Biofilters - the influence of different filter materials and different operating conditions on the reduction efficiency

Abstract

A series of biofilter materials were tested for performance efficiency in treating ventilation air from pig sheds. Two different phases were conducted. In phase A five different biofilter materials were tested with the aim of selecting the best material regarding the odor reduction and over all efficiency. In conclusion of phase A, biochips, a new filter material, was selected due to its high average odor reduction (81%) in combination with a very low flow resistance (less than 30 Pa for filter volume loads of 600 m3 h(-1) m(-3)). In phase B, biochips and coconut fiber peat were tested under different operating conditions. Biofilters number 3 and 4 each with down-flow air supply could realize a higher average odor reduction than biofilter 5 with up-flow air supply. All three filter materials had the same moisture, however the two biofilters with down-flow air supply showed a more homogenous moisture distribution but they also used approximately three times more water than biofilter 5. Like in phase A the specific odor cleaning efficiency was mainly influenced by the specific odor loading rate and showed only slight differences between the five biofilters differing in bulk layer height (0.5 m and 1.0 m) and air supply mode. All in all the investigation showed that the efficiency of biofilters can be optimized by using an new filter material and a appropiate operating mode.

Interactive effects of dietary crude protein and fermentable carbohydrate levels on odour from pig manure

“…Reduction in odour nuisance plays an important role for strategies concerning where to permit pig production facilities to be located and determines the maximum size of the facilities. So far, strategies to reduce odour mainly focused on technical approaches such as bio-filters (Hartung et al, 2001;Sheridan et al, 2002) and bio-scrubbers (Hahne et al, 2003). In addition, studies have been made to limit microbial activities in manure or to mask odour with other odourous compounds (Stevens et al, 1989).…”

Design and Operation of a Biofilter for Treatment of Swine House Pit Ventilation Exhaust

“…Ammonia REs increased as the MC of the medium increased from 20% to 50%. Odor REs were affected to a greater extent by the inlet odor concentration while NH 3 REs were affected to a greater extent by the τ (Hartung et al, 2001). Nicolai and Janni (1997) 4.4 78% 86% 50% Hartung et al 2001 Biofilter 1 (old medium) 6 88% -15%…”

“…Hardwood woodchip medium was used for the biofilter bed that had an EBRT of 3.25 s. The biofilter was able to reduce odor and NH 3 concentrations by 62 and 73%, respectively, and reduced overall emissions from the barn by 58 and 37%, respectively. Hartung et al (2001) examined two parallel biofilters treating emissions from a piggery in Germany. These biofilters' media were of coconut and peat fiber mixture and 6.5 years old.…”

“…Based on this bed surface area and the design airflow rate, the calculated design U value was 0.15 m 3 /m 2 -s (0.5 ft 3 /ft 2 -s). The design U value was in the high end of the range of U values (0.07 -0.2 m 3 /m 2s) that are normally used in agricultural biofilters (Schmidt et al, 2004;Hartung et al, 2001;Nicolai and Janni, 1999). The medium depth could have been increased in order to reduce the effects of the high U based on mass or volume loading rate but a deeper bed would have increased the p through the system reducing fan airflow rate.…”

Assessment and mitigation of airborne transmission of methicillin-resistant Staphylococcus Aureus in animal feeding operations and the outdoor environment

“…In such studies biofilters have been shown to reduce the emissions of odors and volatile compounds up to 90 percent reduction efficiency 169,170 . evaluated several types of filter media for biofilters for odor reduction and found that biochips and coconut peat had a reduction of odor emissions of eighty one percent and wood bark odor reduction of sixty two percent 171 Determine the viable airborne MRSA concentration and particle size both bacterium which has developed resistance to currently available beta-lactams and cephalosporin and has emerged as a pathogen of great public health concern 1,11,31,[173][174][175] .…”