Highly efficient and irreversible removal of cadmium through the formation of a solid solution

JOURNAL OF HAZARDOUS MATERIALS

卷:384

Article

Wang, Chen^1,4  Yin, Hui⁵  Bi, Lei¹  Su, Jing^1,4  Zhang, Meiyi¹  Lyu, Tao^2,3  Cooper, Mick^2,3  Pan, Gang^1,2,3,6 

[1] Chinese Acad Sci, Res Ctr Ecoenvironm Sci, Key Lab Environm Nanotechnol & Hlth Effects, 18 Shuangqing Rd, Beijing 100085, Peoples R China

[2] Nottingham Trent Univ, Sch Anim Rural & Environm Sci, Brackenhurst Campus, Nottingham NG25 0QF, England

[3] Nottingham Trent Univ, Sch Anim Rural & Environm Sci, Ctr Integrated Water Energy Food Studies iWEF, Brackenhurst Campus, Nottingham NG25 0QF, England

[4] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[5] Huazhong Agr Univ, Coll Resources & Environm, Minist Agr & Rural Affairs, Key Lab Arable Land Conservat Middle & Lower Reac, Wuhan 430070, Peoples R China

[6] Chinese Acad Sci, Beijing Adv Sci & Innovat Ctr, Beijing, Peoples R China

关键词: Metal sulfides;    Environmental remediation;    Heavy metal;    Solid solution;   

DOI  :  10.1016/j.jhazmat.2019.121461

来源: Elsevier

【 摘 要 】

Sulfur-containing materials are very attractive for the efficient decontamination of some heavy metals. However, the effective and irreversible removal of Cd2+, coupled with a high uptake efficiency, remains a great challenge due to the relatively low bond dissociation energy of CdS. Herein, we propose a new strategy to overcome this challenge, by the incorporation of Cd2+ into a stable ZnxCd1-xS solid solution, rather than into CdS. This can be realised through the adsorption of Cd2+ by ZnS nanoparticles, which have exhibited a Cd2+ uptake capacity of approximate 400 mg g(-1). Through this adsorption mechanism, the Cd2+ concentration in a contaminated solution could effectively be reduced from 50 ppb to < 3 ppb, a WHO limit acceptable for drinking water. In addition, ZnS continued to exhibit this noteworthy uptake capacity even in the presence of Cu2+, Pb2+, and Hg2+. ZnS displayed high chemical stability. Particles aged in air for 3 months still retained a > 80% uptake capacity for Cd2+, compared with only 9% uptake capacity for similarly-aged FeS particles. This work reveals a new mechanism for Cd2+ removal with ZnS and establishes a valuable starting point for further studies into the formation of solid solutions for hazardous heavy metal removal applications.

【 授权许可】

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