Remediation of oil-based drilling waste using the electrokinetic-Fenton method

Abstract

The large amount of residues and pollutants left over from the drilling industry could cause irreparable damage by entering the human and animal food chain. Therefore, drilling waste management is of particular importance. Electrokinetic (EK) remediation is one of the methods used to remediate all types of soils contaminated with metal and organic pollutants, but the special conditions and properties of drilling wastes make the use of this method more complex for the treatment of this type of waste. In this study, by enhancing the EK method with Fenton technique, which is an advanced oxidation technique, and using copper and iron electrodes as anode, total petroleum hydrocarbons (TPH) were removed from the oil-based drilling waste. The best result in this study was obtained by reducing the initial concentration of TPH from 316,000 to 72,680 mg⁄kg in drilling waste. This 77 % reduction in TPH concentration was achieved using the EK method coupled with Fenton technique along with the use of copper electrode. The use of iron electrode in the EK-Fenton (EK-F) method improved the parameters affecting the removal efficiency and pollutants decomposition and resulted in 69.6 % TPH removal. These results show a 161 % (copper) and 136 % (iron) increase in TPH removal efficiency, respectively, compared to the conventional EK method, in which TPH removal was 29.4 %. These results indicate that the use of EK-Fenton method combined with copper electrode is effective in removing TPH from drilling waste. Overall, the promising results of the present study indicate that the enhanced EK technique could be considered as an effective and environmentally friendly approach for the drilling waste remediation.