活性氧化铝改性除氟性能研究

Performance of modified activated alumina for fluoride removal

为提高活性氧化铝对饮用水中氟的去除效果,采用硫酸、氯化铁、硫酸与氯化铁复合3种方法对活性氧化铝进行改性。采用单因素和正交试验研究3种因素对3种改性活性氧化铝吸附除氟的影响。结果表明,硫酸与氯化铁复合改性的活性氧化铝的除氟效果最好,其最优改性条件组合为H2SO4浓度0.01 mol·L-1,浸泡时间120 min,固液比1:5,FeCl3浓度0.1%,浸泡时间180 min,固液比1:10;硫酸与氯化铁复合改性活性氧化铝的吸附行为更符合Langmuir等温线的拟合,即吸附为单分子层吸附,其最大吸附容量为4.98 mg·g-1,是未改性的3.4倍;且硫酸与氯化铁复合改性活性氧化铝吸附氟后溶液中金属离子不超标。

In order to improve the effect of activated alumina for fluoride removal from drinking water, the modified methods of activated alumina by H2SO4, FeCl3and H2SO4-FeCl3 were investigated. Single factor ex- periment and orthogonal experiment were selected to study three factors on adsorption of fluoride ion by three kinds of modified activated alumina. The results showed that H2SO4 -FeCl3 composite modified activated alumina had the best effect on defluorination, and the optimal modification condition was sulfuric acid （0.01 mol·L^-1）, im- mersion time （120 min）, solid-liquid ratio （1：5）, concentration of ferric chloride （0.1%）, immersion time （180 min）, solid-liquid ratio （1：10） respectively. And the adsorption behavior of H2SO4-FeCl3 composite modified activated alumina conformed to the Langmuir adsorption model that is, monolayer adsorption. Its maximum adsorption ca- pacity was 4.98 mg·g^-1, 3.4 times higher compared with non-modified alumina. And metal ions in the solution were not overweight after H2SO4 -FeCl3-MAA adsorption fluoride.