In 2010, Napier-Reid designed and built a compact Sequencing Batch Reactor for the highway 401 service station located in Mallorytown, Ontario. A small but efficient system was required to treat the sanitary wastewater from the restrooms and restaurants of the service station. The Bio-Batch SBR was selected for the job as it is highly effective in treating raw wastewater even with high variations in flow rate and quality. A typical SBR system utilises two or more tanks alternating between the reception of influent and the discharge of treated effluent, but for this project, the system was condensed down to a one-tank operation which combines all the typical equipment and functions found in a two-tank SBR.
The Bio-Batch SBR treats influent at flow rates of up to 228m3/day, with a total suspended solid level of 960 mg/L, ammonia concentration of 80 mg/L, and total phosphorus of 10 mg/L at temperatures ranging from 6 to 25°C. The effluent produced by this condensed SBR system has total suspended solids of less than 5 mg/L, ammonia concentration of less than 4 mg/L, and total phosphorus of less than 0.15 mg/L.
The equipment supplied and installed by Napier-Reid includes: equalization tank, custom designed steel SBR tank, effluent tank, aerobic digestion tank, continuous backwash filter, UV disinfection system, chemical feed systems, blowers, and PLC control panel. Notably, pre-fabricated steel SBR tanks in conjunction with the third-party supplied fibre reinforced plastic building were chosen to reduce construction time and cost.
The treatment system has been in operation since 2011, and has been meeting effluent limits consistently even under higher than expected BOD and ammonia loadings.