摘要
为提高稻秆的降解率及其厌氧发酵甲烷产量,采用高氨氮畜禽废水作为氮源以驯化稻田土壤微生物,优化其降解稻秆的初始pH值,并评估水解产物液体发酵产甲烷性能.结果表明,混合组驯化的微生物产纤维素酶活性及对稻秆木质素的降解率高于其它组及先前文献报道,分别达到4.01 IU和51.96%,且后期水解液中总有机碳(Total organic carbon,TOC)及还原糖含量最高.随着初始pH值的提高,稻秆中纤维素、半纤维素和木质素的降解率显著增加,稻秆水解液中的挥发性脂肪酸(Volatile fatty acids,VFAs)和TOC含量均显著增加,并在第7 d达到最高值.将水解稻秆7 d的水解液进行厌氧发酵显示,在初始pH=9.0条件下累积甲烷产量达到最大,为37.60 mL·mL^(-1)水解液.本实验结果表明,驯化的稻田土微生物在碱性条件下可以更有效地降解稻秆,提高水解液中TOC及VFAs含量,从而提高厌氧发酵的甲烷产量.
To improve the degradation rate of rice straw and methane yield during anaerobic digestion,this paper aimed to domesticate the paddy soil microorganisms by swine wastewater(high NH_(4)^(+)-N)as nitrogen source,optimize the initial pH value of degraded rice straws and evaluate the methane production of hydrolysates during liquid fermentation.The results showed that the CMCase activity and degradation rate of lignin in mixed group was 4.01 IU and 51.96%,which was higher than other groups.In addition,the total organic carbon(TOC,653.50 mg·L^(-1))and reducing sugar(186.84 mg·L^(-1))content in hydrolysate reached highest value.The degradation rate of cellulose,hemicellulose and lignin of rice straw significantly increased with increase of pH value,and the volatile fatty acids(VFAs,6.76 g·L^(-1))and TOC(6.92 g·L^(-1))content in rice hydrolysate peaked in day 7 at pH 9.0.After 7 d hydrolysis of rice straw,the liquid-hydrolysate was used for anaerobic digestion,the cumulative CH_(4)yield under initial pH 9.0 is maximum value(37.60 mL·mL^(-1)hydrolysate).The above results showed that acclimated paddy soil microorganisms under weak alkaline condition can increase degradation rate of rice straw and methane production by two-step anaerobic digestion of wastewater-rice straw.
作者
王晶晶
曹雷鹏
李聪苗
王玉
刘玉环
卢亚丽
殷智威
阮榕生
WANG Jingjing;CAO Leipeng;LI Congmiao;WANG Yu;LIU Yuhuan;LU Yali;YIN Zhiwei;RUAN Rongsheng(Engineering Research Center for Biomass Conversion,Ministry of Education,Nanchang University,Nanchang 330047;School of Resources Environmental&Chemical Engineering,Nanchang University,Nanchang 330047;Center for Biorefining and Dept of Bioproducts and Biosystems Engineering,University of Minnesota,Paul USA 551082)
出处
《环境科学学报》
CAS
CSCD
北大核心
2022年第7期398-407,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.21878139)
江西省重点研发项目(No.20181BBF60026)
江西省博士后日常资助项目(No.2020RC08)。
关键词
稻秆
畜禽废水
稻田土菌群
挥发性脂肪酸
两步发酵
甲烷
rice straw
swine wastewater
paddy soil flora
volatile fatty acids
two-step anaerobic digestion
methane
