潜流人工湿地处理稀土氨氮废水的实验研究

Experimental Study 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,利用水葱、野茭白、香蒲、李氏禾构建四组潜流人工湿地,研究了所构建的潜流人工湿地对稀土废水中氨氮的处理效果。研究发现,所构建的潜流人工湿地A1B2能够在45 d内实现稳定运行;对稀土氨氮废水中氨氮的去除率为95.40%,出水氨氮浓度低于《稀土工业污染物排放标准(GB26451—2011)》所规定的氨氮间接排放浓度50 mg/L的要求。所构建的潜流人工湿地A1B1能够在75 d内实现稳定运行;对稀土氨氮废水中氨氮的去除率为97.26%,出水氨氮浓度低于《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。A1B2潜流人工湿地中四种湿地植物对稀土废水中的氨氮去除能力呈现为水葱>香蒲>李氏禾>野茭白,水葱和香蒲对稀土废水中的氨氮去除起主导作用,水葱和香蒲表现出良好的稳定性和可靠性。A1B1潜流人工湿地中四种湿地植物对稀土废水中的氨氮去除能力呈现为香蒲>水葱>李氏禾>野茭白,对氨氮去除起主导作用的是香蒲;水葱处理的稳定性和可靠性最强。

In order to study the treatment effect of ammonia in the rare earth wastewater with subsurface flow constructed wetland,four groups subsurface flow constructed wetland with Scirpus validus,Zizania aquatic,Ty-pha L.and Leersia hexandra were constructed.The rare earth wastewater of the Baotou Rare Earth plant was treatmented by the subsurface flow constructed wetland.The research shows that the stable operation of subsurface flow constructed wetland A1B2 can be achieved within 45 days,and the removal rate of ammonia in the rare earth wastewater can be reached 95.40％,the ammonia concentration in effluent water is 40mg/L,less than the requirements of indirect emissions of ammonia concentration （50 mg/L）＂ Emission Standard of Rare Earth Industry （GB26451-2011） ＂.The stable operation of subsurface flow constructed wetland A1 B1 can be achieved within 75 days,and the removal rate of ammonia in the rare earth wastewater can be reached 97.26％,the ammonia concentration in effluent water is 21.95mg/L,less than the requirements of direct emissions of ammonia concentration （25 mg/L） ＂Emission Standard of Rare Earth Industry （GB 26451-2011）＂.The removal capability on ammonia in rare earth wastewater of subsurface flow constructed wetland A1B2 by four kinds of wetland plants is rendered as Scirpus validus ＞ Ty-pha L ＞ Leersia hexandra ＞ Zizania aquatic.Scirpus validus and Ty-pha L play a leading role and have good stability and reliability in rare earth wastewater treatmen with subsurface flow constructed wetland A1B2.The removal capability on ammonia in rare earth wastewater of subsurface flow constructed wetland A1 B1 by four kinds of wetland plants is rendered as Ty-pha L ＞ Scirpus validus ＞ Leersia hexandra ＞ Zizania aquatic.Typha L plays a leading role in rare earth wastewater treatmen with subsurface flow constructed wetland A1B1.The Scirpus validus has good stability and reliability in rare earth wastewater treatmen with subsurface flow constructed wetland A1B1.