餐厨垃圾生物炭强化餐厨废水甲烷发酵效能与作用机制  

Batch experiments on the performance and mechanism of methane fermentation of kitchen wastewater enhanced by food waste biochar

作　　者：姜琪 张波 苏艳 王高骏 王璟 杨阳 李倩[2] 陈荣[2] JIANG Qi;ZHANG Bo;SU Yan;WANG Gaojun;WANG Jing;YANG Yang;LI Qian;CHEN Rong(Xi'an TPRI Water Management & Environmental Protection Co.Ltd., State Key Laboratory of High-Efficiency Flexible Coal Power Generation and Carbon Capture Utilization and Storage;School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology)

机构地区：[1]西安西热水务环保有限公司,高效灵活煤电及碳捕集利用封存全国重点实验室 [2]西安建筑科技大学环境与市政工程学院

出　　处：《环境工程技术学报》2024年第6期1867-1876,共10页Journal of Environmental Engineering Technology

基　　金：中国华能集团有限公司总部科技项目(HNKJ22-H125);国家自然科学基金项目(52000148)。

摘　　要：甲烷发酵是餐厨垃圾处理厂内废水处理的核心工艺。然而,餐厨废水过快的水解酸化速率使得挥发性脂肪酸(VFA)过量积累,极大限制了高有机负荷条件下系统的产甲烷率。针对该技术瓶颈,利用餐厨垃圾处理厂三相分离单元所得的有机固体废物(OSW)为原料制备生物炭(OSW-BC),以批次试验方法考察了其用于厂内餐厨废水甲烷发酵的增促效能。结果表明,500℃热解制得OSW-BC表面形成了丰富的孔道结构与芳香类有机官能团;在甲烷发酵系统的基质/种泥比(SIR)分别为2、3、5的条件下,OSW-BC投加可将产甲烷延滞期缩短53.7%~68.1%,同时将最大比产甲烷速率提升6.1%~62.9%;微生物代谢活力与种群演替解析表明,OSW-BC的投加显著提升了菌群代谢的电子交换系统活力;尤其在高SIR条件下,OSW-BC投加使得互营单孢菌属与二氧化碳还原型甲烷袋状菌属快速富集,同时甲酰基甲基呋喃脱氢酶、甲酰基甲基呋喃-四氢甲硫氨酸N-甲酰转移酶等相关功能基因表达丰度提升了74.2%~118.0%。可见,OSW-BC表面丰富的有机官能团与类石墨结构可能加速了VFA氧化细菌与甲烷袋状菌种间直接电子传递(DIET)过程,由此加速了VFA向甲烷的转化,实现了高SIR条件下餐厨废水发酵系统产甲烷能力的增促。Methane fermentation is the core process for wastewater treatment units in food waste treatment plants However,the rapid hydrolysis and acidogenesis rate of the wastewater can cause volatile fatty acids (VFA)accumulation,which largely limits the methane production rate under high organic load conditions.To cope with this issue,the organic solid waste (OSW) derived from the three-phase separation unit of a food waste treatmen plant was used to prepare biochar (OSW-BC).The benefits of OSW-BC promoting methane fermentation of the wastewater were investigated by batch experiments.The results showed that a rich pore structure and aromatic organic functional groups were formed on the surface of the OSW-BC prepared by pyrolysis at 500℃.When the substrate/inoculum ratio (SIR) of the methane fermentation system was 2,3,5,respectively,OSW-BC addition could shorten the methanogenic lag time by 53.7%-68.1%and meanwhile elevated the maximum methane production rate by 6.1%-62.9%.Microbial metabolic activity and community succession analysis revealed that the addition of OSW-BC dramatically elevated the electron transfer system activity of microbes by enhancing microbia metabolism.Under high SIR conditions,OSW-BC enabled the rapid enrichment of Syntrophomonas and Methanoculleus of the CO_(2) reduction metabolism.Meanwhile,the expression abundance of related functional genes such as formylmethanofuran dehydrogenase and formylmethanofuran-tetrahydromethanopterin N-formyltransferase increased by 74.2%-118.0%.It was indicated that the redox-active groups and graphite-like structure of OSW-BC might accelerate direct interspecies electron transfer (DIET) between VFA oxidizer and Methanoculleus under high SIR conditions,which facilitated the conversion of VFA to methane and thus achieved an increase in methane production capacity of the kitchen wastewater fermentation system under high SIR conditions.

关 键 词：甲烷发酵 生物炭 餐厨垃圾 酸积累 互营产甲烷 

分 类 号：X705[环境科学与工程—环境工程]