Effect of speciation and composition on the kinetics and precipitation of arsenic sulfide from industrial metallurgical wastewater

JOURNAL OF HAZARDOUS MATERIALS

卷:409

Article

Ostermeyer, Pieter^1,4  Bonin, Luiza^1,4  Folens, Karel¹  Verbruggen, Florian^1,4  Garcia-Timermans, Cristina¹  Verbeken, Kim^2,4  Rabaey, Korneel⁴  Hennebel, Tom^1,3 

[1] Univ Ghent, Ctr Microbial Ecol & Technol CMET, Fac Biosci Engn, Coupure Links 653, B-9000 Ghent, Belgium

[2] Ghent Univ UGent, Dept Mat Text & Chem Engn, Technol Pk 46, B-9052 Ghent, Belgium

[3] Umicore, Grp Res & Dev, Competence Area Recycling & Extract Technol, Watertorenstr 33, B-2250 Olen, Belgium

[4] Ctr Adv Proc Technol Urban Resource Recovery CAPT, Coupure L 653, B-9000 Ghent, Belgium

关键词: Arsenate reduction;    Selective metal precipitation;    Rate determining step;    Orpiment;    Metal sulfide;   

DOI  :  10.1016/j.jhazmat.2020.124418

来源: Elsevier

【 摘 要 】

Precipitation of arsenic as As2S3 produces little waste sludge, has the potential for low chemical consumption and for selective metal(loid) removal. In this study, arsenic removal from acidic (pH 2), metallurgical wastewater was tested in industrially relevant conditions. Sulfides added at a S:As molar ratio of 2.5 and 5 resulted in removal of 99% and 84% of As(III) and As(V). Precipitation of As2S3 from the As(III) and industrial wastewater containing 17% As(V) was nearly instantaneous. For the synthetic As(V) solution, reduction to As(III) was the rate limiting step. At a S:As ratio of 20 and an observed removal rate (k(2) = 4.8 (mol L-1) h(-1)), two hours were required to remove of 93% of arsenic from a 1 g As L-1 solution. In the case of As(V) in industrial samples this time lag was not observed, showing that components in the industrial wastewater affected the removal and reduction of arsenate. Speciation also affected flocculation and coagulation characteristics of As2S3 particles: As(V) reduction resulted in poor coagulation and flocculation. Selective precipitation of arsenic was possible, but depended on speciation, S:As ratio and other metals present.

【 授权许可】

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