Study of Badra oil field on soil pollution with some heavy metals in the area surrounding the field

Abstract

To evaluate the state of pollution with some heavy elements (lead, cadmium, nickel, chromium and cobalt), a field study was conducted to determine the effect of Badra oil field in Wasit Governorate on soil pollution with heavy elements in the areas surrounding the field. Soil samples were collected from three sites, which are 400, 800 and 1600 m away from the pollution source, in addition to the fourth site (comparison) in the northeastern part of the oil field at a distance of 5000 m. Soil samples were collected at two depths 0-30 and 30-60 cm and from the southeastern and northwestern parts. The results of the study showed an increase in the total concentration of heavy elements lead, cadmium, nickel, cobalt and chromium in the soil of the study sites in the southeastern part of the field at a depth of 0-30 cm, which is 400 m away (the first site) from the oil field, as it reached 347.40, 11.09, 116.56, 68.78 and 98.45 mg. kg-1 soil in succession, which is higher compared to its concentration in the soil of the fourth site, as its concentration reached 50.87, 1.25, 12.76, 5.77, and 5.98 mg kg-1 soil in succession. As for the concentration of heavy elements in the soil of the northwestern part and for the same depth of the field, the nearby sites recorded values ​​of 116.28, 3.0862.70, 22.56, and 37.54 mg kg-1 soil in succession, which is higher compared to the second depth and for both directions. The concentration of heavy elements in the soils of the study sites and those close to the pollution source has increased above the global limits permitted by the World Health Organization (WHO, 2007) in the southeastern part of the oil field, except for the chromium element, which did not exceed the permissible limits. The study showed that human activity is the main source of the increase in the values ​​of pollution standards (CF, PLI and Igeo), as the average values ​​of the pollution factor CF for lead, cadmium, nickel, cobalt and chromium in the soils of the sites close to the oil field (the first site) and in the southeastern part reached 6.83, 8.87, 9.13, 11.92 and 16.46 respectively, and the value of the pollution factor CF indicates the occurrence of high contamination Considerable Contamination to very high contamination. As for the northern part, the pollution factor CF recorded low values ​​for the soils of the near and far sites compared to the southeastern part of the Badra oil field. The average values ​​of the Pollution Load Index (PLI) for the soils of the sites close to the field and in the southeastern part reached the highest value. 10.16, which is higher compared to the distant sites 3.98. As for the northwestern part, the values ​​of the pollution load index (PLI) decreased compared to the southeastern part, and the values ​​of the index 1<PLI for the study soil sites indicated the presence of a state of deterioration in the soils of the study sites and for the northwestern and southeastern parts and for both depths.