微污染东平河原水的生物预处理特性与效果

Characteristics and Efficiency of Biological Pretreatment of Micropolluted Source Water from Dongping River

以齿轮型生物载体为悬浮填料,在连续或间歇曝气条件下,改变气水比,对氨氮含量为1.5~2.5 mg/L、浊度为15~20 NTU的东平河微污染原水进行生物接触氧化预处理,研究其挂膜与处理特性以及停曝比、气水比等对去除氨氮的影响。结果表明:仅需7 d填料表面即附着一层黄褐色的生物膜,其以菌胶团为主,生物量达70 nmol/g。连续曝气,且气水比为(0.5∶1)和(1∶1)时,对氨氮的平均去除率分别为75%和66%;而在间歇曝气条件下,停曝比为(3∶5)^(3∶1)时,对氨氮的去除率增加显著,达80%~90%。氨氮浓度>2 mg/L时,出水亚硝酸盐氮含量达0.15~0.25 mg/L,但仍满足饮用水水质标准。

Micro-polluted source water with ammonia nitrogen of 1.5 to 2.5 mg,/L and turbidity of 15 to 20 NTU was pretreated by using biological contact oxidation process and gear-type suspended fillers under continuous or intermittent aeration conditions and changing air-water ratio. The characteristics of biofilm formation and treatment, and the influence of ratio of non-aeration time to aeration time and air- water ratio on the removal of ammonia nitrogen were investigated. The results showed that after 7 d for biofilm formation, a yellow brown biofilm adhered to the surface of suspended fillers. The main organisms were zoogloea, and the biomass was 70 nmol/g. Under the conditions of continuous aeration and air-water ratios of 0.5 ： 1 and 1 ： 1, the average removal rates of NH3 - N were 75% and 66% respectively. How- ever, under the conditions of intermittent aeration and ratio of non-aeration time to aeration time of 3 ： 5 to 3 ： 1, the removal rate of ammonia nitrogen was 80% to 90%. When the concentration of ammonia ni- trogen was over 2 mg/L, nitrite nitrogen accumulation in the effluent was 0.15 to 0.25 mg/L, which still met the drinking water standard.