Environmental impact of seawater desalination plants

Enormous amounts of seawater are desalted everyday worldwide. The total world production of fresh water from the sea is about 2621 mgd (9.92 million m³ day^-1 1985 figures). Desalting processes are normally associated with the rejection of high concentration waste brine from the plant itself or from the pretreatment units as well as during the cleaning period. In thermal processes, mainly multistage flash (MSF) thermal pollution occurs. These pollutants increase the seawater temperature, salinity, water current and turbidity. They also harm the marine environment, causing fish to migrate while enhancing the presence of algae, nematods and tiny molluscus. Sometimes micro-elements and toxic materials appear in the discharged brine.This paper will discuss the impact of the effluents from the desalination plants on the seawater environment with particular reference to the Saudi desalination plants, since they account for about 50% of the world desalination capacity.     

Seasonal monitoring of heavy metals and physicochemical characteristics in a lentic ecosystem of subtropical industrial region, India

Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variations of lentic ecosystem (lakes and reservoirs) pollution due to industrial effluent discharge. In this study, nine metals and 15 physicochemical parameters, collected from four sampling sites in a tropical lake receiving the discharge from thermal power plant, coal mine, and chloralkali industry, during the years from 2004 to 2005, were analyzed. For greater efficacy in monitoring of heavy metals, particle-induced X-ray emission has been used during present investigation. Different statistical techniques like analysis of variance, Pearson correlation, principal component analysis, and factor analysis were employed to evaluate the seasonal correlations of physicochemical parameters. Most of the metals and physicochemical parameters monitored in the present study exhibited high spatial and temporal variability. Pertaining to metal pollution, the most polluted site was Belwadah, i.e., waters and sediments had the highest concentration of all the relevant metals. The reference site was characterized by the presence of low concentrations of metals in waters and in sediments. Based on the high metal concentration recorded in lake ambient, drinking, bathing, and irrigation water should not be used by the local people at the effluent discharge points.     

Impact of human activities on the quality of river water: The case of Evrotas River catchment basin,Greece

The impact of point (domestic and industrial effluents) and non-point (agricultural land runoff) pollution sources on the quality of the receiving waters of the Evrotas River (Laconia, Greece) was investigated during a monitoring study from August 1991 to August 1992. The part of the river which was located near the city of Sparta was seasonally influenced by the discharge of effluents from orange juice plants (operating during winter) and by the discharge of septage for the emptying of cesspools which are serving part of the city. The low dilution of incoming pollutants (septage) during the low water flow in summer lead to the decreasing self-purification capacity of the river and the development of septicity conditions in some of its parts. In the vicinity of intensively cultivated areas, the high concentrations of nitrogen and phosphorus which were detected in the river water during winter and spring may be partly attributed to the leaching of the applied fertilizers because of nirogen mobilization and soil erosion, following the season's precipitations. The protection of the Evrotas River water Quality must therefore include adequate treatment of the septage produced in the area, as well as the construction of wastewater treatment plants for the major industries of the area. The non-point pollution could be controlled by the restoration of the Evrotas riparian vegetation, together with a more rational use of fertilizers in the area.     

流域重点工业污染源识别特征成分谱建立技术

研究了基于生产排放全过程、多相、多类污染物并举的污染源识别特征成分谱建立技术。首先建立污染源排放完整图谱,包括原辅料、中间物质、产品、各工艺废水污染物、水处理设施进口和出口污染物等。然后从排放完整图谱中解析出特征污染物。对于废水中的常规污染物和金属污染物,采用与受纳水体浓度相比较的方式得到污染源识别特征污染物,建议将浓度超过受纳水体1倍的污染物定为特征污染物。对于有机污染物,将质量分数之和大于90%的污染物集定为特征有机污染物,并按照有机物类别进行分类。最后开发建立动态的水污染源排放数据库。应用该技术建立了石化行业典型企业的排放特征成分谱,发现这些特征组分具有很好的代表性,为水污染源的识别提供了基础数据。     

