TY - JOUR
T1 - Deep insight on mechanism and contribution of As(V) removal by thermal modification waste concrete powder
AU - Ma, Zihan
AU - Li, Jiang shan
AU - Xue, Qiang
AU - Zhan, Baojian
AU - Chen, Xin
AU - Wan, Yong
AU - Zhao, Yaqin
AU - Sun, Yuehui
AU - Poon, Chi Sun
N1 - Funding Information:
This study is financially supported by the National Key Research and Development Program (Grant No. 2019YFC1804002 ), Funds for International Cooperation and Exchange of the National Natural Science Foundation of China (Grant No. 51861165104 ), The CAS Pioneer Hundred Talents Program in China and the Youth Innovation Promotion Association CAS (Grant No. 2021327 ).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/2/10
Y1 - 2022/2/10
N2 - Expanding the utilization strategy of waste concrete powder (WCP) is conducive to minimizing the environmental burden caused by construction & demolition wastes (C&DW). In this study, WCP prepared in the laboratory was thermally treated and used to remove As(V) from wastewater. Batch adsorption tests were implemented to explore the influence factors such as modification temperature (0–850 °C), pH (1.00–12.00), dosage (2–50 g/L), co-coexisting ions (SO42−, NO3−, Cl− and PO43−) and temperature (25–45 °C). Various methods including spectroscopic tests, Rietveld refinement and sequential extraction process were employed to examine the mechanisms and their contribution to As(V) removal. Results show that the As(V) removal capacity of WCP was slightly enhanced after treatment at 200 °C, the pseudo-second-order kinetics model and Langmuir model could describe the adsorption process well. The maximum uptake capacity for As(V) calculated by Langmuir model at 25, 35 and 45 °C were 31.89, 25.56 and 17.42 mg/g respectively, and the removal rate reached a maximum of 95.37% (C0 = 100 mg/L). Thermodynamically, the As(V) elimination was exothermic and spontaneous. The ettringite produced by rehydration of WCP proved to be essential for As(V) removal. Electrostatic attraction, precipitation, complexation and ion exchange were identified to be the main mechanisms of As(V) adsorption. This study confirmed the potential of WCP in removing As(V) from wastewater and provided a new insight into the removal mechanisms.
AB - Expanding the utilization strategy of waste concrete powder (WCP) is conducive to minimizing the environmental burden caused by construction & demolition wastes (C&DW). In this study, WCP prepared in the laboratory was thermally treated and used to remove As(V) from wastewater. Batch adsorption tests were implemented to explore the influence factors such as modification temperature (0–850 °C), pH (1.00–12.00), dosage (2–50 g/L), co-coexisting ions (SO42−, NO3−, Cl− and PO43−) and temperature (25–45 °C). Various methods including spectroscopic tests, Rietveld refinement and sequential extraction process were employed to examine the mechanisms and their contribution to As(V) removal. Results show that the As(V) removal capacity of WCP was slightly enhanced after treatment at 200 °C, the pseudo-second-order kinetics model and Langmuir model could describe the adsorption process well. The maximum uptake capacity for As(V) calculated by Langmuir model at 25, 35 and 45 °C were 31.89, 25.56 and 17.42 mg/g respectively, and the removal rate reached a maximum of 95.37% (C0 = 100 mg/L). Thermodynamically, the As(V) elimination was exothermic and spontaneous. The ettringite produced by rehydration of WCP proved to be essential for As(V) removal. Electrostatic attraction, precipitation, complexation and ion exchange were identified to be the main mechanisms of As(V) adsorption. This study confirmed the potential of WCP in removing As(V) from wastewater and provided a new insight into the removal mechanisms.
KW - Adsorption
KW - Arsenic
KW - Thermal modification
KW - Waste concrete powder (WCP)
UR - http://www.scopus.com/inward/record.url?scp=85116806186&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.150764
DO - 10.1016/j.scitotenv.2021.150764
M3 - Journal article
AN - SCOPUS:85116806186
SN - 0048-9697
VL - 807
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 150764
ER -