Bio-hydrogen Production from Biodiesel Glycerol Waste from Used Oil by Bacterium Isolated from Waste Water Sludge

Among the bacterial strains which were isolated from the sludge of a milk industry waste water treatment plant, HB41 was found to be the most efficient strain for releasing hydrogen from biodiesel glycerol waste from used oil. The use of 16S rDNA sequences analysis identified HB41 as Escherichia coli U5/41 (Accession No. NR_024570.1) with 99% similarity. Then, it was named E. coli HB41. The effects of substrate, pH, temperature and N-sources on hydrogen production were determined. The optimum parameters for hydrogen liberated were at 2% glycerol concentration, pH 7, temperature 35°C and NH4Cl as N-sources. Fifteen medium formulas were also studied and choosed the best one for hydrogen production. It was found that the most preferable medium should be contained 0.05% NaCl, 2% T-glycerol waste and minerals as follows: 1 g L-1 KH2PO4, 0.1 g L-1 CaCl2.2H2O, 0.05 g L-1 MgCl2, 3 mg L-1 FeSO4.7H2O. Nevertheless, it was found that the H2 content amount of 84% was produced by E. coli HB41 within 12-36 h of the batch process.