Hydrogen Production By Mixed Strain From Corn Straw In Micro-aerobic Conditions

This study did research on the hydrogen production fermentation by corn straw in micro-aerobic environment at mesophilic temperature.In bench-scale tests of 150 mL anaerobic bottle,explored the best hydrogen production in micro-aerobic environment by controlling the amount of oxygen.Did the scale-up experiment in 10 L fermenter at the best condition of hydrogen production,did the comparative study on the gas production and hydrogen production,pH,oxidation-reduction potential,volatile fatty acids,alkalinity and the change of cellulose-based material in the process of micro-aerobic and anaerobic hydrogen production fermentation;and analyzed the change of bacterial community structure.The hydrogen yield was calculated by biogas and hydrogen content.Measured biogas by drainage method or wet type gas meter and determined hydrogen content by gas chromatography.Monitored PH and oxidation reduction potential by pH meter and oxidation reduction potentiometer,respectively.Measured volatile fatty acids by gas chromatography.Measured alkalinity by automatic potentiometric titration instrument measurement.Measured cellulose-based material was by Van Soest.And parsed bacterial community structure in the systems by the PCR-DGGE technique.The bench-scale test shows that the corn straw get the highest hydrogen yield at the amount of oxygen is 280 ml/kg TS·day and the hydrogen production of acid treated corn straw is the best.At the amount of oxygen is 280 mL /kg TS· day,the result of scale-up test shows that the micro-aerobic fermentative hydrogen production is 34.5mL/g TS which is 42.73% higher than anaerobic fermentation hydrogen production;the variation range of PH of micro-aerobic hydrogen production fermentation is 4.7--7.0 and the variation range of ORP is between-300 and-150;the micro-aerobic hydrogen production fermentation and the anaerobic hydrogen production fermentation are the same in liquid end production(which is acetic acid and butyric acid)and fermentation type(which is butyric acid type fermentation);alkalinity declined relatively slower in micro-aerobic fermentative hydrogen production,but system stability is higher than anaerobic fermentation hydrogen production;the utilization of corn straw in micro-aerobic fermentative hydrogen production is higher than in anaerobic fermentative hydrogen production;except for Enterococcus,Bacteroides,Fusobacterium,Lactobacillus,Bifidobacterium,Peptostreptococcaceae in the process of micro-aerobic fermentative hydrogen production,there also are Enterobacter and Citrobacter.