Abstract:
The production of short-chain fatty acids (SCFAs) from waste activated sludge (WAS) via anaerobic fermentation is typically restricted by poor sludge decomposition capacity and low substrate-availability. Therefore, the free ammonia (FA)‑sodium percarbonate (SPC) technology was presented to successfully overcome the limitation while addressing unsatisfactory acidogenic fermentation pretreated with sole FA or SPC. It revealed that FA + SPC co-pretreatment could boost the SCFA concentration to 347.1 mg COD/g VSS at 180 mg/L FA and 0.15 g/g TSS SPC. In-depth studies demonstrated that FA + SPC pretreatment greatly improved sludge disintegration, biodegradability of substrates and acidification of hydrolysis products. Furthermore, FA + SPC co-pretreatment stimulated the activity of hydrolytic and acidogenic enzymes but inhibited methanogenic enzymes while changing the microbial structure and promoting the enrichment of fermentation microorganisms. The synergistic effect of FA and SPC in this work improves the yield of SCFAs from WAS and facilitates the study of WAS carbon resource recovery.
摘要:
通过厌氧发酵从废活性污泥(WAS)中生产短链脂肪酸(SCFA)通常受到污泥分解能力差和底物利用率低的限制。因此,提出了游离氨(FA)-过碳酸钠(SPC)技术,以成功克服该限制,同时解决了用单独的FA或SPC预处理的不令人满意的产酸发酵。结果表明,在180mg/LFA和0.15g/gTSSSPC下,FASPC共预处理可将SCFA浓度提高到347.1mgCOD/gVSS。深入研究表明,FA+SPC预处理能极大地改善污泥的崩解性,底物的生物降解性和水解产物的酸化。此外,FA+SPC共预处理在改变微生物结构、促进发酵微生物富集的同时,刺激水解产酸酶活性,抑制产甲烷酶活性。FA和SPC在这项工作中的协同作用提高了WAS中SCFA的产量,有利于WAS碳资源回收的研究。