天津近岸海域水污染评价

为了认识天津近岸海域水质主要污染指标及污染物随年份的演变规律,根据1996年—2007年天津近岸海域水质监测数据,对天津近岸海域水污染状况进行了时空分析。结果表明,天津近岸海域水质总体呈恶化趋势,劣Ⅳ类海域面积比例呈增加趋势,主要污染因子为无机氮。提出,应确立治海先治陆的思想理念,建立陆源污染排放总量控制制度;加强对海上作业的管理,加强保护开发海域的生态环境。     

生物监测技术在工业废水监测领域的应用研究

生物监测可以系统反映污染物对生物生长的影响及其在生物体内的转化和迁移,在水环境监测与生态健康管理中的重要性日益突出.伴随着工业化的快速发展,中国水环境污染问题依然严峻,工业废水治理和排放问题仍旧突出.为进一步保障工业废水出水及受纳水体水质安全,迫切需要在工业废水监测中引入生物监测技术.对传统微生物群落监测法、水生生物毒...     

船载自动监测系统在水质监测中的应用

水质监测是开展水生态环境评价、监管的基础性工作之一。随着对水生态环境保护与管理要求的提高,人工水质监测与自动水质监测相结合的模式应用越来越普遍。以船舶为载体的水质自动监测系统开展巡测,可实现高密度样品采集、检测及信息的实时传输,在长江泸州以下干流水域的实践中取得了良好效果。系统的应用可弥补常规监测断面间距过大、人工监测频次低、固定站房式水质自动监测站近岸取样等不足,对人工监测和自动监测形成有效补充;船载水质自动监测系统能够实现定点、定深、定时监测,可以在河流污染带监测、入河排污行为的监管以及偷排行为的溯源、水污染应急动态监测等工作中发挥有效作用,既可应用于长江干流等河道较宽且水质可能存在岸别差异的河流,也可应用于滇池、太湖、丹江口等大型湖泊、水库水生态环境监管。     

Assessment of toxic heavy metals in urban lake sediments as related to urban stressor and bioavailability

Aquatic pollution pose a serious challenge to the scientific community worldwide, since lakes or reservoirs find multifarious use and most often their water is used for drinking, bathing, irrigation, and aquaculture. Nine metals and several physicochemical parameters, from four sampling sites in a tropical lake receiving the discharges from a thermal power plant, a coal mine, and a chlor-alkali industry, were studied from 2004 to 2005. Pertaining to metal pollution, the site most polluted with heavy metals was Belwadah, i.e., waters and sediments had the highest concentration of all the metals examined. The reference site was characterized by the presence of low concentrations of metals in waters and sediments. Following the water quality monitoring, 2-month field phytoremediation experiments were conducted using large enclosures at the discharge point of different polluted sites of the lake. During field phytoremediation experiments using aquatic macrophytes, marked percentage reduction in metals concentrations were recorded. The percentage decrease for different metals was in the range of 25% to 67.90% at Belwadah (with Eichhornia crassipes and Lemna minor), 25% to 77.14% at Dongia nala (with E. crassipes, L. minor and Azolla pinnata), and 25% to 71.42% at Ash pond site of G.B. Pant Sagar (with L. minor and A. pinnata). Preliminary studies of polluted sites are useful for improved microcosm design and for the systematic extrapolation of information from experimental ecosystems to natural ecosystems.     

用水氵蚤监测水质

介绍了利用水Sao监测水质的优势及常用方法，探讨了水Sao的实验室培养技术，并了水Sao对污染物的形态、生殖和行为反应，提出利用水Sao监视污水安全排放和生产用水水质的设想。在分析水Sao毒性试验误差来源的基础上，建议对试验生物材料和测试环境进行限定，最终形成操作性强的标准方法。     

Improving water quality through California’s Clean Beach Initiative: an assessment of 17 projects

California’s Clean Beach Initiative (CBI) funds projects to reduce loads of fecal indicator bacteria (FIB) impacting beaches, thus providing an opportunity to judge the effectiveness of various CBI water pollution control strategies. Seventeen initial projects were selected for assessment to determine their effectiveness on reducing FIB in the receiving waters along beaches nearest to the projects. Control strategies included low-flow diversions, sterilization facilities, sewer improvements, pier best management practices (BMPs), vegetative swales, and enclosed beach BMPs. Assessments were based on statistical changes in pre- and postproject mean densities of FIB at shoreline monitoring stations targeted by the projects. Most low-flow diversions and the wetland swale project were effective in removing all contaminated runoff from beaches. UV sterilization was effective when coupled with pretreatment filtration and where effluent was released within a few hundred meters of the beach to avoid FIB regrowth. Other BMPs were less effective because they treated only a portion of contaminant sources impacting their target beach. These findings should be useful to other coastal states and agencies faced with similar pollution control problems.     

