初始pH对产氢发酵液厌氧产甲烷的影响研究

Study on effect of different initial pH on methane production of biohydrogen fermentative liquid

以啤酒厂厌氧颗粒污泥为接种物,对葡萄糖废水产氢后的发酵液进行间歇式中温厌氧发酵产甲烷实验。研究了不同的进水初始pH为5.5±0.2、6.0±0.2、6.5±0.2和7.0±0.2时对产氢发酵液产甲烷的影响,并以产氢发酵液的原始pH（4.2~4.4）作为对照。结果表明：产氢发酵液厌氧产甲烷必须添加一定量的碱加以调节,进水初始pH的最佳选择为5.5~6.0。进水pH为5.5和6.0时,系统内pH在产甲烷菌的适宜范围内,COD去除率可达99%,甲烷含量基本维持在60%~68%,最高时达到72%。而进水pH为6.5和7.0时,系统内pH持续在7.3以上;进水pH为7.0时COD去除率和甲烷含量都比pH为5.5,6.0,6.5时要低;实验组4种情况出水VFA均在300 mg/L以下。

With brewery granular sludge as inoculum,methane production using biohydrogen fermentative liquid under mesophilic anaerobic fermentation condition in a batch digester was tested.In this study,different initial pH（5.5±0.2,6.0±0.2,6.5±0.2 and 7.0±0.2） were tested to investigate the effect of initial pH on methane production using biohydrogen fermentative liquid and the original pH of biohydrogen fermentative liquid（4.2~4.4） was studied as control.Batch test results showed that initial pH of biohydrogen fermentative liquid must be adjusted by adding a certain amount of alkali during anaerobic methane production process,and the optimum initial pH of influent were 5.5~6.0.When the initial pH were 5.5 and 6.0,pH of the system was within the appropriate range of methanogenic bacteria,and the COD removal efficiency of 99% can be obtained,in the meantime,methane contents were in the range of 60%~68% and the highest content could be up to 72%.When the initial pH were 6.5 and 7.0,pH of the system was above 7.3.When initial pH was 7.0,both the COD removal efficiency and methane content were lower.VFA of the effluents in the four experimental groups were all below 300 mg/L.