水解酸化-地下渗滤技术处理生活污水的工艺研究

Effect on sewage treating by the hydrolysis acidification-subsurface infiltration system

为优化水解酸化-地下渗滤系统(Hydrolytic Acidifi-cation-Subsurface Wastewater Infiltration System,HA-SWIS)工艺参数,提高分散式污水处理效果,通过控制HA水力停留时间(Hydraulic Retention Time,HRT)、搅拌速度、SWIS水力负荷(Hydraulic Load Rate,HLR)及干湿比,考察系统COD、NH4+-N、TN和TP的去除效果。由于温度控制在18～22℃,忽略温度对COD、NH4+-N、TN和TP去除效果的影响。结果表明,随优化参数改变,HA-SWIS联合工艺去除污染物效果存在显著性差异(p <0. 05)。当HA搅拌速度为15 r/min、HRT为2 h时,SWIS的HLR为0. 08～0. 12 m3/(m2·d),干湿比为1∶1～2∶1时,联合工艺对COD、NH4+-N、TN和TP的去除效率最高,分别为92. 0%、78. 6%、65%和92. 7%。该装置占地小,基建费用低,无需药剂投入,每吨水处理费用0. 46元/t,处理水质可回用,满足景观水要求(GB/T 18921—2002),适用于管网不完善地区。

The paper is to devote itself to an investigation and optimization of the operation parameters of the hydrolytic acidification subsurface sewage infiltration system(HA-SWIS)in hoping to improve and heighten the removal ability and rate for COD,NH4^+-N,TN and TP.For the above said purpose,it is necessary to do the first run of experiments by regulating the hydraulic retention time(HRT)and the stirring speed of HA,the hydraulic loading rates(HLR)and the dry-wet ratio of SWIS.The total experimental period has to be lasting for 210 d of the 2 runs.And,then,in the second period,it would also be necessary to analyze the HLR and the intermittent operation parameters of the said system.And,last of all,the paper has proposed the optimal operation mode,which can be stated as follows:if the temperature can be controlled between the degrees of 18-22℃,it would be possible to neglect the temperature effect on the removal rates of the COD,NH4^+-N,TN and TP.The results of the aforementioned experimental procedure show that there can be found a significant difference in the removal efficiency of HASWIS in treating the domestic sewage with the variation of the optimized parameters(p<0.05).For instance,on the condition when the HA hydraulic retention time,the stirring speed,the hydraulic loads and the dry-wet ratios of the SWIS stay at 2 h,15 r/min,0.08-0.12 m^3/(m^2·d),1:1-2:1,respectively,the removal efficiency of COD,NH4^+-N,TN and TP can be kept at 92.0%,78.6%,65%and 92.7%,correspondingly,though the HA can only have low removal rates of NH4^+-N and TN,for the nitrification has been in fact inhabited.And so is with the active denitrification,for it is not suitable for removing the TP.Additionally speaking,only 5 000 RMB has to be spent for the HA-SWIS,which just covers a small area(5.6 m^2)with low construction and operation with no need for any chemical input.What’s more,the treating operation cost is rather inexpensive,merely 0.46 yuan of RMB per ton.With no clogging being found,the treated reclaimed sewage can be reused to meet the standard for the landscape plant growing(GB/T 18921-2002)as well.Thus,the HA-SWIS processing technology can be taken to be used by the areas with no well-equipped pipe network.