Industrial effluent quality, pollution monitoring and environmental management

Royal Commission Environmental Control Department (RC-ECD) at Yanbu industrial city in Kingdom of Saudi Arabia has established a well-defined monitoring program to control the pollution from industrial effluents. The quality of effluent from each facility is monitored round the clock. Different strategic measures have been taken by the RC-ECD to implement the zero discharge policy of RC. Industries are required to pre-treat the effluent to conform pretreatment standards before discharging to central biological treatment plant. Industries are not allowed to discharge any treated or untreated effluent in open channels. After treatment, reclaimed water must have to comply with direct discharge standards before discharge to the sea. Data of industrial wastewater collected from five major industries and central industrial wastewater treatment plant (IWTP) is summarized in this report. During 5-year period, 3,705 samples were collected and analyzed for 43,436 parameters. There were 1,377 violations from pretreatment standards from all the industries. Overall violation percentage was 3.17%. Maximum violations were recorded from one of the petrochemical plants. The results show no significant pollution due to heavy metals. Almost all heavy metals were within RC pretreatment standards. High COD and TOC indicates that major pollution was due to hydrocarbons. Typical compounds identified by GC-MS were branched alkanes, branched alkenes, aliphatic ketones, substituted thiophenes, substituted phenols, aromatics and aromatic alcohols. Quality of treated water was also in compliance with RC direct discharge standards. In order to achieve the zero discharge goal, further studies and measures are in progress.     

Efficient control of air pollution through plants, a cost-effective alternative: studies on Dalbergia sissoo Roxb

Plants can be used as both passive biomonitors and biomitigators in urban and industrial environments to indicate the environmental quality and to ameliorate pollution level in a locality. Many studies reveal that plants are negatively affected by the ambient levels of air pollutants. The present study was conducted to evaluate the impact of air pollution on comparative basis with reference to changes in photosynthetic pigments, plant height, leaves, as well as, biochemical parameters of plants of different sites around Udaipur city receiving varying levels of pollution load. The investigated tree species Dalbergia sissoo Roxb. (Family: Fabaceae) exhibited a reduction in various physiological and biochemical growth parameters that correspond with air pollution levels at different sites. The tree species growing in polluted and control areas were compared with respect to foliar dust load, leaf area, and chlorophyll and total carbohydrate and total protein concentration in the leaves. Our studies suggest that D. sissoo Roxb. can successfully be grown in an area for monitoring air pollution, where it is mild and droughts are common. It will prove as an ideal tree species to control pollution effectively beside acting as a shade tree and being a source of food for birds and animals. By plantation of D. sissoo Roxb., mitigative measure at the polluted sites to control generation of particulate matter and the air quality required can be ensured. Our results also confirm that industrial and vehicular air pollution level in Udaipur city is shifting beyond limits.     

洪泽湖流域生态环境问题及治理对策

分析了洪泽湖水环境和污染源特征,针对存在的氮磷超标导致湖体富营养化、生态退化以及入境客水污染等主要环境问题,提出制订入湖河流TN标准、控制污染物排放总量、修复湖泊生态、治理客水和强化水质监控等措施,为有效地改善洪泽湖水环境质量,遏制湖泊富营养化趋势提供科学支撑。     

支撑排污许可制度的固定源监测技术体系完善研究

排污许可制度是固定源核心管理制度,对污染源监测技术提出"便捷、智能、精细"的发展要求,依规发证、依证管理2个阶段均需要污染源监测技术的有效支撑。针对当前污染源监测技术体系现状,应进一步完善自行监测技术指南体系,对发证行业指南实施情况跟踪评估,适时修订;为将工业园区纳入核发排污许可证范围扎牢基础,制定工业园区自行监测技术指南;加快构建支撑证后监管执法的快速便捷方法标准体系和现场快速监测质控体系;加快构建智能化监测数据管理平台,实现"智慧大脑"功能;建立自行监测监督检查技术体系,强化排污许可制度框架下的自行监测质量的监督检查。     

