Liu Shugen, Yang Xi, Yao Xiaofei
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology Kunming 650500 China
Panzhihua University Panzhihua 617000 China.
RSC Adv. 2019 Mar 14;9(15):8379-8388. doi: 10.1039/c9ra00547a. eCollection 2019 Mar 12.
For a thermophilic micro-aerobic digestion (TMAD) system, the pH is closely related to the production of short-chain fatty acids and ammonia release. Batch experiments at different pH values were carried out to elucidate the effects of pH on the biodegradation characteristics of TMAD processes. A digester at pH 9.0 maintained better performance of sludge stabilization than acidic and neutral digestion systems, and the reduction of volatile solids reached ≤41.3% on day-10. We proposed a pathway of proton transfer in the TMAD system. An acidic digestion environment, in general, resulted in K deficiency, low enzyme activity, and oxidative stress. An alkaline digestion environment facilitated substrate oxidation, accelerated humification, and prevented the inhibition caused by the accumulated acids or ammonia nitrogen. The pH and digestion time affected the microbial population and species richness significantly. An alkaline digestion system presented lower bacterial diversity and maintained a higher richness of functional microbes such as and . Hence, an alkaline digestion system maintained a relatively high oxidase activity, and mitigated the potential oxidative stress for thermophiles.
对于嗜热微氧消化（TMAD）系统，pH值与短链脂肪酸的产生和氨释放密切相关。进行了不同pH值的批次实验，以阐明pH对TMAD过程生物降解特性的影响。pH为9.0的消化器比酸性和中性消化系统保持了更好的污泥稳定性能，在第10天挥发性固体的减少率达到≤41.3%。我们提出了TMAD系统中的质子转移途径。一般来说，酸性消化环境会导致钾缺乏、酶活性低和氧化应激。碱性消化环境促进底物氧化、加速腐殖化，并防止由累积的酸或氨氮引起的抑制作用。pH值和消化时间显著影响微生物种群和物种丰富度。碱性消化系统呈现出较低的细菌多样性，并保持了较高的功能微生物丰富度，如 和 。因此，碱性消化系统保持了相对较高的氧化酶活性，并减轻了嗜热菌潜在的氧化应激。
