This study examined the release characteristics of malodorous ammonia (NH3) and hydrogen sulphide (H2S) gases in different areas of a full-capacity operational landfill in Hangzhou, China. Gas samples were collected using static boxes from exposed working areas (EWAs), temporarily covered areas (TCAs), and final closure areas (FCAs), and were analysed using spectrophotometric methods. Gas release increased in the following order: TCA > EWA > FCA. The average concentrations of released NH3 in these areas were 2763, 1171, and 27 mg m-3, respectively, and those of H2S were 2481, 631, and 10 mg m-3, respectively. The concentrations of gases released from holes in the film in the temporarily covered and EWAs were significantly higher than the AEGL-3 level values specified by the Acute Exposure Guideline Levels (AEGL) Advisory Committee. EWAs were identified as key for odour control, where the highest NH3 release was recorded at approximately 12:00. The diurnal variation in H2S release was insignificant (p > 0.05). Therefore, the study shows that working in EWAs should be avoided at approximately noon. Adverse impacts on human health can be reduced by standardising procedures, using higher-quality films, and improving film installation procedures. The results of this study serve as a valuable reference for odour control in operational landfills.
Keywords: China; Landfill; ammonia; exposed working area; human health; hydrogen sulphide; malodorous gas.