MINIMUM-COST BIOFILTERS FOR REDUCING ODORS AND OTHER AERIAL EMISSIONSFROM LIVESTOCK BUILDINGS .2. A MODEL TO ANALYZE THE INFLUENCE OF DESIGN PARAMETERS ON ANNUAL COSTS

A model to optimize the design of biofilters for livestock buildings i s presented. This was developed from four sub-models covering biofilte r size, biological performance, pressure drop and costs. The sub-model for biological performance predicts that for a specified duty, reside nce time multiplied by effective surface area of packing is constant. Hence direct comparison of different packing media can be made without the need to quantify the difficult parameter of odour. Five different packing media were compared, based on given inputs. The model predict s that peat and heather, a common packing medium, is the cheapest pack ing when fewer than 5000 broilers are housed. (C) 1996 Silsoe Research Institute