Natural organic matter (NOM) removal by electrochemical methods — A review

• Electrochemical technologies are effective in NOM removal.
• Reactor design has an effect for the treatment efficiency.
• BDD anodes are effective in humic acid removal.
• Coupling with other technologies enhances the purification results.

Electrochemical techniques such as electrocoagulation (EC) and electro-oxidation (EO) have proved their efficiency in humic acid, coliform and algae removal from surface waters. Many investigations have also been conducted with synthetic wastewaters. Electrocoagulation combined with membrane filtration hybrid systems can increase natural organic matter (NOM) removal rates remarkably. In EO technology, electrolysis efficiency is strongly linked to electrode composition. Efficiency could be increased by changing the reactor design, using commercial electrodes and exploring the semiconducting properties of oxide mixtures. Electrochemical methods may present an attractive alternative to other NOM removal techniques, such as conventional coagulation and chemical oxidation methods, for natural waters. Surface water treatment with electrocoagulation can produce high quality water, for either potable or industrial use. This technology appears to remove some toxic pollutants from wastewater and could be used as a pretreatment in combination with some other purification technology. Boron-doped diamond (BDD) anodes have proved effective in humic acid removal from aqueous solutions and potentially their total mineralization.