A TWO-STAGE BIOTRICKLING FILTER SYSTEM FOR ODORS AND VOLATILE ORGANIC COMPOUNDS REMOVAL

Emission control of odors and volatile organic compounds (VOC) is a major consideration for wastewater treatment plant operation. Biotrickling filters have been employed at many wastewater treatment facilities to remove hydrogen sulfide, a major component of odor emissions. However, their effectiveness for VOC removal is relatively unknown. In this study, the Sanitation Districts of Los Angeles County (Sanitation Districts) tested a 1,500 standard cubic feet per minute (scfm) biotrickling filter system at the Joint Water Pollution Control Plant (JWPCP) in Carson, California to determine its ability of removing both odors and VOC. This biotrickling filter system included two stages; the first stage was designed for hydrogen sulfide removal and the second stage for VOC. The packing for both stages consisted of reticulated foam, and one-foot bed depth of porous rock media was later added to the first stage to minimize media plugging. The performance of the system was evaluated under several different empty bed residence times. The results indicated that the two-stage system was effective for hydrogen sulfide removal (>99%), but the VOC removal performance varied. VOC removals by use of a two-stage system will have to become more consistent for use in full-scale applications.