TY - JOUR
T1 - Process optimization to enhance utilization efficiency of precipitants for chloride removal from flue gas desulfurization wastewater via Friedel's salt precipitation
AU - Ye, Xiaofang
AU - Zhao, Xiaodan
AU - Ming, Qiang
AU - Zhu, Jun
AU - Guo, Jiaming
AU - Sun, Dongqi
AU - Zhang, Sheng
AU - Xu, Jie
AU - Zhou, Zhen
N1 - Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/12/1
Y1 - 2021/12/1
N2 - The treatment cost for Cl− removal by Friedel's salt precipitation depended significantly on utilization rate of the precipitant aluminate. In this study, effects of Ca/Al molar ratio, reaction time, temperature and Al/Cl molar ratio were investigated to maximize Al utilization rate for Cl− removal from flue gas desulfurization wastewater. Batch results showed that the maximum Al utilization rate of 55.8–60.3% was obtained at Ca/Al ratio of 3.00, reaction time of 90 min, temperature of 35 °C and Al/Cl ratio of 0.50 regardless of the initial Cl− concentration. The precipitate obtained at the highest Al utilization rate had the highest interlayer spacing, the best crystal integrity, and the strongest binding energy of the Al–OH bond. The optimized condition made ion exchange between Cl− and OH− easier, and obtained more stable Friedel's salt structure to adsorb Cl−. Pilot-scale results showed that maximizing Al utilization rate with low dosages of precipitants had insignificant effects on the removal of Mg2+, Ca2+ and sulfate compared to the strategy to maximize Cl−, but enhanced Al utilization rate from 38.2% to 56.4%. Economic analysis showed that enhancing Al utilization rate greatly reduced treatment cost of the Friedel's salt precipitation method by 30.5%, and made the two-stage desalination process more feasible and worth popularizing.
AB - The treatment cost for Cl− removal by Friedel's salt precipitation depended significantly on utilization rate of the precipitant aluminate. In this study, effects of Ca/Al molar ratio, reaction time, temperature and Al/Cl molar ratio were investigated to maximize Al utilization rate for Cl− removal from flue gas desulfurization wastewater. Batch results showed that the maximum Al utilization rate of 55.8–60.3% was obtained at Ca/Al ratio of 3.00, reaction time of 90 min, temperature of 35 °C and Al/Cl ratio of 0.50 regardless of the initial Cl− concentration. The precipitate obtained at the highest Al utilization rate had the highest interlayer spacing, the best crystal integrity, and the strongest binding energy of the Al–OH bond. The optimized condition made ion exchange between Cl− and OH− easier, and obtained more stable Friedel's salt structure to adsorb Cl−. Pilot-scale results showed that maximizing Al utilization rate with low dosages of precipitants had insignificant effects on the removal of Mg2+, Ca2+ and sulfate compared to the strategy to maximize Cl−, but enhanced Al utilization rate from 38.2% to 56.4%. Economic analysis showed that enhancing Al utilization rate greatly reduced treatment cost of the Friedel's salt precipitation method by 30.5%, and made the two-stage desalination process more feasible and worth popularizing.
KW - Chloride removal
KW - Flue gas desulfurization wastewater
KW - Friedel's salt
KW - Utilization efficiency
UR - https://www.scopus.com/pages/publications/85114401260
U2 - 10.1016/j.jenvman.2021.113682
DO - 10.1016/j.jenvman.2021.113682
M3 - 文章
C2 - 34526277
AN - SCOPUS:85114401260
SN - 0301-4797
VL - 299
JO - Journal of Environmental Management
JF - Journal of Environmental Management
M1 - 113682
ER -