Mechanism of hydrogen sulfide generation from a composite waste landfill site: a case study of the ‘Sudokwon Landfill Site’, Korea

This study analyzes the mechanism of hydrogen sulfide generation in a composite landfill site where demolition and domestic wastes were deposited. The total amount of organic carbon recorded during the period 2000–2014 was 11.4 times that of SO₄²⁻. The amounts of organic carbon and SO₄²⁻ removed through landfill gas were 16.0 and 6.1 %, respectively, during the same period. The COD/SO₄²⁻ ratio of the leachate was 10.9 in 2001, which drastically decreased to 4.5 in 2007 by the increase in CH₄ concentration; thereafter, no great variations in this ratio were observed up to 2014. It was found that the concentration of H₂S sharply increased after methane concentrations reached their highest levels. The year around 2006 may be the equilibrium time point among the waste supply, LFG generation, and leachate water quality. In conclusion, if the ratio of landfill organic carbon to SO₄²⁻ is about 10, and the COD/SO₄²⁻ ratio is about 9 in the state of equilibrium, there appears to be no hindrance to the generation of CH₄ and H₂S.