沼液预处理对蔬菜秸秆厌氧消化性能的影响

Effect of Biogas Slurry Pretreatment on Anaerobic Digestion of Vegetable Straws

为探究不同沼液预处理时间对蔬菜秸秆厌氧消化产甲烷特性的影响,以黄瓜、番茄、茄子和辣椒4种蔬菜秸秆为原料,用猪粪沼液在(35.0±0.5)℃分别处理3、5、7和9 d后进行中温批式厌氧消化试验。结果表明,预处理时间对蔬菜秸秆木质纤维素降解效果及其厌氧消化性能均有较大影响。随着预处理时间的延长,各蔬菜秸秆中纤维素和半纤维素的降解率逐渐提高(1.53%~24.47%和2.11%~52.48%),但木质素难以降解。不同蔬菜秸秆的最佳预处理时间不同,番茄秸秆和辣椒秸秆的最佳预处理时间均为5 d,最大累积甲烷产量分别为147.95和99.17 mL·g^(-1),较未处理分别提升36.52%和26.33%;黄瓜和茄子秸秆的最佳预处理时间均为7d,最大累积甲烷产量分别为152.42和129.84 mL·g^(-1),较未处理分别提升38.00%和27.42%。同时,沼液预处理能够缩短蔬菜秸秆的厌氧消化周期(T90缩短了3~8 d)。整体上,沼液处理后4种蔬菜秸秆的产甲烷性能从大到小依次为:黄瓜秸秆>番茄秸秆>茄子秸秆>辣椒秸秆。综上所述,猪粪沼液作为预处理剂可以有效提高蔬菜秸秆的厌氧消化性能,且最佳预处理时间为5~7 d。

To investigate the effect of biogas slurry pretreatment on anaerobic digestion of vegetable straws,4vegetable straws(cucumber,tomato,eggplant and pepper)were used as raw materials,which treated by pig manure biogas slurry for pretreatment with 3,5,7 and 9 d at(35.0±0.5)℃,and then carried out the medium temperature batch anaerobic digestion experiment. The results showed that the pretreatment time had a great influence on the degradation effect of vegetable straw lignocellulose as well as anaerobic digestion performance. With the prolongation of pretreatment time,the degradation rates of cellulose and hemicellulose were higher(1.53%~24.47% and2.11%~52.48%),while the lignin was difficult to degrade. The optimal pretreatment time varied from different vegetable straw. Among them,the optimal pretreatment times of tomato straw and pepper straw were 5 d with the maximum cumulative methane production of 147.95 and 99.17 mL·g^(-1),increasing 36.52% and 26.33% compared with that of the untreated,respectively. Cucumber straw and eggplant straw achieved the best methane production for7 days,with the maximum cumulative methane production of 152.42 and 129.84 mL·g^(-1),increasing 38.00% and27.42% compared with that of the untreated,respectively. At the same time,the pretreatment of biogas slurry played a role reducing the cycle of anaerobic digestion(T90shortened by 3~8 d). On the whole,the order of methane production performance of 4 vegetable straws after biogas slurry pretreatment was:cucumber straw>tomato straw>eggplant straw>pepper straw. Pretreatment of vegetable straw with biogas slurry could effectively improve the anaerobic digestion performance,and the optimal pretreatment time was 5~7 d for pretreatment of vegetable straw.