摘要
采用完全混合式反应器R1～R5(进料脱水污泥与餐厨垃圾的湿重混合比分别为1:0、4:1、3:2、2:3和0:1),在半连续运行的状态下,考察了停留时间(solid retention time,SRT)为20 d时脱水污泥和餐厨垃圾混合干法厌氧消化的产气性能、有机质降解性能和系统稳定性.结果表明,随着进料中餐厨垃圾所占比例的增大,系统的产气率和甲烷产率呈上升趋势,产气中甲烷含量呈下降趋势,污泥中添加餐厨垃圾有助于在利用原有消化罐容积的前提下显著提高有机负荷和体积产气率.餐厨垃圾比例越大,混合物料的水解速率常数越大,有机质降解率越高,R1～R4中有机质水解速率常数分别为0.25、0.61、1.09和1.56 d-1,有机质降解率分别为37.4%、50.6%、60.7%和68.2%,水解速率差异是导致VS降解率不同的主要原因.随着餐厨垃圾比例的增大,系统内pH、总碱度(total alkalinity,TA)、总氨氮(total ammonia nitrogen,TAN)和游离氨氮(free ammonianitrogen,FAN)呈下降趋势,当污泥中添加的餐厨垃圾提高60%时,系统内pH、总碱度、总氨氮和游离氨氮分别下降6%、16%、22%和75%.游离氨和Na+分别是影响污泥和餐厨垃圾单独干法消化稳定性的重要因素,污泥和餐厨垃圾混合消化可降低潜在抑制性物质的浓度,显著提高系统稳定性.
At solid retention time（SRT） of 20 days,biogas production,volatile solid（VS） degradation and system stability in co-digestion systems of dewatered sludge（DS） and kitchen garbage（KG） were investigated in semi-continuous completely mixed reactors numbered R1-R5（the DS/KG of their feeding substrate based on wet mass was 1∶0,4∶1,3∶2,2∶3 and 0∶1,respectively）.The results showed that,with larger proportion of KG in feeding substrate,higher methane yield and biogas yield were obtained with lower methane content.For certain reactor at given SRT,KG addition could significantly improve the organic loading rate（OLR） and volume biogas production.System with more KG addition favored higher hydraulic constant k and VS reduction.The hydraulic constant k was 0.25 d-1,0.61 d-1,1.09 d-1 and 1.56 d-1,and the VS reduction was 37.4%,50.6%,60.7% and 68.2% for R1-R4,respectively,indicating higher hydrolysis rates with more KG addition,which led to increased VS reductions.With larger KG proportion in feeding substrate,pH,total alkalinity（TA）,total ammonia nitrogen（TAN） and free ammonia nitrogen（FAN） showed decreasing trend.As KG addition increased by 60%,pH,TA,TAN and FAN decreased by 6%,16%,22% and 75%,respectively.FAN and Na＋ respectively were potential inhibitory chemicals that threatened the stability of the mono-system of DS and KG.In comparison with the mono-system of DS or KG,the co-system showed higher stability by diluting toxic chemicals like ammonia or Na＋ to much lower levels.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2013年第1期321-327,共7页
Environmental Science
基金
国家科技支撑计划项目(2010BAC67B04)
国家水体污染控制与治理科技重大专项(2011ZX07316-004)
关键词
厌氧
高含固
脱水污泥
餐厨垃圾
水解速率
anaerobic
high solids
dewatered sludge（DS）
kitchen garbage（KG）
hydrolysis rate
