[Bio-hydrogen production from different pretreated sludge by Pseudomonas sp. GL1 and changes in the liquid phases]

Batch tests of anaerobic fermentative hydrogen production by Pseudomonas sp. GL1 were investigated using sterilization, microwave and ultrasonication pretreated sludge as substrate. The profiles of soluble COD, protein, carbohydrate and pH value during the fermentation process were monitored. The results showed that only hydrogen and carbon dioxide were produced and methane was not observed during the process. A maximal hydrogen yield (30.07 mL x g(-1)) and bio-hydrogen content (81.45%) were obtained from the sterilization pretreated sludge run. The shortest lag time for hydrogen production was in ultrasonication pretreated sludge run (3 h), while the longest one was in sterilization pretreated sludge run (15 h), and the medial one was in microwave pretreated sludge run (12 h). It was found that the changes of sludge substrates (soluble COD, protein, carbohydrate and pH value) were various with different pretreated sludge during the fermentation process, especially in the sterilization sludge run, which implied that the pretreatment method could affect substrate utilization by Pseudomonas sp. GL1.