Starch Wastewater Treatment in a Three Phase Fluidized Bed Bioreactor with Low Density Biomass Support

Aerobic digestion of starch industry wastewater was carried out in an inverse fluidized bed bioreactor using low density (870 kg/m³) polypropylene particles. Experiments were carried at different initial substrate concentration of 2250, 4475, 6730 and 8910mg COD/L and for various hydraulic retention time 40, 32, 24, 16 and 8h. Degradation of organic matter was studied at different organic loading rate by varying the hydraulic retention time and initial substrate concentration. From the results it was observed that the maximum COD removal of 95.6% occurs at an organic loading rate of 1.35 kg COD/m³/d and a minimum of 51.8% at an OLR of 26.73 kg COD/m³/d. The properties of biomass accumulation on the surface of particles were also studied. It was observed that a constant biomass loading was achieved over the entire period of operation.