Impact of Poultry Processing By-Products on Wastewater Generation, Treatment, and Discharges

Abstract

In 2009, Georgia’s poultry industry slaughtered and further processed more than 1.3 billion chickens, more than any other state, utilizing 7 gallons (26 L) of potable water per carcass and generating over 9 billion gallons of high-strength poultry processing wastewater (PPW). The conversion of a live chicken into safe and wholesome meat products suitable for human consumption takes place in a series of processing steps. Each step of the process utilizes potable water and generates by-products that combine to form the facility’s wastewater stream. Research within the Poultry Science and Bio & Ag Engineering Departments at the University of Georgia is establishing both the variation individual birds have effecting PPW, as well as determining which by-products have the greatest PPW impact. Early experiments have shown that blood plays a major role impacting PPW. Results show that PPW scalder samples collected from groups of broilers bled for 60 seconds had average chemical oxygen demand (COD) and total solids (TS) levels of 9.86g and 8.12g, respectively. Conversely, carcasses bled for 120 seconds averaged COD and TS levels of 6.49g and 5.43g, respectively. Increasing bleed time to 120 sec from 60 sec resulted in mean percent reductions of COD 34%, TS 33%, TSS 34%, TVS 36%, and TKN 29% in scalder PPW.