智能化曝气控制A/O工艺处理低C/N生活污水有效性及其脱氮机制

将新型智能化曝气控制系统（automatic oxygen supply device，AOSD）应用于A/O工艺中，研究AOSD系统曝气模式控制下的A/O工艺（I-A/O）与持续曝气模式的A/O工艺（C-A/O）对低C/N生活污水处理能力的有效性，并从系统活性污泥特性的角度探究I-A/O系统反硝化菌在脱氮过程中对碳素的摄取、利用途径。结果表明：低进水碳源负荷下，I-A/O与C-A/O系统对COD、NH4+-N的平均去除率稳定且均达80%以上；I-A/O系统对TN去除率高出C-A/O系统25.97%，其对TN具有明显的去除优势；2套系统对TP均无去除效果。I-A/O系统活性污泥好氧异养菌产率系数YH为0.142 mg·mg-1，活性污泥衰减系数Kd为0.018 d-1，均低于C-A/O系统；在进水低C/N水平下，I-A/O系统活性污泥可通过更强的吸附贮存碳源能力、较低的好氧异养菌竞争压力、溶胞作用为反硝化菌提供更多的碳源以便脱氮反应。C/N是I-A/O系统曝气总量节省率重要影响因素之一，相比于C-A/O系统，其处理低C/N生活污水可节约曝气系统约52%的曝气量。

Treatment efficiency and nitrogen removal mechanism in low C/N ratio domestic wastewater treatment by intelligent aeration controlled A/O process

In order to evaluate the treatment effectiveness for low C/N ratio domestic wastewater with automatic oxygen supply device (AOSD),AOSD was applied to A/O process. The operation characteristics in treating sewage and carbon uptake way of denitrification process in A/O system was investigated under the intelligent aeration controlled A/O process (I-A/O) and continuous aeration A/O process (C-A/O) in the field of sludge properties. The results demonstrated that with scanty exogenous carbon source supplied, there were more than 80% removal efficiency in COD and NH4+-N could be reached in both I-A/O and C-A/O system steadily. The removal efficiency in TN of I-A/O was 25.97% higher than C-A/O, it had obvious removal advantage in TN and there were no removal efficiency of TP for two sets of system. The sludge yield index of aerobic heterotrophic bacteria and sludge decay coefficient of I-A/O were 0.142 mg·mg-1 and 0.018 d-1, respectively. There were both lower than the level of C-A/O. In low C/N ratio condition, activated sludge in I-A/O system could uptake more carbon for denitrification reaction than C-A/O system by stronger adsorption and storage ability of carbon source, lower competition pressure from aerobic heterotrophic bacteria and using released carbon result from cell rupture. C/N ratio was one of the important influenced factors for energy conservation in I-A/O aeration system. Compared with C-A/O, I-A/O saved about 52% power consumption in aeration system.