摘要
以青稞秸秆为发酵原料,分别研究KOH、NaOH、Ca(OH)_(2)、HCl、H_(3)PO_(4)、H_(2)SO_(4)、尿素、NH_(3)·H_(2)O和H_(2)O_(2)共9种化学试剂预处理对青稞秸秆厌氧发酵特性的影响。结果表明,9种试剂对青稞秸秆木质纤维素降解率和产甲烷性能均有一定的提升。木质纤维素降解率随试剂浓度的增加而增大。不同试剂对纤维素和半纤维素降解率相差不大,但碱试剂特别是KOH对木质素降解率最高。同时,碱试剂处理累积甲烷产量高于酸试剂和其他试剂,也能够缩短发酵周期,处理效果最好,其中7%KOH累积甲烷产量最高,为260.87 mL·g^(-1)VS,且KOH能够被回收利用,是青稞秸秆最优的预处理试剂。尽管个别酸试剂(3%HCl和5%H_(3)PO_(4))也获得了较高的积累甲烷产量,但容易增加回收成本和导致发酵系统不稳定,并不适宜。此外,5%尿素和5%NH_(3)·H_(2)O也能缩短发酵周期,提高累积甲烷产量,分别为224.15和230.82 mL·g^(-1)VS,同样是青稞秸秆较为适宜的预处理试剂。研究显示,KOH是提高青稞秸秆厌氧发酵性能的最优预处理试剂,尿素和NH_(3)·H_(2)O可以提供氮元素,后续可充分利用各试剂优势开展联合处理,在优化降低预处理成本的同时进一步提高青稞秸秆的产甲烷性能。
Taking hulless barley straw as digestion raw material,this study explored the effects of pretreatment with nine reagents,namely KOH,NaOH,Ca(OH)_(2),HCl,H_(3)PO_(4),H_(2)SO_(4),urea,NH_(3)·H_(2)O and H_(2)O_(2),on the anaerobic digestion characteristics of hulless barley straw.According to the results,the nine reagents could enhance the lignocellulose degradation rate and methane production performance of hulless barley straw.With the increase of reagent concentration,the lignocellulose degradation rate increased accordingly.Meanwhile,the degradation rates of cellulose and hemicellulose were similar for the different reagents.However,the alkali reagent had the best degradation effect on lignin,with KOH being the highest when the concentrations were the same.The alkali reagent obtained highest cumulative methane production and could shorten the digestion cycle,which was better than the acid reagent and other reagents.The highest cumulative methane production of 7%KOH was 260.87 mL·g^(−1)VS.Moreover,the KOH could be recycled,making it the optimal pretreatment reagent for hulless barley straw.Although some acid reagents(3%HCl and 5%H3PO4)had also achieved higher cumulative methane production,they tended to increase recovery costs and induced instability in the digestion system and were not suitable.Apart from that,5%urea and 5%NH_(3)·H_(2)O also shortened the digestion cycle and increased the cumulative methane production with 224.15 and 230.82 mL·g^(−1)VS,respectively,which were also more suitable pretreatment reagents for hulless barley straw.As shown by the results,KOH was the optimal pretreatment reagent to improve the anaerobic digestion performance of hulless barley straw,while urea and NH_(3)·H_(2)O could provide the nitrogen element.In addition,the combination of the various reagents could be used to further improve the methanogenic performance of hulless barley straw while optimally reducing the pretreatment cost.
作者
柳丽
韩睿
LIU Li;HAN Rui(Laboratory for Research and Utilization of Germplasm Resources in Qinghai Tibet Plateau,Academy of Agriculture and Forestry Sciences,Qinghai University,Xining 810016,China)
出处
《环境工程学报》
北大核心
2025年第5期1177-1188,共12页
Chinese Journal of Environmental Engineering
基金
青海省自然科学基金面上项目(2023-ZJ-928M)。
关键词
青稞秸秆
厌氧发酵
预处理
木质纤维素
甲烷
hulless barley straw
anaerobic digestion
pretreatment
lignocellulose
methane
