合成沸石的改性及其对氨氮的吸附特性

Synthetic Zeolite Modification and the Characteristics of Its Ammonia-nitrogen Adsorption

采用不同的酸和碱对合成沸石进行了改性。通过静态吸附试验考察了改性沸石对氨氮的吸附效能。结果表明,对氨氮的吸附酸改性效果优于碱改性,以0.1mol/L的HCl作为改性剂最高吸附率可达84.04%。pH值对改性沸石吸附氨氮影响较大,pH值为6时氨氮吸附率达86.88%。合成沸石吸附氨氮等温吸附曲线更符合Freundlich模型(R2>0.994),改性沸石对氨氮的吸附行为属于优惠吸附。Lagergren准二级反应动力学方程比准一级反应动力学方程拟合结果好(R2>0.9994),利用准二级动力学方程获得的平衡吸附量与实测值相差在4.9%以内。

In this study,the synthetic zeolite is modified by the different acids and alkalis.With thestatic method,the mmonia-nitrogen adsorption properties of synthetic zeolite are investigated by static adsorption test.The results show that the modified zeolite has higher adsorption capacity in acids than that in alkalis.Zeolite modified with 0.1mol·L^(-1) HCl solution has the highest adsorption efficiency and the mmonia-nitrogen adsorption rate is as high as 84.04%,pH has less influence on its adsorption,the effect of pH value is the maximum,the adsorption ratio of ammonia-nitrogen is86.88% at pH of 6.The isothermal curve of mmonia-nitrogen adsorption of the synthetic zeolite is consistent with Freundlich model(R2>0.994),the adsorption is favorable.The matching result of Quasi 2nd-order reaction kinetic equation of Lagergren is better than that of the 1st-order equation(R2>0.9994),the difference between the balanced adsorption rate obtained from the 2nd-order reaction kinetic equation and the measured value is within 4.9%.