Steel slag promoted electrocoagulation process for the treatment of produced water

Abstract

Produced water is a by-product produced from the oil and gas industry. It poses a significant threat to the environment due to its high salinity and high pollutant concentration. In this paper, steel slag was used to enhance the efficiency of the electrocoagulation process for the treatment of produced water. The impact of current density, residence time and quantity of steel slag were studied. Results revealed that the slag particles introduced an adsorption surface for the pollutants to adhere to and produced extra coagulating agents which resulted in higher pollutant removal efficiency. For a residence time and current density of 10 min and 10 mA/cm2, respectively, the steel slag containing system (with slag concentration of 5 g/L) achieved 89.7% removal for total suspended solids compared to 55.7% for the conventional system without steel slag. The total operating cost which is comprised of the electrical energy and electrode material costs was maintained minimal at 0.039 $/m3. 2020 Desalination Publications. All rights reserved.