MUSCHIN Tegshi, BORJIGIN Tuul, BAI Aodun, GAO Chunguang
(Inner Mongolia Key Laboratory of Green Catalysis, College of Chemistry and Environmental Science, Inner Mongolia Normal University, Hohhot 010022, China)
Abstract
Significance Nowadays, the increasing concentration of pollutants in industrial wastewater has caused serious pollution of waterresources, which has affected the daily life and health of human beings. The traditional methods of treating water pollutants aremainly divided into biological treatment, physical treatment and chemical treatment. Among them, the adsorption is the mostwidely used in the physical treatment methods, but the traditional adsorbents are limited by their expensive and difficulty in separating from water. Hence, much attention has been paid to the preparation of a new type of adsorbent that is economical and easyfor solid-liquid separation. Kaolin is a resourceful, cheap and easily available, non-toxic non-metallic mineral clay resource. The chemical formula of its crystals is Al2O3·2SiO2·2H2O. The application of kaolin has limited in industrial fields such as paper, paint, rubber, ceramics, etc. , while the fields of catalytic and pollutant treatment are still lack of application. In recent years, these materials have attracted the attention of researchers due to its advantages of abundant, cheap and easy availability.
Progress The development on the adsorption of heavy metal pollutants, organic pollutants and other pollutants such as F-in water byraw kaolin, organo-inorganic modified kaolin and composite modified kaolin is summarized. kaolin itself is reported to have certain adsorption and ion-exchange capacity. However, the adsorption efficiency of raw kaolin is unsatisfactory. Therefore,researchers have tried various possible ways to modify kaolin, such as inorganic acid and alkali modification of the raw or calcinedkaolin, organic modification using silane coupling agent, DMSO, etc., and composite modification with organic substances suchas chitosan or alginate, and inorganic substances including titanium oxide and magnetic iron. The results of adsorption performance of water pollutants show that different modification methods can improve the adsorption performance of kaolin on water pollutants. For example, calcination and acid or base treatment can improve the specific surface area of kaolin and enhance its adsorption performance. The composite modification of kaolin to diversify the adsorption sites and effectively improve the adsorptionperformance is a much-studied topic. Researchers have also discussed the adsorption mechanism to different degrees, and most ofthe adsorption isotherms are fitted with the Langmuir model, and most of the adsorption kinetics is consistent with the pseudo-second-order model.
Conclusions and Prospects The research on the adsorption of kaolin for removal of water pollutants has been gradually developed,with various modification methods. However, there remains a challenge to efficiently improve the adsorption performance of kaolin.More research should be focused on how to improve the adsorption properties of kaolin while exploring low energy consumption, lowcost, simple process, environmentally friendly modification methods that effectively improves the value of kaolin resources.
Keywords:kaolin clay; adsorption; water pollutant; organic modification; inorganic modification; composite modification
Get Citation：MUSCHIN T, BORJIGIN T, BAI A, et al. Recent advances in kaolin for adsorption of water pollutants [J]. China Powder Science and Technology, 2024, 30(1): 46-55.
Received: 2023-08-18,Revised :2023-10-11,Online:2023-11-28。
Funding Project:国家自然科学基金 ,编号 :22061034;内蒙古自治区高等学校科学研究项目 ,编号 :NJZZ21010;大学生创新创业训练计划项目 ,编号 :S202210135020;内蒙古自治区水环境安全协同创新培育中心项目 ,编号:XTCX003。
First Author:特格希 (1980—) ,男(蒙古族 ),副研究员 ,博士 ,硕士生导师 ,研究方向为黏土资源综合利用、水污染物吸附以及多相催化有机合成。E-mail: tegshi@imnu.edu.cn。
Serial No:1008-5548(2024)01-0046-10
CLC No:TQ623. 6; O647. 3; TB4 Type Code:A
DOI:10.13732 / j.issn.1008-5548.2024.01.005
