P.G. and X.M. contributed equally to this work. E-mail:
P.G. and X.M. contributed equally to this work.
Water Sci Technol. 2023 Dec;88(11):2826-2836. doi: 10.2166/wst.2023.378.
The treatment and disposal of activated sludge are currently challenging tasks in the world. As a common biological engineering technology, biological fermentation exists with disadvantages such as low efficiency and complex process. Ozone pretreatments are commonly applied to improve this problem due to their high efficiency and low cost. In this study, the significant function of ozone in anaerobic fermentation gas production was verified with excess sludge. Compared with other untreated sludge, ozone pretreatment can effectively degrade activated sludge. After ozone treatment and mixing with primary sludge, the methane production of excess sludge increased by 49.30 and 50.78%, and the methanogenic activity increased by 69.99 and 73.83%, respectively. The results indicated that the mixing of primary sludge with excess sludge possessed synergistic effects, which contributed to the anaerobic fermentation of excess sludge. The results of microbial community structure exhibited that methanogenic processes mainly involve hydrogenogens, acidogens and methanogens. The relative abundance of both bacteria and microorganisms changed significantly in the early stage of hydraulic retention time, which coincided exactly with the gas production stage. This study provided a feasible pretreatment strategy to improve sludge biodegradability and revealed the role of microorganisms during anaerobic digestion.
目前，活性污泥的处理和处置是世界范围内的一项挑战。生物发酵作为一种常见的生物工程技术，存在效率低、工艺复杂等缺点。由于臭氧预处理具有高效、低成本的特点，因此常被应用于改善这一问题。本研究以剩余污泥为对象，验证了臭氧在厌氧发酵产沼气中的重要作用。与未经处理的污泥相比，臭氧预处理可有效降解活性污泥。经臭氧处理并与初沉污泥混合后，剩余污泥的甲烷产量分别提高了 49.30%和 50.78%，产甲烷活性分别提高了 69.99%和 73.83%。结果表明，剩余污泥与初沉污泥混合具有协同作用，有利于剩余污泥的厌氧发酵。微生物群落结构的结果表明，产甲烷过程主要涉及产氢菌、产酸菌和产甲烷菌。细菌和微生物的相对丰度在水力停留时间的早期阶段发生了显著变化，与产气阶段完全吻合。本研究为提高污泥生物降解性提供了一种可行的预处理策略，并揭示了微生物在厌氧消化过程中的作用。
