LAND TREATMENT SYSTEMS FOR POULTRY PROCESSING PLANTS
Michael R. Overcash, Associate Professor
Biological and Agricultural Engineering Department
North Carolina State University
Raleigh, North Carolina 27650
Glen Taylor, Project Director
Soil Systems, Inc.
Marietta, Georgia 30062
Wade L. Nutter, Staff Associate
Soil Systems, Inc.
Raleigh, North Carolina 27610
INTRODUCTION
With the trends in environmental solutions for wastes from the poultry processing
industry, land treatment or land application is rapidly becoming a method of choice.
The number of facilities which take advantage of the substantial economic and technical
benefits of land application is increasing steadily to include a very wide range of land
price and availability, geographic, climatological, management attitude, and regulatory
acceptance situations. Having developed over thirty land application systems, including
spray irrigation, solids or sludge spreading, and overland flow options, the authors have
observed several common denominator advantages. These are described below, recognizing
that at any given site certain other advantages may also be present. Briefly, (a) the agricultural orientation, (b) low investment and operating costs, (c) conservation of energy,
and (d) compliance as an approach to a zero discharge system are the recurring beneficial characteristics.
The agricultural essence of land-based treatment is the application of waste to a plant-
soil system so that the land remains productive and the waste is satisfactorily assimilated.
This is very similar to the operation of a crop production system. The equipment for
applying solid waste or sludges or for applying liquids are spreaders and irrigation
equipment which evolved from similar farm equipment. The monitoring and assimilation
criteria are largely related to the behavior of the soils and plants which is also agronomi-
cally related. It should be noted that while these systems are agriculturally related, the
agricultural aspects are secondary to the goal of providing waste treatment and environmental protection. The operation of land application can be accomplished using less
formally trained personnel than is required for the successful operation of advanced
wastewater treatment facilities to meet BAT.
The low investment and operating costs characteristic of pretreatment-land application
systems is an implied comparison to advanced wastewater treatment and stream discharge.
The cost of poultry processing land treatment is often one-third to one-half of conventional treatment methods which meet only basic stream discharge water quality regulations. Thus considerable competitive economic advantage can be achieved by a given plant
utilizing land treatment.
The concept of energy efficiency is becoming important in all areas of society, including pollution control. An unrefined but effective comparison was made of several secondary treatment units (trickling filter and activated sludge) followed by sludge landfill or
incineration at existing municipalities versus pond pretreatment followed by effluent land
application [ 1 ]. When expressed on a basis of energy used per unit amount of BOD5
removed, the conventional systems with stream discharge were two to three times more
energy-intensive than pretreatment-land application. It is anticipated that a similar or possibly wider energy-use spread exists for poultry processing industrial waste treatment.
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