摘要
在调查和监测再生水受纳河流凉水河中苯并芘[B(a)P]浓度的基础上,利用Hydrus-1D耦合GMS模型研究B(a)P的时空分布和迁移演变,预测再生水受纳河流对地下水水质的影响。结果表明:B(a)P在包气带的垂直入渗率为0.102 m^(-1),仅为水运移的0.73%。由于吸附和生物降解作用,B(a)P穿透16 m深的包气带时间约为63年,其中吸附和生物降解的贡献率分别为78.4%和19.3%。当B(a)P与地下水相交,受地下水流的推动,B(a)P的迁移以地下水流方向迁移为主。B(a)P在地下水中沿地下水流方向的迁移速率为6.65 m/a,分别为垂直地下水流方向和垂向迁移速率的2.42倍和16.22倍。时空分布表明,地下水中B(a)P浓度随与河流距离的增加而降低,其在平行地下水流方向、垂直地下水流方向和垂向的衰减率常数分别为1.19×10^(-4)、3.05×10^(-4)和3.67×10^(-3)m^(-1),与迁移率呈负相关。然而,地下水中B(a)P浓度随入渗时间的延长而增加,积累率为7.3×10-2d^(-1)。B(a)P的迁移和积累对以地下水为饮用水的沿岸居民造成潜在的危害,导致地下水安全利用范围在20年内将从平行地下水流方向、垂直地下水流方向和垂向的438、276和19.8 m分别缩减至568、324和27.7 m。
To predict the influence of reclaimed water-receiving rivers on groundwater quality,the spatiotemporal distribution and migration evolution prediction of benzo(a)pyrene[B(a)P]was conducted by investigating and monitoring its levels in the Liangshui River,which received reclaimed water,with Hydrus-1D coupled GMS model.The research results were as follows:The vertical infiltration rate of B(a)P in the vadose zone was 0.102 m^(-1),which was only 0.73%that of water migration.B(a)P penetrated the 16 m depth vadose zone for 63 years owing to the attenuation function of adsorption and biodegradation,with contribution ratios of 78.4%and 19.3%,respectively.When B(a)P intersected with groundwater,driven by groundwater flow,the migration of B(a)P was mainly in the direction of groundwater flow.The migration rate of B(a)P in groundwater along the direction of groundwater flow was 6.65 m/a,which was 2.42 times and 16.22 times of the diffusion rate in the vertical groundwater flow direction and vertical downward direction,respectively.The spatiotemporal distribution indicated that B(a)P concentration decreased with the crow-fly distance from the river with attenuation rate constants of 1.19×10^(-4),3.05×10^(-4),and 3.67×10^(-3)m^(-1)in parallel groundwater flow direction,vertical groundwater flow direction and vertical downward direction,respectively,which were negatively correlated with migration rate.However,B(a)P content increased over the extension of infiltration time with an accumulation rate of 7.3×10-2 d^(-1).The migration and accumulation of B(a)P induced potential harm to coastal residents taking groundwater as drinking water,which would result in the groundwater safety utilization range decreasing from 438,276,and 19.8 m to 568,324,and 27.7 m far from the river in parallel groundwater flow direction,vertical groundwater flow direction and vertical downward direction,respectively,20 years later.
作者
任杰
马伟芳
REN Jie;MA Weifang(School of Environmental Science and Engineering,Beijing Forestry University)
出处
《环境工程技术学报》
CAS
CSCD
北大核心
2023年第3期1061-1069,共9页
Journal of Environmental Engineering Technology
基金
国家自然科学基金项目(51678052)。
关键词
苯并芘[B(a)P]
河流入渗
数值模拟
溶质运移
benzo(a)pyrene[B(a)P]
river water infiltration
numerical modelling
solute transport
