Isolation And Characteristics Of Biohydrogen-Producing Bacterium From Activated Sludge

In the 21st century, human beings are facing with two problems- energy shortage and environmental pollution. H2 is considered an ideal clean energy, because of its colorless, odorless, non-toxic and combustion products. Microorganism can produce H2 through the metabolism, which is non-pollution and low cost. Hydrogen-producing reaction of dark fermentative bacteria can happen under normal temperature, normal atmospheric and neutral conditions, therefore it is a promising bio-hydrogen production technology. Screening biohydrogen-producing bacteria has been hotspot.To obtain appropriate acid treatment conditions, reduce energy consumption and provide reference to the related techniques, the effect of acid treatment (pH value and time) on cassava starch activated sludge for hydrogen production were investigated. The activity of treated sludge was higher than that of the untreated. The best condition was pH at 4.0 for 0.5 h. With glucose for carbon source and initial pH at 7.0, sludge yielded the greatest gas production and hydrogen production after 48 h fermentation. Compared with blank, it increased 14.0% and 60.3%, respectively.The anaerobic training techniques were adopted for bacteria screening,16S rDNA gene sequence determining and traits of biohydrogen-producting bacteria determining. According to the experimental results, hydrogen commonly occur in the early or middle cell growth logarithm stage.Under batch conditions of glucose concentration of 7 g/L, pH at 7.0 controlled, the higher hydrogen yield was 213±11 mL/g. So low substrate concentration and neutral condition can reduce hydrogen-producting cost and greatly improve the use of strain Clostridum sp.D2. The research was a foundation of optimizing hydrogen-producting conditions and improving hydrogen yield.