Batch tests were carried out to investigate the production of H2 considering the effects of: substrate concentration in a range of 3–25 g-COD/L; Initial pH: from 4 to 7 and 11 and temperatures of: 20, 35, 45 and 55 °C. The optimal substrate was 25 g-COD/L, with a reduction of COD of 73% and a yield of H2 of 5.95 mM/gCOD; and the optimal initial pH was 11.0, with a 70% of COD reduction and a H2 yield of 4236 mM/gCOD. The optimum temperature for pH = 11 was 35 °C, with a COD reduction of 69.8% and H2 yield of 6.3 mM/gCOD. Escherichia, Acinetobacter, Alcaligenes, Brevibacterium, Clostridium and Mycobacterium were isolated from pretreated inoculum samples and identified by 16S rDNA sequencing. The results suggest that biofilm reactors developed on a natural support such as Opuntia imbricata have good potential for hydrogen production from dairy wastewater.
- Diary wastewater
- Opuntia imbricata