Atmospheric emissions of volatile organic compounds from a mine soil treated with sewage sludge and tomato plants (Lycopersicum esculentum L.)

Abstract

Aims. The study investigated the emissions of volatile organic compounds (VOCs) from a mining soil amended with sewage sludge and irrigated with wastewater with or without tomato plants. The aim is to find out whether amendment and irrigation change VOC emissions from the soil and whether tomato changes emissions compared to uncultivated soil.Methods. Soil and plant experiments were done in assembled pots. All pots were placed inside a closed glass chamber inside an isolated and windowless room. Experiments with soil without plants were done independently from experiments with soil and plants. An aspirating pump coupled with Tenax adsorbent tubes was used for sampling of VOCs emitted from pots. Volatile organic compounds trapped in the tubes were quantified by gas chromatography-mass spectrometry detection.Results. The study detected a total of nine VOCs emitted from the polluted soil: benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene, styrene, benzene-1,2,4-trimethyl and tetrachloroethylene, among which the most abundant were toluene, m-xylene and styrene. Differences between pots with or without amendments (C and A pots) showed a general tendency to a decline of VOCs emissions in the mining soil amended with sewage sludge. Plants contributed to increase significantly the emissions of all VOCs in both A and C- pots.Conclusion. The soil amended with sewage sludge reduced the emission of VOCs: styrene in pots without plants and benzene and xylenes in pots with plants. Tomato plants contributed to increase significantly the emissions of all VOCs except styrene in both amended and non-amended soils.