Preventing Hazardous-Level Generation of Hydrogen Sulfide Gas in Landfill Sites: Possibilities and Administrative Criteria

【Paper】
Preventing Hazardous-Level Generation of Hydrogen Sulfide Gas in Landfill Sites: Possibilities and Administrative Criteria
Yusaku Ono* and Nobutoshi Tanaka**
* Group of Waste Management, Center for Environmental Science in Saitama
** Graduate School of Eng., Hokkaido University
† Correspondence should be addressed to Yusaku Ono:
Group of Waste Management, Center for Environmental Science in Saitama
（914 Kamitanadare Kisaimachi, Saitama, 347-0115 Japan）

Abstract
In many large municipalities, a large amount of construction/demolition wastes and waste gypsum wallboard are generated. This usually contains a lot of organic matter. Large quantities of hydrogen sulfide gas（H2S）and water returned blackish by ferrous sulfides therefore create an environmental pollution problem when they are disposed of on top of these wastes in landfill sites. In order to elucidate the condition for generation of H2S, an anaerobic cultivation experiment was conducted using several samples which were separated out of the construction/demolition wastes and waste gypsum wallboard.
First, 1,000ppm was assumed to be acute toxicity as the hazardous gas concentration level for H2S. The amount of H2S being generated（gas concentration becomes the hazardous level in gas space through the waste landfill layer）was calculated to be 0.13mmol-S per kg of wastes.
Consequently, the following conclusions were derived from the assumed hazardous level and experimental results. The wastes which generate H2S amounts beyond the hazardous level are those whose ignition loss is over 20％ for the samples separated out of the construction/demolition wastes, and those whose ignition loss is more than 4％ for waste gypsum wallboard originating from demolition wastes. Common criterion for both separated wastes shows that the TOC concentration in filtrate obtained from the elution test where the ratio of water to waste is 10mL/g is more than 30mg/L.

Key words: hydrogen sulfide gas, sulfate reducing, construction and demolition waste, gypsum board waste, sanitary landfill