Valappil, R.S.K.Vijayanandan, A.S.Mohan Balakrishnan, R.M.2026-02-052019Journal of Water Supply: Research and Technology - AQUA, 2019, 68, 8, pp. 675-686https://doi.org/10.2166/aqua.2019.086https://idr.nitk.ac.in/handle/123456789/24752In this work, the photocatalytic activity of the biosynthesized cobalt oxide (Co<inf>3</inf>O<inf>4</inf>) nanoparticle (NP) is investigated using a textile dye Reactive Blue 220 (RB220) and decolorization % was monitored using UV–Vis spectrophotometer. The photocatalytic activity has been observed maximum at alkaline pH of 9, NP dosage of 250 mg/L, and reaction time of 270 min. In the presence of UV light irradiation, a maximum dye concentration of 10 mg/L was treated effectively using 150 mg/L NP, and 67% decolorization was achieved. Reaction kinetics has been analyzed, and the reaction followed the pseudo kinetics model with an activation energy of -484 kJ mol-1. © IWA Publishing 2019Activation energyAlkalinityCobalt compoundsEnzyme kineticsKineticsNanoparticlesPhotocatalysisPhotocatalytic activitySynthesis (chemical)Cobalt oxidesDecolorizationDye concentrationPseudo-kineticsRB220Reactive bluesTextile dyesUV-light irradiationReaction kineticsactivation energycobaltdyenanoparticlephotolysispollutant removalreaction kineticstextile industryultraviolet radiation