胶州湾水质及主要营养盐季节性变化分析

于2010年4个季度对胶州湾水质进行了调查,根据单因子污染指数法,利用计算机软件绘制了水质分区图,分析了胶州湾水质的最新状况及不同季节的水质变化情况,同时对胶州湾主要营养盐无机氮和活性磷酸盐的变化进行了分析。调查结果显示,2010年胶州湾水质定性评价为差,无机氮和活性磷酸盐的平均浓度分别为0.393 mg/L、0.018 mg/L,高值区主要分布在胶州湾东北角,无机氮和活性磷酸盐的平均浓度及空间分布随着季节的变化而呈现了一定的变化。     

山东省近岸海域水质现状及变化趋势研究

通过对2003-2007年山东省近岸海域水质监测数据的分析，总结其近岸海域的水质状况及污染特征，并采用秩相关系数法对山东省近岸海域水质状况时空变化趋势进行分析与评价。结果表明，山东省近岸海域水质以一、二类海水为主，黄海近岸海域水质略好于渤海。全省近岸海域污染以有机污染为主，主要污染因子为无机氮和化学需氧量。2003-2007年，山东省近岸海域水质变化趋势基本稳定，但主要污染物化学需氧量的含量呈上升趋势。     

北戴河近岸海域叶绿素a分布特征及影响因素

2015年及2016年的6月—8月,在北戴河近岸海域设立4个站点,进行海水叶绿素a及理化指标分析。监测结果显示,鸽子窝海域叶绿素a含量最高,平均值为8.93μg/L,老虎石海域含量最低,平均值为6.61μg/L;最大值发生在鸽子窝海域,为19.4μg/L,最小值发生在金沙滩海域,为2.01μg/L。总体上,北戴河近岸海域水质达到国家二类海水水质标准。与叶绿素a相关性显著的影响因素有无机氮、PO4-P、CODMn和pH值。     

环保部要求近岸海域水质自动监测数据实时公布

正7月3日,环保部表示将向社会发布《中国近岸海域环境质量公报》及公开近岸海域国控监测站位水质监测信息。环保部要求,建有近岸海域水质自动监测系统的应当公布水质自动监测实时数据。环保部表示,将要发布的近岸海域环境监测信息包括,近岸海域海水水质监测信息,入     

大连市近岸海域水质时空特征及原因分析

“十三五”期间大连市近岸海域水质状况良好,主要污染指标无机氮浓度总体呈下降趋势,但个别海湾仍存在无机氮污染问题。在全面分析近岸海域水质及无机氮时空分布特征的基础上,从海域综合治理措施、入海河流水质及污染物入海通量、海湾地理特征等方面深入分析原因,并对持续改善海域环境质量提出了切实可行的防治措施。     

沱江富顺段水质分析及污染状况研究

为了解沱江富顺段水质情况,采用相应的国家标准方法对沱江水体的氮、磷、化学需氧量、生化需氧量等指标进行监测。3个监测断面TN、TP的平均浓度分别为3．31mg／L、0．247mg／L,其中TN含量超标3倍以上,TP含量超过标准的1．2倍,建议相关部门应在河流平水期和枯水期严格控制氮、磷的排放,可通过调高工业废水、污水处理厂氮、磷排放标准,缓解沱江氮、磷污染程度。     

河北省近岸海域环境质量评价及分析

利用2017年度河北省近岸海域相关监测数据,采用单一因子法对近岸海域环境质量进行了评价与分析。结果表明:2017年河北省近岸海域环境质量点位以二类水质类别为主,整体水质状况为一般。一类水质比例为0%;二类水质比例为76.9%;四类及劣四类水质比例为23.1%。近岸海域水质状况为一般,超标因子为无机氮,入海河流及直排入海污染源携带污染物对近岸海域水质影响明显,因此河北省近岸海域污染控制重点应在无机氮污染。     

