摘要
为探究人工强制混合充氧与诱导持续混合对水质改善的影响及人工强制混合与自然混合的衔接条件,以李家河水库为例,于2017年6月至2019年4月开展水质及水文气象指标监测,分析自然过程及人工诱导混合过程各时期水温、溶解氧及水质变化特征.结果表明:①自然过程分层期持续时间长,混合期仅为2.5个月,人工诱导混合过程通过扬水曝气系统的运行,9月底水体达到完全混合且进入降温期,诱导自然混合条件具备,表层水温、平均气温分别为20.17℃和16.5℃,此时系统关闭后水体持续自然混合,混合周期延长至5.5个月;②自然过程污染物浓度较高,混合期表层污染物浓度呈现先增加后降低的趋势,氧跃层伴随热分层出现,底部厌氧周期达6个月;③相较于自然过程,人工诱导混合过程水体等温层厌氧消除且污染物控制效果良好,10月至翌年3月同期底层NH+4-N、TP、Fe和Mn浓度的削减率为76.2%、75.5%、82.2%和82.1%,均达到地表水环境质量标准,人工诱导混合过程有利于水质改善及混合作用时效的延长.
To explore the effects of water quality improvement by artificial destratification and artificially-induced mixing,as well as realize the conditions of artificial mixing and natural mixing,the Lijiahe Reservoir was selected to monitor the indexes of water quality and hydrometeorology from June 2017 to April 2019 and to analyze the characteristics of variations in water temperature,dissolved oxygen,and pollutants during the natural and induced-mixing processes.The results demonstrated that:①The natural process had the features of a long period of thermal stratification and only a short period of mixing of about 2.5 months.Through the operation of water-lifting aerators(WLAs)during the induced-mixing process,the water body was completely mixed and entered the cooling period at the end of September,achieving the conditions of induced-natural mixing.The surface water temperature and average air temperature were 20.17℃and 16.5℃,respectively,and the water body continued to be naturally mixed after the WLA system was shut down,which led to a natural mixing cycle of 5.5 months.②During the natural-mixing process,the concentration of pollutants was relatively high in the whole period,and the concentration of surface pollutants in the mixing stage presented a trend of increasing first and then decreasing.The oxycline appeared with thermal stratification,and the anaerobic cycle in the bottom of water column reached 6 months.③Compared with the natural-mixing process,the hypolimnetic anaerobic condition was eliminated and the control effects of pollutants dominated during the induced-mixing process.Simultaneously,the concentrations of NH+4-N,TP,Fe,and Mn in the bottom of the water column were cut by 76.2%,75.5%,82.2%,and 82.1%,respectively,during the same period from October to March of the following year,and met the"Environmental Quality Standards for Surface Water".This study shows that the artificially-induced mixing process contributes to water quality improvement and mixing-period prolongation.
作者
温成成
黄廷林
李楠
张海涵
林子深
李衍庆
杨尚业
董亚军
WEN Cheng-cheng;HUANG Ting-lin;LI Nan;ZHANG Hai-han;LIN Zi-shen;LI Yan-qing;YANG Shang-ye;DONG Ya-jun(Key Laboratory of Northwest Water Resource,Environment and Ecology,Ministry of Education,School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Shaanxi Key Laboratory of Environmental Engineering,School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Lijiahe Reservoir Management Co.,Ltd.,Xi'an 710016,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2020年第3期1227-1235,共9页
Environmental Science
基金
国家自然科学基金项目(51979217)
陕西省重点研发计划项目(2018ZDXM-SF-020,2019ZDLSF06-01,2019ZDLSF06-02)。
关键词
水源水库
诱导混合
自然混合
水质改善
混合周期
drinking water reservoir
induced mixing
natural mixing
water quality improvement
mixing period
