摘要
针对餐厨垃圾高负荷厌氧消化极易酸化且缺乏有效预警指标的技术问题,在中温条件下进行模拟餐厨垃圾单相厌氧消化实验。通过分析对比pH值、产气量、挥发性脂肪酸(VFA)以及胞外聚合物(EPS)等指标在消化过程中的变化,比较了这些指标的酸化预警能力与时间上的先后性。结果表明:pH值在第26 h降到5.5以下,产气量在第22 h增幅小于1%,VFA质量浓度在第22 h超过10000 mg/L,以常规指标作为酸化预警指标存在一定的滞后性。EPS能更敏感地对体系变化做出反映,即在体系酸化前胞外多糖质量浓度下降,胞外蛋白质质量浓度上升,蛋白质与多糖质量浓度比值整体趋势持续上升直至酸化。以EPS中的蛋白质与多糖质量浓度比作为酸化预警指标能比传统指标提前约5 h,便于对体系及时作出调整,减少工程上不必要的损失。
The single-phase anaerobic digestion of food waste suffers from systematic instability at high loading.Traditional indicators of acidification only give a belated warning.In this work,warning of acidification based on changes in pH value,gas production rate,and changes in amounts of volatile fatty acid(VFA)and extracellular polymeric substances(EPS)have been compared during anaerobic digestion of simulated food wastes.It was found that pH values and gas production have serious hysteresis effects.The amount of VFA is of limited use in early warning due to its wide variations in different systems and fermentation types.However,the EPS composition is closely related to the state of the microorganisms,and thus can response sensitively to acidification.After 18-20 h of anaerobic digestion,the content of extracellular polysaccharide decreased significantly,and the content of extracellular protein increased significantly.The ratio of protein to polysaccharide(PN/PS)increased continuously before acidification.Thus,the PN/PS ratio can be used as an early warning indicator of acidification,since it shows a response five hours before traditional indicators.
作者
冯江华
韩国然
朱凯
朱保宁
FENG JiangHua;HAN GuoRan;ZHU Kai;ZHU BaoNing(College of Chemical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《北京化工大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第2期1-7,共7页
Journal of Beijing University of Chemical Technology(Natural Science Edition)
基金
国家杰出青年科学基金(21838001)。
关键词
餐厨垃圾
厌氧消化
酸化预警
胞外聚合物
food waste
anaerobic digestion
warning of acidification
extracellular polymeric substances