篦齿眼子菜对废水中氮和磷的去除行为研究

一些常见的沉水草本植物对水质具有较强的净化作用,能够有效控制氮和磷的浓度。本试验通过模拟氮、磷污染的水质条件,采用篦齿眼子菜对氮、磷营养盐的吸附和去除效果进行研究。结果表明:设定模拟废水中的初始总氮(TN)浓度在1~50 mg/L范围内,培养30天后的植株对总氮的去除率最高可达85.4%,随着初始培养环境中总氮浓度的增加,去除效率呈下降的趋势;模拟废水水体中的总磷浓度范围为0.2~10.0 mg/L时,对总磷(TP)去除效率最高为78.3%。使用蓖齿眼子菜对实际的废水进行氮、磷营养盐的去除处理,效果较好。由此可见,水生植物富集废水中高浓度营养盐的能力具有较大的应用前景,本研究可为蓖齿眼子菜应用于废水预处理工艺提供可靠的理论支持。     

烟台市近海海域水质污染研究

烟台市海洋渔业资源丰富,水产业在该市农业经济中占有重要的地位,但近海海域存在石油、无权氮和活性磷酸盐的污染,水质污染对水力业构成了严重危害．为控制该市近海海域水质污染,本文建议当地政府加强对工业污染源的管理,尽快兴建新的污水处理工程,加强海上船舶排污的监督与管理力度,以及引导农民合理应用化肥．     

昌吉市头屯河水质变化趋势及原因分析

为改善头屯河水环境质量,对头屯河2017～2019年水质进行分析评价。结果表明:头屯河主要污染因子是氨氮和总磷,在调查期间,河流氨氮和总磷的污染得到有效控制;2019年头屯河4个断面的pH、溶解氧、化学需氧量、高锰酸盐指数监测指标均符合Ⅰ类水质标准,其中八钢断面的氨氮浓度最高,4个断面的总磷浓度在6月份和9月份均超出Ⅰ类水质标准;八钢断面的水质无明显改变,电线厂断面水质类别由Ⅱ类升为Ⅰ类;皮革厂断面及化工厂断面氨氮浓度明显下降;头屯河水质下一步整治目标应是在继续控制人为污染及农业污染造成的氨氮和总磷浓度超标的基础上,重点关注耗氧性物质的浓度变化。     

南京市水质自动站的发展趋势及管理模式探讨

从水质自动站发展特点和管理两个方面,阐述了南京市水质自动站的做法和经验,总结了水质自动站的发展趋势。     

Three-dimensional numerical simulation of water quality and sediment-associated processes with application to a Mississippi Delta lake

A three-dimensional water quality model was developed for simulating temporal and spatial variations of phytoplankton, nutrients, and dissolved oxygen in freshwater bodies. Effects of suspended and bed sediment on the water quality processes were simulated. A formula was generated from field measurements to calculate the light attenuation coefficient by considering the effects of suspended sediment and chlorophyll. The processes of adsorption–desorption of nutrients by sediment were described using the Langmuir Equation. The release rates of nutrients from the bed were calculated based on the concentration gradient across the water–sediment interface and other variables including pH, temperature and dissolved oxygen concentration.The model was calibrated and validated by applying it to simulate the concentrations of chlorophyll and nutrients in a natural oxbow lake in Mississippi Delta. The simulated time series of phytoplankton (as chlorophyll) and nutrient concentrations were generally in agreement with field observations. Sensitivity analyses were conducted to demonstrate the impacts of varying suspended sediment concentration on lake chlorophyll levels.     

