Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 755-8611, Japan.
Environmental Engineering Study Program, Faculty of Engineering, Udayana University, Bali 80361, Indonesia.
Int J Environ Res Public Health. 2022 May 8;19(9):5728. doi: 10.3390/ijerph19095728.
In wastewater treatment plants (WWTP), anaerobic digester (AD) units are commonly operated under mesophilic and thermophilic conditions. In some cases, during the dry season, maintaining a stable temperature in the digester requires additional power to operate a conditioning system. Without proper conditioning systems, methanogens are vulnerable to temperature shifts. This study investigated the effects of temperature shifts on CH gas production and microbial diversity during anaerobic digestion of anaerobic sewage sludge using a metagenomic approach. The research was conducted in lab-scale AD under stepwise upshifted temperature from 42 to 48 °C. The results showed that significant methanogen population reduction during the temperature shift affected the CH production. With 70 days of incubation each, CH production decreased from 4.55 L·g-chemical oxygen demand (COD) at 42 °C with methanogen/total population (M·TP) ratio of 0.041 to 1.52 L·g COD (M·TP ratio 0.027) and then to 0.94 L·g COD ( M·TP ratio 0.026) after the temperature was shifted to 45 °C and 48 °C, respectively. was the most prevalent methanogen during the thermal change. This finding suggests that the genus was a thermotolerant archaea. , and were bacterial genera and grew well in shifted-up temperatures, implying heat-resistant characteristics.
在废水处理厂 (WWTP) 中，厌氧消化器 (AD) 单元通常在中温和高温条件下运行。在某些情况下，在旱季，为了使消化器中的温度保持稳定，需要额外的电力来运行调节系统。如果没有适当的调节系统，产甲烷菌容易受到温度变化的影响。本研究采用宏基因组学方法研究了温度变化对厌氧消化污水污泥过程中 CH 气体产生和微生物多样性的影响。研究在实验室规模的 AD 中进行，温度逐步从 42°C 升高到 48°C。结果表明，温度变化期间甲烷菌种群的大量减少影响了 CH 的产生。经过 70 天的孵育，CH 的产生量从 42°C 时的 4.55 L·g-化学需氧量 (COD)（甲烷菌/总种群 (M·TP) 比为 0.041）降至 45°C 时的 1.52 L·g COD（M·TP 比为 0.027）和 48°C 时的 0.94 L·g COD（M·TP 比为 0.026）。在热变化过程中， 是最普遍的产甲烷菌。这一发现表明， 属是一种耐热古菌。 、 和 是细菌属，在升温后生长良好，表明具有耐热特性。
