Odour Impact and Control at a Landfill Site in Hong Kong

In Hong Kong, landfill dumping has been a main approach for municipal solid wastes disposal and will be continued in the near future. However, gaseous emission from municipal waste may causes offensive odours and disturbs the neighbours around landfill sites. Usually there are not enough buffer zones between landfill sites and the nearest sensitive receptors due to a land restriction in Hong Kong. In this study, a comprehensive investigation about odour pollution impact from a local landfill site was performed, in which a local landfill site was selected as an odour emission source to study its odour pollution impact to the surrounding areas and also identify its major characteristics. The investigation was conducted with three approaches of olfactometry with a dispersion modelling, odour patrol monitoring, and application of an e-nose technique. The odour pollution impact with reference to the criteria proposed by the Hong Kong Government was assessed based on the results of grap sampling and the previous 5 years weather data. A “Factor of Two” method is recommended to assess the odour impact based on the olfactometry results. Electronic nose analysis indicates that the odour in the boundary area of the landfill site has a similar nature to municipal wastes including the waste sludge from conventional biological treatment processes, municipal refuse from residential areas and construction wastes, but a different nature to some chemical wastes including the sludge from a chemically enhanced precipitation process, and some industrial wastes