Abstract: Mesophilic anaerobic digestion(AD)on the feedstocks of household kitchen waste(HKW)and restaurant food waste(RFW)was performed.Five kinds of dewaterability indicators-total solids(TS),total solids after centrifugation(CTS),normalized capillary suction time(NCST),specific resistance to filtration(SRF)and bound water content(BW)were used to evaluate the dewaterability of digestate produced from different stages of AD.TS of digestate ranged from 3.0% to 9.9%,CTS ranged from 10.9% to 31.0%,SRF was 2.1×10¹³—13.8×10¹³ m·kg^-1,BW was 2.3—15.1 g·(g TS)^-1 and NCST was 50.8—163.7 s·L·(g TS)^-1.The cumulative methane yield of the digester fed with RFW was always higher than the digester fed with HKW,maximum cumulative methane yield of the former was up to 381 ml·(g VS_added)^-1,while that of the latter was just 280 ml·(g VS_added)^-1.The dewatering performance of digestate was mainly affected by duration of anaerobic digestion and the digestate produced from RFW was able to achieve a higher dewatering degree,while the dewatering rate of the digestate from HKW was higher.Furthermore,there were significant correlations among TS,normalized CST,SRF and BW of digestate,but the correlation with CST was not significant.

Key words: household kitchen waste, restaurant food waste, digestate, dewaterability, cumulative methane yield

摘要： 以餐厨垃圾和厨余垃圾为原料进行中温厌氧消化反应,采用含固率(TS)、离心脱水后含固率(CTS)、模化毛细吸水时间(NCST)、过滤比阻(SRF)以及结合水含量(BW)为脱水性能评价指标,研究不同厌氧消化阶段产生沼渣的脱水性能。研究发现:沼渣TS变化范围为3.0%～9.9%,CTS为10.9%～31.0%,NCST为50.8～163.7 s·L·(g TS)^-1,SRF为2.1×10¹³ ～13.8×10¹³ m·kg^-1,BW为2.3～15.1 g·(g TS)^-1。厌氧反应器的累计甲烷产量始终是餐厨垃圾高于厨余垃圾,前者最高可达381 ml·(g VS_added)^-1,而后者仅为280 ml·(g VS_added)^-1;沼渣的脱水性能主要受厌氧消化时间的影响。同时,以餐厨垃圾为原料的沼渣可以达到的脱水程度较高,而以厨余垃圾为原料的沼渣的脱水速率较快;沼渣TS与NCST、SRF和BW脱水指标的两两间相关性显著,而与CTS没有明显相关性。

关键词: 厨余垃圾, 餐厨垃圾, 沼渣, 脱水性能, 累计甲烷产量