Water Quality Modeling of Municipal Discharges from Sea Outfalls,Mumbai

The island city of Mumbai with a population of about 10 million generates about 2000 million liters per day (mld) of sewage from the seven service areas of the city sewerage network and discharges it into the adjoining west coast and the two creeks in the Arabian Sea. This has resulted in degradation of coastal water quality, contamination of the adjoining beaches and seafronts. The Municipal Corporation of Greater Mumbai has therefore, undertaken the task of delineating appropriate sewage disposal system to achieve cleaner marine ecosystem through marine outfalls at specific locations. This paper presents the results of the mathematical simulations on the impacts of discharge is-a-vis the length of the outfall and level of land treatment apriori. The results of the simulation indicate the level of bacterial pollution to be higher near the diffuser locations as compared to nearshore regions. 48 hsimulation result analysis shows that FC counts nearthe diffuser location will be in the range of 2000–8000 counts per 100 ml.     

Water Quality Modeling for a Typical Urban Lake Based on the EFDC Model

Urban lakes are typically characterized by fragile ecological capacities and complex management of their hydrospheric ecosystems. The aims of this study are to establish a reliable hydrodynamic-water quality model for an urban lake, to investigate the responses of water quality to different extreme hydrological conditions associated with rainstorms, and to explore the results from different modeled scenarios surrounding the pollution threats associated with a sewage leak. A three-dimensional hydrodynamic water quality model was developed in this study. The model was calibrated and validated using observed data. The model results agreed well with the observed data, and the averaged relative root mean-squared error (RRMSE) for all of the compared variables was 33.3 %. The validated model was applied to analyze water quality responses for different extreme historical rainfall scenarios from January 1, 2012 to December 31, 2012. The model results indicate that for Lake Tianyinhu, rainstorms adversely affect water quality due to larger nutrient loads, generated by larger rainfall events, and the limited water storage capacity of the lake. Moreover, the responses of water quality to sewage leak events were studied through four scenarios with different leak intensities and durations. The model results indicate that sewage leaks have measureable negative effects on water quality and that it is vital to inspect and promptly eliminate any possible leaks within pipes surrounding the lake. This study may provide a useful tool for hydrological ecosystem protection and management techniques for similar urban lakes.     

MATLAB在QUAL ò水质模型计算中的应用

通过实例介绍了MATLAB计算机软件具有的运用计算机工具处理综合水质模型的各离散数据、绘出采样点位置，以及处理模型各变量关系图和检验采样数据精确性及计算准确性等功能。对QUAL-Ⅱ水质模型和计算机图形用户界面的设计及计算结果可视化做了介绍。指出运用MATLAB计算机软件既可以解决计算复杂且太过专业化的问题，又可以利用图像表达各量之间的关系。     

工业企业水污染物排放总量计算方法比较研究

通过对3家企业开展现场监测与调查,深入研究了利用手工监测数据计算工业企业水污染物排放总量的方法,并和自动监测数据法、排污系数法进行了比较研究,指出了3种方法的影响因素和适用范围,为合理计算企业污染物排放总量提供了思路.     

淮河干流河南段水质预测模型试验研究

淮河干流在河南省境内总长417 km,随着区域经济的发展和人口的增长,淮河干流水环境质量形势不容乐观。根据水体扩散理论,建立了淮河干流水质预测相关模型,并进行了科学验证。对淮河干流河南段氨氮、化学需氧量衰减系数及富氧和耗氧系数4个项目开展现场试验及科学分析,为水资源保护规划中计算水体纳污能力、预测污染物浓度、制定污染物控制方案等提供坚实基础和技术支持。     

中国21世纪城市供水新概念--分质供水

结合我国城市一直使用的统一给水方式已与当前水资源紧缺,用水多样化,人们饮用水质质化的状况极不适应的情况,提出对传统的给水方式进行改革的最适宜方式是分质供水。     

应用水质标识指数法评价太湖湖滨带水质

以2009年12月和2010年4、8月的全太湖湖滨带水质监测数据为基础,以TN、TP、NH₃-N、COD_Mn、DO为评价指标,采用水质标识指数评价法对太湖湖滨带水质进行评价。水质指标基本信息显示,NH₃-N冬季、春季空间变异较大,TP夏季空间变异较大;单因子标识指数评价结果显示,太湖湖滨带水体水质因子污染风险时空差异显著,TN冬季、春季全区域污染风险均较大,NH₃-N冬季和夏季在竺山湾、西部沿岸区域污染风险较大,TP三季在竺山湾、西部沿岸区域污染风险较大;综合标识指数评价结果显示,东太湖、东部沿岸、贡湖区域水质较好,为Ⅲ类水,竺山湾和西部沿岸水体水质最差,为Ⅴ类水,且竺山湾和西部沿岸水体三季均处于重度污染状态。该研究可为太湖湖滨带水环境的生态恢复和标识指数应用的推广提供一定的科学依据。     

