无回流生物滤床净化槽脱氮效果的研究

构建一种脱氮的无回流生物滤床家庭生活污水处理一体化净化槽,研究其处理效果;改变各区内的曝气形式,形成A/O/A/O的脱氮工艺,通过测定各区COD、NH+4-N、NO-3-N和TN的浓度变化,考察其处理效果。结果表明:随着净化槽各区生物滤床的加入,反应器抗冲击性增强,处理效果明显提高。但A/O/A/O系统中第二级厌氧过程因碳源不足,脱氮效果不佳,改用分段进水后,净化槽不仅运行稳定,而且取得了很好的处理效果,出水COD平均浓度12.3 mg·L~(-1),NH+4-N平均浓度2.7 mg·L~(-1),TN平均浓度13.0mg·L~(-1),均达到国标(GB 18918—2002)一级A标准。A/O/A/O生物滤床新型净化槽不仅在结构上形成一体化,而且由于生物滤床的使用,不需要污泥回流,节省能耗,通过分段进水可以实现过程脱氮。     

Optimization and Operation Strategy of Hydraulic Retention Time in Modified Four Step-feed Process

A pilot modified four step-feed process was applied to deal with weak municipal wastewater. After 133 days of continuous operation with different hydraulic retention time(HRT) and operation strategy, the results are obtained as the following: (1)When HRT is reduced from 8.7h to 6h, there is almost no effect on performance of COD and TP, but would lead to increase effluent NH4 +-N and TN. Meanwhile, the influent carbon source utilization and simultaneous nitrification and denitrification (SND) are correspondingly decreased. (2)When HRT is 6h, the DO concentration in areobic zones are controlled between 1.0-1.5 mg·L -1 and adding suspended carriers in aerobic zones, the effluent performance of COD, NH4 +-N, TN and TP are 25.92, 1.98, 14.5and 0.47 mg·L -1 respectively. (3)Suspended carriers can be used to optimize the effluent ammonia and SND performance, and achieve 22% of TN removed through SND with suspended carriers. However, it's not obvious for suspended carriers to improve the influent carbon source effective utilization.