Performance evaluation of biofilters and biotrickling filters in odor control of n-butyric acid

Abstract

With the rapid development of swine production in China, odor pollution associated with piggery facilities has become an increasing environmental concern. N-butyric acid (n-BA) is one of the key odor compounds selected to represent volatile fatty acids (VFAs) found in piggery facilities. In this study, two biofilters (BFs) packed with compost (BFC) or sludge (BFS) and two biotrickling filters (BTFs) packed with pall rings (BTFP) or multidimensional hollow balls (BTFM), respectively, were compared with regard to their performances in the removal of n-BA. The non-biological removal capacities of packing material of the bioreactors on a per unit volume basis were BFS>BFC>BTFM>BTFP. Maximum biological removal capacities per unit volume of packing material of the bioreactors all exceeded 9.1 kg/m³·d and in the order of BFC>BTFM>BFS>BTFP. Kinetic analysis as well as overall evaluation by radar graphs showed that the BTFs achieved superior removal rates to the BFs in the order of BTFM>BTFP>BFC>BFS. The biotrickling filter packed with multidimensional hollow balls could be an effective technology for VFAs removal. Results from this research provide economical and effective alternatives for odor control in piggery facilities.

Keywords:

• Biofilters
• biotrickling filters
• n-butyric acid
• biodegradation
• environmental preservation
• kinetic parameters

Acknowledgments

The research was supported by the Natural Science Foundation of China (41001147) and the fund from Science and Technology Department of Zhejiang Province, China (Project 2008C13022-1). The authors wish to thank Dr. Stephen D. Deglonia and Dr. William F. Hunt for their critical reading and useful comments made on the manuscript.