钠化沸石处理稀土冶炼氯铵废水中的氨氮

Study of the Ammonia-Nitrogen Removal from Ammonium Chloride Wastewater from Rare Earth Smeltery by Na-Pretreated Zeolite

研究了沸石处理稀土冶炼氯铵废水中氨氮的各种影响因素和再生条件。实验结果表明:进水氨氮质量浓度为250 mg/L,沸石投加量125 g,粒径小于5 mm,pH 7-8,吸附时间1 h的条件下,氨氮去除率达到90%以上。选择质量比为3∶7的NaCl与NaOH混合液作为沸石的再生剂,再生效果好,可进行多次重复使用,有效寿命可达30 h。

The various influence factors and regeneration conditions of removing ammonia--nitrogen from rare earth refining wastewater were studied by using Na--pretreated zeolite. The result showed that when the ammonia concentration in the wastewater was 250 mg/L, zeolite dosage 125 g/L, zeolite size less than 5 mm, maintaining pH was from 7 to 8, after adsorption time 1 h, the removal rate of ammonia was up to 90%. The best regenerated catalyst was a combination of NaCl and NaOH with 3 ： 7, which can be reused for many times, and its effective life reached about 30 h.