Enrichment of Expanded Granular Sludge Bed Reactor during Start-Up Phase

Abstract

The start-up period in anaerobic treatment process is generally measured as the period engaged for stable operation to be attained. A 14.47 litres working volume of bench scale anaerobic Expended Granular Sludge Bed Reactor was designed and fabricated for the treatment of slaughter house wastewater. The reactor has been continuously operated at mesophilic range with an organic loading rate from 0.013 to 0.014 kg COD/m3.day with an Influent COD of 592 to 648 mg/l during start-up process with a HRT of 3 days. In anaerobic treatment process the main complexity to develop most suitable microbial culture in the reactor in terms of the granular formation and establishment of biomass. Throughout 70 days of continuous monitoring of the reactor, it was found that the Expended Granular Sludge Bed Reactor was attained a steady state from 54th day to 61th day with maximum of 91.14% removal efficiency during start-up phase. During the start up period Volatile Fatty Acid accumulation was also observed from 18th day to 27th day. The pH level also declined at these stages.