Discharge water temperature assessment of thermal power plantusing remote sensing techniques

Thermal power plants are generally constructed near to sea coast to meet their requirement of coolingwater. The warm water discharge from the thermal power plant is one of the major environmentalconcerns in view of the thermal pollution in the sea water. The temperature limit for the warm waterdischarge from the thermal power plant has to be monitored and controlled. Coastal Gujarat PowerLimited (CGPL) operates (24×7) at an “once-through system” based sea water circulation for powergeneration. The used sea water is then discharged into the sea through an outlet channel. As per environmental norms, the discharge water temperature needs to be maintained below the stipulated “delta”rise (+7 ℃) with respect to ambient sea surface temperature at the inlet. We demonstrate the applicability of thermal remote sensing data in understanding the seasonal and temporal variations of thetemperature difference between the discharge water and the ambient sea water. We used thermal banddata from Landsat-8 satellite imagery to map water surface temperature and create temperature profilesalong the intake and outflow channels (till the sea), to understand the variation of temperature andestimate the “DT” between intake point and various observation points along the outflow. This analysiswas carried out for all 11 months (except June) of the year 2018 to correlate temperature variations withseasonal changes. Tidal conditions during the time of data acquisition were also considered to accountfor the effect of tides on DT. The result shows that the average temperature rise between intake andoutflow are maintained at ~3 ℃ across all the months of 2018, with minor variations in the months ofJuly and August. Further, average temperature drop from outflow to cooling channel (before diaphragm)is seen to be ~2 ℃ across all the months with similar seasonal fluctuations.

Characteristics and applications of diffuse discharge of water electrode in air

Plasma water treatment technology, which aims to produce strong oxidizing reactive particles that act on the gas-liquid interface by way of discharging, is used to treat the organic pollutants that do not degrade easily in water. This paper presents a diffuse-discharge plasma water treatment method, which is realized by constructing a conical air gap through an uneven medium layer. The proposed method uses water as one electrode, and a dielectric barrier discharge electrode is constructed by using an uneven dielectric. The electric field distribution in the discharge space will be uneven, wherein the long gap electric field will have a smaller intensity, while the short one will have a larger intensity. A diffuse glow discharge is formed in the cavity. With this type of plasma water treatment equipment, a methyl orange solution with a concentration of 10 mg 1-1 was treated, and the removal rate was found to reach 88.96%.

Water Quality from the Purification Unit of Thiakhar (Diourbel, Senegal) and Impact of Discharges from Treatment on Water Resources

The installation of a purification unit since 2008 in the village of Thiakhar has improved the physico-chemical and bacteriological quality of the water supply. However about 55% of the raw water comes out of the unit as discharges (approximately 14 m3 per day) highly concentrated in fluoride and chloride ions. Based on historical samples, we find that the volumes of water consumed together with the volumes of water discharged are increasingly significant from year to year. The storage of waste water is carried out in a septic tank connected to a leaking cesspool sink. Significant excesses of these discharges are visible on the site and a flow of concentrate is observed creating a puddle of water that attracts birds and straying cattle. The study describes the following substantial impacts on the natural and human environment: 1) contamination of groundwater, 2) soil salinization 3), impact on flora and fauna, 4) impact on health. The study concludes by identifying measures to mitigate the negative impacts related to the discharges and by proposing alternative solution.

Influence of Rainfall, Discharge, Wave and Alongshore Transport on Microbiological Pollution in Southern California Coastal Beaches

The coastal zone is the significant environmental setting where ocean interfaces land. In addition, it is economically important because of its high residential, commercial and recreational values. Meanwhile, in the United States, public coastal areas are increasingly off-limits due to elevated levels of fecal pollution and other contaminants. This study investigates the effects of rainfall, discharge, wave, and alongshore transport on coastal FIB （fecal indicator bacteria） concentrations at adjacent beaches in Orange County, California, over three years＇ period from October 2001 to September 2004. In order to identify the dominant tempora land spatial patterns of fecal pollutions along the coastal beaches, Empirical Orthogonal Function analysis was utilized for the three-year measurements （n = 39,525） of FIB concentration data from 17 sampling stations. Through the data analysis and the empirical orthogonal function analysis, it was found that the dominant factor effecting coastal FIB concentration is precipitation event and consequent water discharge from Santa Ana River in the area. The Empirical Orthogonal Function analysis revealed the potential non-point FIB sources around northern part of Orange County beaches. In addition, this study confirmed the existing alongshore transport by wave-driven surf zone current and offshore tidal currents.

