小麦秸秆的氨化厌氧发酵工艺及影响因素研究

为了提高小麦秸秆的产气效率,利用4.5%的尿素对其进行氨化预处理,并将预处理后的秸秆进行厌氧发酵,分别研究了氨化时间对预处理效果的影响及在不同温度和原料组分配比下的氨化厌氧发酵过程。结果表明：氨化预处理20d后的秸秆COD溶出量与未添加预处理剂相比增加了95.43%,VS增加9.07%,在第15d时已达20d溶出总量的94.61%,采用扫描电镜（SEM）及视频光学接触角扫描仪（GBX）观察发现,氨化15d已可有效破坏秸秆的纤维结构,增加表面亲水性能;在预处理后的发酵实验中,中温发酵（35℃）显现出明显的产气优势,经40d厌氧发酵TS产气率可达193.8mL.g-1;当发酵原料组分配比为秸秆：牛粪：污泥=1：0.5：0.5（干物质质量比）时,其厌氧发酵的累积产气量最大,达6505mL。

Process and Influence Factors of Ammoniation Anaerobic Fermentation with the Wheat Straw

To improve the biogas production effiency in anaerobic fermentation of wheat straw,the effects of ammoniation duration on ammoniation pretreatment were studied after pretreated with 4.5% urea,and the effects of temperature and ratios of ingredients on biogas production were studied in the subsequent anaerobic fermentation process.The results showed that the highest COD dilution and VS（volatile solids） were observed after pretreated for 20 d,they were 95.43% and 9.07% higher than the contro（lwithout urea pretreatment）,respectively.The COD dilution pretreated for 15 d reached 94.61% of that for 20 d.The observations using scanning electron microscopy（SEM）and video optical contact angle locato（rGBX）showed that the straw stalk fiber structure were broken effectively after pretreated for 15 d,and the surface hydorphilism also increased.The highest biogas production were observed in the mesophilic fermentation（35 ℃）,it reached up to 193.8 mL.g-1 after fermentated for 40 d.The ratio of the ingredients favourable for the biogas production was straw：cow dung：sludge =1：0.5：0.5（dry mass）,which lead to a highest cumulative biogas production（6505 mL）.