碳氮比对气水交替式膜生物反应器同步脱氮除碳的影响

Effect of 碳氮 ratio on simultaneous removal of carbon and nitrogen by a gas-water alternate membrane bioreactor

为确定气水交替式膜生物反应器(AMBR)处理污水时的适宜碳氮比,实现较好的同步脱氮除碳效果,构建以2片亲水性聚丙烯中空纤维膜轮流作为曝气膜和出水膜的AMBR,在150 d连续运行的时间内,考察碳氮比对AMBR处理模拟生活污水同步脱氮除碳的影响.结果表明:将混合液中DO的质量浓度控制在0.5 mg/L左右,进水COD和NH4+-N质量浓度分别为100～350 mg/L和34 mg/L,碳氮比在3～10之间的条件下,碳氮比的增加不影响AMBR对COD和NH4+-N的去除,在150 d的运行时间内,出水COD和NH4+-N质量浓度始终分别保持在20 mg/L和2 mg/L左右;但碳氮比的增加有利于AMBR去除TN,当碳氮比大于5时,TN去除率超过66%,出水TN质量浓度低于15 mg/L,满足国家GB 18918—2002中一级A的要求.

In order to investigate the optimal C/N ratio for simultaneous nitrogen and carbon removal by a gas-water alternate membrane bioreactor（AMBR）treating wastewater,an AMBR in which two hydrophilic polypropylene hollow-fiber membrane modules was used for aeration and filtration alternately was constructed,and the effect of C/N ratio on simultaneous removal of nitrogen and carbon by AMBR treating synthetic wastewater was studied during the 150 days＇ continuous operation.The results showed that under the condition that DO in the mixed liquor was 0.5 mg/L around,the influent COD and NH4＋-N was（100-350）mg/L and 34 mg/L,and C/N ratio was in the range of 3-10,increase of C/N ratio had no influence on COD and NH4＋-N removal.During the 150 days＇ operation,COD and NH4＋-N in effluent maintained 20 mg/L and 2 mg/L around,respectively.However,increase of C/N ratio was beneficial to TN removal by AMBR.When C/N ratio was more than 5,TN removal efficiency was more than 66%,and the effluent TN was lower than 15 mg/L,which met the First A-level requirement of national GB 18918—2002.