Economic Evaluation of Biofilters

Abstract

During studies on the optimization of biofilters for the reduction of odours from piggeries, two filter materials and different designs were tested parallel in a stall for fattening pigs. Measured mean odour reduc- tion amounted to 70 to 80%. Odour concentration in the waste air consti- tutes the main influencing factor for odour reduction. Sufficient material moisture in the entire volume of the filter material is an essential prereq- uisite for odours to be reduced significantly and as continuously as pos- sible. The use of coarsely structured materials such as biochips allows larger bulk heights and filter volume loads to be reached, which reduces the investment cost considerably. However, flow resistance and, hence, operating expenses for electricity, grow disproportionately. Therefore, these effects must be given special attention when designing a biofilter and calculating the resulting total cost.