柘林水库污染物来源及水体分层对水质的影响

Pollution sources and the stratification effects on water quality of Zhelin Reservoir

为探究水源水库污染物来源及水质变化规律,以九江市水源地柘林水库为研究对象,于2013年4月—2014年4月逐月对柘林水库进行水质监测.现场测定水温、溶解氧等指标,分层取样测定水体CODMn、TOC、TN、TP、Fe、Mn等水质指标.结果表明,柘林水库主要污染物来源为上游来水,其对CODMn、TN、TP贡献率分别达88.3%、76.2%和67.6%.在水体稳定分层期,底部水体CODMn、TOC、TN、TP、Fe、Mn质量浓度分别升高至3.8、2.4、1.12、0.14、0.42和0.34 mg/L;藻类计数及藻种鉴定结果表明,此时期主库区最大藻密度达2.25×106L-1,以绿藻为主.水体混合后出现Mn质量浓度超标问题,达0.16 mg/L.

To explore the pollutants sources and the water quality variation rules of the water source reservoirs, monthly monitoring of water quality from April 2013 to April 2014 was carried out in Zhelin Reservoir, which is the main water source of Jiujiang City. The dynamic variations of water temperature and DO concentrations were measured in situ, while CODMn, TOC, TN, TP, Fe and Mn were determined in the laboratory. The results showed that the main pollution source of Zhelin Reservoir was the upstream runoff, and its percentage contribution to the bulk pollutants was 88.3% for CODMn, 76.2% for TN and 67.6% for TP, respectively. During the stable stratification period, the maximum concentrations of CODMn, TOC, TN, TP, Fe and Mn in the bottom water reached 3.8, 2.4, 1.12, 0.14, 0.42 and 0.34 mg/L, respectively. The algae population and algal species identification results demonstrated that the maximum density of algae was 2.25× 10^6 cells/L, in which green algae was predominated. However, during the mixing period, Mn concentration exceeded the drinking water standard.