Role of cationic surfactant in the removal of chromium(VI) by sodium borohydride Fatima M. Sashanan Al‐Zahrani, Soha M. Albukhari, Zoya Zaheer Canadian Journal of Chemical Engineering, 2026 Sodium borohydride (NaBH 4 ) is one of the most effective reductants for chromium(VI), a severely toxic natural water and soil contaminant. Spectroscopic investigations of oxidative degradation of potassium dichromate (Cr(VI)) by NaBH 4 have been studied in aqueous media. At lower concentrations of oxidant, researchers observed the formation of a coordination complex between chitosan, Cr(VI), and borohydride (BH 4 − ) prior to the rate‐determining step. Removal efficiency decreases from 87.1% to 17.5% with increasing the pH from 3.0 to 8.0 of the reaction mixtures. Activation parameters (activation energy = 59.5 kJ/mol, enthalpy of activation = 57.2 kJ/mol and entropy of activation = −67.8 JK −1 mol −1 ) were determined for Cr(VI) removal and compared with the literature values. Post‐micellar effect was negligible due to the strong coordination between the cetyltrimethylammonium bromide (CTAB) aggregates and reactants. CTAB is an effective inhibitor (removal efficiency decreases sharply from 80.2% to 18.1% with CTAB concentration, from 0.0 to 3.0 mM) and environmentally friendly, and this research showed that the use of CTAB can be a promising approach for the inhibition of the fast removal of water contaminants and resistant compounds.
