Combination of electrocoagulation and photocatalysis/photoelectrocatalysis techniques for the treatment of oil produced water

Abstract

Petroleum is of great importance to the world economy as it is the raw material to produce high value-added products, such as fuels and lubricants. During the oil extraction process, large volumes of wastewater are produced, the so-called produced water. This residue presents considerable levels of mutagenic and carcinogenic aromatic compounds, such as phenolic compounds and BTEX (benzene, toluene, etilbenzene and xylene). In order to contribute to the mitigation of possible damages caused by this waste, the present project aims to study and optimize the unprecedented coupling of electrocoagulation and photocatalysis/ photoelectrocatalysis techniques in the treatment of produced water. For this propose, it is intended to establish, in a single reactor, a two-step treatment, the first step being the electrocoagulation process, performed in an electrochemical system with titanium electrodes, and the second one being the photoelectrocatalysis process, which will be executed in a photoelectrochemical system with titanium dioxide nanotubes as photoanode. Intending to optimize this new method, experimental parameter such as: current density; stirring; initial pH and reaction time in the case of electrocoagulation and initial pH; applied potential and reaction time in the case of photoelectrocatalysis, will be varied and the performance of the process evaluated by measures of: biochemical oxygen demand (BOD); chemical oxygen demand (COD); total organic carbon (TOC); turbidity and quantification of BTEX. (AU)