碳酸氢盐对沉积物中砷迁移转化的影响  

Effects of HCO Concentrations on the Migration and Speciation of Arsenic in Sediment

作　　者：黄中情 杨常亮[2] 张璟 宋梦萍 王晟 王洁[2] 曾绍宇 HUANG Zhongqing;YANG Changliang;ZHANG Jing;SONG Mengping;WANG Sheng;WANGJie;ZENG Shaoyu(Institute of International Rivers and Eco-security,Yunnan University,Kunming 650091,China;School of Ecology and Environmental Science,Yunnan University,Kunming 650091,China)

机构地区：[1]云南大学国际河流与生态安全研究院,云南昆明650091 [2]云南大学生态与环境学院,云南昆明650091

出　　处：《环境科学与技术》2020年第11期69-75,共7页Environmental Science & Technology

基　　金：国家自然科学基金资助项目(51168047)。

摘　　要：该研究以砷污染湖泊阳宗海的沉积物及其上覆水为对象,考察了在有微生物存在与没有微生物存在2种情况下,提高上覆水中HCO3-离子浓度,沉积物-上覆水界面砷的迁移转化的规律及其影响机制。研究结果表明:上覆水中HCO3-离子的竞争吸附作用对沉积物中砷的溶出量只起到微弱的促进作用。铁砷(氢)氧化物的还原性溶解能在实验初期解吸释放出砷和铁,但铁与砷的浓度变化趋势并不同步,Fe的还原性溶解只是造成砷浓度升高的原因之一。而微生物的还原活动是砷解吸的主要影响因素,微生物活动增加了As(Ⅲ)在总砷中的占比,提高了砷的生物有效性,增加了造成二次砷污染的生态风险。The mechanism of microbial transformation of arsenic in overlying water and sediment was studied.The results showed that the competitive adsorption of HCO3-ions in the overlying water only slightly promoted the dissolution of arsenic in the sediment.The reductive dissolution of iron arsenic(hydrogen)oxide can desorb arsenic and iron at the beginning of the experiment,but iron was not synchronized with the change trend of arsenic concentration.The reductive dissolution of Fe was only one of the reasons for the increase in arsenic concentration.The reduction activity of microorganisms was the main influencing factor of arsenic desorption.Microbial activity increased the proportion of As(Ⅲ)in total arsenic,improved the biological effectiveness of arsenic,and increased the ecological risk of secondary arsenic pollution.

关 键 词：砷迁移 沉积物 解吸 HCO3- 

分 类 号：X524[环境科学与工程—环境工程]