Composting is widely used for the treatment of solid organic wastes; however emissions from composting are becoming a threat to humans due to the release of toxic volatile organic compounds (VOCs). VOCs from composting operations are characterized by high flow rates and, normally, low pollutant concentration. Typical VOCs include a large amount of terpenes (-65% of total VOCs). This study was to investigate the efficiency of biofiltration in controlling terpene emissions from composting operations using a laboratory-scale unit. The performance of a biofilter was investigated as a function of inlet flow rate, inlet concentration, and bed length/bed diameter (L/D) ratio of bed. At the lowest total inlet flow rate, removal efficiency of limonene and beta-pinene was more than 90%. With the decrease in inlet concentration and increase in L/D ratio, the removal efficiency was effectively increased. Removal efficiency of more than 85% for Limonene and 45% for beta-Pinene was attained at a loading rate of 55 g/m3-hr. The maximum elimination capacity was found for 109.7 g/m3-hr for limonene and 10.3 g/m3-hr for beta-pinene at a critical loading of 150.1 g/m3-hr Based on this study, the compost bed could function as a biofilter for controlling terpene odors during the composting process.
Implications: The purpose of this research project is to investigate the efficiency of biofiltration in controlling limonene and beta-pinene emissions from composting operations using a laboratory scale. In addition, the performance of a biofilter as a function of inlet flow rate, inlet concentration, and L/D ratio of bed was evaluated. Establishing a nexus between the operational parameters and efficiency would be useful in design and operation of compost bed as a biofilter for controlling terpene odors during the composting process.