RELATIONSHIPS BETWEEN WATER QUALITY AND PHOSPHORUS CONCENTRATIONS FOR PUGET SOUND REGION LAKES1

Regression relationships were developed between summer mean total phosphorus (P) concentrations in near-surface water and both chlorophyll a concentrations and Secchi disc transparency for Puget Sound region lakes. Total P concentrations in the lakes studied ranged from 7 to 66 μ/L. The relationship between total P and chlorophyll a, based on data from 69 lakes, explained 57 percent of the variance in chlorophyll a. Predicted chlorophyll a concentrations and 95 percent confidence intervals ranged from 1 ⁺³_-0.5μg/L for 7 μg/L P to about ⁺³⁵_-10μ/L for 66 μ/L P. The relationship between total P and Secchi disc, based on data from 71 lakes, explained 53 percent of the variance in Secchi disc. Predicted Secchi disc transparencies and 95 percent confidence intervals ranged from 5.5 ^+5.5_-3.0 m for 7 μ/L P to 1.4 ^+1.5_-0.7 m for 66 μ/L P.     

MUNICIPAL POINT SOURCE AND AGRICULTURAL NONPOINT SOURCE CONTRIBUTIONS TO COASTAL EUTROPHICATION1

ABSTRACT: Tidally influenced reaches of several coastal rivers in eastern North Carolina are suffering from very serious water quality problems — massive surface blooms of noxious blue-green algae, major fish kills from anoxic water, epidemics of red sore disease among fish, fresh water intrusion into estuarine waters, and declining commercial and sports fisheries. An intensive investigation of point source and nonpoint source inputs of nutrients was conducted in one of the eutrophic rivers, the Chowan River. Nonpoint source loading dominated the estimated annual flu of nutrients from the river basin. Automated water quality samplers were utilized to record nutrient levels in stormflow and baseflow from several small agricultural watershed in the basin. Levels of nitrate nitrogen and total phosphorus were from five to 40 times greater in these agricultural watersheds than levels in mostly forested watersheds. Existing water quality data in these eutrophic river basins implicate agricultural activities – particularly animal operations and cropland in watersheds with extensive drainage improvements – as the major contributing factor to the water quality problems.     

A Sensitivity and Error Analysis Framework for Lake Eutrophication Modeling1

ABSTRACT: A framework for sensitivity and error analysis in mathematical modeling is described and demonstrated. The Lake Eutrophication Analysis Procedure (LEAP) consists of a series of linked models which predict lake water quality conditions as a function of watershed land use, hydrolgic variables, and morphometric variables. Specification of input variables as distributions (means and standard errors) and use of first-order error analysis techniques permits estimation of output variable means, standard errors, and confidence ranges. Predicted distributions compare favorably with those estimated using Monte-Carlo simulation. The framework is demonstrated by applying it to data from Lake Morey, Vermont. While possible biases exist in the models calibrated for this application, prediction variances, attributed chiefly to model error, are comparable to the observed year-to-year variance in water quality, as measured by spring phosphorus concentration, hypolimnetic oxygen depletion rate, summer chlorophyll-a, and summer transparency in this lake. Use of the framework provides insight into important controlling factors and relationships and identifies the major sources of uncertainty in a given model application.     

石河子蘑菇湖水库富营养化成因及防治对策

15年来，蘑菇湖水库一直处于富营养化状态，但污染物排放总量没有随着城市经济与人口的增加而成比例增加，相对污染物进库勘晓少。本文主要从水质状况、底泥、水生生物三方面入手，分析了蘑菇湖水库富营养化的成因，阐述水体富营养防治对策的同时。提出了蘑菇湖水库治理的建议。     

改性丝瓜络填料对富营养化水体的高效脱氮特性

生物膜技术是污水处理的研究热点之一,但存在挂膜时间长、反硝化碳源供给不足等问题.为解决这一问题,以不同浓度NaOH溶液（对照组、2%、5%和10%）对丝瓜络进行改性处理,再将其作为挂膜填料构建BDBR（biofilm denitrification batch reactor,生物膜原位脱氮系统）,研究BDBR的脱氮效能.结果表明:①当系统运行至第4天时,对照组、2%组、5%组和10%组反应器的COD_Cr去除率趋于稳定,分别为78.9%、76.8%、80.8%和73.9%;当系统运行14 d时,对照组、2%组、5%组和10%组反应器的TN去除率趋于稳定,分别为67.2%、90.8%、91.9%和83.2%;而当系统运行至第10天时,2%组、5%组和10%组反应器对NH₃-N的去除率趋于稳定,依次为82.8%、88.4%和78.8%,显著高于对照组（68.1%）.②改性丝瓜络反应器的膜生物量（2%组、5%组和10%组）均显著高于未进行改性处理的对照组,且随NaOH溶液浓度从2%增至10%,对应反应器膜生物量从12.12×106 nmol（以每g干质量磷脂计）增至24.02×106 nmol.③改性丝瓜络填料上的生物膜的硝化、反硝化菌数量均显著高于未改性处理的丝瓜络填料的硝化、反硝化菌数量.研究显示,丝瓜络填料所构建的BDBR对富营养化河道水中的COD_Cr均有较高的去除能力,这与丝瓜络是否进行改性无关.但用浓度为2% NaOH溶液对丝瓜络进行改性处理后构建的BDBR体现出了最高的生物膜硝化、反硝化菌数量和最好的脱氮效果,可应用于富营养化水体的BDBR中,以实现生物膜的快速构建和系统的稳定运行.      

