HN-AD菌强化生物转盘工艺处理养牛场废水

Treatment of Cattle Farm Wastewater by Rotating Biological Contactor Enhanced with HN-AD Bacteria

养牛场废水中COD和氨氮浓度高、碳氮比高,且具有一定的生物毒性,处理过程中存在脱氮效果差、工艺流程复杂、启动周期长等问题。为此,采用以三维结构盘片为载体的生物转盘(RBC)反应器,以异养硝化-好氧反硝化(HN-AD)菌为生物强化剂,考察了生物强化RBC工艺对养牛场废水的处理效果。在驯化阶段(进水为模拟废水),当氨氮> 400 mg/L时,未经HNAD菌强化的RBC2反应器对污染物的去除率明显降低,而经过HN-AD菌强化的RBC1反应器对氨氮的耐受浓度可达600 mg/L,对NH4^+-N、NO3^--N、TN和COD的去除率要比RBC2反应器分别高40. 75%、32. 15%、34. 68%和24. 25%。运行稳定后,采用RBC1反应器处理实际养牛场废水,对NH4^+-N、NO3^--N、TN和COD的平均去除率分别为81. 65%、72. 14%、65. 79%和80. 53%,明显优于传统处理技术。高通量测序结果表明,生物强化后系统的优势HN-AD菌为Acinetobacter,其丰度由接种菌剂中的1. 34%上升至18. 56%,由此推测Acinetobacter是起异养硝化-好氧反硝化作用的主要菌属。SEM观察发现,生物强化后,盘片的生物膜表面附着了大量杆状菌和球状菌。

Cattle farm wastewater is characterized by high ammonia nitrogen,high COD,high C/N ratio and even contains certain toxicity. There are several problems when the wastewater is treated,such as poor nitrogen removal,complex process and the long start-up cycle. Therefore,the effect of bioenhanced rotating biological contactor (RBC) on the treatment of cattle farm wastewater was investigated by using three-dimensional structure disks as the carrier and the heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria as bio-fortifier. During domestication stage (the influent was simulated wastewater),the removal rate of pollutants in RBC2 without enhancement of HN-AD bacteria decreased significantly when ammonia nitrogen was more than 400 mg/L,while the RBC1 enhanced with HN-AD bacteria could withstand ammonia nitrogen higher than 600 mg/L,and the removal rates of NH4^+-N,NO3^--N,TN and COD were 40. 75%,32. 15%,34. 68% and 24. 25% higher than that in RBC2,respectively. Then, the RBC1 enhanced with HN-AD bacteria was used to treat real cattle farm wastewater,and the average removal rates of NH4^+-N,NO3^--N,TN and COD were 81. 65%,72. 14%,65. 79% and 80. 53%,respectively,which was significantly higher than that of the traditional treatment technology. High-throughput sequencing results showed that Acinetobacter was the dominant bacterium in the bio-enhanced system,and its abundance increased from 1. 34% to 18. 56%. Therefore,it was speculated that Acinetobacter was the main bacterium with the function of heterotrophic nitrification-aerobic denitrification. It was found by SEM observation that a large number of rods and coccus attached on the surface of the biofilm.