Malachite green removal using ionic flocculation

Abstract

The use of ionic flocculation is proposed to remove malachite green (MG), in this case, from water. A surfactant with the polluted solution and calcium is added. The surfactant-calcium reaction forms a precipitate, which aggregates into flocs on agitation. The flocs adsorb MG, which can then be removed by centrifugation. Ionic flocculation was assessed by varying parameters including: surfactant and MG concentrations, electrolyte content, pH, contact time, etc. The isotherm and adsorption kinetic models that best fit this process are the Langmuir and pseudo-second-order models, respectively. MG removal efficiency of 96% was obtained at pH 9, with surfactant concentration 1,400 mg L−1, MG concentration 10 mg L−1 and contact time 10 minutes. The process has potential for pollutant removal. HIGHLIGHTS Surfactant-based vegetable fat removes malachite green.; Ionic flocculation is a fast process.; Equilibrium quickly reached.; Physicochemical analysis of post-process effluent.; Malachite green removal efficiency up to 96%.;

Keywords

• adsorption
• ionic flocculation
• isotherms
• kinetics
• malachite green
• surfactant