【摘要】 采用以陶粒和天然沸石为填料的两级上向流曝气生物滤池处理模拟废水,进水COD浓度为176~353 mg/L,NH4+-N浓度为56~175 mg/L,水力负荷范围为0.03~0.09 m/h,考察了水温、溶解氧(DO)、游离氨(FA)和游离亚硝酸(FNA)以及反冲洗对NO2--N积累的影响。结果表明,水温在6~10℃和≥22℃时能够实现NO2--N的积累,而13~18.2℃并未出现短程硝化特性;水温6~10℃时,BAF N段最佳DO浓度范围为2.43~4.75 mg/L,NO2--N平均积累率为65.8%,NH4+-N平均去除率为84.1%;另外,FA、FNA对亚硝酸盐氧化菌(NOB)具有联合抑制作用,能够实现NO2--N累积,最佳抑制浓度分别为0.10 mg/L≤FA≤8.77 mg/L和0.069 mg/L≤FNA≤0.249 mg/L,对应NO2--N平均积累率分别为67.7%和56.9%;反冲洗有利于NO2--N积累,反冲洗10 h后BAF N段对NH4+-N总去除率提高到80%,17 h后NO2--N积累率为82.5%,明显高于反冲洗前的74.5%。更多还原

【Abstract】 A two-stage up-flow biological aerated filter with ceramsite and natural zeolite was used to treat simulation wastewater,the influent COD and NH4+-N concentrations were 176~353 mg/L and 56~175 mg/L respectively,hydraulic loading was from 0.03 to 0.09 m/h,the inf1uence of water temperature,dissolved oxygen(DO),free ammonia(FA),free nitrous acid(FNA)and backwash to nitrite accumulation were studied. Results showed that nitrite accumulation achieved at6 ℃~10 ℃ and ≥22 ℃ but failed at 13 ℃~18.2 ℃. The optimal DO concentration range of BAF N at 6 ℃~10 ℃ was from2.43 to 4.75 mg/L,with average nitrite accumulation efficiency and NH4+-N removal efficiency as 65.8% and 84.1%respectively. In addition,FA and FNA have the inhibitory effect on nitrite oxidizing bacteria,the optimal FA and FNA concentration range was from 0.10 to 8.77 mg/L and from 0.069 to 0.249 mg/L,average nitrite accumulation efficiency was67.7% and 56.9% respectively. Backwashing is favorable for nitrite accumulation. NH4+-N total removal efficiency of BAF N increased to 80% after 10 h of backwashing. The maximum nitrite accumulation efficiency was 82.5% after 17 h,which was significantly higher than 74.5% of pre-backwashing.更多还原