摘要
土壤淋洗废液处理难点在于废水中含有高浓度的稳定重金属络合物.本研究分离了一株硫酸盐还原菌(Shewanella sp.JN01),探讨了其对模拟淋洗废液中不同络合态Cu(Cu-乙二胺四乙酸(Cu-EDTA)、Cu-谷氨酸N,N-二乙酸(Cu-GLDA)、Cu-柠檬酸(Cu-CA)和Cu-混合淋洗剂(Cu-MC))的去除效果及机理.结果表明,活菌体和死菌体对不同络合态Cu的去除率分别大于80%和小于8%.显然,死菌体细胞表面吸附作用对络合态Cu去除效率的贡献十分有限.因此,Shewanella sp.JN01去除络合态Cu的主要机制是先破络,再形成CuS沉淀.Shewanella sp.JN01对不同络合态Cu的去除率为Cu-CA>Cu-MC>Cu-GLDA>Cu-EDTA,这一变化趋势与它们的稳定性常数和毒性的变化趋势相反,结果进一步证实了破络是微生物去除络合态重金属的限制性步骤.Shewanella sp.JN01能够有效去除土壤淋洗废液中重金属络合物,在淋洗废液再生利用方面具有潜在应用前景.
The difficulty in the treatment of soil washing effluent lies in its high concentrations of stable heavy metal complexes.This study isolated a strain of sulfate-reducing bacteria(Shewanella sp.JN01)to explore the removal efficiency and mechanism of different heavy metal complexes[Cu-ethylenediaminetetraacetic acid(Cu-EDTA),Cu-N,N-bis(carboxymethyl)glutamic acid(Cu-GLDA),Cu-citrate(Cu-CA)and Cu-mixed chelator(Cu-MC)]from the simulated soil washing effluent by Shewanella sp.JN01.The results showed that removal efficiencies of different Cu complexes by the alive and dead Shewanella sp.JN01 were above 80%and below 8%,respectively.Evidently,the contribution of sorption of Cu complexes by cell surface of the dead strain to its total removal efficiency was limited.Therefore,the dominant removal mechanism of Cu complexes by Shewanella sp.JN01 was related to dechelation first and then formation of CuS precipitation.The removal efficiencies of different Cu complexes by Shewanella sp.JN01 varied as the trend of Cu-CA>Cu-MC>Cu-GLDA>Cu-EDTA,which was opposite to the trend of their stability constants and toxicity.This finding further confirmed that the dechelation was a limiting step to remove heavy metal complexes by microorganisms.Collectively,the results of this study indicate that Shewanella sp.JN01 can effectively remove the heavy metal complexes from soil washing effluent,which has potential application prospects for recycling use of soil washing effluent.
作者
高羽
韩玮
张桂香
郭晓方
吉莉
柳丹丹
GAO Yu;HAN Wei;ZHANG Guixiang;GUO Xiaofang;JI Li;LIU Dandan(School of Environmental Science and Engineering,Taiyuan University of Science and Technology,Taiyuan,030024,China)
出处
《环境化学》
CAS
CSCD
北大核心
2023年第6期2087-2095,共9页
Environmental Chemistry
基金
山西省自然基金(20210302123204)
国家自然科学基金(42177057,41401584)资助。
作者简介
通信联系人:郭晓方,Tel:13994214814,E-mail:guoxiaofang@tyust.edu.cn。
