生物基质对SWIS脱氮效果及微生物的影响

Effect of biological matrix on denitrification and microorganisms of SWIS

为考察不同地下渗滤系统装置沿程脱氮效果的差异和脱氮微生物群落结构的分布状况,构建了2套改良装置(煤渣-生物基质的1~#、煤渣的2~#),对沿程出水的COD、氨氮、TN浓度和填料内的脱氮微生物丰度进行了测定分析。结果表明:系统在水力负荷为15 cm·d^(-1)下,1~#和2~#装置对氨氮平均去除率分别为75.59%、80.00%,对TN平均去除率分别为60.63%、57.96%,1~#的脱氮效果略优于2~#装置;由沿程氮污染物浓度变化可知,2套装置的TN去除范围主要在层高60～80 cm处。与2~#装置相比,添加生物基质的1~#装置TN去除率提高了9.60%,且其装置内的Bradyrhizobium、Pseudolabrys、 Dongia、 Rhodanobacter、 Rudaea等脱氮细菌的丰度也分别提升了0.51%、 1.52%、 1.02%、 10.49%和3.15%。因此,生物基质可促进SWIS内部脱氮微生物丰度提升,并通过提供反硝化的碳源来强化脱氮效果。

In order to explore the difference of denitrification effect along the devices and the distribution of denitrifying microbial community structure in different subsurface wastewater infiltration systems,two modified devices with cinder-biological matrix(1#)and cinder matrix(2#)were constructed.The COD,ammonia nitrogen,TN concentration in the effluent along the reactors and the abundance of denitrifying microorganisms in the filler were measured and analyzed.The results showed at the hydraulic load of 15 cm·d-1,1#and 2#devices could remove ammonia nitrogen with the average removal rates of 75.59%and 80.00%,respectively,and remove TN with the average removal rates of 60.63%and 57.96%,respectively,the denitrification effect of device 1#was slightly higher than 2#.Through the change of nitrogen pollutant concentration along the reactor of two devices,the TN removal mainly occurred at the 60~80 cm height.Compared with device 2#,the TN removal rate of device1#with bio-matrix increased by 9.60%,and the abundance of denitrifying bacteria such as Bradyrhizobium,Pseudolabrys,Dongia,Rhodaanobacter,and Rudeea in it increased by 0.51%,1.52%,1.02%,10.49%and3.15%,respectively.Therefore,the biological matrix can promote the abundance of denitrifying microorganisms in the SWIS,and provide the denitrification carbon source to enhance the denitrification effect.