摘要
北京市再生水主要用于河湖补水,但再生水中污染物本底值较高,对周边水体产生了一定影响。本文基于2015—2017年北京潮白河顺义段再生水、地表水和浅层地下水的水位、水质监测数据,运用数理统计和水化学分析等方法,研究了再生水长期补给河道后周边水体的特征。结果表明:(1)受再生水水质影响,再生水补给河道的地表水总氮在所有监测点均出现超标;河道沿程氮、磷含量降低,pH值升高,夏季更为显著,与藻类光合作用和反硝化作用等因素有关。(2)周边浅层地下水水位稳定,仅存在季节变化;水化学类型以HCO3·Cl-Na·Ca型为主,与再生水相似;140个水样中120个符合地下水Ⅳ类及以上标准,沿地下水流向水质有变好趋势;19个水样氨氮超标,主要出现在河南村橡胶坝附近,氮素可能来源于周边农、林地土壤氮素和灌溉施肥输入。(3)浅层地下水与地表水的主要水化学组分存在差异,与入渗过程中发生阳离子交换吸附作用和混合作用有关;河流渗漏影响到了距离河道中心约425 m的浅层地下水水质。本文可为进一步改善潮白河及其周边地下水水质和提高再生水利用率提供参考。
Reclaimed water is used primarily for replenishing rivers and lakes in Beijing,but the impact of reclaimed water on ambient water environment has also been a concern.This research monitored the water quality of the reclaimed water,surface water,and shallow groundwater in the Chaobai River in Beijing from 2015 to 2017.This study used mathematical statistics and hydrochemical analysis to investigate the characteristics of the ambient water bodies under longterm reclaimed water recharge to the river.The results show that the total nitrogen in surface water exceeded the quality standard at all monitoring points because the reclaimed water had a high nutrient content.The concentration of nitrogen and phosphorus decreased and the p H value increased along the river,which was more significant in the summer.This is related to photosynthesis and denitrification.The surrounding shallow groundwater level showed seasonal variation only.The hydrochemical type of shallow groundwater was mainly HCO3·Cl-Na·Ca type,which was similar to the reclaimed water.But the main ion concentrations in different water bodies were different due to cation exchange and absorption during the infiltration process and mixing.The maximum distance of the reclaimed water impact on shallow groundwater quality was about 425 m away from the center of the river course.Of the 140 water samples,120 met the classⅡto IV groundwater quality standard,and the groundwater quality tended to get better along the groundwater flow direction.The ammonia nitrogen concentration of 19 water samples exceeded the quality standard.It mainly occurred near the Henan Village dam.Nitrogen might have come from soil nitrogen,irrigation,and fertilization input in the surrounding agricultural and forestry lands.This study provided important references for improving the water quality of the ambient water bodies in the Chaobai River and increasing the utilization of reclaimed water.
作者
姜瑞雪
韩冬梅
宋献方
杨丽虎
李炳华
JIANG Ruixue;HAN Dongmei;SONG Xianfang;YANG Lihu;LI Binghua(Key Laboratory of Water Cycle&Related Land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;Beijing Water Science and Technology Institute,Beijing 100048,China)
出处
《资源科学》
CSSCI
CSCD
北大核心
2020年第12期2419-2433,共15页
Resources Science
基金
国家自然科学基金重点项目(41730749)。
关键词
再生水
地表水
地下水
水质
水位
潮白河
reclaimed water
surface water
groundwater
water quality
water level
Chaobai River
