改性火山石对氟离子的吸附性能研究

Research on adsorption capacity of modified volcanic stone for fluoride ion

选用盐酸改性天然火山石作为吸附剂,研究了其对水中氟离子的去除性能,探究吸附时间、改性火山石投加量和溶液pH值对氟离子吸附效果的影响。结果表明,盐酸改性提高了火山石对氟离子的吸附能力。改性火山石对含氟废水的处理时间较短,120min即可达到平衡;吸附剂投加量为8g·L-1时,氟离子的吸附去除率达到最大,为82.4%;溶液pH为4～7的范围内,对氟离子的吸附去除率达到75%以上。正交实验结果发现,当吸附时间为60min,改性火山石投加量为8g·L-1,溶液pH为4时,对氟离子的吸附效果较好。改性火山石吸附氟离子的过程更符合Langmuir模型,吸附过程更接近单层吸附,吸附容量可达0.91mg·g-1,吸附动力学符合Lagergren二级动力学方程,吸附速率快。

Hydrochloric acid has been chosen for the modification of natural volcanic stone to study the removal performance of fluoride.The effects of adsorption time,modified volcanic stone dosage and pH value on adsorption properties were investigated for the scheme.The results showed that hydrochloric acid modification could improve the adsorption capacity of volcanic stone.The treatment time of modified volcanic stone for fluorine-containing wastewater was relatively short,and the adsorption equilibrium could be reached within 120 min.When the adsorbent dosage was 8 g·L^-1,the maximum adsorption removal rate of fluorine ion was 82.4%.The modified volcanic stone adsorbed fluoride ion was efficiently with the pH range(4~7),and the removal rates were above 75%.Orthogonal experiment results indicated that when the adsorption time was 60min,the modified volcanic stone dosage was 8 g·L^-1,and the pH was 4,the adsorption effect of fluoride ion was higher.The process of fluorine ion adsorption from modified volcanic stone was more consistent with Langmuir model,which was the single-layer adsorption,and the adsorption capacity could reach 0.91 mg·g^-1.It was also found that the adsorptive dynamics followed pseudo-second order kinetics equation.