摘要
为研究硫酸盐对受酸性矿山废水污染土壤中Fe和As转化释放的影响,设计开展灭菌、非灭菌和加硫非灭菌3组淹水释放实验,在厌氧手套箱中连续处理30 d,每5天取样一次,测定上清液pH、氧化还原电位(Eh)、Fe(Ⅱ)和As浓度,以及土壤中盐酸提取态Fe(Ⅱ)和As的含量。结果表明:实验初始阶段,在微生物的作用下,土壤悬液pH升高、Eh降低,硫酸盐的添加会增强这一趋势。实验前5 d为铁矿物还原转化阶段,土壤中Fe和As活化速率较高,释放速率也较大,硫酸盐的加入会增大活化释放量。之后,随还原性增强,硫酸盐大量被还原,亚铁硫化物矿物生成,土壤中的铁矿物被继续活化但速率降低,加硫非灭菌组仍有较高的活化量,同时土壤被活化的As含量减少,释放Fe和As的过程被抑制,促使溶液中Fe(Ⅱ)和As的浓度降低。实验后15 d,虽然受生成铁矿物沉淀的控制,溶液Fe浓度能够持续维持在较低水平,但As浓度却持续增加,硫酸盐的加入会增加As的释放量。
The effects of sulfate on transformation and release of iron and arsenate in the soil contaminated by acid mine drainage were investigated by means of flooding release experiment in this study. Three kinds of comparative tests were designed and conducted, including sterilization treatment, non-sterilization treatment and sulfation non-sterilization treatment. Each treatment was incubated for 30 days in an anaerobic incubation box, and the supernatants of each treatment were sampled every 5 days, to determine pH values, redox potential(Eh), and ferrous iron and arsenic concentrations. The HCl-extractable Fe(Ⅱ) and arsenic concentrations in the soil were also determined. In the initial stage, pH in soil solution increased, yet Eh decreased with the help of soil microorganisms. In the first 5 days(stage of reduction and transformation of iron minerals), the activation rate of iron and arsenic in the soil and the release rate were higher than comparative treatment, and the addition of sulfate would increase the rate of release. After then, a large amount of sulfate was reduced and ferrous sulfide minerals were formed due to the enhancement of reduction strength in soil. The reduction rate of iron oxides in the soil was kept at a lower level, except for sulfurization non-sterilization treatment, and the content of activated arsenic in the soil decreased. The process of iron and arsenic release was suppressed. The iron concentration in the solution was maintained at a lower level after 15 days of the experiment, which was probably resulted by the formation of iron oxides deposits. However, the arsenic concentration increased gradually and the addition of sulfate could enhance the release of arsenic.
作者
刘涛
张翅鹏
郝瑶玲
邱丽娟
黄臣臣
LIU Tao;ZHANG Chipeng;HAO Yaoling;QIU Lijuan;HUANG Chenchen(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China)
出处
《浙江农业学报》
CSCD
北大核心
2020年第4期678-684,共7页
Acta Agriculturae Zhejiangensis
基金
国家自然科学基金(41403088)
国家自然科学基金委员会-贵州省人民政府喀斯特中心项目(U1612442)
贵州大学引进人才科研项目(贵大人基合字〔2014〕53号)。
关键词
土壤微生物
硫酸盐
铁
砷
soil microorganism
sulfate
iron
arsenic
