Volatile organic compounds in landfill odorant emissions on the island of Mallorca

Abstract

This study provides data on the occurrence of volatile organic compounds (VOCs) in the biogas emission from a landfill located on the island of Mallorca (Balearic Islands, Spain), where 200,000 tonnes of urban solid wastes are dumped every year. Three different sampling cells, of differing waste ageing were investigated in August 2008, during the main tourist season and the warmest possible weather conditions. Samples were collected in Nalophan™ bags according to the standard European method EN 13725 followed by VOCs adsorption onto Carboxen 1000™ and Tenax TA™ materials prior to thermal desorption and analysis by GC-MS. In total 42 VOCs were analysed, using external standards, out of which 36 were positively identified. Detected VOCs in µg m−3 were alkanes (19–62), aldehydes (65–98), ketones (78–129), alcohols (67–78), esters (25–33), BTEX (83–106), halogenated compounds (16–39), terpens (1.4–2.4) and reduced sulphur compounds (2.6–4.2), showing different concentrations on each one of the three cells. Emitted VOCs showed some similarities with other previous studies from China and Turkey, while large differences to an Italian study. The benzene-to-toluene ratio (B:T) showed values in the range of 0.13 to 0.20 characteristic of biogas. H2S and NH3 gases emitted by the landfill were measured in-situ utilising Dräger™ Tubes for Short-Term-Measurements, showing concentration levels of ≤800 µg m−3 and <300 µg m−3, respectively, which is higher than the determined VOCs in accordance with previous studies. Samples were examined with dynamic olfactometry following standard European method EN 13725, to determine a potential statistical linear correlation between odour and VOC concentrations. Such correlations were not observed probably owing to the large number of compounds emitted from garbage which are not quantified, yet causing positive results in olfactometry.