NaOH预处理对香蕉秸秆厌氧发酵产沼气的影响

EFFECT OF NaOH PRETREATMENT ON ANAEROBIC FERMENTATION OF BANANA STRAW FOR BIOGAS PRODUCTION

以农村废弃资源香蕉秸秆为原料,采用试验室自制的厌氧发酵装置,在恒温35℃和发酵料液总固体质量分数为6%的条件下进行沼气发酵试验,研究不同质量分数(2%、4%、6%、8%) NaOH的预处理对香蕉秸秆厌氧发酵产气效果的影响。研究结果表明:香蕉秸秆经过NaOH预处理后与对照组(未经NaOH预处理)相比产气量明显增加,其中,NaOH预处理浓度为6%的处理组,发酵58 d时的总产沼气量、总产甲烷量、总固体(TS)产气量、总固体(TS)产甲烷量均最高,分别为21581. 00 mL、11878. 30 mL、548. 87 mL/g、302. 10 mL/g。经过NaOH预处理后的香蕉秸秆发酵过程中pH值在适宜的范围内波动,发酵前后发酵液中COD的降解率均达到60%以上。故综合来看,NaOH预处理能缩短香蕉秸秆厌氧发酵的启动时间,增加发酵体系的缓冲性和稳定性,提高产气效果,且NaOH预处理浓度为6%时,香蕉秸秆厌氧发酵效果最优。

Under the condition of 35℃ and total solid mass fraction of 6%, the effect of different concentrations(2%、4%、6%、8%)of NaOH pretreatment on anaerobic fermentation of banana straw for biogas production were studied,using the self-made anaerobic fermentation equipment.Results showed that gas yield of NaOH pretreatment groups increased significantly compared with the control.The pretreatment group with NaOH concentration of 6% had the largest total gas production yield and total methane production yield which achieved 21581.00 mL and 11878.30 mL separately, after 58 days′ fermentation.The TS gas production yield and the TS methane production yield reached 548.87 mL/g and 302.10 mL/g separately.During the fermentation process, the pH value of NaOH pretreatment group fluctuated within the appropriate range.The degradation rate of COD was up to 60% or more after anaerobic fermentation.On the whole, the NaOH pretreatment of banana straw could not only shorten the starting period of anaerobic fermentation, but also create a well buffering environment for anaerobic fermentation system and improve the stability of gas production.NaOH pretreatment of banana straw could improve the ability to biogas production of banana straw.The optimized concentration of NaOH pretreatment for banana straw was 6%.