环境保护科学2025，Vol.51Issue(5)：35-44,10.DOI:10.16803/j.cnki.issn.1004-6216.202409056
同步去除水体中As(Ⅴ)-F的改性生物炭基复合材料的筛选
Screening of modified biochar-based composites for simultaneous removal of As-F from water
摘要
Abstract
High-arsenic(As)and high-fluoride(F)groundwater is widely distributed worldwide,and there is an urgent need to find an efficient adsorbent material for the simultaneous removal of As and F.Using crop straws(wheat straw,corn cob)and agricultural by-products(peanut shell,almond shell)as raw materials,biochar was obtained by carbonization at 500℃ for 2 hours.Biochar-based composite materials were optimized by loading Fe and La,which were used for the simultaneous adsorption of As(Ⅴ)and F-in water.By simulating the groundwater concentration in high-As and high-F areas,their adsorption performance for As(Ⅴ)and F-was investigated,and the optimal adsorbent was selected through comparison.Additionally,the influence of dosage on the adsorption of As(Ⅴ)and F-was discussed.The results showed that the adsorption capacity of Fe and La-modified biochar increased by 3～4 times compared with that of raw biochar,and the removal rate was improved by 62％～80％.Among them,Fe and La-modified wheat straw biochar exhibited the best removal effect,with a removal rate of up to 99％for As(Ⅴ)and F-.In the As(Ⅴ)-F composite system,the maximum adsorption capacities for As(Ⅴ)and F-were 0.94 mg/g and 7.62 mg/g,respectively.After adsorption,the equilibrium concentration of As(Ⅴ)in water was lower than the limit for dryland irrigation water(≤ 0.1 mg/L),and the equilibrium concentration of F-was lower than the limit specified in drinking water standards(≤ 1.0 mg/L).The adsorption mechanism of As(Ⅴ)was mainly that hydroxyl groups were consumed during the adsorption process of Fe/La-modified wheat straw,and ligand exchange reactions occurred between surface metal hydroxyl groups and As(Ⅴ),resulting in the formation of Fe/La-O-As inner complexes.The adsorption mechanism of F-was mainly that F-in water could undergo ligand exchange with hydroxyl groups(La-OH)to form La-F coordination bonds,thereby generating more stable coordination compounds,coupled with ion exchange.关键词
地下水/生物炭/As-F/吸附Key words
groundwater/biochar/arsenic fluoride/adsorption分类
环境科学引用本文复制引用
王美娟,罗艳丽,宋振,何佳乐,张千,解新哲..同步去除水体中As(Ⅴ)-F的改性生物炭基复合材料的筛选[J].环境保护科学,2025,51(5):35-44,10.基金项目
国家自然科学基金项目(42067053) （42067053）
