Chemical fixation of toxic metals in stainless steel pickling residue by Na2S·xH2O,FeSO4·6H2O and phosphoric acid for beneficial uses  

作　　者：Peidong Su Junke Zhang Yadong Li 

机构地区：[1]Department of Civil&Environmental Engineering,Jackson State University,Jackson,MS,39217,USA

出　　处：《Journal of Environmental Sciences》2020年第4期364-374,共11页环境科学学报（英文版）

基　　金：supported by Tsinghua University Graduate School in Shen Zhen,China and Jackson State University,USA through a collaborative effort

摘　　要：The leaching concentrations of different metals in stainless steel pickling residue(SSPR)were determined and the toxic metals were treated using Na2 S·xH2 O,FeSO4·6 H2 O,and phosphoric acid.A modified European Community Bureau of Reference(BCR)sequential extraction was used to identify the speciation of the concerned metals.Results showed that SSPR contains a large amount of Ca(58.41%),Fe(29.44%),Cr(3.83%),Ni(2.94%),Mn(2.82%)and some of Al,Cu,Mg,Zn.Among them,Cr and Ni were the most toxic metals in SSPR,thus the raw SSPR falls into hazardous waste category due to the leaching amount of Cr.In addition,the leached Cr was identified as Cr6+(MgCr04)in the waste.BCR test revealed that risk assessment code(RAC)of Cr and Ni were 33.29%and 61.7%,indicating they posed"high"and"very high"risk to the environment,respectively.After fixing by Na2 S·xH2 O and FeSO4·6 H2 O,the leaching concentrations of Cr and Ni were less than 1.5 and 0.5 mg/L,respectively.After fixing by Na2 S·xH2 O and FeSO4·6 H2 O the tre ated SSPR can be safely reused as roadbed materials,concrete and cement aggregates.This study provides a useful implication in treatment and beneficial reuse of heavy metal-containing hazardous wastes.

关 键 词：Stainless steel pickling residue Leaching toxicity Cr(Ⅵ) Chemical fixation Beneficial reuses 

分 类 号：X757[环境科学与工程—环境工程]