TY - JOUR
T1 - Stabilization treatment of arsenic-alkali residue (AAR)
T2 - Effect of the coexisting soluble carbonate on arsenic stabilization
AU - Wang, Xin
AU - Ding, Jiaqi
AU - Wang, Linling
AU - Zhang, Shuyuan
AU - Hou, Huijie
AU - Zhang, Jingdong
AU - Chen, Jing
AU - Ma, Miao
AU - Tsang, Daniel C.W.
AU - Wu, Xiaohui
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (No. 41671311 ), the China Scholarship Council (Grant No. 201806165010 ), and the Program for HUST Academic Frontier Youth Team (No. 2018QYTD05 ). The authors would like to thank the Analytical and Testing Center at Huazhong University of Science and Technology, and the Geological Experimental Testing Center of Hubei Province, China, for their assistance on sample characterization. We also acknowledge the kind help of Dr. Aimal Khan. Appendix A
Publisher Copyright:
© 2019
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/2
Y1 - 2020/2
N2 - Arsenic-alkali residue (AAR) from antimony smelting is highly hazardous due to its ready leachability of As, seeking for proper disposal such as stabilization treatment. However, As stabilization in AAR would be challenging due to the high content of coexisting soluble carbonate. This study conducted the stabilization treatments of AAR by ferrous sulfate and lime, respectively, and revealed the significant influence of coexisting carbonate. It was found that ferrous sulfate was more efficient than lime, which required only one-tenth of dosages of lime to reduce the As leaching concentration from 915 mg/L to a level below 2.5 mg/L to meet the Chinese regulatory limit. The combining qualitative and quantitative analyses based on XRD, SEM–EDS, and thermodynamic modeling suggested that the formation of insoluble arsenate minerals, ferrous arsenate or calcium arsenate, was the predominant mechanism for As stabilization in the two treatment systems, and their efficiency difference was primarily attributed to the coexisting carbonate, which had a slight effect on ferrous arsenate but severely obstructed calcium arsenate formation. Moreover, the examination of As leaching concentrations in 1-year-cured samples indicated that the long-term stability of ferrous sulfate treatment was far superior to that of lime treatment. This study provides ferrous salts as a promising and green scheme for stabilization treatment of AAR as well as other similar As-bearing solid wastes with coexisting soluble carbonate.
AB - Arsenic-alkali residue (AAR) from antimony smelting is highly hazardous due to its ready leachability of As, seeking for proper disposal such as stabilization treatment. However, As stabilization in AAR would be challenging due to the high content of coexisting soluble carbonate. This study conducted the stabilization treatments of AAR by ferrous sulfate and lime, respectively, and revealed the significant influence of coexisting carbonate. It was found that ferrous sulfate was more efficient than lime, which required only one-tenth of dosages of lime to reduce the As leaching concentration from 915 mg/L to a level below 2.5 mg/L to meet the Chinese regulatory limit. The combining qualitative and quantitative analyses based on XRD, SEM–EDS, and thermodynamic modeling suggested that the formation of insoluble arsenate minerals, ferrous arsenate or calcium arsenate, was the predominant mechanism for As stabilization in the two treatment systems, and their efficiency difference was primarily attributed to the coexisting carbonate, which had a slight effect on ferrous arsenate but severely obstructed calcium arsenate formation. Moreover, the examination of As leaching concentrations in 1-year-cured samples indicated that the long-term stability of ferrous sulfate treatment was far superior to that of lime treatment. This study provides ferrous salts as a promising and green scheme for stabilization treatment of AAR as well as other similar As-bearing solid wastes with coexisting soluble carbonate.
KW - Arsenate minerals
KW - Arsenic stabilization
KW - Arsenic-alkali residue
KW - Coexisting soluble carbonate
KW - Ferrous sulfate
KW - Lime
UR - http://www.scopus.com/inward/record.url?scp=85076631426&partnerID=8YFLogxK
U2 - 10.1016/j.envint.2019.105406
DO - 10.1016/j.envint.2019.105406
M3 - Journal article
C2 - 31864033
AN - SCOPUS:85076631426
SN - 0160-4120
VL - 135
JO - Environmental International
JF - Environmental International
M1 - 105406
ER -