26 - Advances in aerobic systems for treatment of food processing wastewater

Abstract

Food processing wastewater exhibits extreme variation in characteristics due to the amount of organic materials it carries. The concentration of organic matter in food processing wastewater varies with each type of processing, but generally the Volatile Suspended Solids (VSS) concentration for food processing wastewater is high due to the carryover of food product from processing into the wastewater stream. The wastewater contains various levels of bacteria, viruses, and other pathogens, depending on the food manufacturing process, type of food, and the facility. Treatment of food processing wastewater utilizes a combination of chemical, physical, and biological processes. Each food processing wastewater stream's characteristics, flow rates, and regulatory requirements will determine which physical, chemical, and biological treatment processes will be needed. Physical processes can include screening, clarification, and filtration. Chemical processes may consist of neutralization, enhanced coagulation, and precipitation. The biological treatment processes include both aerobic and anaerobic processes, such as aerobic suspended growth processes, aerobic and anaerobic attached growth processes, and aerobic and anaerobic digestion processes. The major advantages of aerobic processes as compared to anaerobic processes include a generally higher treatment rate and fewer obstacles to meeting effluent dissolved oxygen regulatory requirements.