某水库夏季水质垂直分布原因分析及启示意义

Analysis of the Vertical Distribution of Water Quality Parameters in a Reservoir in Summer and Its Implications

监测某水库夏季水质多项指标((水温、pH、溶解氧(DO)、高锰酸盐指数、总有机碳(TOC)、氨氮(NH4+-N)、铁(Fe)、锰(Mn)、硫化氢(H2S))垂向分布,探究其成因。结果表明,该水库水质呈明显垂直分布,距水面2~16 m,水温从32.2℃降至23.5℃,DO从8 mg/L急剧降至0.26 mg/L;上层水体呈弱碱性,深层呈弱酸性;有机物含量垂向变化不大(1.50~2.20 mg/L);氨氮浓度随水深增加而增大,在6m、10 m处发生2次突跃;距水面10 m处出现Fe、Mn污染问题;水深12 m处H2S浓度突增。根据水质分层特征,提出应对对策,帮助以该水库为水源的水厂合理选择取水点,确保城市供水安全。

Researches on vertical distribution of multiple indicators(temperature,pH,DO,CODMn,TOC,NH4-N,Fe,Mn,H2S)were conducted to explore the genesis of stratification characteristics for the reservoir in summer.A typical vertical water quality distribution of reservoir was observed:from 2 m to 16 m distant from the surface of the reservoir,the temperature was reduced from 32.2℃to 23.5℃,while DO value was sharply decreased from 8 mg/L to 0.26 mg/L.The upper-water body presents weak alkalinity,while the deep-water body was weakly acidic.The amounts of organic matter(CODMn,TOC)at different depths of the reservoir were relatively stable(1.50~2.20 mg/L).The ammonia nitrogen concentration induced with the increase of water depth and two sudden leaps were observed at the depth of 6 m and 10 m.Fe and Mn problems occurred in water bodies over 10 meters from the water surface,and H2S problems deteriorated at the depth of 12 m.Based on the stratification characteristics of reservoir,countermeasures were proposed to help water plants using the reservoir as water source select water intake points,and ensure the safety of urban water supply.