Preliminary Study on Formulating Water Quality Standards for Estuaries of China

In China,the water quality standards in operation include the Environmental Quality Standard for Surface Water（GB3838-2002）and Water Quality Standards for Seawater（GB3097-1997）.However,these two standards are currently not suitable for the estuarial zones of China because of the unique properties of water environment in estuaries.We proposed preliminarily a basic idea and technical workflow in formulating water quality standards for the estuaries of China based on analyzing the water environment properties of estuaries comprehensively and comparing various parameters and their standard values mentioned in these two standards above.Issues pertinent to the formulation of the water quality standards for estuaries,e.g.nutrient,heavy metals and persistent organic pollutants（POPs）,are highly concerned.The objective of this paper is to provide technical support for the formulation of scientific water quality standards and the assessment of water quality of the estuaries of China.

Diagnosis of Lead Pollution of Surface Waters of a River: Case of the Djiri River in the Republic of Congo

This research work focuses on the physico-chemical analysis of surface water from the Djiri River with the aim of preventing the population against possible water pollution. The analysis of samples taken from the Djiri river revealed the presence of lead in these waters at levels exceeding the WHO guideline values: an average annual pollution (0.93 mg/l) which is visibly higher than the value. WHO guide (0.01 mg/l) in situ data from the Djiri River revealed a significant drop in flow between the 2016 period characterized by a divergence index of 0.82344, thus highlighting a hydrological situation for which national hydrological stakeholders will absolutely have to implement measures, remedial measures or mechanisms to protect this river against possible disappearance by elimination of lead in the water.

Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

POLLUTION TREND IN THE TUMEN RIVER AND ITS INFLUENCE ON REGIONAL DEVELOPMENT

The Tumen River had failed to meet Grade Ⅲ and Ⅳ levels in the environmental quality standard for surface water, and had exceeded Grade Ⅴ level. Surface water pollution is serious. The major excessive standard pollutants were COD Mn and SS. After taking effective treatment steps, the worsening trend of water pollution will be basically under control. But the change of runoff in the Tumen River is large in a year, especially during as long as five month freezing period, smaller flow and lower temperature of river waters led to weak dilution and self purification capacity. The water quality of the Tumen River will not reach the appoint functional water quality standards, even if sewage meets discharge standard, which will influence water resources utilization in the lower reaches of the Tumen River and regional economic development. Therefore water pollution has become the major restrictive factor of the development of the Tumen River area.

Water Quality Assessment of a Trout Farming Effluent,Bocaina,Brazil

The concern in mitigating the negative impact generated by the discharge of nutrients in the receiving water body is a challenge for the sustainable development of Brazilian fish farms. Thus, the purpose of this study was to evaluate the water quality and environmental impact caused by trout farming system effluent with focus on discharge of phosphorus. Sampling was performed on a weekly basis in triplicate from September to November 2010. Sample sites were distributed according to the water flow: upstream from trout farming system, water supply, effluent, artificial wetland, mixing zone and downstream (60 m from effluent). In the field, pH, conductivity, dissolved oxygen, water temperature and turbidity were measured. In laboratory, nitrogen and phosphorus series, chlorophyll a, total solids suspended and their organic and inorganic fractions were analyzed. For the good growth of trout in production system, the abiotic factors described in the water quality monitoring demonstrated acceptable values. Environmentally, after passing through the production system and artificial wetland, there was an increase in concentrations of total phosphorus, total nitrogen, orthophosphate, ammonium, chlorophyll a, total solids suspended and their organic and inorganic fractions (P < 0.05). These results are related with the quality of feed, feeding management and the inefficiency of the artificial wetland. Therefore, it is necessary to use best quality feed to meet the nutritional requirements of trout, maintaining an optimal feed conversion and reducing pollution generated by effluent.

