尿素氨化预处理对稻秆厌氧发酵产气特性的影响  

Effect of Urea Ammoniation Pretreatment on Anaerobic Fermentation Characteristics of Rice Straw

作　　者：丁绍兰 张敏娜 黄振侠 吁安 张咪 龚贵金 

机构地区：[1]陕西科技大学环境科学与工程学院,陕西西安710021 [2]江西省农村能源管理站,江西南昌330000 [3]西省农业科学院农业应用微生物研究所,江西南昌330200 [4]正合环保工程有限公司,江西南昌330030

出　　处：《生态环境学报》2018年第1期18-23,共6页Ecology and Environmental Sciences

基　　金：国家科技支撑计划课题(2014BAC04B02);江西现代农业科研协同创新项目(JXXTCX2016003)

摘　　要：水稻秸秆作为一种重要的生物质资源,将其用于厌氧发酵产沼气是中国大力倡导的生物质固废处理方式之一,但稻秆复杂的木质纤维结构使其不易被厌氧生物菌消化利用,导致厌氧发酵效率低下。为了提高稻秆厌氧发酵效率,本研究使用不同质量分数(3%、4.5%、6%)尿素对稻秆进行氨化预处理,并采用环境扫描电镜(SEM)及视频光学接触角测量仪分别对预处理前后的稻秆形态结构及亲水性进行观察测定,以探明尿素预处理对稻秆产气效率影响的内在原因,考察不同质量分数尿素氨化预处理对稻秆厌氧发酵产气特性的影响。SEM结果显示,预处理能够破坏稻秆的致密结构,增大微生物作用面积。接触角测定图像表明,尿素氨化预处理破坏了稻秆表面的蜡质层,表面由疏水性变为亲水性,使其更易被微生物利用,说明稻秆中木质素-纤维素结构的变化是影响其产气效率的内在原因,通过对各实验组进行对比,发现4.5%尿素氨化预处理产气效果最佳,累积产气量达到17 053 mL,比对照组提高了50.67%,并相对缩短了产气周期。As an important biomass resource, rice straw is used for biogas produced by anaerobic fermentation, which is one way advocated greatly in China for waste treatment of biomass solid. However, the complicated wood fiber structure of rice straw makes it hard to digest and utilize anaerobic bacteria, which leads to the low efficiency of anaerobic fermentation. In order to improve the efficiency of anaerobic fermentation of rice straw, the study used the urea with different mass fractions （3%, 4.5% and 6%） to pretreat ammoniation on rice straw and an environmental scanning electron microscopy （SEM） and video optical contact angle locator was adopted to observe the rice straw morphological structure and hydrophilicity before and after the pretreatment so as to find out the internal effects of pretreatment on the biogas producing efficiency and investigate the effects of the urea ammoniation pretreatment with various mass fractions on biogas producing characteristics from anaerobic fermentation of rice straw. SEM results showed that the pretreatment could break the dense structure of rice straw and increased the action area of microbe. The images of the contact angles showed that the urea ammoniation pretreatment had destroyed the wax layer on the surface of the rice straw. The hydrophobic surface was changed into the hydrophilic one, making it easier to be used by microorganisms, which explained that the change of lignocellulosic structure in rice straw was the internal reason of affecting the biogas producing efficiency. Compared with other experimental groups, it was found that the urea ammoniation pretreatment with 4.5% mass fractionhad the optimal effect on biogas production, and the cumulative gas production reached 17053 mL, which was 50.67% higher than that of the control group and relatively shortened the gas production cycle.

关 键 词：氨化 预处理 水稻秸秆 厌氧发酵 

分 类 号：X705[环境科学与工程—环境工程]