WCW26

In Winnipeg, Manitoba, industries discharging industrial wastewater to the municipal collection system are required to meet wastewater quality limits set forth by the City’s Sewer By-law No. 106/2018. Given the strict discharge limits for biological oxygen demand (BOD), total suspended solids (TSS), pH, and fats, oils and grease (FOGs), many industries utilize onsite wastewater treatment systems to reduce these parameters prior to discharging their wastewater to avoid costly surcharges. However, for industries that produce a variety of different products, such as large-scale food processing facilities, the resulting wastewater quality can be highly variable making it difficult for onsite wastewater treatment systems to maintain optimal treatment conditions, such as coagulant dose. Therefore, industries are burdened with needing to continually monitor and manually adjust their onsite wastewater treatment system in order to minimize the discharge of overstrength wastewater and avoid surcharges. Given that most industries do not have dedicated wastewater treatment system operators, the onsite wastewater system often goes unattended and operates outside of the optimal treatment conditions, particularly when the industry produces highly variable wastewater quality.
To better control their onsite wastewater treatment system, a large-scale food processing facility installed a real-time monitoring system (i.e., an S::CAN Monitoring Station) to continually measure water quality prior to and following the onsite dissolved air flotation (DAF) system and automatically adjust coagulant and polymer dosing to meet treated water targets. The S::CAN system consisted of two (2) online UV-Vis spectrophotometers that would measure BOD, TSS, and FOGs as well as ORP and pH meters to monitor pre and post-treated water quality. Initially, the pre and post-treated water quality was monitored for approximately 3 months to evaluate the variability in the incoming wastewater quality and to identify periods where the production of a particular food product resulted in wastewater that was difficult to treat using DAF at the set coagulant and polymer dose. For production periods identified as producing wastewater that was particularly challenging for the DAF to treat, jar-testing was used to determine the optimal coagulant and polymer dose. Following the initial evaluation and optimization period, the wastewater quality data and optimal chemical dose ranges were used to develop and refine feedback logic used to control the chemical delivery system.
Overall, the implementation of the real-time S::CAN monitoring and automated dosing control system enabled the facility to transition from reactive, manual process adjustments to a proactive, data-driven treatment approach. By continuously characterizing influent variability and linking water quality measurements to optimized coagulant and polymer dosing strategies, the facility improved the stability and performance of its DAF system despite highly variable production schedules. The project demonstrates that integrating real-time monitoring with adaptive control logic can significantly enhance onsite industrial wastewater treatment reliability, particularly for food processing facilities with fluctuating wastewater characteristics.