农村生活污水处理的脉冲生物滤池工艺改良与调试

Improvement and Commissioning of Pulsed Biofilter Process for Rural Domestic Wastewater Treatment

脉冲生物滤池在江苏省农村生活污水处理中有着广泛的应用,但脉冲水箱故障导致生物滤池水力负荷过大是运维过程中普遍存在的问题。为此,本研究尝试取消脉冲水箱,通过时间控制开关和流量控制模块联合控制水力负荷的方式对生物滤池进行了改良,开展了进水时间分别控制为8、12、16、20 h工作模式的现场调试对比研究。结果表明,在进水水质COD_(Cr)、氨氮、TN、TP质量浓度分别为30~156、14.2~85.0、21.4~96.0、0.97~7.50 mg/L的情况下,相同容积负荷下改良型生物滤池在12 h工作模式下对COD_(Cr)、氨氮、TP的整体去除率最高,最高分别为63.0%、87.4%、53.4%,在16 h工作模式下对TN的整体去除率最高,最高为33.0%。12 h工作模式下进水COD_(Cr)、氨氮、TN和TP的容积负荷分别在0.3~0.5、0.05、0.06、0.005 kg/(m^(3)·d)以内,可保证COD_(Cr)、氨氮、TN、TP去除率在57.3%、65%、19.7%、43.8%以上,比原脉冲生物滤池平均去除率分别高23.8%、36.5%、9.6%、28.8%。8、12、16 h和20 h工作模式下,改良型生物滤池出水溶解氧平均质量浓度分别为4.7、5.5、3.8 mg/L和3.1 mg/L,表明12 h工作模式下复氧效果最好,COD_(Cr)、氨氮去除率最高。同时对改良型生物滤池在12 h工作模式下,氨氮平均质量浓度为50 mg/L时,水力负荷与COD_(Cr)、氨氮、TN污染物去除率之间的关系进行了研究,结果表明水力负荷控制在1~3 m^(3)/(m^(2)·d),COD_(Cr)、氨氮、TN去除率分别可达到62.4%、76.1%、20.7%以上。

Pulsed biofilter has been widely used in rural domestic wastewater treatment in Jiangsu Province.However,the hydraulic load of biofilter caused by pulsed water tank failure is a common problem in its operation and maintenance.To solve this problem,this study attempted to cancel the pulsed water tank,and improved the biofilter by combining the time control switch and the flow control module to control the hydraulic load.The on-site commissioning and comparative study of the influent time of 8,12,16 h and 20 h were carried out.The results showed that when the concentrations of COD_(Cr),ammonia nitrogen,TN and TP in the influent water were 30~156,14.2~85.0,21.4~96.0,0.97~7.50 mg/L,respectively,under the same volume load,the overall removal rates of COD_(Cr),ammonia nitrogen and TP in the improved biofilter were the highest under the 12 h working mode,with the highest removal rates of 63.0%,87.4%,53.4%,respectively.Under the 16 h working mode,the overall removal rate of TN was the highest,with the highest removal rate of 33.0%.When the influent volume load of COD_(Cr),ammonia nitrogen,TN and TP were within 0.3~0.5,0.05,0.06 kg/(m^(3)·d)and 0.005 kg/(m^(3)·d)under the 12 h working system;the removal rates of COD_(Cr),ammonia nitrogen,TN and TP were above 57.3%,65%,19.7%and 43.8%,respectively,which were 23.8%,36.5%,9.6%and 28.8%higher than those of the original pulse biofilter,respectively.The average concentrations of dissolved oxygen were 4.7,5.5,3.8 mg/L and 3.1 mg/L at 8,12,16 h and 20 h,respectively,which indicated that the effect of reoxygenation was the best and the removal rates of COD_(Cr)and ammonia nitrogen were the highest at 12 h.At the same time,the relationship between the hydraulic load and the removal rates of COD_(Cr),ammonia nitrogen and TN was studied when the average concentration of ammonia nitrogen was 50 mg/L and the modified biofilter was operated for 12 h.The results showed that when the hydraulic load was controlled within 1~3 m^(3)/(m^(2)·d),the removal rates of COD_(Cr),ammonia nitrogen and TN were more than 62.4%,76.1%and 20.7%,respectively.