硅藻土的可控沸石化及其对铅离子的吸附固定  

Controlled zeolitization of diatomite for the adsorption and its immobilization of Pb(Ⅱ) ions

作　　者：杨晨[1] 吴俊书[1] 王金淑[1] 孙领民 徐梦 杜玉成[1] YANG Chen;WU Junshu;WANG Jinshu;SUN Lingmin;XU Meng;DU Yucheng(Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学,北京100124

出　　处：《无机盐工业》2022年第4期128-134,共7页Inorganic Chemicals Industry

基　　金：国家自然科学基金(52172290);河南省水体污染防治与修复重点实验室开放基金(CJSP2021009)。

摘　　要：铅离子已造成严重的环境污染,所以开发高效的处理材料势在必行。以硅藻土作为基材和原料,采用水热合成的方法对硅藻土进行沸石化改性,制备出硅藻土/沸石复合吸附剂。将这一吸附剂用于水相以及多相体系(如土壤)中铅离子的吸附、固定,室温下水溶液中铅(Ⅱ)的最高吸附量可达448.20 mg/g。土壤连续浸提(BCR)实验结果表明,500 mg/kg铅污染土壤中加入质量分数为1%至10%的复合吸附剂,固定钝化7 d后易迁移的可交换态(EX)铅质量分数从9.25%降至1.97%,转化为稳定的组分,且随着时间延长至60 d,可交换态铅含量仍维持在较低水平。上述结果证实了合成的硅藻土/沸石复合材料具有良好的铅离子吸附和固定性能,在环境净化领域表现出经济、绿色、便捷的特点,因此具有较大的推广应用潜力。Lead ions have caused serious environmental pollution,and it is imperative to develop efficient treatment materials.Diatomite/zeolite composite adsorbent was prepared by zeolitization of diatomite by hydrothermal synthesis method by using diatomite as substrate and raw material.When this adsorbent was used for the adsorption and fixation of lead ions in aqueous and heterogeneous systems(such as soil),the maximum adsorption capacity of Pb(Ⅱ)in aqueous solution at room temperature could reach 448.20 mg/g.The results of soil continuous extraction(BCR)experiment showed that the mass fraction of exchangeable and mobile(Ex)lead was decreased from 9.25%to 1.97%after 7 days of fixed passivation by adding mass fraction of1%to 10%composite adsorbent in 500 mg/kg lead contaminated soil,and transformed into stable components.With the extension of time to 60 d,EX remained at a low level.The above results confirmed that the synthesized diatomite/zeolite composite had good lead ion adsorption and fixation properties,and showed the characteristics of economy,green and convenience in the field of environmental purification.Therefore,it had great potential for popularization and application.

关 键 词：硅藻土 沸石化 离子交换 吸附固定 

分 类 号：TQ134.33[化学工程—无机化工]