Control of hydrogen sulfide emissions using autotrophic denitrification landfill biocovers: engineering applications

Hydrogen sulfide (H 2S) emitted from construction and demolition waste landfills has received increasing attention. Besides its unpleasant odor, long-term exposure to a very low concentration of H 2S can cause a public health issue. In the case of construction and demolition (C&D) waste landfills, where gas collection systems are not normally required, the generated H 2S is typically not controlled and the number of treatment processes to control H 2S emissions in situ is limited. An attractive alternative may be to use chemically or biologically active landfill covers. A few studies using various types of cover materials to attenuate H 2S emissions demonstrated that H 2S emissions can be effectively reduced. In this study, therefore, the costs and benefits of H 2S-control cover systems including compost, soil amended with lime, fine concrete, and autotrophic denitrification were evaluated. Based on a case-study landfill area of 0.04 km 2, the estimated H 2S emissions of 80900 kg over the 15-year period and costs of active cover system components (ammonium nitrate fertilizer for autotrophic denitrification cover, lime, fine concrete, and compost), ammonium nitrate fertilizer is the most cost effective, followed by hydrated lime, fine concrete, and yard waste compost. Fine concrete and yard waste compost covers are expensive measures to control H 2S emissions because of the large amount of materials needed to create a cover. Controlling H 2S emissions using fine concrete and compost is less expensive at landfills that provide on-site concrete recovery and composting facilities; however, ammonium nitrate fertilizer or hydrated lime would still be more cost effective applications.