Assessment of benzene, toluene and xylene in groundwater of Tripoli-Lebanon

Abstract

Organic compounds are a major pollution problem in groundwater. Their presence in water can create a hazard to public health and the environment. In this work, we will focus on studying the Benzene, Toluene and Xylene in the groundwater of Tripoli. One of the most common sources for BTX contamination of groundwater are spills from fuel stations involving the release of petroleum products such as gasoline, diesel fuel and lubricating and heating oil from leaking oil tanks. Because of their polarity and very soluble characteristics, the BTX's of petroleum products will be able to enter the groundwater systems and cause serious pollution problems. Assessment of the BTX concentration in groundwater in 24 private wells was monitored during winter, spring and summer by using Gas chromatography–Mass Spectrometry (GC–MS), headspace injection method. It has been found that: 1- The concentration of BTX in all water wells in the city of Tripoli are above the Maximum Contaminate Level (MCL) set by the Environmental Protecting Agency (EPA), thus not suitable for drinking and quotidian use. 2- The concentration of BTX changes with seasons. In general, the concentration of BTX is less in winter than in spring and summer in all Tripoli, and the reason is the dilution of the groundwater due to rain and infiltration. 3- Xylene concentration is the biggest followed by Toluene then Benzene. This difference in concentrations is due to the low volatility of Xylene , the slow biodegradation of Xylene in groundwater and the high percentage of Xylene in gasoline according to other components.