Abstract: The impacts of hydraulic retention time (HRT), dissolved oxygen (DO) and recycling flow rate (R) on performance of nitrogen removal were studied in the treatment of domestic sewage using combined biofilm reactor. The results showed that without recycling of effluent, HRT and DO affected the removal of ammonia nitrogen obviously while had little influence on removal of total nitrogen. After recycling started, the removal rate of TN increased greatly. Under the conditions of temperature at 19~28℃, COD concentration of 208~496 mg/L and NH4+-N concentration of 29.5~89.5 mg/L, respectively, the best removal efficiencies of NH4+-N and TN could be obtained at HRT of 3 h, R of 150%, DOO of 3~4 mg/L and DOB of 6~7 mg/L, respectively. The average removal rates of NH4+-N and TN were 98.97% and 76.27%, respectively, while the effluent concentrations of NH4+-N and TN were 0.43 and 11.2 mg/L, respectively, and met with the strictest requirement of discharge standard of GB18918-2002.

Key words: biofilm process, nitrogen removal, domestic sewage, dissolved oxygen, hydraulic retention time, recycling flow rate

摘要： 利用生物膜组合反应器处理实际生活污水，探讨了水力停留时间(HRT)、溶解氧(DO)和回流比(R)对系统脱氮性能的影响. 结果表明，在无回流时，HRT和DO仅对氨氮(NH4+-N)去除影响较大，而对总氮(TN)去除影响不大，硝化液回流后，系统TN去除率明显提高. 在水温为19~28℃、进水COD浓度为208~496 mg/L及NH4+-N浓度为29.5~89.5 mg/L的条件下，当HRT为3 h，O和B段DO分别为3~4和6~7 mg/L、系统回流比为150%时，该生物膜组合反应器对NH4+-N和TN的去除效果达到最佳，其平均去除率分别为98.97%和76.27%，此时系统出水NH4+-N和TN分别为0.43和11.2 mg/L，达到GB18918-2002规定的一级A标准.

关键词: 生物膜法, 脱氮, 生活污水, 溶解氧, 水力停留时间, 回流比