Hydrogen Production From Orgnic Components Of Sludge Fermentation Liquid In Microbial Electrolysis Cell

Microbial electrolysis cell(MEC)as a new technology for hydrogen production,which has a wide range of substrates,can handle complex organic matter.Using sludge to produce hydrogen by MEC can not only solve the sludge outlet,but also obtain clean energy hydrogen.This paper aimed to examine the efficiency of hydrogen generation in different mixing ratios of substrates for the character of protein and carbohydrates rich in fermentation liquid of sludge.The sludge was pretreated then combined the anaerobic fermentation.And the glucose and bovine serum albumin are used as the substrates during experiment.At the same time,under the optimized hydraulic retention time,the fermentation liquid which pretreated in different and optimum conditions are used as substrates for MEC to produce hydrogen.The yield of organic matter was higher in different degree after acid,alkali and heat treatment was carried out.The yield of volatile acid was also increased significantly,and it turned out that the dissolution effect of alkaline pretreatment was better than that of acid,and the difference between heat treatment and alkali treatment was not significant.Acetic acid was the main component of volatile acid generated during the anaerobic fermentation process,the yield of acetic acid is decreased with the increase of fermentation time for the reason that the consumption of acetic acid.Considering the economy,acetic acid yield,soluble carbohydrate and protein,so we chosed the 24 h as the best fermentation time.And the optimum pretreatment values under different pretreatment conditions were pH3,pH 10,70?.Compared with the start-up effect of sodium acetate,the hydrogen production efficiency was significantly decreased when using glucose and bovine serum albumin as MEC substrate,and methane bacteria were active relatively.with a successful start by substrate of sodium acetate,the efficiency of hydrogen production was significantly decreased after replacing the reaction substrate with different mixing ratio of glucose and bovine serum albumin.The hydrogen production with a rate of 1:0 is better than that of other mixing ratio,and the maximum hydrogen production is up to 1.00 m3H2/m3-reactor/d,hydrogen production rate of 1:1 was more stable then others,the amount of hydrogen production with bovine serum albumin ranged significantly during every cycle.the COD removal rate decreased with the decrease of the glucose content in the mixed solution.The soluble sugar of the sugar solution with different mixing ratio was fully utilized,and the consume of the soluble protein was fluctuating.the use of protein in MEC is not as good as glucose.The effect of hydraulic retention time on the hydrogen production efficiency and substrate removal effect of MEC was obvious.HRT-24 has a better removal efficiency and the maximum hydrogen production rate can reached 1.50 m3H2/m3-reactor/d.The effect of MEC production in different pretreatment fermentation broth was not significant.Acetic acid is the main use of MEC hydrogen production substances,The use of dissolved organic matter is less than volatile acid.the rate of hydrogen production in the pretreated fermentation broth was higher than that in the control group,and the hydrogen production rate in the 70? group was the best,reached to 0.36 m3H2/m3-reactor/d,and increased by 24.03%.