Removal of algae using hydrodynamic cavitation, ozonation and oxygen peroxide: Taguchi optimization (case study: Raw water of sanandaj water treatment plant)

Algal blooms can have both direct and indirect harmful impacts on water quality, resulting in changes in coloration, unpleasant taste and odor, turbidity, and During such blooms, algae cells may produce and release unpleasant algal metabolites such as taste and odor-causing compounds and cyanotoxins, which can have adverse impacts on water quality. The purpose of this study is to remove of dominant algae from water entering the water treatment plant of Sanandaj using Hydrodynamic Cavitation, Ozonation, and Hydrogen peroxide and process optimization using the Taguchi design method. Seven parameters that are effective in Algae Removal, including pH, retention time, Cavitation pressure, flow, The distance of the orifice plate from the beginning of the cavitation tube, Ozone concentration, and Hydrogen peroxide concentration, were selected as the major factors; Each factor has three levels. the optimal conditions for removal of Melosira and Oscillatoria are the Cavitation pressure: 5 bar, the Retention Time: 90 min, pH: 5, the Flow: 1 m3/s, The distance of the orifice plate: 25 cm, the Ozone rate: 3 gr/h, Hydrogen Peroxide: 2 gr/l. Based on the percentage portion of each factor, the Cavitation Pressure was introduced as the most effective factor in the removal of the Melosira and the Oscillatoria (38.16% and 35.76%, respectively). Hydrodynamic cavitation presents great potential to treat eutrophic water bodies due to the high efficiency shown in microalgae inactivation. Moreover, hydrodynamic cavitation represents a sustainable removal technique, since it does not produce secondary pollution.