Simultaneous biohydrogen production and wastewater treatment in biofilm configured anaerobic periodic discontinuous batch reactor using distillery wastewater

Biohydrogen (H2) production with simultaneous wastewater treatment was studied in anaerobic sequencing batch biofilm reactor (AnSBBR) using distillery wastewater as substrate at two operating pH values. Selectively enriched anaerobic mixed consortia sequentially pretreated with repeated heat-shock (100 °C; 2 h) and acid (pH -3.0-3.0; 24 h) methods, was used as parent inoculum to startup the bioreactor. The reactor was operated at ambient temperature (28±2∘C) with detention time of 24 h in periodic discontinuous batch mode. Experimental data showed the feasibility of hydrogen production along with substrate degradation with distillery wastewater as substrate. The performance of the reactor was found to be dependent on the operating pH. Adopted acidophilic microenvironment (pH 6.0) favored H2 production (H2 production rate—26 mmol H2/day; specific H2 production—6.98 mol H2/kg CODR-day) over neutral microenvironment (H2 production rate—7 mmol H2/day; specific H2 production—1.63 mol H2/kg CODR-day). However, COD removal efficiency was found to be effective in operated neutral microenvironment (pH 7—69.68%; pH 6.0—56.25%). The described process documented the dual benefit of renewable energy generation in the form of H2 with simultaneous wastewater treatment utilizing it as substrate.