成果归属机构：

水资源与环境学院

作者：

Wang, Shenjin ; Liu, Xiaoxi ; Zhang, Chenyang ; Hu, Wenjihao ; Liu, Yaochi ; Fu, Xinzhuang ; Yao, Jun ; Sun, Wei

单位：

Cent South Univ, Coll Resource Proc & Bioengn, Engn Res Ctr, Minist Educ Carbon Emiss Reduct Met R, Hunan Int Joint Res Ctr Efficient & Clean Utilizat, Changsha 410083, Peoples R China;Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China;China Univ Geosci Beijing, Sch Water Resource & Environm Engn, Sino Hungarian Joint Lab Environm Sci & Hlth, Beijing 100083, Peoples R China

关键词：

AQUEOUS-SOLUTIONS; GREEN FABRICATION; BASES HSAB; SOFT ACIDS; REMOVAL; WATER; PALYGORSKITE; EFFICIENT; PB(II); KINETICS

摘要：

The utilization of attapulgite (ATP for short) is widely employed in the remediation of heavy metal-contaminated wastewater and soil. However, its precise mechanism of action remains unclear. This study delves into the adsorption and selectivity mechanisms of Pb2+ and Cd2+ on calcined attapulgite surfaces. The investigation aims to elucidate the intricate processes by which these heavy metal ions interact with the modified attapulgite, shedding light on their respective affinities and preferences for binding sites. The modificated ATP (BS-ATP for short) was prepared through calcination at 450degree celsius to remove Pb2+ and Cd2+ from aqueous solutions. X-ray diffraction, thermogravimetric analysis, and infrared spectrum revealed that the crystal structure of BS-ATP remained fundamentally unaltered following the process of calcination. X-ray photoelectron spectroscopy confirmed the stable adsorption of both Pb2+ and Cd2+ by BS-ATP. The adsorption experiment revealed that BSATP exhibited a significantly greater equilibrium adsorption capacity for Pb2+ (84.64 mg/L) compared to Cd2+ (23.10 mg/L), indicating a pronounced selective adsorption preference for Pb2+. Density functional theory (DFT) calculations have revealed that the adsorption energy of BS-ATP for Pb2+ is lower (-111.2KJ/mol) than for Cd2+ (-35.2KJ/mol). Furthermore, a distinct bonding interaction has been observed between Pb and the hydroxyl oxygen in the BS-ATP surface, with the Pb-O bond length ranging from 2.52 & Aring; to 2.92 & Aring;. The combined experimental and theoretical findings show that Pb2+ has a higher affinity and greater stability in adsorbing onto BS-ATP surfaces compared to Cd2+. This research enhances our understanding of the molecular mechanisms behind the selective adsorption of Pb2+ by attapulgite.

基金：

National Key R & D Program of China [2023YFC3707600]; Hunan Innovative Province Construction Special Fund [2023SK2061]; Science and Technology Innovation Program of Hunan Province [2022RC1183]; Changsha Science and Technology Project (Outstanding Innovative Youth Training Program); Innovation driven program of Central South University [2023CXQD002]; National 111 Project [B14034]

语种：

英文

DOI：

10.1016/j.seppur.2024.128377

来源：

SEPARATION AND PURIFICATION TECHNOLOGY,2025():.

出版日期：

2025-01-19

提交日期：

2024-07-23

引用参考：

Wang, Shenjin; Liu, Xiaoxi; Zhang, Chenyang; Hu, Wenjihao; Liu, Yaochi; Fu, Xinzhuang; Yao, Jun; Sun, Wei. Adsorption and selective mechanism of Pb2+and Cd2+on the surface of calcined modified attapulgite[J]. SEPARATION AND PURIFICATION TECHNOLOGY,2025():.