尾矿浆替代粉煤灰合成泡沫地聚合物以高效去除重金属污染物:行为和机理研究
Synthesis of foamed geopolymers by substituting fly ash with tailing slurry for the highly efficient removal of heavy metal contaminants:Behavioral and mechanistic studies
江杰 1罗豪豪 1王树飞 1欧孝夺 1苏建 2陈俊霖1
作者信息
- 1. School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China
- 2. Guangxi Bossco Environmental Protection Technology Co.,Ltd,Nanning 530001,China
- 折叠
摘要
本研究旨在以铝土矿开采的副产品尾矿泥浆合成多孔地聚合物,以用作地下水修复的材料.研究了液固比、发泡剂和稳泡剂掺量等因素对地聚合物孔隙结构和吸附性能的影响.通过批量实验和微观表征评估地聚合物对二元重金属(Pb和Cu)的吸附能力和作用机理.结果表明,调整发泡行为可得到孔隙率为81.4%、连通性为17.2%、吸水率为122.9%的多孔地聚合物.封闭孔隙和毛细管的存在降低了重金属的去除性能.优化发泡行为可通过改善孔隙连通性,进而将重金属的吸附能力从7.49 mg/g提高到24.95 mg/g.重金属的主要去除机理包括物理封装、重金属离子与—OH的化学沉淀以及T(Si,Al)—O—M(Pb,Cu)键的形成.基于尾矿浆的多孔地聚合物表现出卓越的重金属去除性能,在修复矿山污染地下水方面具有巨大潜力.
Abstract
This study aimed to synthesize porous geopolymers from tailing slurry,a byproduct of bauxite mining,for use as potential materials for groundwater remediation.The effects of various factors,such as foaming agents,liquid-solid(L/S)ratio,and foam stabilizers,on the geopolymers'pore structure and adsorption properties were investigated.Batch experiments and characterization methods were conducted to evaluate the adsorption capacity and mechanism of the geopolymers on binary heavy metals(Pb2+and Cu2+).The results showed that adjusting the foaming behavior resulted in a porous geopolymer with porosity of 81.4%,connectivity of 17.2%,and water absorption rate of 122.9%.The presence of closed pores and capillaries hindered the removal performance of heavy metals.In contrast,optimizing foaming behavior could increase the adsorption capacity of Pb2+from 7.49 mg/g to 24.95 mg/g by improving pore connectivity.The main removal mechanisms include physical sealing,chemical precipitation of heavy metal ions with—OH,and the formation of chemical bonds T(Si,Al)—O—M(Pb,Cu).Tailing slurry-based porous geopolymers(TPGs)demonstrated excellent heavy metal removal performance and exhibited great potential in remediating mine-polluted groundwater.
关键词
多孔地聚合物/尾矿泥浆/可渗透反应墙/孔隙特征/重金属修复Key words
porous geopolymer/tailing slurry/permeable reactive barrier/pore characterization/heavy metal removal引用本文复制引用
基金项目
国家重点研发计划(2019YFC1803500)
Nanning Key Research and Development Program Projects,China(20223040)
Innovation Project of Guangxi Graduate Education,China(YCBZ2022008)
出版年
2024
NETL
NSTL
万方数据