Removal of amaranth dye by modified Ngassa clay: Linear and non-linear equilibrium, kinetics and statistical study

Abstract

This study aimed at the adsorption of an anionic dye (amaranth) in a batch aqueous medium onto a local clay material collected in Cameroon. The prepared adsorbents were tested towards various adsorption parameters and the characterization was performed using X-ray Fluorescence (XRF), X-ray Diffraction (XRD),Fourier transform Infrared Spectroscopy (FTIR).The surface morphology of clay was revealed using scanning electron microscopy (SEM). The Brunauer–Emmett–Teller(BET) surface area, pore volume and pore diameter of Row-Clay, Na-Clay and Al-Clay were determined. The surface ereas found were 57.50; 65.83 and 67.65 respectivily for Raw-Clay, Na-Clay and Al-Clay. Statistical errors analysis were used to show the best fitting isotherm or kinetic models of the adsorption data. The results revealed that, natural and modified clay materials are made up of various functional groups characteristics of the minerals present on the surface of clay as shown by FTIR, qnd XRD. The equilibrium kinetic was reached at contact time of 5 min, 15 min and 20 min at pH = 3. According to the error analysis, the best isotherms that fit adequately the adsorption data was Sips and Hills isotherms of three parameters, Langmuir and Freundlich two parameters. Therefore, it was concluded that the local clay material has a dye removal capacity and could be exploited by the local people in clothing and textile industry as dye removal agent.