Evaluation and determination of polycyclic aromatic hydrocarbons (PAHs) in drilling wastes(Case study: Southern Azadegan Oil Field)

Contamination made by polycyclic aromatic hydrocarbons is one of the most common contaminations in oil-rich regions of Khuzestan province. The main purpose of this study was to investigatate the amounts of polycyclic aromatic hydrocarbons in drilling mud wastes ofSouthern Azadegan Oil Field. Drilling muds samples were taken from six drilling oil rigs and also a control soil sample was collected in two seasons of winter and spring, 2015.
Samples were homogenized after they were collected and transported to the laboratory and PAHs in them were extracted. Then 16 compounds of PAHs were measured by meansof GC-MS. Furthermore, the amounts of pH, EC, organic material and grading of mud were measured.
Findings: The results showed that the amount of PAHs in drilling mud collected from the stations Pad 69, Pad 20, Pad 78, Pad 15, Pad 56 and Pad 51 were respectively 284/51, 866/03, 358/59, 299/84, 612/93 and 386/47in the winter and 317/54, 1209/92, 427/61, 491/48, 750/73 and 602/38 mg/kg dried-form weight in the spring.The results collected based on molecular ratio showed that PAHs in all stations contain a mixture of payerolitic and pethrogenic sources.
According to the results obtained from all stations, compounds such as benzo (b) fluorantene, benzo (k) fluorantene and dibenzo (ah) antheracene were found to be exceeding the standard limits mentioned in Canadian Soil Quality and also control soil sample showed no pollution of polycyclic aromatic hydrocarbons.