接种比对餐厨垃圾中温厌氧消化的影响

Influence of inoculum-substrate ratio on food waste mesothermal anaerobic digestion

在(37±1)℃条件下采用批式厌氧消化试验方法,研究接种比(m(接种物)∶m(底物),按挥发性固体(VS)计)为1∶1、2∶1、3∶1和4∶1时去油和未去油餐厨垃圾的厌氧消化性能.结果表明:未去油和去油后餐厨垃圾发酵过程中,接种比为3∶1时产气量最高,单位挥发性固体(VS)沼气累积产气量分剐为951.2和851.4 mL/g,单位VS甲烷累积产气量分别为546.1和499.1 mL/g;接种比为1∶1时,产气量最低,单位VS沼气累积产气量分别为831.5和730.3mL/g,单位VS累积产甲烷量分别为524.1和425.8mL/g.接种比为1∶1时,未去油和去油后餐厨垃圾在厌氧消化初始阶段pH较低,且沼气日产气量和甲烷浓度也明显低于其他各组.未去油餐厨垃圾累积产气量比去油后餐厨垃圾累积产气量高12.6％.随着接种比逐渐提高(1∶1～4∶1),未去油和去油后餐厨垃圾发酵过程延滞期逐渐缩短;未去油餐厨垃圾在适宜接种比(2∶1～4∶1)范围内延滞期均高于去油餐厨垃圾.餐厨垃圾油脂含量较高,厌氧消化延滞期较长;提高接种比有利于缩短消化时间,提高反应器运行效率.

The influence of inoculum-substrate ratio (ISR) on the anaerobic digestion of food waste were studied.For this purpose,several batch reactor experiments were performed using food waste (FW) and de-oiling food waste (DOFW) as the substrate for ISRs in the range of 1 ∶ 1-4 ∶ 1,under the temperature of (37 ± 1) ℃.The results showed that the highest biogas yield and methane yield were 951.2,546.1 for food waste,851.4 and 499.1 mL/g for de-oiling food waste respectively at ISR of 3 ∶ 1.The lowest biogas yield and methane yield were 831.5 and 524.1 mL/g for food waste and 730.3 and 425.8 mL/g for de-oiling food waste respectively at ISR of 1 ∶ 1.In the startup phase,due to the low pH,the daily biogas and methane concentration of FW and DOFW at ISR of 1 ∶ 1 were lower than the other ISRs.Cumulative biogas production of FW increased 12.6％ than that of DOFW.With ISR increased,the lag phases of FW and DOFW were getting shorter.The lag phases of FW were longer than that of DOFW in the range of 2 ∶ 1-4 ∶ 1.The result indicated that increasing ISR is beneficial to shorten digestion time and improve the efficiency of the reactor.As the oil content of food waste increasing,the lag phases of anaerobic were becoming longer.