污水土地好氧生物过滤系统反冲洗效果研究

[目的]研究反冲洗对污水土地好氧生物过滤系统的影响。[方法]在流量1.4 m~3/d和曝气量1.8 m~3/h的条件下,以海泊河污水厂初沉池出水为试验进水,系统19 d完成挂膜。在气冲强度13.9 L/(m~2·s),水冲强度0.1 L/(m~2·s)的条件下,研究系统不同反冲洗周期(4、8 d)和反冲洗时间(1、2、4、6 min)下进出水COD和氨氮含量。[结果]4 d周期反冲洗4、2、1 min对系统生物膜破坏较小,平均出水COD含量为76.0 mg/L,出水氨氮含量均在5 mg/L以下,维持系统连续运行28 d。在8 d反冲洗周期中,反冲洗1、2、4 min后平均出水COD含量为93.0 mg/L、氨氮含量为6.8 mg/L,与4 d周期时出水相比略高;反冲6 min后,系统生物膜受到一定程度的破坏,出水COD和氨氮分别上升至130.8和14.1 mg/L,系统恢复需要4 d。[结论]建议对类似系统4~8 d进行1次4 min的反冲洗,如果出现堵塞可进行6 min反冲洗。

Effect of Backflush on Sewage Land Aerobic Biological Filtration System

Objective] The aim was to study effects of backflush on sewage land aerobic biological filtration system .[ Method] In the flow of 1.4 m3/d and aeration 1.8 m3/h, the water test conditions to primary sedimentation tank effluent of Haibohe wastewater treatment plant, bio-film had been completed for 19 days in the system, the effluent COD removal rate reached 80%.Under the condition that in air impact strength 13.9 L/(m2?s), water impact strength 0.1 L/(m2?s), we studied the removal efficiency of COD and NH4+-N of the system with dif-ferent backflushing interval (4, 8 d) and backflushing time(1, 2, 4, 6 min).[Result] The results showed that: under the conditions that backflushing interval 4 d and backflushing time(1, 2, 4 min), the biofilm was less damged, the effluent average COD was 76 mg/L and NH4+-N was lower than 5 mg/L, the system could run for 28 days.Under the conditions that backflushing interval 8 d and (1, 2, 4 min), the effluent average COD was 93.0 mg/L and NH4+-N was 6.8 mg/L, and the effluent was slightly higher than that of the 4 day period; in back-flushing time 6 min, the system biofilm certain degree of damage, the effluent COD and NH4+-N increased to 130.8 mg/L and 14.1 mg/L, it should take 4 days to recover the system.[ Conclusion] 4 min backflush is recommended for similar system 4-8 d, 6 min backflush should be carried out if there is a blockage.