26 January 2004, SS concentrution decreased to 51 mg/L with the wind speed smaller than 2 m/s lasting for about half a day. Then after five continuous waveless days, SS concentration decreased to 21 mg/L on 30 January 2004. The observed results confirmed that sediments in Lake Taihu would be intensively suspended if the surface wind speed is greater than 8 m/s, and the magnitude of SS would increase with increasing wind-speed. Coupled with the intensive sediment suspending, concentrations of TP, DTP and SRP on 23 January were 0.210, 0.048 and 0.035 mg/L, respectively. And they were 0.299, 0.054 and 0.026 mg/L on 24 January, which were significantly higher than those on 26 and 30 January. SRP concentration on 23 January was twice as high as that observed on 30 January. It indicates that the strong wind may result in an outbreak release of phosphorus. Moreover, AAP contents in suspended solids were 132, 97 and 226 mg/kg on 23, 24 and 26 January, respectively. Therefore, it could be estimated that this strong wind process resulted in 987 t of TP, 80 t of SRP and 167 t of AAP releasing from sediments into overlying water. Since such strong wind process is frequent in the area of Lake Taihu, dynamical release driven by wind-induced wave disturbance may be the main mode for internal release of phosphorus. It must have important effects on the nutrient supply during Microcystis bloom in Lake Taihu.     

EM菌技术降解长春师范学院人工湖富营养化水质的研究

利用有效微生物EM(Effective Microorganisms)菌对长春师范学院人工湖水进行治理,结果表明:有效微生物EM菌可使水质中的COD、氨氮值含量降低;随着时间的增加及有机生态菌投放数量的增多,水质中的COD、氨氮含量明显降低,湖水水质得到进一步净化。     

湖泊氮磷循环的关键过程与定量识别方法

针对湖泊氮磷循环的3个关键过程: 源过程、去除过程和内部转化过程, 识别不同过程(如底泥释放、反硝化等)对湖泊的影响机制及其对富营养化的贡献, 总结对比湖泊氮磷循环及其关键过程的实验与模型等不同研究方法的优劣。基于文献综述分析提出, 未来的研究需将机理模型、实验观测及室内模拟结合起来, 通过机理模型定量表征氮磷循环的物质平衡, 辅以实验观测识别关键过程, 通过室内模拟实验分析循环关键过程的影响因素与响应机制。这种多层次多手段的研究方法体系可以为湖泊氮磷循环的深入探究提供技术支持。     

西泉眼水库富营养化状况及浮游藻类群落分析

根据综合营养状态指数法对西泉眼水库入口、库心和出口不同采样点全年6次监测结果的综合营养状态指数统计,全年平均值入口为56.2077;库心为54.4001;出口为55.1350,说明水库已处于轻度富营养化状态.并对各采样点的差异进行方差分析,F值为3.548,小于F_(0.05),说明各采样点间富营养化程度差异不显著.经配时数据t检验,3个水期间富营养化程度差异都达到显著水平:丰水期>平水期>枯水期.对水库浮游藻类3次采样共观察到29属,在浮游藻类的种类数上,表现为丰水期>平水期>枯水期.     

用绿藻提取“绿色燃油”

绿藻是富营养化的湖沼等滋生繁殖的一种微细藻类,大量发生不仅污染大气环境．还会严重影响渔业生产。但是,绿藻能吸收温室气体二氧化碳．对环境的适应能力非常强,生长迅速,而且含油量高,被各国视为潜在的可持续能源。最近,日本电力中央研究所能源技术所开发出一种低成本、高效率从绿藻中提取燃油的新工艺。     

三峡库区消落带磷素源-汇转换机理研究述评

三峡工程作为长江开发的关键工程,随着三峡工程建设的顺利进行,成库后的水环境安全问题日益受到国内外的广泛关注,水体富营养化是库区水环境安全的主要隐患。三峡库区消落带土壤作为特殊的淹水土壤,受库水周期性的淹没、冲刷、淤积,将会成为包括磷在内的水体污染物的源和汇。通过对三峡库区消落带土壤这一特殊淹水土壤中磷素源-汇功能转换及其机理进行阐述,旨在为三峡库区生态与环境问题研究提供借鉴。     

富营养化水体中磷的去除研究

对富营养化水体中磷的去除方法进行了综述,并对各方法的优缺点和适用范围做了评价.     

丹江口水库营养程度分析评价及富营养化防治研究

选取丹江口水库丹库和汉库的15个监测断面,采用相关加权综合营养状态指数评价法,对2018年丹江口水库水体营养状态进行了逐月评价,同时对相关水质参数包括高锰酸盐指数、总磷、总氮、透明度和叶绿素a等营养状态参数的权重结果进行了分析. 结果表明:2018年丹江口水库总体呈中营养状态,综合营养状态指数范围为31.9~37.9,汉库高于丹库. 其中汉库中心、柳陂镇山跟前2个监测断面在7—8月份接近轻度富营养化;总氮和叶绿素a是影响丹江口水库水体营养程度最重要的2个参数,其次是总磷和透明度,高锰酸盐指数对水库水体营养程度影响较小. 在营养状态分析和评价的基础上,提出了丹江口水库富营养化防治的对策建议,包括加强水库管理、构建生态过滤净化技术措施、开展水库总氮控制和藻类防治科学研究.      

基于数据挖掘的太湖蓝藻生长水环境关键因子研究

为探究太湖水体富营养化演变机理,识别影响太湖富营养化及蓝藻生长的水环境关键因子,对2006—2018年太湖多源监测序列数据开展数据准备和数据清洗,采用K-means均值聚类方法获取离散的布尔型关联规则挖掘候选数据集,构建基于Apriori算法的太湖水环境关键因子关联规则挖掘模型,对影响太湖水体富营养化的水环境关键因子进行识别。结果表明:表征太湖富营养化程度的Chl-a质量浓度与TP质量浓度、NH₃-N质量浓度、pH和COD_Mn质量浓度均呈现不同强度的关联性,其中Chl-a质量浓度在0~18.36 mg/m³区间内与TP质量浓度在0~0.045 mg/L区间内关联性最强;从水环境治理角度看,若将太湖TP质量浓度控制在0.045 mg/L以下,则全湖Chl-a质量浓度小于18.36 mg/m³的概率最大,可以有效控制蓝藻数量总体处于较少状态,避免太湖蓝藻水华大规模暴发。     

土壤中好氧反硝化菌分离研究

传统的反硝化作用,由微生物在厌氧或微厌氧条件下将硝酸盐还原成氧化亚氮或氮气。本文力图从土壤中找出在好氧条件下,既有硝化作用,也有反硝化作用的脱氮细菌,若将该细菌应用于控制水体富营养化、处理污水和净化水域,有着极大的实用价值。