摘要
为提高秸秆好氧水解的生物可降解性,试验选用切碎揉丝的青贮玉米秸秆,水解液按照体积比为10%的量添加,以水解液溶氧量(1、2、3、4、5、6mg/L)和搅拌速率(50、100r/min)为变化因素,温度控制在35～38℃、总固体为5%,进行优化设计。研究发现,进行8 d,pH值及氧化还原电位(oxidation-reduction potential,ORP)值趋近于稳定;搅拌速率为50 r/min、溶氧量为1～4 mg/L;以及搅拌速率为100 r/min、溶氧量为1～2 mg/L范围内,曝气量的提高,对脂肪酸的积累显著,且搅拌和曝气都可促进乙酸、丙酸和正丁酸的积累;搅拌速率为100 r/min,可溶性需氧量(soluble chemicaloxygendemand,s COD)的浓度整体呈现出高于搅拌速率为50 r/min时的状况;以纤维素降解为例,在搅拌速率为100 r/min条件下,溶氧为2 mg/L时,木质纤维素具有较高的降解率,达到48%。
Corn straw belongs to lignocellulose biomass,and its cell walls are interwoven by cellulose,hemicellulose and lignin.Lignin can’t be degraded under anaerobic conditions,which hinders the contact of extracellular enzymes with cellulose and hemicellulose.The degradation of lignin is an aerobic reaction.Microporous aerator is the main equipment for microbial micro-aeration hydrolysis process.In this process,the air supplied by air compressor is sent to the micro-porous aerator distributed at the bottom of the aeration tank through the pipeline system at the bottom of the aeration tank.The compressed air is blocked by micro-holes on the diaphragm of the micro-porous aerator to form micro-bubbles with a diameter of less than 3 mm.The micro-bubbles are distributed and diffused into the water of the micro-aeration hydrolysis pretreatment tank to fully contact with the hydrolysate so as to effectively dissolve oxygen.To meet the needs of microbial metabolism and biochemical degradation in the hydrolysate of water supply,the purpose of pretreatment of corn straw is achieved.In the presence of molecular oxygen,lignin can be degraded by aerobic hydrolysis microorganisms.Therefore,the aerobic hydrolysis of straw in the anaerobic fermentation of straw is conducive to improve the biodegradability of straw.In this study,a wet micro-aerated hydrolysis pretreatment process with continuous feed-in and feed-out was used to treat corn straw.By controlling the water content of the aerobic hydrolysis fermentation system,the fermentation reactants can be fluidized by the pretreatment with micro-aeration hydrolysis.Stirring can promote heat and mass transfer,the extracellular hydrolase produced by microorganisms can be fully contacted with corn straw,and the occurrence of local over-degradation can be effectively prevented.In this process,by controlling temperature,microbial metabolism in micro-aeration hydrolysis,the pretreatment can be ensured to have high activity,so that the hydrolysis pretreatment reaction can run steadily.In a r
作者
黄开明
赵立欣
冯晶
姚宗路
于佳动
罗娟
魏世萌
Huang Kaiming;Zhao Lixin;Feng Jing;Yao Zonglu;Yu Jiadong;Luo Juan;Wei Shimeng(Center of Energy and Environmental Protection,Chinese Academy of Agricultural Engineering,Key Laboratory ofEnergy Resource Utilization from Agriculture Residue,Ministry of Agriculture,Beijing 100125,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2019年第1期213-219,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
公益性行业(农业)科研专项"中部平原地区沼气多元化利用技术及配套设备集成与示范"(201403019)
关键词
秸秆
水解
氧
青贮玉米秸秆
微曝气水解
预处理
降解特征
straw
hydrolysis
oxygen
silage corn straw
micro aeration hydrolysis
preprocessing
degradation characteristics
