贫营养条件下MBR与IAMBR脱氮效果分析

以膜生物反应器(Membrane Bio-Reactor,MBR)工艺和间歇曝气式膜生物反应器(Intermittent Aeration Membrane Bio-Reactor,IAMBR)工艺进行对比运行试验,探求贫营养条件下系统的运行和脱氮特性。定期测量各项氮指标及混合液污泥浓度等数据,结果表明:IAMBR系统整个周期内的氨氮去除率(平均值为81%)基本高于MBR(平均值为76%);IAMBR的总氮去除率虽然有限,但基本维持了理论上的出水总氮质量浓度小于进水总氮质量浓度,优于MBR的总氮去除率负值状态;试验末期,MBR的污泥质量浓度迅速下降至3 650 mg/L以下,而间歇曝气式IAMBR的污泥质量浓度仍旧保持在4 530 mg/L。因此,整体来看IAMBR系统比MBR更能经受贫营养环境的冲击。

Analysis of nitrogen removal efficiency of MBR or IAMBR in the oligotrophic condition

The paper is to dedicate itself to an analysis of nitrogen removal efficiency of MBR or IAMBR in the oligotrophic condition.For the said purpose,we have managed to use a membrane bio-reactor and an intermittent aeration membrane bio-reactor as a means to remove the residual chlorine in terms of 24-hours a day to explore the nitrogen-removing characteristic features as an artificial influent without carbon source to achieve the oligotrophic condition with 20 L tap-water.With the testing device made ready,the experiment can be done with the tap-water as raw material to cultivate and treat the ammonium sulfate of 120 mg/L,the sodium bicarbonate of 50 mg/L,the potassium dihydrogen phosphate of 50 mg/L,the magnesium sulfate of 23 mg/L,the ferric chloride of 4 mg/L,in addition to the calcium chloride of 10 mg/L.When the liquid-mixed sludge taken from a MBR reaction tank is treated with the concentration of about 5 500 mg/L,the reaction is expected to be made in terms of 24 days continuously.The results of our experimental analysis indicate that the removal rates of ammonia nitrogen in MBR and IAMBR are expected to decrease for the first 7 days,and then the removing rate of the ammonia nitrogen tends to increase from 73％ to 82％ in the IAMBR with the MBR being decreased from 76％ to 71％.Moreover,it has been found that the average removal rate of ammonia nitrogen in IAMBR proves higher than that in MBR,though the removal rate of TN in the IAMBR turns to be limited.What is more,the TN concentration of the effluent should be lower than that of the influent,which is better than the negative removal rate of MBR,whereas the concentration of NO3--N should be higher than that of NO2--N in the effluents of the two reactors,so that there would be no accumulation of NO2--N in them.We have also noticed that,the SVI concentration of the two reactors tends to increase at the beginning of the experiment,but later tends to decrease though no excessive growth of filamentous bacteria can be found.What is more,the SVI concentration in the two may have been found decreasing obviously from 7th to 11th day.And,finally,the sludge concentration in MBR tends to reduce to 3 650 mg/L,whereas the concentration in IAMBR turns to be 4 530 mg/L.Thus,it can be concluded that IAMBR proves to be more stable than MBR in the oligotrophic condition.