摘要
高砷地下水具有极高的毒性,人类长期饮用高砷地下水可造成砷中毒。在查明山阴地区高砷地下水污染特征的基础上,将室内批试验与PHREEQC软件数值模拟相结合,考察了投料比、pH值对铁硫化物除砷效果的影响,为原位修复高砷地下水工艺确定了最佳条件。结果表明:山阴地区砷超标地下水样的pH值为7.6~8.5,总砷浓度为17~242μg/L;反应体系的投料比和pH值是影响铁硫化物除砷效果的关键因素;仅投加Na_(2)S对地下水中As(Ⅲ)的去除效果极差,提高FeCl_(2)相对于Na_(2)S的投加量能有效地增大铁硫化物除砷的效果;当pH=7、投料比c[FeCl_(2)∶Na_(2)S∶As(Ⅲ)]为24∶12∶1时,铁硫化物对地下水中总砷的去除率可达99.6%,反应后的地下水中砷浓度满足《生活饮用水卫生标准》(GB 5749-2006)的要求;与弱酸性条件相比,弱碱性环境更有利于铁硫化物除砷;PHREEQC软件数值模拟结果显示,试验条件的改变会影响砷硫化物和铁硫化物的饱和指数(SI),从而影响铁硫化物对地下水中砷的去除效果。
The groundwater with high arsenic has a high toxicity,and long-term consumption of high arsenic groundwater can cause arsenic poisoning.Based on the pollution characteristics of high-arsenic groundwater in Shanyin area,this paper researches the effects of feed ratio and pH on the removal of As(Ⅲ)by iron-sulfide in high-arsenic groundwater through indoor batch experiments and PHREEQC simulation.The results shows that the pH of the high-arsenic groundwater is 7.6~8.5,and the total arsenic concentration is 17~242μg/L in Shanyin area.The feed ratio and pH of the reaction system both significantly affect the As(Ⅲ)removal efficiency in groundwater.The removal efficiency is extremely low by solely adding Na_(2)S,but is dramatically increased by adding excessive FeCl_(2).When the pH is 7,and the feed ratio c(FeCl_(2)∶Na_(2)S∶As(Ⅲ))is equal to 24∶12∶1,the removal rate of total arsenic reaches 99.6%,and the concentration of arsenic is lower than the limits in Standards for Drinking Water Quality(GB 5749-2006).The weakly alkaline environments are more conducive for the As(Ⅲ)removal.The simulation results of PHREEQC show that the experimental conditions affect the saturation index(SI)of arsenic sulfide and iron sulfide in the reaction system,thereby affecting the removal effects of iron sulfide on As(Ⅲ).
作者
易曼玲
李义连
华骏
陆立波
YI Manling;LI Yilian;HUA Jun;LU Libo(School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430078,China;Wuhan Jimeizhidi Co.,Ltd.,Wuhan 430014,CAzna;Wuhan Central Business District Investment Holding Group Co.,Ltd,,Wuhan 430023,China)
出处
《安全与环境工程》
CAS
CSCD
北大核心
2021年第2期213-219,225,共8页
Safety and Environmental Engineering
基金
国家自然科学基金项目(41572233)。
关键词
高砷地下水
原位修复
铁硫化物
投料比
PH值
山阴地区
high-arsenic groundwater
in-situ remediation
iron sulfide
feed ratio
pH
Shanyin area