Assessment of Heavy Metal Concentration in Hand Dug Well Water from Selected Land Uses in Wukari Town, Wukari, Taraba State, Nigeria

Hand dug well water remains the major source of domestic (drinking) water in the city of Wukari. This study was aimed at the assessment of heavy metal concentration in hand dug well water from four land uses of abattoir (A), waste dump site (B), residential (C) and commercial (D) in Wukari Town, Wukari, Taraba State. There are about 76 hand dug wells in the study area and for the purpose of this study. Yamane (1967) sample size technique was adopted. Based on this, 95% confidence level and an error limit of 5% were adopted. Thus, four (4) samples A, B, C and D of hand dug well water purposively drawn from the study area used sterilized bottles. The heavy metals tested for in the water samples include: zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), potassium (K), phosphate, and chromium. The results of the analyses were compared with the NSDWQ*MPL and FEPA (2001) standards. The results shows that the concentration of magnesium and manganese in hand dug well water samples A, B, C and D had higher concentrations than the maximum permissible limits of NSDWQ*MPL and FEPA (2001) standards and the concentration of zinc, copper, iron, potassium, phosphate and chromium in hand dug well water sample A, B, C and D was at different compliance level with NSDWQ*MPL and FEPA (2001) standards. ANOVA (F-ratio) statistics at P_0.05 for variation in heavy metal concentration in hand dug well water from land uses A, B, C and D were insignificant. For now, it can be concluded that hand dug well water in Wukari Town is fit for domestic use, but that efforts should be made to reduce the magnesium and manganese concentration by having control on the anthropogenic factors that lead to such high concentration levels or else, soon this source of water may become unfit for domestic use. It was recommended that aggressive public awareness and enlightenment on possible impacts of hand dug well water pollution from human activities should be embarked upon by relevant agencies.

Analyses of Physical and Chemical Parameters in Surface Waters nearby a Cement Factory in North Central, Nigeria

Water samples were collected from three stations along the water course of Oinyi River, Kogi State, Nigeria, bi-monthly for 12 months (October 2010 to September 2011). A total of 16 physical and chemical parameters (temperature, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, electrical conductivity, flow velocity, depth, nitrate, nitrite, phosphate, ammonia, pH, turbidity, total suspended solids, total dissolved solids and colour) were analyzed and results showed that pH (6.8 to 7.26), conductivity (106.0 to 211.7 μS/cm), colour (3.87 ± 0.159 Pt.Co), turbidity (14 - 22.7 NTU), total suspended solids (45 - 54 mg/l), biochemical oxygen demand (2.05 - 2.89 mg/l), chemical oxygen demand (17.19 ± 0.15 mg/l), temperature (24°C to 27°C) and depth (0.23 to 0.35 m) were significantly different across the different stations and between the months. However, total dissolved solids (52.7 to 108.8 mg/l), dissolved oxygen (6.02 to 7.01 mg/l), ammonia (0.00 to 0.02 mg·l-1), nitrite (0.01 - 0.09 mg·l-1), nitrate (0.045 ± 0.006 mg·l-1), phosphate (0.2 to 2.05 mg·l-1) and flow velocity (0.1 to 0.35 m·s-1) showed variations within the sampling stations. Maximum conductivity (211.7 μS/cm), colour (5.83 Pt.Co), turbidity (22.7 NTU), total suspended solids (54 mg/l), total dissolved solids (108.8 mg/l), nitrite (0.09 mg/l) and nitrate (0.006 mg/l) values were recorded at station 2 which is the discharge point of industrial waste. River water did show significant pollutional increase at the effluent impacted site during the present study. Dissolved oxygen showed direct relation with temperature, biochemical oxygen demand and chemical oxygen demand. The non-stop and continuous discharges of cement waste water into the river lessened water quality with significant or corresponding effect on the biota of the studied area, thus paving way for clear assertion that the water quality deterioration was as a result of the impacts of the waste water from cement industry.

