Industrial wastewater is an aqueous discard and by-product from a variety of industrial processes, such as battery manufacturing, pharmaceutical manufacturing, petroleum refining, mineral extraction, power generation, etc. The specific liquid waste generated can vary widely among the industrial sectors. It can encompass toxic pollutants (e.g. heavy metals, volatile organic compounds), high concentrations of dissolved solids, organic matter or nutrients (e.g. oil, grease, ammonia nitrogen), and naturally occurring radionuclides. Therefore, the wastewater must be pre-treated to remove and eliminate these pollutants, and then converted into an effluent comply with the regulations regarding disposal of wastewaters into sewer system.
In practice, electrocoagulation-flotation (ECF) process has been proven to present better pollutant removal capabilities with less sludge production, thus lowering the sludge disposal cost. Electro-coagulation (EC) is a process which causes the in situ electrochemical production of coagulated species and metal hydroxides that destabilize and aggregate particles or precipitate the dissolved contaminants. Generally, it will be often followed by an electro-flotation (EF) process that floats pollutants to the surface of a water body via tiny bubbles of hydrogen and oxygen gases generated from water electrolysis.
The efficiency of treatment processes significantly depends on the operating parameters, including electrodes materials, solution pH, and current density. Our mixed metal-oxides coated anodes, consist of a titanium base metal covered by a thin conducting layer of IrO2/RuO2 film, have been widely used due to their excellent electrochemical performance at high current densities.