SEQUENCING BATCH REACTORS FOR THE TREATMENT OF EGG PROCESSING WASTE-WATER

Due to plant expansion, a British Columbia egg processor was looking f or a means of increasing the capacity of an aerated lagoon system for treating egg processing wastewater. To avoid a major capital investmen t, upgrading to a sequencing batch reactor (SBR) appeared to be an att ractive option. For this reason, two parallel lab-scale SBR systems we re operated over an eight month period for the treatment of egg proces sing wastewater. The results showed very good removal rates of 99% for BOD, 88% for GOD, and 65% for TSS. Aeration requirements were found t o be 1.5 L/min and 0.5 L/min for two 4 litre reactors in series. The c oefficients a and b, for the determination of oxygen requirements, wer e established at 0.68 g O-2/g BOD and 0.32 d(-1), respectively. Dissol ved oxygen levels between 1 and 3 mg/L were maintained at a design mea n cell residence time of 20 days. Coliforms were reduced from 3500 MPN /100 mt in the influent to 80 MPN/100 mt in the effluent. Confirmed co liforms were identified as Bacillus sp. and Micrococcus sp. Salmonella and fecal coliforms were not detected in either the influent or efflu ent wastewater.