大水深水库内源污染特征及控制技术

Study on the characteristics and control of endogenous pollution in source water reservoir with great depth

对黑河金盆水库水温、溶解氧、pH和底部水质的监测分析结果表明,黑河金盆水库属于稳定的大水深分层型水库,水体分层阻碍了上下层水体之间的物质交换,在水体和底泥耗氧的双重作用下,溶解氧从表层水体的8 mg/L左右降低到底层水体的0.1～0.2 mg/L;在厌氧条件下,底部沉积物中N、P、Fe和Mn等污染物大量释放,导致底部水体中NH3-N、TN、TP、Fe、Mn和COD均值分别达到2.22、2.30、0.05、0.13、2.53、74.00 mg/L。针对水体分层对底部水质产生的不利影响,认为扬水曝气技术适宜于大水深水库的水质原位改善和内源污染控制。

14 sampling points were set up for monitoring the some water-quality indexes such as temperature, dissolved oxygen, pH, and pollutant concentration in Heihe Jinpen reservoir. The monitoring results demonstrated that Heihe Jinpen reservoir was a kind of steady layered reservoir with great depth, and its steady stratification influ- enced the mass exchange between the upper and lower layer waters. Under the twofold oxygen consumption effects of water and sediment, the concentration of dissolved oxygen decreased gradually from surface of 8 mg/L to bottom of 0.1-0.2 mg/L. The anaerobic condition in bottom layer of water accelerated the release of N, P, Fe and Mn from sediment, and the concentration of NH3-N, TN, TP, Fe, Mn and COD released from the sediment could reach 2.22 mg/L,2.30 rag/L, 0.05 mg/L, 0.13 mg/L, 2.53 mg/L and 74.00 mg/L respectively. In view of the adverse impact of stratification on the bottom water quality, water lifting aerator was considered more suitable for solving the prob- lem caused by endogenous pollution and improving the water quality in source water reservoir with great depth.