A Generalized Water Quality Index for Taiwan

By exploring the behavior and limitations of conventional methods for quality evaluation, a better overall index for water quality in Taiwan and its application in Keya River are proposed. The thirteen variables are employed for the quality assessment. Numerical scales relating to the degree of quality are established for each variable to assess variations in quality and to convey findings in a comprehensive manner to others. The employed variables are categorized into three aspects referred to the principal components analysis, which are 'organics', 'particulates' and 'microorganisms'. The overall index consists of the geometric mean for the three defined aspects and multiplying by three coefficients, which reflect quality degrees of temperature, pH and toxicity, respectively. Besides, the arithmetic mean is addressed among the variables associated in the same aspect. Finally, a fresh, mixed aggregation function is developed for ensuring that the index score tells us something useful and does not hide important information. A case study of the Keya River is made to illustrate the application of this new index system. The new proposed index provides comprehensive information for water quality assessment, than the existing index used in Taiwan does.     

Telemetric System for Hydrology and Water Quality Monitoring in Watersheds of Northern New Mexico, Usa

This study utilized telemetric systems to sample microbes and pathogens in forest, burned forest, rangeland, and urban watersheds to assess surface water quality in northern New Mexico. Four sites included remote mountainous watersheds, prairie rangelands, and a small urban area. The telemetric system was linked to dataloggers with automated event monitoring equipment to monitor discharge, turbidity, electrical conductivity, water temperature, and rainfall during base flow and storm events. Site data stored in dataloggers was uploaded to one of three types of telemetry: 1) radio in rangeland and urban settings; 2) a conventional phone/modem system with a modem positioned at the urban/forest interface; and 3) a satellite system used in a remote mountainous burned forest watershed. The major variables affecting selection of each system were site access, distance, technology, and cost. The systems were compared based on operation and cost. Utilization of telecommunications systems in this varied geographic area facilitated the gathering of hydrologic and water quality data on a timely basis.     

滨海新区地表水水质评价与污染源分析

滨海新区在大力发展工业的同时,面临水资源紧缺与水环境恶化等问题,基于2020年至2021年滨海新区内15个监测站位的丰水期、枯水期实测数据,通过改进型加拿大水质指数模型对滨海新区地表水进行水质评价,在水质评价的基础上,利用相关性分析与绝对主成分-多元线性回归模型分析影响地表水水质状况的污染源。15个水质监测站位水质评价结果表明：丰水期水质指数为32.27～82.80,良好水质站位1个,中等水质站位6个,较差水质站位7个,差等水质站位1个;枯水期水质指数为47.28～81.36,良好水质站位1个,中等水质站位12个,较差水质站位2个。污染源分析结果表明：丰水期中,污染源为生活污水、农业面源污染、养殖尾水点源污染;枯水期中,主要污染源为工业废水、生活污水、养殖尾水面源污染。     

A Three-Dimensional Water Quality Model of Chicago Area Waterway System (CAWS)

As outfalls from various water reclamation plants, pumping stations, and combined sewer overflow outfalls discharge into the Chicago Area Waterway System (CAWS), an enhanced understanding of the final fate of crucial water quality state variables is of utmost importance. This paper reports the development and application of a 3D water quality model for a modified CAWS combined with the hydrodynamic kernel of Environmental Fluid Dynamics Code (EFDC). The modified CAWS is used to demonstrate the usefulness of the model while eliminating complications beyond the scope of this initial effort. The water quality model developed and presented in this research is a simplistic dissolved oxygen (DO)—biochemical oxygen demand model with the facility to account for the interaction between the water column and the bed. The aforementioned model is applied for the month of May 2009. The results from the hydrodynamic (EFDC) and water quality model is validated with the help of the observed data obtained from United States Geological Survey gaging stations and Metropolitan Water Reclamation District of Greater Chicago monitoring stations present inside the modeled domain. The 3D modeling captured the hydrodynamic and water-quality processes in CAWS in a satisfactory manner. Furthermore, modeling results showed and proved the interdependence of water quality characteristics in Bubbly Creek and CAWS with the effluent concentration from Racine Avenue Pumping Station situated at the head of Bubbly Creek, South Fork of South Branch of Chicago River.     

