Abstract

Hydrogen sulfide (H<inf>2</inf>S) isclassified as toxic gases that are commonly known to be generated from an anaerobic process, volcanic explosion and petroleum related processes. Low concentration of H<inf>2</inf>S causes irritation on human eyes and respiratory system as well as nuisance problem due to its rotten-egg smell. Insanitary dumpsite of municipal wastes containing high organic fraction could be a source of H<inf>2</inf>S emission, which affects the quality of life of nearby communities. This study assessed the H<inf>2</inf>S dispersion from dumpsite in Nakhon Si Thammarat using the source dispersion model, AERMOD. Emission rate of H<inf>2</inf>S generated at dumpsite was estimated using emission factor of 1.76 mg.m<inf>-2</inf>.d<inf>-1</inf> taken from AP-42 (USEPA.). For meteorological data, hourly average data in 2012 were collected from three meteorological stations which were Nakhon Si Thammarat, Surat Thani and Trang Provinces. Meteorological data were primarily utilized from Nakhon Si Thammarat. Only missing values were filled by the data from Surat Thani and Trang, respectively. Results revealed that maximum concentrations of H<inf>2</inf>S in 2012 were 0.595, 0.066 and 0.058 ppb, respectively for 1 hour average (1^st highest), 24 hour average (1^st highest) and annual average over the study area of 10 km × 10 km surrounding the source. Maximum concentration of H<inf>2</inf>S emitted from dumpsite was mainly confined within 1.5 km surrounding the sources, particularly to the east and northeast area. The simulated concentrations of H<inf>2</inf>S did not exceed the suggested standard values; however, the 1^st highest hourly average concentration was reached the odor threshold (0.5 ppb). To clarify the simulated H<inf>2</inf>S concentrations, further works should be included the field sampling of H<inf>2</inf>S at dumpsite to obtain the actual emission rate. Meteorological data in several years should be also used to provide the concrete pattern of H<inf>2</inf>S dispersion. © (2014) Trans Tech Publications, Switzerland.