Assessment of Water Quality of the Trans-Boundary Zarafshan River in the Territory of Uzbekistan

The Zarafshan river is a main trans-boundary river of the Aral Seabasin. As the main water resource, the Zarafshan river water is mainly used by the republics ofTajikistanandUzbekistan. We explored the trends of space-time pollution of river water with ammonium, nitrates, phosphates, biological oxygen demand (ВОD), fluorine and some heavy metals at seven water sampling points along theZarafshanRiver inUzbekistan. The experimental data showed that the water quality of the Zarafshanriver in 2002-2009 has undergone a considerable transformation, even by the length of the river. The chemical composition of the Zarafshan river water underwent changes due to the agricultural collector-drainage discharges and the sewage of the cities of Samarkand and Navoi. The water pollutants of the Zarafshan river, as a con- sequence of the agricultural pollution, consisted of mineralization, ammonium, nitrate, phosphate, and pesticides. Therefore, it is necessary to monitor the chemical composition of the large agricultural collector-drainage discharges into the river. The main sources of the heavy metals (primarily arsenic and zinc) in the Zarafshan river water were probably ore processing manufactures located interritoryofTajikistan.

我国典型地区水厂纳滤净化系统产生浓水的水质特征及处理需求分析

近年,纳滤净化技术在我国城镇水厂得到一定规模的推广应用,普遍取得了较好的净化效果,但在净化过程中生成了一定量的浓水,其净化处理和资源化回用受到人们关注,并制约了纳滤净化工艺的推广应用。论文基于国内纳滤净化工艺应用目标的调研结果,分析了纳滤浓水的产生、影响因素及其典型水质特征,论述了浓水排放和处理处置方面的典型研究进展,探讨了纳滤浓水处理处置的优化策略。论文可为纳滤净化系统在国内的推广应用提供一定的指导和借鉴。

农村灰水一体化PMBF处理技术研究

针对农村灰水水量大、污染物浓度低、易于处理和资源化利用的特点,结合农村灰水一体化处理技术欠缺及资源化利于水平低的现状,研发了以“强化预处理+多介质渗滤”为主体工艺并优化集成的农村灰水一体化PMBF处理技术。取化粪池上清液调配至目标水质作为中试装置的进水,稳定运行后,主要污染物指标COD、NH_(4)^(+)-N、TN、TP去除率分别为76.2%、77.4%、14.8%、11.5%,出水可达到农村生活污水污染物排放要求,消毒后可满足《城市污水再生利用城市杂用水水质》(GB/T 18920-2020)中道路清扫、绿化、建筑等用水需求。一体化PMBF工艺占地面积小,运行维护管理简单,经济成本低,设计规模10 m^(3)/d的处理设施,吨水占地约2 m^(2)/m^(3),吨水建设成本约7000元/m^(3),吨水运行成本约0.2元/m^(3)。

基于“船载舱养”模式国内养殖工船的大气和水污染排放控制研究

基于“船载舱养”的养殖工船模式构建理念,结合10万吨级大型养殖工船建造项目,阐述目前法规、国标对养殖工船防止大气污染和防止水污染的控制措施,并对养殖工船设计、建造和营运给出建议。

水资源污染综合治理措施及其防治效果评估研究

长期的水污染会破坏水环境,造成生态系统的破坏和失衡,影响人类的生产和生活。为此,研究水资源污染综合治理措施并评估防治效果。在分析了水资源污染物的4种主要类型后,从工业生产、市政管理以及工程保障3方面提出相应的治理措施,并使用模糊综合评价法对治理后的效果评价,将评价结果分为5个等级,利用加权平均原则对评价结果定量计算。将所提治理措施应用在某市生态公园调节塘内,经一段时间后检验该塘水质有了明显改善,防治效果评估结果为优秀,证明所提方法在水资源污染治理方面具有可行性。