平顶山市湛河水水质预报模型研究

运用随机理论－－马尔科夫过程预报平顶山市湛河水质,并通过平顶山市湛河近十年的水质监测数据验证了模型的可靠性,对2000年前后湛河水质进行预报,为使2000年淮河流域水质变清,给平顶山市的管理层提供了一定的理论依据。     

一种水源地气温-水温-水质关系智能预警算法

设计了一种两阶段算法,引入水温作为中间桥梁,第一阶段利用多变异位自适应遗传算法解析气温与水温数学关系,第二阶段根据遗传算法改进的BP神经网络通过水温对水质进行预测,进而设计气温-水温-水质组成的水质预测算法GA-GABP,并将该算法应用于秦皇岛石河水库的水质监测模拟。结果表明,整个过程算法寻优速率快,网络学习时间短,其最终拟合、预测效果理想,能够对水质预警作出有效分析。     

北京市妫水河水质现状评价

2017年分3个时期(丰水期、平水期、枯水期)采集妫水河及其支流12个断面表层水样,分析了COD、氨氮、TP、DO、pH值等水质指标,采用单因子评价法、水污染指数法、主成分分析法和模糊综合评价法对水质进行评价,根据4种水质评价方法的评价结果,分析4种方法在小流域河流评价中的适用性。结果表明:目前妫水河12个断面中S2、S10和Z2 3个断面水质较差,基本属于地表Ⅴ类水,污染程度为重度污染;其他9个断面水质等级为地表Ⅳ类水,污染程度为中度污染;中段世园会段水质较好,优于上段和下段,主要污染指标为COD;妫水河主要污染源于农业和生活,枯水期水质优于平水期和丰水期。水污染指数法更适合小流域水体水质的定性定量评价,且计算方便简单。     

新疆主要城市集中式饮用水源地水质评价

2007年新疆环保系统的调查和评价结果表明,新疆16个主要城市的31个现役集中式饮用水源地总供水量为4.47×10^8m^3,担负着供应420万常住城市人口的生活饮用水、部分工业用水和城市生态用水的责任;城市饮用水源地总体水质良好,水质达标比例为83.9%,不同地区、不同水源类型间存在差异;由于受原生土壤地质条件和人类活动的影响,目前有5个集中式饮用水源地超过国家规定的水质标准,而且部分饮用水源地中有机污染物有多项检出;受水源保护区划工作滞后、监管力度不够等因素影响,部分城市饮用水源地存在一定的环境安全隐患。     

M-估计在水质监测中的应用

Ｍ估计是极大似然估计的一种简称。以水质蒸馏后４氨基安替比林分光光度法测定挥发酚和纳氏试剂比色法测定氨氮为例,分别考察了Ｍ估计与传统的最小二乘法（ＬＳ）所获取的校准曲线方程。回收试验结果表明个别异常值（＜３０％）不影响Ｍ估计,而ＬＳ估计则不然,前者在水质监测中的稳健性亦得以充分证明     

天津市基于新标准的空气质量预报模型效果评估

利用2015年环境空气质量监测数据,对天津市OPAQ空气质量统计预报模型预测效果进行验证评估。结果表明,模型对天津市AQI和PM_(2.5)、PM_(10)、O_3、NO——2的预测结果与实测结果具有较好的趋势一致性,且预测时间越临近,拟合度越好,24 h预报的相关系数r全部达到0.8以上。对PM_(2.5)的预报性能明显优于PM_(10)、O_3和NO_2,PM_(2.5)平均值预测略呈正偏差,但重污染预测值偏低约15%;O_3和NO_2预测值呈明显负偏差,O_3峰值预测不足,NO_2预测值整体偏低,均以24 h预报趋势性最好,但负偏差最为突出。     

Evaluation of Numerical Modeling Methods for the Management of Produced Water Discharges in the Coastal Region with a Canadian Case Study

This study aims at evaluating two numerical methods for 3D simulation of marine pollutant dispersion problems: the random walk particle tracking (RWPT) method and an explicit second-order finite difference method (FDM) for assessing produced water discharges from offshore oil platform. Test cases in a steady flow field were used to evaluate the efficiency and accuracy of simulating pollutant concentration profiles obtained using both the FDM and RWPT method in comparison with an analytical solution. Additionally, a field study was conducted to simulate the lead concentration distribution of produced water discharged from an oil platform off Canada’s east coast, based on the Princeton Ocean Model modeling the ocean flow in the study area with field verifications. Results indicate that, with proper configuration of grid resolution and particle resolution, both FDM and RWPT method can provide accurate results with reasonable computational costs for complex field cases. Particularly, the satisfactory 3D simulations of marine pollutant dispersion in the far field by both FDM and RWPT numerical methods enable effective assessment and management of offshore waste discharges.     

执行GB 3838- 2002《地表水环境质量标准》的思考

指出GB3838－2002《地表水环境质量标准》的内容与GHZB1－1999《地表水环境质量标准》相比有了较大的改动；适用范围增加了具有特定功能的水域，执行相应的专业用水水质标准，标准项目由75项增加至109项，突出了对集中式饮用水源地水质的保护；基本项目标准限值的变化体现Ⅰ、Ⅱ、Ⅲ类水从严，其余放宽，少数几项指标从严，总体放宽的原则。分析了GB3838－2002《地表水环境质量标准》水质评价和水质监测的内容,提出环境监测站应关注该标准中水质监测变化的内容。