天目湖沙河水库热分层变化及其对水质的影响

为揭示亚热带水库热分层的季节性变化特征、影响因素及水质效应,以最大水深11 m的江苏溧阳天目湖沙河水库为例,基于对水库坝前区(TM1)3~11月逐时的水温监测及对该水库2009~2016年相关水质和气象指标监测,分析了该水库热分层的形成和消失时间、驱动因素及其对水质的影响.结果表明,天目湖沙河水库呈典型的亚热带单循环混合模式:春季随着太阳辐射的增强,水温逐渐升高,当表层水温升至21℃左右时,热分层稳定形成,在整个5~9月期间水体热分层十分稳定;秋季随着太阳辐射的减弱,水温逐渐降低,当表层水温降至19℃左右时,热分层基本消失,在10~4月期间水体呈混合状态.热分层期间,表层和底层的水温差随太阳辐射的增强而增加;日均气温超过30℃的情况下,水体热分层更加稳定;夏季强降雨过程降低了水体表层的温度、减弱了上层5 m水体的温度分层,但对5 m以下深度的热分层状况基本无影响.水温分层对水库水质产生一定的影响:热分层期间,底层水体处于厌氧状态,底层水体氨氮浓度明显增加;热分层消失后,底层水体溶解氧、总磷及悬浮颗粒物含量均增加.研究表明,对于四季分明的亚热带中等深度的水库而言,水体热分层主要受太阳辐射的控制,稳定的热分层有利于蓝藻门相关种属藻类的生长,热分层形成及消散阶段改变了沉积物的营养盐释放及供给水体的强度,对水体水质形成冲击.在水库水质监控及生态保护管理中,应关注热分层过程的不利影响,并探索相关灾害的防控技术.     

中国地表水环境质量标准研究

《地表水环境质量标准》是水环境管理的尺度,在推动我国水污染防治、公众健康与水生态安全保障等方面发挥着十分重要的作用.随着我国进入生态文明建设新阶段,水环境保护和社会经济发展形势发生深刻变化,如何与时俱进,及时修订丰富现行标准成为迫在眉睫的问题.全面剖析了我国现行GB 3838—2002《地表水环境质量标准》修订历程、修订依据、重要贡献、存在问题及国家需求,结合国际标准发展趋势和我国社会发展阶段,提出未来将《地表水环境质量标准》由单项标准向系列标准转变的修订思路框架.初步阐述了由系列标准构成的“1+N”的标准体系框架,其中,“1”是地表水环境质量基本项目标准,用于判断地表水环境质量的优劣程度,反映水环境功能的基本水质要求;“N”是不同的特定保护项目标准,包括保护水生生物的有毒有害污染物项目水质标准、地表饮用水源地水质标准、湖泊营养物状态评价标准以及地表水水生物状况评价标准,并提出了各分标准的相关制修订方案.      

水华过程水质参数与浮游植物定量关系的研究——以太湖梅梁湾为例

考虑到太湖水华暴发过程中水质参数（如营养盐或水体理化参数）对浮游植物增殖的滞后效应,利用有滞后变量参与的格兰杰因果关系检验和向量自回归模型,分析了太湖梅梁湾湖区2000年~2012年的监测数据,探讨了湖泊水质参数对于水华暴发的影响和定量关系.结果发现,表征浮游植物生物量的叶绿素a（Chl-a）浓度与总磷（TP）、氮磷比（N/P）、水温（WT）之间存在长期的均衡关系,格兰杰因果关系模型和向量自回归模型（VAR）的结果显示,水体中TP浓度、N/P和WT是Chl-a含量变化的格兰杰原因,上述结果提供了湖泊水质参数与蓝藻生物量的定量关系,在其他水质参数保持不变的情况下,约1%湖泊TP含量、N/P和水温的变化分别造成0.97%、0.078%和0.55%的浮游植物生物量的变化.本研究为水华暴发研究过程中水质参数的定量化影响提供一个新颖的视角,考虑了时间滞后变量的时间序列分析方法也可以加深对水华暴发过程的理解.     

SEDIMENT NUTRIENT FLUXES IN A TIDAL FRESHWATER EMBAYMENT1

ABSTRACT: Sediment-water exchanges of ammonium, nitrate, and phosphate are incorporated into a eutrophication model of Gunston Cove, Virginia. The exchange rates are obtained from laboratory measurements and are modeled as empirical functions of temperature, concentration, and pH. Simulation of the period from June 1 to September 30, 1983, indicates nitrogen, phosphorus, and chlorophyll ‘a’ are correctly modeled only when the sediment-water nutrient exchanges are taken into account.     

Heterotrophic Nano- and Microplankton under Conditions of Anthropogenic Eutrophication of the Bay of Novorossiisk

Seasonal and long-term dynamics of heterotrophic plankton in the Bay of Novorossiisk are discussed. It is shown that specific variation in the biomass of nanoheterotrophs and infusoria is associated with the processes of anthropogenic water eutrophication. The biomass of infusoria has increased ten times and that of zooflagellates two times since 1985–1986. Infusoria of the genera Strombidium, Strobilidium, and Mesodiniumare dominant in the protozoan plankton. The annual average level of Oligotrichadevelopment in the bay is characteristic of eutrophic water bodies (112–417 mg/m³); in the spring–summer season, however, it may increase to 500–1034 mg/m³. In the part of the bay near the port, which is exposed to a strong anthropogenic impact, the biomass of ciliate protozoa can reach 2 g/m³.