水热/臭氧预处理促进餐厨垃圾中典型废弃油脂厌氧发酵产甲烷

Promoting anaerobic fermentative methane production by hydrothermal/ozonation pretreatment of typical waste lipids in food waste

为了缓解餐厨垃圾中大量未降解油脂包覆微生物,对厌氧发酵产生严重抑制的问题,本文采用水热或臭氧预处理有效降解油脂,预处理进行厌氧发酵.扫描电子显微镜和傅里叶变换-红外光谱分析表明,经过水热或臭氧预处理后,厌氧发酵过程油脂降解程度提高.经过臭氧预处理的火锅废油厌氧发酵甲烷产率提升至(854.20±10.28) mL·g^(-1)(每克有机质干重所产生的甲烷量,以毫升计,下同),在第20 d达到产甲烷速率峰值(122.06±3.46) mL·g^(-1)·d^(-1),较之未处理组达到甲烷峰值速率的时间缩短4 d,甲烷产率提升17.4%.总体能量转化效率由未经预处理的64.88%提升到臭氧预处理后的76.18%,说明臭氧或水热预处理可以促进油脂的降解,并且提高产甲烷菌对底物的利用从而提高发酵产甲烷的效率,从而在一定程度上缓解目前工业生产中存在的油脂难以降解以及包裹厌氧微生物的问题.

In order to alleviate the inhibition to anaerobic digestion by a large number of microorganisms entrapped with lipids in food waste, hydrothermal and ozonation pretreatments were used to promote anaerobic digestion. SEM and FTIR analysis results showed that after hydrothermal or ozonation pretreatment, the lipid degradation in anaerobic digestion process increased, and the lipid entrapment of microorganisms was alleviated. The methane yield of ozone-pretreated hotpot lipid increased to(854.20±10.28) mL·g^(-1), reaching a peak methane production rate of(122.06±3.46) mL·g^(-1)·d^(-1) on day 20, which was 4 d shortened and the methane yield increased by 17.4% compared to the untreated group. The energy conversion efficiency increased from 64.88% to 76.18% after ozonation pretreatment. These indicate that ozonation or hydrothermal pretreatment can promote the degradation of lipids and improve the utilization of substrates by microorganisms to improve the efficiency of anaerobic digestion, thereby alleviating the problem that undegraded lipids entrapment of microorganisms in industrial production.