High pollutant levels of produced water around Al-Ahdab oil field in Wasit governorate (Iraq)

Abstract

Exploration activities of the oil and gas industry generate loads of formation water called produced water (PW) up to thousands of tons each day. Depending on the geographic area, formation depth, oil production techniques, and age of oil supply wells, PW from different oil fields contain different chemical compositions. Currently, PW is also known as industrial waste water containing heavy metals that are toxic to humans and the environment, requiring special processing so that they can be disposed of in the environment. To determine the heavy metals content in PW from the Al-Ahdab oil field (AOF), the Ministry of Science and Technology/Agricultural Research Department determined some parameters including the concentrations of Cd, Co, Cr, Pd, and Ni using instrument inductively couple plasma (ICP-OES). Results of this study showed high concentrations of Cd (0.51-2.05, Cr (0.06-1.81), Co (0.11-0.72), Ni (0.12-0.22) and Pb (5.52-20.6) in the AOF compared to concentrations in water bodies about 16 km outside the field; Cd (0.01-0.32), Cr (0.01-0.11), Co (0.03-0.18), Ni (0.02-0.11) and Pb (0.04-1.73). These findings indicate there are increased levels of pollutants in the PW within the AOF of the Main Outfall Drain (MOD). The PW could not be as a source of drinking water and other daily activities, including fisheries and crop planting, unless advanced treatment, to remove the heavy metal content.