Selection and Optimization of Composting Packing Media for Biofiltration of Mixed Waste Odors

Abstract

Biological filtration is an effective biological treatment method for odorous pollutants. The aim of this study was to determine the relationship between the humification degrees of the media and the removal efficiency of the odors. The biological treatment of a mixed waste gas system in four biofilters packed with COM1, COM2, COM3, and COM4 media (media with different humification degrees) was studied. The pilot experiment showed that with the mixed waste gases, the removal rate of methyl mercaptan was 100% via all four different packing media. The finished product composting (COM4) had the best removal efficiency on ammonia, hydrogen sulfide, toluene, and methyl mercaptan, with values of 97.38%, 97.03%, 98.31%, and 100%, respectively. Therefore, the media of COM4 was applied in the compost plant for treating odors and its practical application value was verified. And results of field experiment showed that before replacing the filter, the least removal efficiency of methyl mercaptan of the biofilter was 17.22%. After changing the filter, the value was up to 100%. Besides that, the removal efficiencies of ammonia increased from 38.10% to 89.84% and hydrogen sulfide increased from 24.05% to 87.95%, and the removal rate of carbon disulfide increased by 51%. The higher humification degrees of the media is proved to be beneficial to the removal of odors.