Biofuel generation from high-fat effluent in a biofilm reactor with backwash

ABSTRACT The performance of an up-flow 0.5 m high and 0.076 m diameter fixed-film bioreactor treating lipid-rich synthetic wastewater has been investigated under the present study. The initial porosity of the filter bed using immobilised microorganisms were on the support matrices has been measured to be 0.67. Excess biomass accumulation on the support leads to an increase in biofilm thickness with time. The filter bed has been regenerated by backwashing after the stipulated time to regain its efficiency in terms of COD removal through the revival of the contact surface. A mathematical model has been developed to predict the loss of contact area and decrease in the porosity of bed with operation time. The backwashing time has been correlated to the inlet concentration of substrate. Methanogens like Methanococcus sp. and Methanosarcina sp. are detected in the mixed anaerobic consortia and favourable growth condition for methanogens in the reactor leads to a maximum cumulative methane production at the exit of the reactor estimated to be 785 ml CH4 (STP)/(g VSS added). The originality of the present research lies in investigating erucic acid-rich wastewater in a bioreactor with backwash and proposing an integration of this bioconversion with syngas-based 2G-Biorefinery. GRAPHICAL ABSTRACT