摘要
迄今为止,水环境的BTEX(苯系物)污染仍然是一个尚未解决的环境问题,研究在水位波动条件下BTEX在土壤介质中的运移过程是充分了解BTEX对水环境影响的前提.本实验以甲苯为污染物,建立了土壤水环境中有机污染物运移实验模型,并通过控制砂柱饱和-非饱和状态转化来实现土壤所处环境(水位波动条件或饱水条件)的不同,对比研究了两种条件对污染物运移和相关的水文地球化学特征的影响.利用中砂、细砂、含10%黏土的细砂等3种土壤介质的实验数据对实验模拟进行验证.结果显示,在水位波动条件下中砂、含10%黏土的细砂介质中甲苯的衰减速率(6.4 mg·L^(-1)·d^(-1)、5.3 mg·L^(-1)·d^(-1))均大于饱和条件下甲苯的衰减速率(0.57 mg·L^(-1)·d^(-1)、0.59 mg·L^(-1)·d^(-1)).水位波动条件对水环境电导率没有影响,但甲苯的加入使水环境的pH升高.甲苯和地下水位波动的共同作用推迟了地下水环境中NO_3^-、SO_4^(2-)和NO_2^-达到平衡的时间.
Petroleum contaminated water remains an unsolved environmental problem. It benefits to understand the impact on water environment by knowing the migration process of BTEX in soil media under the effect of water level fluctuation. An experiment model was established to simulate the migration of toluene in soil water environment,realize different water environments（ water level fluctuation or full water）,and control the saturated-unsaturated state of the sand columns. The difference between the two conditions on the pollutant migration and hydrogeochemical characteristics was compared. The experiment model was verified by the laboratory experiments conducted in the soils of medium sand,fine sand and fine sand with 10% clay. Results showed that the attenuation rates of toluene under the condition of water level fluctuation（ 6. 4 mg·L^-1·d^-1,5.3 mg·L^-1·d^-1）were bigger than the saturation condition（ 0. 57 mg·L^-1·d^-1,0. 59 mg·L^-1·d^-1）. Water level fluctuation had no effect on the conductivity of water. Toluene elevated the pH of water environment.The equilibrium time of NO_3^-,SO_4^（2-） and NO_2^- in the water environment was delayed due to groundwater level fluctuation and toluene.
出处
《环境化学》
CAS
CSCD
北大核心
2017年第8期1842-1848,共7页
Environmental Chemistry
基金
国家自然科学基金(41272255,41472237)
辽宁省创新团队项目(LT2015017)资助~~
关键词
水位波动
土壤水环境
甲苯衰减
水文地球化学
土壤介质
water table fluctuation
soil water environment
toluene attenuation
hydrochemistry
soil media
