羟基铁覆膜膨润土对砷的吸附性能研究

PROPERTIES STUDY ON As ADSORPTION BY HYDROXY-FE COATED BENTONITE

本研究用Fe(NO3)3·9H2O和NaOH合成羟基铁并对膨润土进行覆膜。探索最宜覆膜方式,并考察吸附剂投加量与pH值对覆膜膨润土吸附砷的影响,并采用Langmuir、Freundlich吸附等温线模型和准一级动力学模型、准二级动力学模型对实验数据进行拟合。结果表明:当铁碱比为1∶2时以及水样pH=4.5时,吸附效果最佳;覆膜膨润土对砷的吸附符合Freundlich方程和准二级动力学模型,最大吸附量为40.69 mg/g,存在明显的化学吸附。

Fe( NO3)3·9H2O and NaOH were used to compound Hydroxy-Fe,and then coated bentonite. The influence of dosage and pH were investigated on adsorption effects of hydroxyl-Fe coated bentonite through dynamic tests. Langmuir,Freundlich isotherm equation and quasi-first-order kinetics equation,quasi-second-order kinetics equation were applied to simulate the experimental parameters. The results showed that the hydroxyl-Fe coated bentonite had the best adsorption efficiencies when the proportion of Fe( Ⅲ) and OH-was 1∶ 2,the pH was 4. 5. The process of adsorption on As by hydroxylFe coated bentonite met Freundlich isotherm equation and quasi-second-order kinetics equation. The maximum adsorption capacity was 40. 69 mg / g,and an obvious chemical adsorption existed.