Abstract:
Anaerobic co-digestion was conducted on the solid residues after three-phase separation of kitchen waste (KWS) and waste-activated sludge (WAS), the synergistic effects and process performance were studied during co-digestion at different ratios of KWS to WAS. KWS and WAS mix ratios of 0:1, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1 and 1:0 (based on TS). The results showed that a ratio of KWS to WAS of 1:1 got a very high methane recovery with a methane yield of 310.45 ± 30.05 mL/g VSadded. The highest concentration of free ammonia among all reaction systems was only 70.23 ± 5.53 mg/L, which was not enough to produce ammonia inhibition in the anaerobic co-digestion system. However, when the KWS content exceeded 50%, methane inhibition and prolongation of the lag phase were observed due to the accumulation of volatile fatty acids (VFAs), and during the lag phase. Microbial community analysis showed that various bacterial groups involved in acid production and hydrolysis were mainly dominated by phylum Firmicutes, Chloroflexi, Proteobacteria and Bacteroidetes. Hydrogenotrophic methanogen was found to dominate all archaeal communities in the digesters. Co-digestion of KWS with WAS significantly increased the relative abundance of Methanobacterium compared with anaerobic digestion of WAS alone.
摘要:
对餐厨垃圾(KWS)和废活性污泥(WAS)三相分离后的固体残渣进行厌氧消化,研究了在不同KWS与WAS比例下共消化过程中的协同作用和工艺性能。KWS和WAS的混合比例为0:1、1:4、1:3、1:2、1:1、2:1、3:1、4:1和1:0(基于TS)。结果表明,KWS与WAS的比例为1:1时,甲烷回收率很高,甲烷产率为310.45±30.05mL/g。所有反应体系中游离氨的最高浓度仅为70.23±5.53mg/L,这不足以在厌氧消化系统中产生氨抑制。然而,当KWS含量超过50%时,由于挥发性脂肪酸(VFA)的积累,观察到甲烷抑制和滞后期的延长,在滞后阶段。微生物群落分析表明,参与产酸和水解的各种细菌群主要以厚壁门为主,氯氟菌,变形杆菌和拟杆菌。发现氢营养产甲烷菌在消化器中的所有古细菌群落中占主导地位。与单独的WAS厌氧消化相比,KWS与WAS的共消化显着增加了甲烷细菌的相对丰度。