YX-WQMS在左卫国控点水质自动监测站的应用

官厅水系左卫国控点水质自动监测站的YX-WQMS系统，由采水系统、配水系统、在线水质分析仪器、PLC控制和数据采集举统、数据处理和传输系统，监测站房和配套设备六个部分组成。表文重点介绍了该自动监测系统的关键技术和分析权的特点。     

MODELING THE IMPACT OF SUBSURFACE NUTRIENT FLUX ON WATER QUALITY IN THE LOWER TRUCKEE RWER,NEVADA1

ABSTRACT: The impacts of regional groundwater quality and local agricultural activities on in-stream water quality in the Lower Truckee River, Nevada, were assessed through a detailed program of monitoring and computer simulation. An agricultural diversion and return-flow were monitored in great detail to determine mass loading rates of nutrients from agriculture in the area. Once characterized, the cumulative impacts of agricultural diversions and return-flows were evaluated using the Water Quality Assessment Program (WASP) to model nitrogen, phosphorus, periphyton, and dissolved oxygen. Monitoring showed that a significant proportion of the water diverted for agricultural purposes returned to the river as surface point return-flow (estimated at 13.9 percent $ 0.1 percent), and as groundwater diffuse return-flow (estimated at 27 percent $ 6 percent). Modeling efforts demonstrated the significant effect of assumed regional groundwater quality (nitrate) upon predicted periphyton growth and associated diel fluctuations of dissolved oxygen.     

Modeling biological oxygen demand of the Melen River in Turkey using an artificial neural network technique

Artificial neural networks (ANNs) are being used increasingly to predict and forecast water resources' variables. The feed-forward neural network modeling technique is the most widely used ANN type in water resources applications. The main purpose of the study is to investigate the abilities of an artificial neural networks' (ANNs) model to improve the accuracy of the biological oxygen demand (BOD) estimation. Many of the water quality variables (chemical oxygen demand, temperature, dissolved oxygen, water flow, chlorophyll a and nutrients, ammonia, nitrite, nitrate) that affect biological oxygen demand concentrations were collected at 11 sampling sites in the Melen River Basin during 2001-2002. To develop an ANN model for estimating BOD, the available data set was partitioned into a training set and a test set according to station. In order to reach an optimum amount of hidden layer nodes, nodes 2, 3, 5, 10 were tested. Within this range, the ANN architecture having 8 inputs and 1 hidden layer with 3 nodes gives the best choice. Comparison of results reveals that the ANN model gives reasonable estimates for the BOD prediction.     

Spatial Variations in the Relationships between Land Use and Water Quality across an Urbanization Gradient in the Watersheds of Northern Georgia, USA

A spatial statistical technique, Geographically Weighted Regression (GWR) is applied to study the spatial variations in the relationships between four land use indicators, including percentages of urban land, forest, agricultural land, and wetland, and eight water quality indicators including specific conductance (SC), dissolved oxygen, dissolved nutrients, and dissolved organic carbon, in the watersheds of northern Georgia, USA. The results show that GWR has better model performance than ordinary least squares regression (OLS) to analyze the relationships between land use and water quality. There are great spatial variations in the relationships affected by the urbanization level of watersheds. The relationships between urban land and SC are stronger in less-urbanized watersheds, while those between urban land and dissolved nutrients are stronger in highly-urbanized watersheds. Percentage of forest is an indicator of good water quality. Agricultural land is usually associated with good water quality in highly-urbanized watersheds, but might be related to water pollution in less-urbanized watersheds. This study confirms the results obtained from a similar study in eastern Massachusetts, and so suggest that GWR technique is a very useful tool in water environmental research and also has the potential to be applied to other fields of environmental studies and management in other regions.     

Long term changes in the eutrophication process in a shallow Mediterranean lake ecosystem of W. Greece: response after the reduction of external load

