ali akbari

To evaluate petroleum contamination of groundwater and air and identify its sources in the Marvdasht, a wastewater-irrigated area located in the southwest of Marvdasht, concentrations of aliphatic hydrocarbon components were analyzed by gas chromatography. The analysis revealed the presence of biogenic and degraded petrogenic hydrocarbons. For water, petroleum pollution and degradation levels were significantly higher in October 2012 [total aliphatic hydrocarbons (TAH): 706.2–9834.7 μg L−1] than those in May of the same year (TAH: 310.4 to 5821.2 μg L−1). For air, the concentrations of Σn-alkanes, unresolved complex mixture (UCM), and TAH were lowest in winter (Σn-alkanes: 71.1 μgm−2 d−1, UCM: 131.2 μgm−2 d−1, and TAH: 218.8 μgm−2 d−1); the n-alkanes were more abundant in spring (794.5 μgm−2 d−1); and UCM and TAH were more abundant in summer and autumn (UCM: 10333.1 μgm−2 d−1 and TAH: 11598.1 μgm−2 d−1). Through principal component analysis, the water and air sampled in different seasons and sites were differentiated based on their degree of petroleum pollution and various aliphatic hydrocarbon compositions. Through redundancy analysis, we found the effect of irrigation water on the surface soil was much higher than that of atmospheric deposition. The variance of hydrocarbon composition in soil, explained by the hydrocarbon composition in water collected in the main irrigation period, May 2012, was 73.1%, whereas the value for atmospheric deposition was only 11.3%.