Case Study: Contaminants Removal from Snack Food Manufacturing Wastewater

This presentation describes the full-scale installation of the wastewater treatment system at the Portion Pack Industries (Division of Heinz) plant in Chatsworth, California. The plant manufactures various products including salad dressing, sauces, ketchup, mayonnaise, honey mustard, toppings, condiments and other snack food products. More than twenty different products are manufactured at the same facility. Produced wastewater, therefore, varies on an hourly, daily and seasonal basis. Wastewater resulting from the manufacturing process contains significant amounts of suspended solids (TSS), fats, oil and grease (FOGs), and suspended and dissolved organics (COD and BOD), with occasional high salinity (sodium chloride). TSS and FOGs can sediment and deposit in pipes, pumps and tanks at the municipal treatment plant (POTW). It is therefore advisable to remove such contaminants on site and avoid costly fees and fines. Pilot studies indicated that hybrid centrifugal – dissolved air flotation (the GEM System) can almost completely remove TSS and FOGs and significantly reduce COD and BODs. In Spring 2007, a system including large underground equalization tanks, screen, coagulation, flocculation, GEM System flotation, sludge draining and pH controls was installed. The treatment system removes TSS and FOGs to less than 20 and 1 mg/l respectively, while producing sludge with more than 20% solids loading. The system responds very fast (within minutes) to changes in wastewater quality. CODs and BODs are also reduced (50-75% reductions). Contaminants removal results in significant savings in fees and fines.