An efficient integrative method for a sustainable environmental management of produced water: Application on the Zelten oil field, sirte basin, Libya

Oil produced water (OPW) has a complex composition with different, toxic organic and inorganic pollutants. These compounds are generally insoluble and disperse in water as an emulsion. Disposal without treatment causes adverse environmental effects. Therefore, the aim of this study is to develop a simple and dedicated remedial process specifically adapted to the oil field in Libya and to determine how to benefit from this treated water. At this level, samples were collected in both the outer separators and the disposal pit of the Zelten oilfield, Libya. Water samples were analyzed to determine their hydrocarbons (HC) contents, heavy metals, chemical oxygen demand, turbidity, salinity, and total dissolved solids, before and after treatment by sand filter, sanddolomite filter, activated carbon-sand filter, sand-activated carbon-dolomite filter, and extraction by solvent. HC processing efficiency was evaluated by using gas chromatography-mass spectrometry. Using a descriptive and analytical design, this study achieved 50, 81, 87, 91, and 97.97 % respective efficiencies; sand activated carbon filters, slurry filter column, and the solvent showed higher hydrocarbon removal efficiency (81 and 97 %). Treated OPW can be reused for many applications, including irrigation and re-injection into depleted wells.