A SURVEY OF WASTEWATER TREATMENT PRACTICES IN THE BROILER INDUSTRY

Traditionally, poultry processing operations have been large users of potable water, and consequently, large generators of wastewater. A typical poultry slaughter facility will generate 5–10 gallons of wastewater per bird processed, containing on average, >2,000 mg/L of biochemical oxygen demand (BOD), >4,000 mg/L of total suspended solids (TSS), and >3,000 mg/L of fats, oil and grease (FOG). With many plants processing 150,000 to 200,000 birds per day, the generation of 1.0 to 2.0 million gallons per day of high strength wastewater is typical. Most of the soluble and particulate organic material in the wastewater must be removed prior to discharge from the plant in order to achieve compliance with established environmental regulations. Depending on the degree of treatment required poultry processors have the option of utilizing physical, chemical and/or biological treatment systems. Each system type possesses unique treatment advantages and operational difficulties.To assist the poultry processing industry in determining the future focus of scientific and engineering research related to the treatment of wastewater, the U.S. Poultry & Egg Association (USPOULTRY) sponsored an independent University of Georgia Engineering Outreach Program survey aimed at identifying the current practices and experiences of the industry in the area of wastewater treatment. The survey was distributed nationwide. The completed surveys were complied and results are summarized in this paper. The survey goals were to determine the extent to which wastewater treatment processes are used by the industry, the context in which they are used, problems commonly encountered in their operation, and solutions that have been attempted to control such problems.Twenty-three poultry processing facilities, located in 11 states, returned completed surveys. Surveys were received from slaughter, further processing and rendering plants. Details on plant processing types, production levels, potable water use, wastewater generation and laboratory analytical testing are provided. Thirteen (57%) of the facilities reported wastewater treatment system operational problems. Of the operational problems reported, the majority involved the inadequate separation of dissolved air flotation (DAF) skimmings and activated sludge bulking. Other problems reported and discussed include poor phosphorus removal and high effluent BOD, total kjeldahl nitrogen (TKN) and ammonia nitrogen (AN) levels.