Spatial and Seasonal Variation of Volatile Organic Compounds (VOCs) in Ambient Air of an Open Dumpsite, Benin City, Southern Nigeria

Abstract

Volatile organic compounds in municipal solid waste dumpsites are considered as one of the major issues in recent years. Open burning is also very common, which emits volatile organic compounds and pose a serious threat to the associated environment. Air samples were collected by passive sampler (ORSA 5). The air samplers were mounted at a height of 1.5 – 2.0 m and sampling were carried out four times a month for a period of 12 months. The adsorbed VOCs were desorbed with carbon disulfide (CS2), and the solution analyzed using a Gas Chromatography (GC) instrument fitted with a flame ionization detector (FID). The results from the analysis of the air samples showed that twenty-six (26) VOCs were identified and quantified in the open dumpsite during the dry and wet seasons. The VOCs in the open dumpsite during the dry season were classified as follows: Alcohol 9%, aromatic 45%, halogenated compound 38%, ester, and terpinene 4% each. The levels of VOCs obtained in the studied areas in the dry season are 2 to 3 times higher than in the wet season. This may be attributed to metrological parameters and a greater number of anthropogenic activities such as storage and movement of waste, waste combustion, solvent discharge, vehicular exhaust, and petroleum product emissions. Principal component analysis revealed that the major sources of VOCs in the open dumpsite are mainly anthropogenic.