Source contributions of Polycyclic Aromatic Hydrocarbons in soils around oilfield in the Brahmaputra Valley.
Surface soils from Borholla oilfield in the upper Brahmaputra Valley in India were studied for the USEPA's 16 priority Polycyclic Aromatic Hydrocarbons (PAHs). Analysis of PAHs was carried out by high performance liquid chromatography (HPLC) system equipped with an UV detector. Seasonality in PAHs concentrations was evident and the concentrations were found to be greater in post-monsoon season. There has been a dominance of low molecular weight PAHs (80-90% of total PAHs) indicating recent deposition from combustion sources. The concentration profiles appeared in the decreasing order of 3-ring >2-ring >4-ring >5-ring >6 ring PAHs. The sources of PAHs were identified using isomer pair ratios and Principal Component Analysis-Multiple Linear Regression (PCA-MLR) and Positive Matrix Factorisation (PMF). The ratios of diagnostic pairs indicated for both pyrogenic and petrogenic input of PAHs. The PCA-MLR modelling revealed that the <16% of contribution came from petrogenic origin and the rest 85% was found to be from pyrogenic sources. The PMF model also shown that <19% of PAHs source were petrogenic origin whereas rest from pyrogenic origin. The correlations of black carbon (BC) with PAHs also supported the pyrogenic contribution. The analysis of air mass back trajectories revealed that there has been contribution of both local and distant sources, through long range transport of pollutants, which were deposited to the site.
['Deka|Jinu|J|', 'Sarma|Kali Prasad|KP|', 'Hoque|Raza Rafiqul|RR|']
D004784:Environmental Monitoring D007194:India D016014:Linear Models D008962:Models, Theoretical D061329:Oil and Gas Fields D011084:Polycyclic Aromatic Hydrocarbons D025341:Principal Component Analysis D012621:Seasons D012987:Soil D012989:Soil Pollutants
PAHs PCA-MLR PMF Oilfield soil Source apportionment