电站运营对北溪下游水质影响探讨及改进建议

文章通过对利水电站坝上、坝下布设监测断面,进行为期近一个月的枯水期水质监测,分析上下游水质的变化以期对梯级电站的建设与运营对北溪下游水质的影响进行研究,认为梯级电站的建设运行,形成梯级水库,流速变缓,大气覆氧能力降低,水中溶解氧下降,导致水体自净能力减弱,使水环境容量降低,对污染物的稀释、混合和降解能力减弱,湖库富营养化是水库的主要生态环境问题。为此,提出污染防治对策,并提出当上游污染水团下泄时,作为补救和改善水质时电站应采取的运行方式,为今后河流的突发污染防治、水质保护与改善提供经验借鉴。     

滆湖富营养化进程及其综合整治对策研究

在2010年全年涡湖富营养化现状调查基础上,评价了涡湖营养程度,并分析了20年来（1986年-2006年）总氮TN、总磷TP、氮磷比TN／TP和CODMn的发展趋势。结果表明,按照综合营养状态指数法,目前涡湖呈轻度富营养化,且有进一步恶化的趋势。20年来TN,TP和CODMn有较大增长,氮磷比下降。由此,提出了漏湖富营养化综合防治的建议措施,包括污染源控制、围网养殖调整、清淤工程和沉水植被恢复工程。     

近五年广西茅尾海富营养化成因分析及综合防治对策

利用2006至2010年监测结果和统计资料,评价广西茅尾海近5年富营养化状况,分析富营养化变化与钦州市人口、地区生产总值(GDP)、入海污染物结构、河流入海污染物之间的关系,探讨近年来茅尾海富营养化不断加重的原因,并针对性的提出该海域富营养化的综合防治对策。结果表明近5年茅尾海富营养化程度显逐渐加重的趋势,到2010年茅尾海富营养化程度很严重,河口附近富营养化明显。近5年钦州市人口和经济急剧增长引起的入海污染物不断增加是茅尾海富营养化程度加重的主要原因,尤其以磷酸盐的增加对海湾富营养化及赤潮现象的影响最为显著。因而茅尾海富营养化的综合防治应注重对钦江和茅岭江流域的综合整治以及海湾周边入海污染源的管理,加强污水的脱磷处理等。     

人工湿地除磷存在的问题及其对策探讨

人工湿地是20世纪七八十年代发展起来的一种污水生态处理技术,能高效去除有机污染物,氮、磷等营养物,近年来得到了广泛的应用。对磷的去除不同于常规化学除磷或生化处理工艺,而是集物理化学法和生物法于一体,即通过基质、水生植物及微生物的协同作用完成。基质容易达到饱和是人工湿地除磷面临的主要问题,进水水质、水力条件、温度变化等条件也不同程度影响人工湿地的除磷效果。针对以上问题,提出了相应对策,以实现人工湿地除磷系统的稳定运行。     

北运河下游典型河网区水体中氮磷分布与富营养化评价

选择北运河下游典型河网区(闸坝多、水流慢和湖库化)为研究对象,通过为期1 a的水质监控,阐述了河网区氮、磷的时空变化特征,并利用对数型幂函数普适指数公式对其水体营养状态进行了评价.结果表明,河网区水体中TN平均质量浓度为12.50 mg.L-1(NH4+-N占67.41%),TP为1.45 mg.L-1(SRP占80.81%).河网区水体中氮、磷的时空分布特征明显,TN和NO 3--N质量浓度随季节变化特征趋于一致,NH 4+-N稍有不同;TP和SRP质量浓度随季节变化特征基本一致.从河网区进水带至出水带,水体中氮、磷质量浓度均呈逐渐下降趋势,其中TN、NH4+-N和NO3--N平均质量浓度分别从19.30、13.22和2.19mg.L-1降至7.98、4.45和1.50 mg.L-1;TP和SRP分别从1.95和1.59 mg.L-1降至1.11和0.91 mg.L-1.富营养化评价综合指数表明,河网区水体在时空尺度上均处于"极富"营养状态.     

