Formation And Emission Of Volatile Organosulfur Compounds In Landfill

Volatile organosulfur compounds(VOSCs)in landfill gas have gained considerable research attention for their low odor threshold and high volatility.In this study,two typical VOSCs:methyl mercaptan(MM)and dimethyl sulfide were researched from the perspective of their formation,migration,transformation and emission in landfills,aiming to settle the theoretic basis of landfill VOSCs odor control.Firstly,the phase of rapid degradation of landfills was simulated using lab-scale reactors.Results showed that sulfate and oxygen inside landfills have negligible effect on the final product of MM and DMS,while the existence of oxygen can efficiently lower the emission rate of MM and shorten the time of DMS risking surrounding air environment.Secondly,degradation processes of various organosulfur substrates were simulated to uncover their biochemical VOSCs potentials,which can be evaluated within 500 h.Food wastes rich in proteins showed highest biochemical VOSCs potentials.The MM and DMS potentials were 46.1 and 11.5 ?/g,respectively.Finally,simulated landfill reactors were established to study the generation,migration,transformation and emission of MM and DMS in a long-period experiment,finding that the generation of MM and DMS tend to occur in the acidification and methane production phase of a landfill.Aeration can efficiently lower the maximum release concentration of MM by 87.4-94.9%and DMS by 31.7-93.7%,and leachate recirculation shall shorten MM and DMS influence time promisingly.The conclusions of this study can provide theoretical basis for the control of MM and DMS emission.