微孔曝气对潜流人工湿地处理稀土氨氮废水效果的影响

Effects of Microporous Aeration on Rare Earth Wastewater Treatment with Subsurface Flow Constructed Wetland

以包头某稀土厂稀土生产废水为处理对象,研究了微孔曝气对所构建的潜流人工湿地处理稀土氨氮废水的效果。研究发现,在所构建的潜流人工湿地系统中,微孔曝气有利于稀土废水中氨氮的去除,对潜流人工湿地运行的稳定性和可靠性均有增强。在曝气量为50和100 L/h时,所构建的潜流人工湿地能在40 d内实现稳定运行,稀土氨氮废水中的氨氮去除率由95.4%提高到98.2%以上,出水氨氮浓度稳定在5~24 mg/L,低于《稀土工业污染物排放标准（GB26451-2011）》所规定的氨氮直接排放浓度25 mg/L的要求。考虑到潜流人工湿地的运行成本,理想的曝气量应选为50 L/h。

Effects of the subsurface flow constructed wetland under microporous aeration assisted on removal of ammonia-nitro- gen in the rare-earth wastewater of the Baotou Rare Earth plant was studied. The research showed that the stable operation of subsurface flow constructed wetland under microporous aeration assisted could be achieved within 40 days as the aeration rate of 50 or 100 L/h. The removal rate of ammonia-nitrogen in the rare-earth wastewater could be increased to more than 98.2%. The ammonia-nitrogen concentration in the effluent water was 5~24 mg/L, less than the requirement of direct emis- sions of ammonia-nitrogen concentration （25 mg/L） （GB26451-2011）. Taking into account the running costs of the subsurface flow constructed wetland,the amount of aeration should be chosen as 50 L/h.