PROCESS EXPO | Expert in Residence
The Right Wastewater for the Right Job
Chris Simmons | UC Davis
Not all wastewaters in food processing are created equal. Wastewater properties are as varied as the products and unit operations in food processing. However, wastewater streams, also called effluents, from different operations within a food processing facility are often consolidated for treatment or disposal. This can be a missed opportunity to capitalize on the unique reuse and value potential of individual wastewater streams.
Such water conservation opportunities are particularly important in prolific food processing regions such as the drought-stricken California Central Valley. Certain effluents, such as condensed water removed from product in evaporators, can be quite clean. This water might be used to rinse facility surfaces, provide make-up water for flumes or boilers, or seal pumps.
Moreover, the low-grade waste heat in such effluents may be reclaimed to pre-heat product going into various heat exchange processes. Effluents not suitable for reuse within the processing facility might be used to irrigate adjacent fields. If the concentration of organic compounds in the effluent exceeds acceptable limits for irrigation, processors may consider technologies such as anaerobic digestion to simultaneously treat the wastewater and produce methane for on-site use.
Of course, any effluent reuse must be supported by testing to maintain product safety and excellency. However, if food processing facility operators explore the water quality demands of each of their unit operations and match them to the properties of individual effluents, they may find new and creative ways to extract value from their wastewater.