麦秸生物炭添加对猪粪中温厌氧发酵产气特性的影响

为探明不同热解温度生物炭添加对猪粪中温厌氧消化产气的影响，以400、500、600℃热解制成的麦秸生物炭（BC400、BC500、BC600）为研究对象，采用批次发酵试验，探讨了生物炭添加对猪粪中温（37±1）℃厌氧发酵产气特性的影响。研究结果表明：麦秸热解生物炭可显著（P<0.05）提高猪粪发酵系统的产气潜力和甲烷含量，其影响从大到小依次为BC600>BC500>BC400。厌氧发酵49 d期间，添加生物炭处理的产气量和产甲烷量分别为260.7~288.7 mL·g-1 VS和163.7~185.5 mL·g-1 VS，较纯猪粪处理提高了77.1%~96.1%和78.1%~101.8%。同时，添加生物炭可明显提高猪粪厌氧发酵系统的消化效率（T90），缩短厌氧发酵的延滞期。不同热解温度麦秸生物炭对猪粪厌氧消化产气特征的影响明显不同，对畜禽养殖场沼气工程运行中的物料选择和条件优化有实际的指导意义。

Effect of biochar pyrolyzed from wheat straws at different temperatures on biogas production characteristics of pig manure during mesophilic digestion

During anaerobic digestion(AD), microbial intermediate metabolites often inhabit biogas production. Biochars may adsorb these metabolites and improve biogas production when co-existing with manure during anaerobic digestion because of their large surface. In this study, the effects of different biochars on biogas production characteristics of pig manure during mesophilic digestion were examined. Biochars were obtained from wheat straws by pyrolysis at 400, 500℃and 600℃(i.e., BC400, BC500 and BC600)and added to the AD re-actor at mesophilic condition(37±1)℃. Biogas and methane productivity were measured in the bench-scale batch AD experiment. Results showed that the biogas and methane production was significantly(P<0.05)enhanced by biochar addition, with an order of BC600>BC500>BC400. During 49 d AD, the biogas and methane production was 260.7~288.7 mL·g-1 VS and 163.7~185.5 mL·g-1 VS, for biochar addi-tions, increments by 77.1%~96.1%and 78.1%~101.8%, respectively, compared with pig manure alone. Biochar additions also significantly enhanced the digestion efficiency(T90)of pig manure and reduced the ignition time of AD system. The biogas production was obviously dif-ferent among different biochar treatments, which was ascribed to the different characteristics of biochars, such as surface area and porosity. These findings indicate that optimal biochar material and digestion condition should be considered during the operation of biogas plants.