Water treatment process intensification by combination of electrochemical and photochemical methods

• Combination of technologies leads to overall process time reduction.
• Electro-coagulation removes inorganic pollutants well and organic pollutants partly.
• Photochemical oxidation successfully removes organic contaminants.
• Electro-coagulation intensifies photochemical oxidations.

Wastewater contamination is typically characterized by a combination of organic and inorganic compounds rendering treatment relying on a single treatment approach almost always unfeasible. The treatment of complex waste matrices not only poses the process challenge of reducing the concentration of a number of contaminants to safe levels but also achieving it through an efficient, affordable and simple process. A key challenge in achieving this is the identification of techniques that operate symbiotically to: enhance the performance of the system as a whole and; reduce the number of process steps. Here such process symbiosis is presented, through the treatment of a model effluent containing iron and nitrobenzene, by electro-coagulation (EC) and photooxidation (PO), individually and in combination. It was found that the combination of two techniques, which individually were unable to completely remove contamination, achieved 100% contaminant removal in a shorter reaction time and consuming less H2O2.