煤矸石的改性及其对稀土生产废水中氨氮的吸附

采用热改性、盐酸改性、硫酸改性、碱改性的方法分别制备了4种改性煤矸石吸附剂,研究了吸附工艺条件对4种改性煤矸石吸附剂对稀土生产废水中氨氮去除效果的影响以及吸附机理.实验结果表明:4种改性煤矸石吸附剂吸附氨氮的最佳工艺条件为:吸附剂加入量0.02 g/mL,振荡时间2.5 h,废水pH 7～8;4种吸附剂氨氮去除率大小顺序为:碱改性煤矸石＞硫酸改性煤矸石＞盐酸改性煤矸石＞热改性煤矸石;碱改性煤矸石的氨氮去除率最高,为59.19％;碱改性煤矸石吸附剂对含氨废水中氨氮的吸附较好地符合Langmuir方程和Freundlich方程,在一定程度上符合Temkin方程.

Modification of Coal Gangue and Adsorption of Ammonia Nitrogen in Rare Earth Production Wastewater

4 kinds of modified coal gangue adsorbents were prepared by thermal modification,hydrochloric acid modification,sulfuric acid modification and alkali modification respectively.The effects of adsorption conditions on the removal of ammonia nitrogen from rare earth production wastewater and the adsorption mechanism were studied.The optimum adsorption conditions are as follows:adsorbent dosage 0.02 g/mL,oscillation time 2.5 h,wastewater pH 7-8;The order of ammonia nitrogen removal efficiencies of the 4 adsorbents is as follows:alkali modified gangue>sulfuric acid modified gangue>hydrochloric modified gangue>thermally modified gangue;The ammonia nitrogen removal efficiency of alkali modified gangue is the highest(59.19%);Ammonia nitrogen adsorption on the alkali modified gangue accords with Langmuir equation and Freundlich equation well and Temkin equation to a certain degree.