Lake Pamvotis is a shallow Mediterranean lake located in Western Greece near the city of Ioannina. The lake has been recognized as an internationally important conservation site under European Community legislation due to its rich biodiversity. However, during the last three decades the trophic status of the lake has changed as a result of anthropogenic activity (among others irrigation and domestic sewage discharge), resulting in serious problems. Here we present data about the long-term development in eutrophication of Lake Pamvotis. Water samples were collected and analyzed (water temperature, pH, dissolved oxygen, nutrients, chlorophyll-a) during three monitoring periods: 1985-1989, 1998-1999, 2004-2005. The high nutrient concentrations in the lake water during the three monitoring periods, as well as its eutrophic to hypertrophic status reflect the degree of impact anthropogenic activity has had on the lake. Commencement of a restoration plan in 1995-1996, involving sewage diversion, led to a reduction in external nutrient load and consequently to lower in-lake nutrients and Chlorophyll-a concentrations. Orthophosphate concentration decreased by about 87%, nitrates fell below 1.20mg/l, whilst the total reduction of inorganic N compounds showed a weaker downward trend, fluctuating between 0.39 and 1.24mg N/l with an average value of 0.76mg N/l. However, after a short-term recovery the eutrophic status of the lake remains eight years later (2004-2005), suggesting the importance of the internal loading process and the absence of the top-down effect of fish. This study provides evidence for the need of greater restoration efforts utilized in Mediterranean shallow lakes.     

闽江口海域化学需氧量与溶解氧周年变化特征分析

根据2008年1—12月的调查数据，对闽江口海域海水中的COD和DO分布状况与特征进行周年的研究表明，闽江口海域全年的COD含量为0．63～1．70mg／L，符合第一类海水水质标准，季节性变化的规律不明显，受闽江冲淡水的影响，海水中的COD平面分布呈现近岸高，向外逐渐降低的趋势。海水中的DO含量为5．46—8．03mg／L，海水中DO较充沛。尽管受闽江每年向闽江口海域输送大量COD的影响，但是海水中的COD含量仍然较低，该海域具有较大的COD环境容量。     

SUPPLEMENTATION OF MISSING VALUES IN WATER QUALITY DATA1

ABSTRACT The problem of estimating missing values in water quality data using linear interpolation and harmonic analysis is studied to see which one of these two methods yields better estimates for the missing values. The data used in this study consisted of midnight values of dissolved oxygen from the Ohio River collected over a period of one year at Stratton station. Various hypothetical cases of missing data are considered and the two methods of supplementing missing values are evaluated using statistical tests. The results indicate that when the percentage of missed data points exceeded ten percent of the total number in the original sample, harmonic analysis usually yielded better estimates for both the regularly and irregularly missed cases. For data that exhibit cyclic variation, examples of which are dissolved oxygen concentration and water temperature, harmonic analysis as a data generation technique appears to be superior to linear interpolation.     

WATER QUALITY STRATIFICATION IN SHALLOW WASTEWATER STABILIZATION PONDS1

ABSTRACT: The physical limnology of three modern wastewater stabilization ponds serving a small community in Minnesota was investigated over a 1-year period (July 1989 - October 1990). Water temperatures and associated meteorological parameters were recorded continuously; underwater light, dissolved oxygen, pH, and Secchi depth were measured intermittently (about weekly). Measurements of nutrients and planktonic species were made by other investigators. Water quality stratification dynamics were studied by analyzing variations of water temperature, dissolved oxygen, and pH distributions with time and over depth. Intermittent stratification and mixing of the shallow waste stabilization ponds (1–2 m deep) were documented and related to weather. The strong response of the ponds to seasonal and daily weather variations was observed. Three types of pond stratification conditions have been identified: (1) completely mixed during consecutive day and night, (2) stratified during the day and well-mixed during the night, and (3) continuously stratified during day and night. A diurnal cycle of stratification dynamics was first noticed in late April and persisted through summer and into fall. Differences in light attenuation and hence temperature stratification and DO distribution between pond 1 (primary), pond 2 (second primary) and pond 3 (secondary) in the wastewater treatment system were documented and related to different waste loading conditions. Temperature stratification affects chemical, microbial, and planktonic processes in the ponds. Results presented in this paper can be used to provide guidance for water quality sampling in monitoring of pond performance. Information on true mixing conditions is also needed to gain better understanding of important factors affecting pond operation, and for process simulations and reactor modeling of waste stabilization ponds.