INVESTIGATION OF BIOLOGICAL AERATED FILTRATION FOR IMPROVED BOD REMOVAL FOLLOWING HIGH-RATE CLARIFICATION OF MUNICIPAL WASTEWATER

Abstract

The Wastewater Systems Effluent Regulations (WSER) were enacted in 2012 under the Fisheries Act and is the primary federal legislation in Canada to regulate national wastewater treatment. The regulations specified that the effluent concentration of Total Suspended Solids (TSS) and Biochemical Oxygen Demand (BOD) each must not exceed 25 mg/L: standards which are generally achievable through secondary wastewater treatment. The Dartmouth Wastewater Treatment Plant (DWWTP) was one of many treatment facilities commissioned prior to the enactment of the WSER and has been unable to meet the standards with system optimization alone. Lack of secondary biological treatment in the current facility will make it difficult to remove BOD at the capacity required to consistently meet the standards. The objective of the presented research was to investigate a bench-scale secondary biological treatment system which would be a suitable upgrade for the DWWTP to consistently meet the WSER standards, particularly BOD removal.