Abstract for presentation at 14th IUAPPA World Congress

The current government policy toward food waste management encourages composting for resource recovery. Malodor emission from these composting plants would impact ambient air quality and health. This study used olfactometry, gas chromatography- mass spectrometry (GC-MS) and gas detector tubes to evaluate the ambient air at three of the largest food waste composting plants in Taiwan. Ambient air inside the plants, at exhaust outlets and plant boundaries was examined to determine the comprehensive odor performance, critical components, and odor elimination efficiencies of various odor control engineering. Analytical results identified 29 compounds, including ammonia, amines, acetic acid, and multiple volatile organic compounds (VOCs) (hydrocarbons, ketones, esters, terpenes and s-compounds) in the odor from food waste composting plants. Concentrations of six components — ammonia (1,263±3 μg m^-3), amines (5,911±14 μg m^-3), dimethyl sulfide (759 μg m^-3), acetic acid (612 μg m^-3), ethyl benzene (11±10 μg m^-3), and p-Cymene (67±11 μg m^-3) — exceeded human olfactory thresholds. Ammonia, amines, dimethyl sulfide and acetic acid accounted for most odors compared to numerous VOCs. The results also show the biotrickling filter was better at eliminating the concentrations of odor,NH₃, amines, S-compound and VOCs than the chemical scrubber and biofilters. All levels measured by olfactometry at the boundaries of food waste composting plants (range, 74~115 Odor Concentration (OC)) exceeded Taiwan’s EPA standard of 50 OC. This study indicated that the malodor problem continued to be a significant problem for food waste recovery.