【摘要】 对污染物来源和水质演变规律的深入认识是水源水库水质污染控制的前提.李家河水库是西安市的重要水源地,为加强李家河水库水源地保护工作,于2016年12月～2017年12月逐月对李家河水库进行水质监测.结果表明,李家河水库的主要污染物来源是上游来水,其对高锰酸盐指数、TN和TP的贡献率分别达99. 52%、99. 41%和99. 23%;上游东采峪葛牌小学河段和草坪服务区以上河段污染负荷较高,西采峪主要污染源汇入点为养鸡场和渔场.夏秋季水库会形成热分层,水体稳定分层期,在外源污染汇入和底部厌氧释放双重作用下水体中TN、TP、高锰酸盐指数、TOC、Fe和Mn的质量浓度分别高达3. 32、0. 177、5. 21、3. 01、0. 21和0. 235 mg·L-1,其中TN、TP、Fe和Mn质量浓度均超过《地表水环境质量标准》(GB3838-2002)Ⅲ类水限值;较高的营养盐水平促进了藻类的大量繁殖,水体稳定分层期表层水体藻密度最高达到2. 18×108个·L-1,优势藻种为蓝藻门的铜绿微囊藻和束丝藻,对水质安全威胁较大.因此李家河水库水质污染控制的首要任务是采取有效措施控制藻类繁殖,同时加强水库上游污染源治理,降低污染物输入负荷.更多还原

【Abstract】 An in-depth understanding of the source of pollutants and the evolution of water quality is a prerequisite for water pollution control in source water reservoirs. Lijiahe Reservoir is an important water source for Xi’an. To strengthen the protection of Lijiahe Reservoir,water quality monitoring was carried out monthly from December 2016 to December 2017. The results showed that the main pollutant source was upstream water,and its percentage contribution to the bulk pollutants was 99. 52% for permanganate index,99. 41% for TN,and 99. 23% for TP. The main source of pollution in the upstream Dongcaiyu was the upper reach with Gepai Primary School and the turf service area. The main source of pollution in Xicaiyu was the upper reach with a chicken farm and fishery. In summer and autumn, Lijiahe Reservoir exhibited thermal stratification. During the stable stratification period, the maximum concentrations of TN,TP,permanganate index,TOC,Fe,and Mn in the water body were as high as 3. 32,0. 177,5. 21,3. 01,0. 21,0. 235 mg·L-1,respectively,under the dual effects of exogenous pollution and bottom anaerobic release. The maximum concentrations of TN,TP,Fe,and Mn exceeded the Class Ⅲ water limit of Surface Water Environmental Quality Standards( GB 3838-2002). The higher nutrient levels promoted large-scale reproduction of algae. The density of algae in the upper water reached 2. 18 ×108 cells·L-1,and the dominant algae species were Microcystis aeruginosa and Aphanizomenon flosaquae,which pose a significant threat to water quality. Therefore,the primary goal for water pollution control in Lijiahe Reservoir is to take effective measures to control algae blooms,and at the same time,reduce the input of upstream pollutants.更多还原