斜发沸石处理氨氮废水

Adsorption of ammonium-nitrogen in wastewater by clinoptilolite

以斜发沸石为吸附剂处理氨氮废水,研究了斜发沸石粒径、反应时间、废水pH、废水氨氮初始浓度、斜发沸石用量对吸附的影响,分析了斜发沸石的吸附动力学和热力学特征。结果表明,在298 K下,当斜发沸石用量为7 g/100 mL,沸石粒径小于74μm,废水氨氮初始浓度为200 mg/L,pH为7,吸附时间为3 h时,废水中氨氮的去除率可达到92.71%,斜发沸石吸附氨氮符合拟二级动力学方程。在温度为298~318 K之间时,吸附等温线更好地符合Freundlich方程。在此基础上,热力学计算发现,ΔH0〉0、ΔG0〈0、ΔS0〉0,表明氨氮在斜发沸石上的吸附是自发吸热过程,以物理吸附为主。

Using the clinoptilolite as adsorbing agent to adsorb ammonium-nitrogen of wastewater,various factors were studied,including clinoptilolite particle size,chemical reaction time,optimal pH,initial ammonium（ NH＋4） concentration and clinoptilolite dosage,the kinetic and thermodynamic models were analyzed. The experimental data indicated that when the dosage was 7 g /100 mL,the grain size was less than 74 μm,the ammonium（ NH＋4） concentration was 200 mg/L,the pH was 7,and the reaction time lasted 3 h,its removal rate was 92. 71%. The pseudo second-order kinetic model provided more excellent kinetic data fitting at 298 K. At the temperature of 298 ~ 318 K,the Freundlich model agreed more with experimental data. Thermodynamic parameters analysis showed enthalpy（ ΔH0） 0,free energy（ ΔG0） 0 and entropy（ ΔS0） 0. These results indicated that the exchange of ammonium ion by clinoptilolite was spontaneously endothermic,mainly dominated by physical adsorption.