氨吹脱处理稀土分离厂中氨氮废水试验研究

Experimental research on treatment of ammonia nitrogen wastewater by ammonia stripping in a rare earths separation factory

稀土分离厂排放大量含氨氮废水，为了使该类废水能得到有效的处理，对稀土废水中中等浓度的氨氮废水进行了氨吹脱试验研究。发现pH、温度和气液比是氨氮去除效率高低的关键因素，废水初始浓度对去除率无影响。调节废水pH=12，气液比在3 000-4 000，温度在35-45℃范围，浓度为1 570 mg/L的碳铵沉淀洗涤废水经氨吹脱处理可使出水残余氨氮浓度控制在100 mg/L以下，去除率达94%以上。

An abundant of wastewater with ammonia nitrogen was discharged in rare earths separation factories. In order to effectively treat the wastewater, the experimental studies of ammonia stripping on removal of middle concentration of ammonia nitrogen in rare earths wastewater were performed, which found that pH, temperature and air-liquid ratio are the key factors, and the initial concentration has no effect on removal efficiency. Adjusting pH to 12, air-liquid ratio to the range of 3 000～4 000 and temperature to the range of 35～45℃, after the washing wastewater from deposited ammonium carbonate that the initial concentration of ammonia nitrogen was 1 570 mg/L was treated by ammonia stripping, the residual concentration of ammonia nitrogen was controlled to below 100 mg/L and removal efficiency reached to over 94%.