渤海富营养化现状、机制及其与赤潮的时空耦合性

通过对历年调查与监测数据的整理,从污染物源强、渤海富营养化状况、赤潮发生的时空分布三个角度,分析了渤海近岸海域富营养化的"压力—状态—响应"耦合作用机制。根据文献及调查资料研究渤海营养要素的来源及通量,指出渤海污染物主要来自于陆源输入,并且以河流携带的营养盐输入为主。在对渤海近岸海域历年营养盐含量及富营养化水平分析的基础上,结合赤潮发生的时空变化特征,就富营养化对渤海赤潮的诱导作用与耦合关系进行初步讨论。     

新安江水库水环境主要问题及保护对策

新安江水库是钱塘江的重要水源,对保障钱塘江中下游的生态安全和水体功能起着举足轻重的作用。为阐明新安江水库在流域经济发展和人类活动的影响下水环境的主要问题及保护对策,促进饮用水安全保障及构建健康水域生态系统,本文对新安江水库历年的水环境指标、浮游生物群落结构及其变化及水域生态灾变事件资料进行了综合分析。目前新安江水库存在上游来水变差、局部水域藻类异常增殖、渔业生产不合理、营养程度加重等众多问题,但其突出问题是藻类生物量增长过快。新安江水库水环境保护工作要从关注水质向维持生态系统健康转变,并尽快开展生态保育工作,控制流域污染、降低藻类数量、减少藻类异常增殖影响、科学合理渔业生产是其下一步保护的关键。而关于新安江水库的研究,虽然有一定的研究基础和资料,但对水域生态系统缺乏系统认识。研究气候变化条件下新安江水库水域生态系统的结构和功能以及长期演变规律;水利调度导致水位调整对区域水动力学条件、营养物输送过程的影响及评价水利调度对水库重要环境因子和生态系统影响;渔业养殖对水环境的影响,特别是鲢、鳙鱼大水面积养殖对水库生态系统的影响应是今后新安江水库主要的研究领域和方向。     

氯化镧改性黏土固化湖泊底泥中磷的研究

用氯化镧对14种黏土进行改性并研究了这些改性黏土固化磷的效果.研究了pH对改性高岭土磷吸附率和镧离子溶出的影响.结果表明,通过氯化镧改性,不同黏土的磷固定率由改性前的3%～14%提高到改性后的52%～95%.氯化镧改性高岭土在pH为5时,达到磷吸附率的最大值94.85%,并在pH值4～8范围内,保持较高的磷吸附率（>80%）.在pH>6.5的范围,La³⁺溶出浓度低于0.0178 mg/L.     

Long-term joint effect of nutrients and temperature increase on algal growth in Lake Taihu, China

To study how global warming and eutrophication affect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to Lake Taihu to quantitatively study the relationships between algal biomass and both nutrients and temperature using long-term data. To qualitatively assess which factor was a limitation of the improved model, temperature variables were calculated using annual mean air temperature (AT), water temperature (WT), and their average temperature (ST), while substrate variables were calculated using annual mean total nitrogen (TN), total phosphorus (TP), and their weighted aggregate (R), respectively. The nine fitted curves showed that TN and AT were two important factors influencing algal growth; AT limited growth as algal photosynthesis is mainly carried out near the water surface; N leakage of phytoplankton and internal phosphorus load from sediment explains why TN was the best predictor of peak biomass using the Monod model. The fitted results suggest that annual mean algal biomass increased by 0.145 times when annual mean AT increased by 1.0℃. Results also showed that the more eutrophic the lake, the greater the effect AT had on algal growth. Subsequently, the long-term joint effect of annual temperature increase and eutrophication to water ecosystems can be quantitatively assessed and predicted.     

A restoration-promoting integrated floating bed and its experimental performance in eutrophication remediation

Numerous studies on eutrophication remediation have mainly focused on purifying water first, then restoring submerged macrophytes. A restoration-promoting integrated floating bed （RPIFB） was designed to combine the processes of water purification and macrophyte restoration simultaneously. Two outdoor experiments were conducted to evaluate the ecological functions of the RP1FB. Trial 1 was conducted to compare the eutrophication purification among floating bed, gradual-submerging bed （GSB） and RPIFB technologies. The results illustrated that RPIFB has the best purification capacity. Removal efficiencies of RPIFB for TN, TP,NH4＋-N, NO3-N, CODcr, Chlorophyll-a and turbidity were 74.45%, 98.31%, 74.71%, 88.81%, 71.42%, 90.17% and 85%, respectively. In trial 2, influences of depth of GSB and photic area in RPIFB on biota were investigated. When the depth of GSB decreased and the photic area of RPIFB grew, the height of Potamogeton crispus Linn. increased, but the biomass of Canna indica Linn. was reduced. The mortalities of Misgurnus anguillicaudatus and Bellamya aeruginosa in each group were all less than 7%. All results indicated that when the RPIFB was embedded into the eutrophic water, the regime shift from phytoplankton-dominated to macrophyte-dominated state could be promoted. Thus, the RPIFB is a promising remediation technology for eutrophication and submerged macrophyte restoration.