Landfills are nettlesome sources of malodorous gases as well as methane that has the second largest radiative forcing of long residence-greenhouse gases, followed carbon dioxide. Because methane and malodorous gases are simultaneously emitted in landfills, investigation of whether or not methane and malodorous gases affect each other’s degradation is important. Amines such as monomethylamine(MMA), dimethylamine(DMA) and trimethylamine(TMA) are representative malodorous gases from landfills. In this study, the effect of amines on the bio-oxidation of methane was evaluated using a methane-oxidizing consortium where the dominant bacteria were Methylocystis spp. Amines inhibited the methane oxidation by the consortium, and the inhibition effect increased in the order of TMA > DMA > MMA. Methane oxidation rates in the consortium decreased with increasing amine/methane ratio(mol/mol). These results can be used to design and optimize the biological processes for simultaneous removal of methane and malodorous gases.
Aliphatic amine compounds have very low detectable threshold value concentrations, and especially trimethyl amine is one of the main odor-active compounds in atmospheric environment. Concentration of a large amount (10~100 L) of air sample was needed to detect trace amounts of amine compounds by GC/FTD. Amine compounds in ambient air were absorbed in sulfuric acid solution by using impingers and sampling pump. Some amount of the absorption solution was injected in bubbling bottle which a concentration tube was connected with, and that amine gas which was isolated from bubbling bottle was trapped in a concentration tube dipped in liquid argon under a constant helium flow. A concentration tube was disjoined from the bubbling bottle and was connected to injection port of gas chromatograph. Amine compounds trapped in a concentration tube was introduced into the packed column by thermal desorption after flow rate of carrier gas and detector signal had been stabilized enough. Sampling volume of ambient air was different from place to place in the range of 10~100 L, and flow rate through impingers was 5 L/min. Atmospheric concentrations of trimethyl amine were below 16.0 ppbv in the boundary of business establishment and below 420.0 ppbv at the gas releasing port of business establishment in the industrial area.