NaOH预处理对小麦秸秆中温厌氧发酵效率的影响  

Effects of NaOH Pretreatment on Mesophilic Anaerobic Fermentation Efficiency of Wheat Straw

作　　者：张鸣[1,2] 李昂 杨彩玲[2,3] 郭军霞 ZHANG Ming;LI Ang;YANG Cailing;GUO Junxia(College of Urban Environment,Lanzhou City University,Lanzhou 730070,China;Provincial Key Laboratory of Gansu Higher Education for City Environmental Pollution Control,Lanzhou 730070,China;School of Chemical Engineering,Lanzhou City University,Lanzhou 730070,China)

机构地区：[1]兰州城市学院城市环境学院,兰州730070 [2]城市环境污染控制高校省级重点实验室,兰州730070 [3]兰州城市学院化学工程学院,兰州730070

出　　处：《西北农业学报》2023年第12期2022-2030,共9页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：甘肃省自然科学基金(20JR10RA283);甘肃省高等学校创新基金(2022B-224)。

摘　　要：2020-2021年,通过自行设计的厌氧发酵装置,研究NaOH预处理对小麦秸秆中温厌氧发酵效率的影响,探索在确保小麦秸秆预处理效果的前提下,通过改变预处理时间来减少NaOH用量,降低二次污染风险,为小麦秸秆沼气生产提供理论依据。研究采用0%、3%和6%(以秸秆干质量计)NaOH对小麦秸秆预处理7、14、21和28 d,未预处理的小麦秸秆作对照,发酵液pH不做调节。结果表明,小麦秸秆经3%NaOH预处理7~28 d后,纤维素、半纤维素和木质素的脱除率分别为5.9%~8.3%、38.3%~41.8%和45.8%~49.2%,与6%NaOH预处理相当,显著高于0%NaOH预处理。在中温(35℃)厌氧发酵时,3%NaOH预处理的产气效果优于相同预处理时间0%和6%NaOH预处理,在预处理7~28 d时,干物质累积产气量为185.5~310.5 mL·g^(-1),产气速率为38.1~84.2 mL·d^(-1)。最优组合预测模型显示,3%NaOH预处理小麦秸秆11.4 d的效果最好,86.0 d发酵完全,产气速率为47.9 mL·d^(-1),最大干物质累积产气量为257.6mL·g^(-1)。综合判断,在小麦秸秆中温(35℃)厌氧发酵过程中,利用3%(以秸秆干质量计)NaOH对其进行预处理是可行的,能够获得良好的产气效果。Effects of NaOH pretreatment on anaerobic fermentation efficiency of wheat straw were studied using the“system of anaerobic fermentation technology”designed by us as mesophilic temperature from 2020 to 2021,the objective was to reduce the amount of NaOH and the risk of secondary pollution while ensuring the pretreatment effect of wheat straw,thereby providing a theoretical basis for biogas production of wheat straw.Wheat straw samples were pretreated with 0%,3%,and 6%(dry mass of wheat straw)NaOH for durations of 7,14,21,and 28 days,respectively,with unpretreated wheat straw as control.The results showed that the removal rates of cellulose,hemicellulose and lignin were 5.9%-8.3%,38.3%-41.8%,45.8%-49.2%,respectively,which was similar to the treatment of 6%NaOH and significantly higher than that of 0%NaOH pretreatment when wheat straw was pretreated with 3%NaOH for 7-28 d.The 3%NaOH treatment demonstrated the highest effectiveness compared to the control and 6%NaOH treatment for the same pretreatment duration under anaerobic fermentation of wheat straw at mesophilic temperature(35℃).The cumulative biogas yields of dry matter ranged from 185.5 mL·g^(-1)to 310.5 mL·g^(-1),with a biogas production rate of 38.1 mL·d^(-1)to 84.2 mL·d^(-1)when wheat straw was pretreated with 3%NaOH for 7-28 days.The superior combination forecasting model showed that the treatment of 3% NaOH was the most effective,and the optimum pretreatment time was 11.4 d after 86.0 d completed fermentation,the rate of biogas production was 47.9 mL·d^(-1),the maximum cumulative biogas yields of dry matter was 257.6 mL·g^(-1).In conclusion,it is feasible to use 3%(dry mass of wheat straw)NaOH pretreatment wheat straw under mesophilic(35℃)anaerobic fermentation,which can obtain good biogas production effect.

关 键 词：小麦秸秆 厌氧发酵 NAOH 预处理 产气速率 累积产气量 

分 类 号：S216.4[农业科学—农业机械化工程]