TY - JOUR
T1 - Efficient chloride removal by macroporous pseudo-boehmite
T2 - Performance and mechanistic insights in diverse cationic environments
AU - Cheng, Mingquan
AU - Zhao, Xiaodan
AU - Xu, Yuchen
AU - Zheng, Yunya
AU - Zhu, Qiaoling
AU - Ma, Yitao
AU - Zhang, Yiwei
AU - Liao, Zhenlong
AU - Xia, Qing
AU - Zhou, Zhen
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2026/4/17
Y1 - 2026/4/17
N2 - Flue gas desulfurization (FGD) wastewater represents a significant environmental challenge due to its high chloride ions (Cl−) content, which accelerates corrosion and compromises operational issues in coal-fired power plants. The Friedel's salt precipitation (FSP) method is a promising zero liquid discharge (ZLD) strategy for Cl− removal. However, the conventional process using NaAlO2 faces intrinsic limitations due to Na+-induced side reactions and low aluminum utilization rate (AUR). This study introduces macroporous pseudo-boehmite (MPB) as a novel, sodium-free aluminum source to overcome these restrictions and achieve highly efficient Cl− removal via cation-specific coordination pathways. Systematic investigation of MPB dissolution under varied hydrochemical conditions revealed enhanced aluminum leaching kinetics. Batch tests in NaCl, CaCl2, and MgCl2 solutions demonstrated that Ca2+/Mg2+ significantly enhanced Cl− removal (up to 88 %) and AUR (∼59 %) by facilitating direct FS formation, avoiding charge compensation, and inhibiting competing byproducts. Kinetic and phase analyses indicated that Na+ accelerated initial dissolution but favored by-product (Ca3Al2OH12) formation at high temperatures, whereas Ca2+/Mg2+ enhanced FS stability. The MPB-based FSP process achieved faster equilibration (20 min at 80 °C) and higher efficiency, positioning it as a sustainable alternative for ZLD implementation of hazardous high-chloride wastewater.
AB - Flue gas desulfurization (FGD) wastewater represents a significant environmental challenge due to its high chloride ions (Cl−) content, which accelerates corrosion and compromises operational issues in coal-fired power plants. The Friedel's salt precipitation (FSP) method is a promising zero liquid discharge (ZLD) strategy for Cl− removal. However, the conventional process using NaAlO2 faces intrinsic limitations due to Na+-induced side reactions and low aluminum utilization rate (AUR). This study introduces macroporous pseudo-boehmite (MPB) as a novel, sodium-free aluminum source to overcome these restrictions and achieve highly efficient Cl− removal via cation-specific coordination pathways. Systematic investigation of MPB dissolution under varied hydrochemical conditions revealed enhanced aluminum leaching kinetics. Batch tests in NaCl, CaCl2, and MgCl2 solutions demonstrated that Ca2+/Mg2+ significantly enhanced Cl− removal (up to 88 %) and AUR (∼59 %) by facilitating direct FS formation, avoiding charge compensation, and inhibiting competing byproducts. Kinetic and phase analyses indicated that Na+ accelerated initial dissolution but favored by-product (Ca3Al2OH12) formation at high temperatures, whereas Ca2+/Mg2+ enhanced FS stability. The MPB-based FSP process achieved faster equilibration (20 min at 80 °C) and higher efficiency, positioning it as a sustainable alternative for ZLD implementation of hazardous high-chloride wastewater.
KW - Cationic environments
KW - Chloride removal
KW - Friedel's salt
KW - Macroporous pseudo-boehmite
KW - Zero liquid discharge
UR - https://www.scopus.com/pages/publications/105025811556
U2 - 10.1016/j.seppur.2025.136652
DO - 10.1016/j.seppur.2025.136652
M3 - 文章
AN - SCOPUS:105025811556
SN - 1383-5866
VL - 387
JO - Separation and Purification Technology
JF - Separation and Purification Technology
M1 - 136652
ER -