热水解高含固污泥的有机物分布及厌氧消化特性

Organic matter distribution and anaerobic digestion of thermal hydrolysis pretreated high-solid sludge

以热水解后高含固污泥及其脱水后固、液分离产物为对象进行厌氧消化试验,通过生物化学甲烷势(BMP)及脱水性能测定,研究其产气量、有机物分布、污泥脱水性能及生物质能转化特性,评估高含固污泥热水解-脱水-脱水液厌氧消化工艺的可行性.结果表明,经热水解预处理的高含固污泥进行厌氧消化后,其毛细吸收时间(CST)及脱水泥饼含水率由247.5±0.9 s和71.1%±1.3%上升至568.0±1.6 s和80.7%±1.0%,即厌氧消化会导致热水解后污泥脱水性能下降.污泥中74.0%的有机物在水热预处理之后被转移至液相,是厌氧消化所产沼气的主要来源.物质能量衡算结果表明,高含固污泥采用热水解-脱水-脱水液厌氧消化工艺可以有效地将消化装置容积大大减少;沼气燃烧所产能量实现该工艺能量自给自足.

To evaluate the feasibility of high-solid sludge thermal hydrolysis pretreatmentdewatering-anaerobic digestion（ THP-DW-AD） process,the biomass conversion characteristics of thermal hydrolysis pretreated high-solid sludge was investigated by biochemical methane potential（ BMP） test,dewatering performance test and analysis of organic matter distribution and gas production in solid and liquid phase. The results showed that anaerobic digestion process had negative effects on the dewatering ability of pretreated sludge,in that its Capillary Suction Time（ CST） value and moisture content of sludge cakes increased from 247.5±0.9 s to 568.0±1.6 s and 71.1% ±1.3% to 80.7% ± 1.0%,respectively. About 74.0% of organic matter converted to biogas in AD process,was transferred to liquid phase after thermal hydrolysis pretreatment. Digester＇s volume in THP-DW-AD process can be much less than that in AD process. The advantage of THP-AD-DW process is that the energy input needed can be satisfied from the excess energy production of the process itself,resulting in an energetically self-sufficient process.