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不同营养水平下沉水植物的抑藻效应 总被引:1,自引:0,他引:1
控制水体的营养盐浓度,尤其是磷浓度,可以控制藻类水华的发生.然而,经济成本很高.相对藻类而言,沉水植物对水体营养盐升高敏感性更低,且沉水植物的存在可以改变藻类的群落结构和生长速率.为探讨沉水植物在营养盐与蓝藻水华控制关系中的作用,本研究探讨了有无水生植物存在下,不同营养盐浓度(磷浓度分别为0.025、0.05、0.1 mg·L~(-1),对应地表水Ⅲ~Ⅴ类)下蓝藻水华暴发(chlorophyll-a10μg·L~(-1))的频率、强度和持续时间.结果表明,初始藻浓度为5μg·L~(-1)和10μg·L~(-1)情况下,3种磷浓度下都会发生水华,磷浓度的升高会导致蓝藻水华暴发的强度和持续时间增加.然而,在加入水生植物金鱼藻后,初始藻浓度为5μg·L~(-1)的条件下,没有形成水华.初始藻浓度为10μg·L~(-1)的条件下,各处理组在实验初始时会形成短暂水华,之后,各处理组的叶绿素a浓度均低于10μg·L~(-1),显示蓝藻生长受到抑制.因此,沉水植物存在情况下,在营养盐较高的水体,蓝藻水华也不会发生. 相似文献
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某退役溶剂厂有机物污染场地燃气热脱附原位修复效果试验 总被引:7,自引:1,他引:6
热脱附技术一般用于土壤中有机物的异位修复,然而对于受有机物污染较深土壤的原位修复却鲜有报道.本文以某退役溶剂厂土壤中苯、氯苯和石油类为目标污染物,运用燃气热脱附技术进行原位修复.本文介绍了燃气热脱附技术的工艺设计流程,针对场地目标污染物进行燃气热脱附的工程化试验,结果显示热脱附处理后土壤中苯、氯苯和石油类最高去除率接近100%.本文还探讨了温度、停留时间、土壤含水率和土壤质地对热脱附效率的影响,发现在温度和停留时间相同情况下,含水率较小、孔隙率较大的粉砂土热脱附效果更好.试验表明,燃气热脱附原位修复技术处理场地挥发性有机污染物效果良好,可以进行大规模的实际运用. 相似文献
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NOX作为一种致命的环境污染物,是引起温室效应和光化学反应、酸雨产生的重要危害物质之一。NOX最主要排放源就是火电厂。由于传统火电厂的低氮燃烧技术已无法满足氮氧化物的排放标准。在此情况下,烟气选择性催化还原技术(Selective Catalyst Reduction,简称SCR)诞生了,这项工艺的发明有效地降低电厂氮氧化物对环境所带来的负面影响。 相似文献
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Numerical surface water hydrodynamic and transport models have been traditionally applied to predict power plant thermal impacts under design conditions. The need to understand both thermal impacts and receiving water biogeochemical impacts and associated ecological and health risks under highly variable transient conditions on seasonal to annual time scales necessitates the use of predictive multidimensional modeling systems. Over the last decade, three-dimensional hydrodynamic and reactive transport modeling has matured from a research subject to a practical analysis technology. Simultaneously, computational requirements for realistic three-dimensional modeling have changed from super computers and high-end workstations to economical commodity personal computers. This paper describes a three-dimensional surface water model system, the Environmental Fluids Dynamics Code (EFDC), capable of addressing a variety of power plant impact issues, including thermal transport, water quality-eutrophication, and toxic contaminant transport and fate, in surface water systems. The development history of the model and its previous applications, as well as its theoretical and computational formulations are presented. Model extensions addressing coupled near- and far-field thermal transport due to high velocity cooling water discharges are discussed in detail. To illustrate the model’s capabilities, preliminary results of thermal transport in Conowingo Pond associated with the Peach Bottom Atomic Power Station’s (PBAPSs) discharge are presented and compared with field observations. 相似文献
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介绍了火电厂除尘器应用现状,论述了电除尘器、袋式除尘器和电袋复合式除尘器的原理及特点,分析了电除尘器和袋式除尘器存在的问题,强调了根据火电厂情况合理选择除尘器类型. 相似文献
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纳米铜粉对中肋骨条藻的毒性效应 总被引:2,自引:0,他引:2
以中肋骨条藻作为受试藻种,研究铜离子、纳米铜和微米铜对它的毒性效应.结果表明,3种铜试剂在不同程度上都会抑制中肋骨条藻的生长,藻密度和叶绿素的增加值与铜试剂加入量基本呈负相关.在整个实验周期96h内,当Cu2+浓度大于0.1mg/L时会对藻产生很大的抑制作用,而纳米铜浓度大于0.15mg/L会严重影响藻密度和叶绿素,在24h内当微米铜浓度低于2mg/L时会促进藻的生长,在96h时高浓度(>1mg/L)会抑制其生长.纳米铜对中肋骨条藻的毒性作用一方面是溶出的铜离子,另一方面是纳米粒子本身. 相似文献
