厌氧消化液不同投加方式对AOA-SBR系统处理效果的影响

Effects of Different Feeding Modes of Anaerobic Digestion Supernatant on AOA-SBR Efficacy

为研究厌氧消化液的不同投加方式对AOA-SBR(厌氧/好氧/缺氧序批式反应器)系统处理效果的影响,在温度为20.0℃、生活污水与厌氧消化液体积比为24∶1、污泥中AOB(氨氧化菌)所占比例为7.34%条件下,考察了不投加、厌氧阶段开始一次性投加、好氧阶段开始一次性投加和好氧阶段分次投加等6种厌氧消化液投加方式(分别记为SBR-a、SBR-b、SBR-c、SBR-d、SBR-e、SBR-f)下AOA-SBR系统中SCODCr(溶解性化学需氧量)、PO43--P、NH4+-N的处理特性.结果表明:厌氧消化液的投加方式对SCODCr的去除基本没有影响,但厌氧消化液的投加使系统中PLR(PO43--P进水容积负荷)提高了104.88%,导致除SBR-a外各试验组出水ρ(PO43--P)均大于2.0 mg/L,为AOA-SBR处理生活污水与厌氧消化液联合废水的主要限制因素.SBR-b^SBR-f的SNPR(比亚硝酸盐生成速率)均高于SBR-a,表明厌氧消化液的添加有助于稳定污水短程硝化.研究显示,厌氧开始阶段一次投加厌氧消化液(SBR-b)对系统脱氮效果影响最小,为最佳进水方式,此时SAUR(比氨氧化速率)为0.168 0 g/(g·d),SNPR(比亚硝酸盐产生速率)为0.136 3 g/(g·d),SND(同步硝化反硝化)作用率为26.64%.

The effects of six feeding modes in treating anaerobic digester（ AD） supernatant and domestic sewage were investigated using shortcut nitrification sequencing batch reactor（ SBR） by anaerobic-aerobic-anoxic（ AOA） processes. Batch experiments were incubated at 20. 0 ℃ in domestic sewage-AD supernatant（ 24 ∶ 1） media,and the ratio of ammonia oxidizing bacteria（ AOB） was 7. 34%. AD supernatant was injected at the beginning of the anaerobic or aerobic phase and dosed two or three times during the aerobic phase,hereafter referred to as SBR-a,SBR-b,SBR-c,SBR-d,SBR-e and SBR-f. Soluble chemical oxygen demand（ SCODCr）,PO43--P and NH4＋-N concentrations were also determined in the present study. The results showed that adding AD supernatant had no effect on removal of organic matter at various feeding modes. However,removal of PO43--P was low when AD supernatant was treated in AOA-SBR combined with domestic sewage. In fact,phosphate loading rate（ PLR） increased by 104. 88%. Concentrations of PO43--P in the effluents were also higher than 2. 0 mg/L in all experimental conditions,which could have been the limitation of the AOA-SBR system. Specific nitrite production rate（ SNPR） in dosing AD supernatant was significantly higher than that of AOA-SBR,but only in the treatment of domestic sewage,which indicated that the addition of AD supernatant helped stabilize shortcut nitrification.Adding AD supernatant at the beginning of the anaerobic phase in AOA-SBR attained the best results, with increases in specificammonia uptake rate（ SAUR）（ 0. 1680 g/（ g·d））,SNPR（ 0. 1363 g/（ g·d））,and simultaneous nitrification denitrification（ SND） rate to26. 64 %.