温度对餐厨垃圾自由厌氧发酵性能的影响

Effect of temperature on digestion performance in a short-term free anaerobic fermentation from food waste

通过批次实验研究温度对餐厨垃圾自由厌氧发酵(不控制pH)性能的影响。考察了室温(25℃),中温(35℃)和高温(55℃)条件下发酵基质的降解程度和有机酸的产量以及组成情况。结果表明,尽管高温条件下颗粒态有机物有最快的水解速率,但室温条件下有机酸浓度却达到了最大值(8.85 g COD·L^(-1));乳酸和乙酸是自由发酵过程中最主要的有机酸,室温下乳酸和乙酸的含量分别为总有机酸的72.86%和25.11%,而中温和高温时乳酸和乙酸的含量比值均在43.6%~50%之间。实验表明,自由发酵条件下,最佳的水解酸化温度是25℃。

We conducted batch experiments to determine the effect of temperature on the digestion performance during short-term free anaerobic fermentation（ without pH adjustment） of food waste. We analyzed organic-acid products and the degree of degradation of the fermentation substrate at room temperature（ 25 ℃）,mesophilic temperature（ 35 ℃）,and thermophilic temperature（ 55 ℃）. The results revealed that the fastest rate of degradation of organics corresponded to 55°C,but the most abundant total organic-acid products（ 8. 85 g COD·L^-1）are obtained at 25 ℃. Lactic and acetic acids were the most prevalent organic-acids produced during the experiments,and their proportions in total acid content at 25 ℃ were 72. 86% and 25. 11%,respectively,but they showed close levels（ between 43. 6% and 50%） at 35 and 55 ℃. All results showed that 25 ℃ is the most suitable temperature for hydrolysis and acidogenesis in a free digestion process.