国内外钢铁工业水污染物排放标准对比及启示

钢铁工业是国民经济重要的基础产业,其用水量大,涉及的生产工艺流程长,排放的污染物种类也较多。为了加强钢铁工业的水污染物排放管理,美国、德国、欧盟等国家(地区)以及世界银行均针对钢铁工业制定了水污染物排放标准,各钢铁工业水污染物排放标准具有各自的特点。梳理了国内外钢铁工业水污染物排放标准,对各标准的适用范围、污染物项目以及排放限值、超标判定要求等主要技术内容进行了对比研究。最后,为了完善我国钢铁工业水污染物排放标准,提出了相关工作建议。

明渠非标准断面法测流水位流量关系的率定及影响因素分析

为探究明渠非标准断面法测流的水位流量关系曲线的率定问题,以新疆第三师某团场25处渠道量水断面为研究对象,利用FlowTracker 2手持式声学多普勒流速仪进行了水位流量关系率定工作.根据实测结果,率定了各渠道量水断面的水位流量关系曲线,并对所率定出的曲线进行了符号检验、适线检验和偏离数值检验及误差分析,在此基础上,对流量拟合参数的影响因素进行了分析.结果表明:所率定的25处渠道量水断面中,14处具有稳定的水位流量关系,5处受回水影响、6处受渠道淤积影响为不稳定的水位流量关系;在渠道粗糙系数Ra、边坡系数m及坡降i相同的条件下,流量拟合参数与渠道底宽b总体上呈正相关;在渠道粗糙系数Ra、边坡系数m及底宽b相同的条件下,流量拟合参数与渠道坡降i总体上呈负相关.研究结果可以为灌区自动化量水设备测流准确性的校核提供参考依据.

清潩河流域水污染物排放标准实施评估

污染物排放标准评估是排放标准执行周期中的重要环节,但中国对流域型水污染物排放标准实施效果评估的实践探索较缺乏。在现有规范指南的基础上,针对《清潩河流域水污染物排放标准》(DB 41/790—2013)构建了适用于清潩河流域特点的水污染物排放标准评估体系,并在清潩河流域对该标准实施情况进行了评估。结果表明,该标准对重点污染物控制处于中等水平,在分区域精细控制方面略有欠缺,该标准实施实现了流域内污染源排放方式优化,促进了污染物排放量的削减、产业结构优化、落后产能淘汰;该标准实施后流域水环境得到较大改善,但也存在对行业排污控制针对性、约束性不足等问题。

基于减污降碳和水质目标约束下的黄河干流兰州段城区污水处理厂出水排放限值研究

为科学合理地提出黄河干流兰州段城区污水处理厂出水排放限值,实施精准科学治污,持续改善黄河干流兰州段水环境质量,本文以兰州市城区四座有代表性的污水处理厂(西固、七里河安宁、盐场和雁儿湾污水处理厂)为研究对象,统计四座污水处理厂主要污染物排放浓度、中水回用率、主要污染物去除率及减排效果,分析四座污水处理厂入河排污对黄河干流兰州段水质的影响,梳理污水处理厂运行阶段的碳排放情况.结果表明:(1)兰州市城区四座污水处理厂中水回用率低,介于0.86%~4.66%之间.(2)四座污水处理厂主要污染物的去除率高于国内污水处理厂主要污染物去除率的平均水平,COD、NH_(3)-N年均减排量分别为114584.1、8234.6 t,减排效果明显.(3)在黄河枯水期上游来水水量小、水质接近或超出GB 3838-2002《地表水环境质量标准》Ⅱ类水质目标限值的条件下,叠加区间其他入河排污口的影响,兰州市城区四座污水处理厂均按照设计规模及设计出水水质排污会对下游河段水质造成影响.因此,不能一味地追求出水水质,盲目提标改造,要综合考虑污水处理厂运行过程中的碳排放,在满足受纳水体水质目标前提下,统筹考虑减污降碳.