Performance Study and Kinetic Parameter Evolution of Mixed Microbial Consortia for Removal of Organic Carbon and Nitrogen from Wastewater Through Batch Test

Abstract

In this study, biological treatment of waste water was carried out by mixed culture in a laboratory-scale batch reactor for combined removal of soluble organics and nitrogen using wastewater feed solution. The study include the preparation of acclimatized seeds for SCOD (soluble chemical oxygen demand) removal, ammonia nitrogen (NH4 +-N) oxidation, nitrate nitrogen (NO3-N) reduction and finally an investigation was carried out for removal of SCOD, ammonia nitrogen (NH4 +-N) and nitrate nitrogen (NO3-N) in a batch fed reactor using the mixed culture and subsequently estimated the bio-kinetic coefficient such as maximum rate of substrate utilization (k), Half saturation concentration (Ks), yield coefficient (Y), decay coefficient (kd) using the batch experimental data. Various input combinations were tried on the basis of different proportion of initial substrate concentration (SCOD, NH4 +-N and NO3-N) along with different mixed liquor suspended solid (MLVSS) concentration. It was observed that removal of 94.53 to 97.39% and 82.93 to 86.05% of SCOD was occurred after 48 hr for all experimental sets having initial SCOD concentration of 500±50 mg/L and 1000±50 mg/L respectively. Similar removal trend of 85.30 to 93.13% and 81.56 to 87.08% of NH4 +-N with respect to time was also observed after 48 hr for all sets of experiments corresponding to initial NH4 +-N concentration of 90±10 mg/L and 140±10 mg/L respectively. Almost 80.64 to 90.59% and 76.91 to 85.47% of NO3-N removal was found after 48 hr for all experimental sets having initial NO3-N concentration of 40±10 mg/L and 90±10 mg/L respectively.