Industrial effluent is the dirty wastewater from non-residential sources generally require additional preliminary treatment steps than what is needed for sewage. Many industries, such as metal finishers, power plants, dairy plants and breweries, produce wastewater high in chemical and biological pollutants that have a negative effect on both our environment and health. These harmful pollutants must be removed before the water can be safely discharged back to the environment, or reused in plant operations.
As a combination process of electro-flotation and electro-precipitation, electro-flocculation is a water treatment technology of applying direct electrical current to treat and flocculate contaminants that are generally more difficult to remove by filtration. It can effectively remove suspended solids to sub-micrometre levels, breaks emulsions such as oil and grease or latex, and oxidizes and eradicates heavy metals from water.
Typically, an electrolytic cell in electroflocculation consists of pairs of conductive metal sheets in parallel, which act as monopolar electrodes. When connected to an external power source, the anode will electrolytically liberate metal ions that produce coagulants, destabilize impurities, and split emulsions. Meanwhile, gas micro bubbles (H2), which are generated at the cathode, capture the flocculated pollutants and float them to the water surface where it can be more easily concentrated and removed by a motorised skimmer. To consider how effective the process reactor can be, the electrode materials must be considered. Instead of sacrificial metals (such as iron or aluminum), titanium electrodes with mixed metal oxides coating has been practiced with increasing popularity.
