不同进水有机物浓度下移动床生物膜反应器(SBMBBR)脱氮除磷特性

Nitrogen and phosphorus removal characteristics in a SBMBBR under different influent organic carbon concentrations

考察了不同进水有机物浓度下厌氧/好氧序批式移动床生物膜反应器(SBMBBR)污染物去除特性,实验结果表明,SBMBBR能够实现低碳源污水中氮和磷的同步去除,在进水TN和TP浓度分别为116.7 mg.L-1和11.5 mg.L-1、COD浓度为456 mg.L-1的条件下,TN和TP去除率分别达到94.3%和92.2%以上.反应器除磷是基于常规生物除磷和反硝化除磷过程实现的,脱氮主要是基于好氧段发生的同时硝化反硝化(SND)作用而完成.由于生物膜内部存在的DO扩散梯度,在好氧阶段混合液DO浓度不断提高的条件下反应器内具有良好SND反应的发生.进水COD浓度由149 mg.L-1提高至456 mg.L-1的过程中,反应器硝化效果不变,反硝化和除磷效果改善.反应器在好氧阶段pH值基本维持在7.0—7.1之间,为各类菌群的生长创造了条件.碱度变化较pH值更能反映硝化和反硝化反应发生的程度.反应器中微生物相丰富,生物膜以丝状菌为骨架,其上附着大量的球状菌和杆状菌,而悬浮活性污泥中丝状菌较少,形成了由细菌、真菌到原生动物和后生动物的复杂的生态体系,为系统取得稳定的污水处理效果提供了有效的保证.

Nitrogen and phosphorus removal characteristics in a sequencing batch moving bed biofilm reactor（SBMBBR） under different influent organic carbon concentrations were investigated.The experimental results indicated that under the influent condition of 116.7 mg · L-1 TN concentration,11.5 mg · L-1 TP concentrations and 456 mg · L-1 COD concentration,removal efficiencies of TN and TP attained to above 94.3% and 92.2% respectively.Phosphorus removal was realized through conventional phosphorus removal and denitrifying phosphorus removal processes,while nitrogen removal was mainly accomplished through simultaneous nitrification and denitrification（SND） process in the aeration phase.Due to the existence of DO diffusion limit in the biofilm,smooth SND process occurred throughout the aeration phase when DO concentration increased to 6.7 mg · L-1 and ORP increased to 111 mV.With the increase of influent COD concentration from 149 mg · L-1 to 456 mg · L-1,nitrification effect was not affected,and denitrification and phosphorus removal efficiencies improved.pH value during the aeration phase was maintained at 7.0—7.1 for microorganisms propagation.Compared with the pH value,variation of alkalinity concentration in the reactor better reflected the extent of nitrifying and denitrifying.The reactor was quite rich in micro-organisms.The biofilm was found to be composed of large amounts of coccus and bacillus which adhered on the filamentous bacteria,while filamentous bacteria in suspended active sludge was less.A complex ecological system was formed in the reactor by bacteria,fungi,protozoa and metazoan,which provided effective guarantee for stable sewage treatment effect.