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The Watershed Analysis Risk Management Framework (WARMF) was applied to calculate the total maximum daily load of total phosphorus discharged to a reservoir without violating the water quality criteria of 20 μg/l of chlorophyll-a (algae). In addition to a hydroelectric plant at the dam, the reservoir has a thermal power plant on the shore. To simulate the impact of the thermal power plant, WARMF withdraws 113 cms of cooling water from the lake bottom, adds heat to it, and discharges the thermal effluent to the reservoir surface. The circulating water brings the hypolimnion water, which is typically rich in nutrients but low in algae, to the epilimnion. The surface water is enriched in phosphorus but diluted with respect to algae concentration. For the example case, the dilutional effect on algae was found to be more significant than the stimulatory effect of phosphorus. As a result, the total maximum daily load of phosphorus was higher with a thermal power plant than without. Policy makers can learn, through this type of scientific analysis, about the impacts of a thermal power plant and make rational decisions about phosphorus TMDL. 相似文献
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《Atmospheric Environment. Part B. Urban Atmosphere》1992,26(3):331-338
Air quality due to the release of sulphur dioxide from the thermal power plant within the city limits of Ahmedabad has been computed employing a point, area and line dispersion model. To estimate probable air quality, the meteorological data for 3 consecutive days in the middle of each month of 1983 is used. The concentration of sulphur dioxide is computed at a distance of every 500 m in 16 directions up to the city limit. The air quality in the worst case is estimated in downwind distances under unfavourable meteorological conditions.The probable zones of high concentrations of sulphur dioxide over residential, commercial and industrial areas of the city are below the ambient air quality standards set by the U.S. EPA in 1971 almost throughout the year. However, in the months of April and October the zone of high concentration (500 μg m−3) exceeds the EPA standard. Also, under the most unfavourable meteorological conditions, the estimated high ground-level concentration of sulphur dioxide can reach up to 1000 μg m−3 at a distance of 1.25 km from the thermal power plant. This may be attributed to the effect of fumigation. 相似文献
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选取同天过境的Landsat5TM和HJ-1B红外相机数据,在获取3个大气参数后,结合辐射传输模型分别对大亚湾核电基地附近海域海表温度和温排水温升区的分布情况进行遥感监测,对比结果显示,环境卫星遥感监测数据与TM数据监测所得温排水在空间分布上具有较高一致性,二者反演出的绝对温度相差不超过1.1℃,相同温升等级范围内的相对温度均值也不超过0.4℃.因此,HJ-1B红外相机可满足核电站热污染的监测需求. 相似文献
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《Journal of Cleaner Production》2001,9(3):233-242
Energy produced in Estonia from oil shale is studied using the inventory analysis of the product life cycle assessment (LCA) method. The life cycle is taken as an oil shale mine and thermal power plant with consumer supply systems, which are close to each other and are technologically interconnected.The effectiveness of energy production over the whole life cycle is calculated and the energy and the material balances are presented. Local environmental effects of the oil shale extraction and the energy production are briefly described.The first step in defining the oil shale energy as an important input parameter for the LCA studies of all other products of Estonia is made. The collected data can serve as a basis for the environmental improvement programs. 相似文献
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《Atmospheric Environment. Part B. Urban Atmosphere》1990,24(3):443-448
A case study on air quality impact assessment for a proposed expansion of a thermal power plant situated in Bombay is presented. The major aim was to finally estimate a total impact assessment score, which is easy for interpretation and communication. The assessment variables chosen for the power plant are concentration levels of the pollutants SO2, NOx and total suspended particulate matter (TSP), as well as visibility, episode potential and noise. The changes in these parameters for future years, ‘with’ and ‘without’ the power plant, have been estimated. The parameter estimates are then normalized in commensurate units to get a final impact assessment score. 相似文献
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