东江下游污染源和纳污水体的雌激素效应水平

利用重组双杂交酵母快速检测技术分析了东江下游两个污水厂、8个工业废水排放口和6条受纳河流水体共16个样品中的雌激素效应物质浓度,并按照雌二醇当量(EEQ)计算了水中雌激素效应水平。在被检测废水样品中,排水的EEQ值处于0.3~2.8ng/L之间,其中造纸厂与纸制品厂排水具有明显雌激素效应。采自河涌的6个样品有4个样品检出雌激素活性,雌激素效应水平在1.9~8.8ng EEQ/L之间。结果表明,东江下游行业废水处理厂出水中的EEQ浓度应与河涌水体中的EEQ在相同数量级, 与国内报道的其他地区河流及工厂排水污染水平类似。污染较为严重的河涌水体雌激素水平明显高于污水处理厂及工厂排水,推断污染河涌水体中的雌激素效应物质应来自未经处理的污染源。     

Real-time monitoring of water quality using fish and crayfish as bio-indicators: a review

Water quality monitoring using fish and crayfish as bio-indicators requires an understanding of the state of pollution of waters, choice of bio-indicators, physiological and behavioral endpoints of fish and crayfish, and principles of the methodology and their potential applications. Here, we discuss telemetry, acoustic monitoring, vision-based monitoring, measures of ventilatory activity, electrocardiography, and fiber-optic plethysmography. Assessment of water quality must be based, not only on physicochemical characteristics of the current environment as determined by chemical analyses, but also on observations of the physiology and behavior of its inhabitants. Real-time biomonitoring is suggested as the most reliable method, since it incorporates living organisms into the system to serve as biosensors. The potential application of the methods discussed includes use at water treatment plants and water supply stations for prevention of hazardous toxicological events, and, for aquaculture, in ponds, lakes, and aquariums for monitoring growth, population size, and behavior traits.     

生活垃圾与危险废物的焚烧工艺及污染防治措施比较

比较、归纳、总结了生活垃圾和工业危废焚烧项目在生产工艺、污染源产生及治理、污染物排放标准等方面的异同点,提出必须重视废气排污口设施与在线监测仪器的安装,应完善事故防范措施与应急预案等检查要求,为环保部门验收监测、监督管理工作提供技术支持.     

建立深圳市机动车氮氧化物排放因子初探

针对国内机动车排放因子研究处于起步阶段的实际情况,因地制宜地确定了深圳市当地的机动车氮氧化物排放因子研究技术路线,通过大量的调研、实测建立深圳市道路和联片建成区机动车氮氧化物排放因子,为深圳市机动车排气污染研究和控制提供了参数.     

浅谈地表水重金属污染监测现状及对策

介绍了重金属污染的现状及危害,并分析了国内外重金属监测现状.阐述当前地表水重金属监测的主要方法和原理,指出地表水重金属监测工作存在的主要问题,并对重金属监测工作提出了对策和建议.     

Monitoring of Distribution Water Qualities Under Various Source Water Blending

The main goal of this large-scale pilot distribution study was to systematically investigate the impacts of blending different source waters on distribution water qualities. The principal source waters investigated were conventionally treated ground water (G1), surface water processed by enhanced treatment (S1), and desalted seawater by reverse osmosis membranes (RO). Due to the nature of raw water quality and associated treatment processes, G1 water had high alkalinity, while S1 and RO sources were characterized as high sulfate and high chloride waters, respectively. One year of pilot pipe study demonstrated that water quality was significantly deteriorated by increased color when source water blends with characteristics different from historic groundwater were introduced to pipe distribution systems. Elevated color was associated with release of iron corrosion products, mainly from aged unlined cast iron pipes. Iron release increased significantly when exposed to RO and S1 waters: that is, the greater iron release was experienced with alkalinity reduced below the background of G1 water. Lead and copper release to water, on the other hand, enhanced with the application of RO and G1 waters, respectively.