Evaluation of Emission Pattern, Quantity and Control of Korean Food Waste Composting Odorants in a Pilot-Scale Packed-Bed Scrubber

摘要

Olfactometry and analytical methods (GC-FID, FPD, MS and HPLC/UV) were used toevaluate the release of twelve regulated malodorous compounds (S and N-derived odors,aldehydes and volatile organic compounds) from a Korean municipal solid waste treatmentfacility as mandated by the Ministry of Environment (MOE) Odor Control Law of 2005.Ammonia and methylamine accounts for majority of the odors as compared to other VOCswhile concentrations of some regulated odors in the composting exhaust outlet exceededindustrial regulation criteria. Ammonia and methylamine gases, considered to be one of thegreatest nuisance odors, are useful indicators for the evaluation of the decomposition ofnitrogenous organics during food waste composting processes. In this study, a 0.5-m diametercolumn randomly packed with polypropylene Hi-Rex 200 was designed for absorption ofcomposting exhaust gases in dilute H_2SO_4 scrubbing liquid. The long-term operation periodrevealed highest emission profile during summer (May-July) while lowest in the winter(December-February) season. An odor index of 31 and 26 was measured at the scrubber inletand outlet, respectively, using triangular odor bag method. Solution pH control was found tobe the critical factor that dictates the effectiveness of the scrubbing system. Results showedfavorably for the removal of NH_3 and methylamine at contact time as low as 0.94 sec up tovolumetric loading rates of 3819.22 m~3/m~3-hr. High absorption efficiencies were achievedwith pH maintained below 6. Higher removal rates for methylamine were also observed thanNH_3 due to its higher solubility. Mass transfer characteristics were evaluated as well asoptimum operating parameters to achieve basis for process scale-up.