人工湿地功能填料火山岩对氮的吸附特征及脱氮转化过程

Sorption and Transformation of Nitrogen on Volcanic Rock in Simulated Constructed Wetland

以某污水处理厂出水为受试污水,研究人工湿地功能填料火山岩对氨氮(NH_(3)-N)的静态吸附特征,并比较206天内火山岩填料系统和砾石填料系统对氮的去除性能和转化过程,为火山岩湿地填料应用提供理论参考。火山岩对NH_(3)-N吸附速率快,1小时内NH_(3)-N的去除率可以达到71.8%;温度升高时NH_(3)-N的去除率明显增加,而当温度降低时NH_(3)-N的初始浓度对其吸附去除率的影响显著增大;产地对火山岩吸附影响较小。火山岩填料系统NH_(3)-N平均去除率53.66%,低于砾石填料系统(69.19%);其总氮(TN)去除率(13.51%)略优于砾石填料系统(6.11%)。系统运行前期,火山岩填料系统硝酸盐氮(NO_(3)-N)降低而砾石填料系统逐步增加,表明砾石填料中硝化细菌更活跃,火山岩填料中反硝化细菌发育更好。鉴于此,将两种填料系统组合成运用可协同去除NH_(3)-N和TN。

Taking a municipal wastewater treatment plant effluent as the experimental sewage,the static sorption characteristics of volcanic rock toward ammonia nitrogen were studied.Simulated wetland substrate packing systems were constructed to evaluate the nitrogen removal efficiency of volcanic rock and gravel within 206 d,and the conversion process of nitrogen were also investigated.Results indicated that fast sorption of ammonia nitrogen exhibited on volcanic rock,and the removal rate reached 71.8%at 1 h.The sorption of volcanic rock toward ammonium enhanced when increasing the temperature,and was greatly influenced by the initial ammonium concentration at low temperature,but the effect of volcanic rock origin was insignificant.The average ammonia nitrogen removal rate of volcanic rock packing system was 53.66%,much lower than that of gravel packing system(69.19%)whereas the total nitrogen removal rate(13.51%)was slightly better than that of gravel packing system(6.11%).In the early stage of system operation,the nitrate nitrogen of the volcanic rock packing system decreased while the gravel packing system gradually increased,indicating that the nitrifying bacteria in the gravel packing system were more active and the denitrifying bacteria grew better in the volcanic rock packing system.In view of this,combining the two packing systems into operation can simultaneous removal ammonia nitrogen and total nitrogen.