Removal of malachite green dye from aqueous solution using Kenaf core fiber as adsorbent

In the present study, the use of low-cost and eco-friendly adsorbent kenaf core fiber has been reported as an alternative to the current expensive methods of removing Malachite green (MG) dye from aqueous solution. The characteristics of MG dye and kenaf core fiber were studied using FTIR analysis. Besides that, the adsorption of MG on kenaf core fiber was confirmed by FTIR study, as it showed the change in characterization before and after adsorption. The effects of different variables such as adsorbent size, adsorbent dosage, the effect of initial dye concentration at different contact time and pH were investigated and optimal experimental conditions were ascertained. 2 g of 0.710 mm adsorbent at pH 10 was fixed as an optimum condition for this research. Two adsorption models which are Langmuir isotherm model and Freundlich isotherm model were employed in this study to predict the adsorption mechanism. In spite of that, the adsorption favours more to Freundlich isotherm model compared to Langmuir isotherm model. In this research, Freundlich isotherm model is chosen as the most suitable for adsorption as the adsorption capacity was 0.9919 mg/g whereas for Langmuir isotherm model it is just 0.0484 mg/g. Furthermore, pseudo-first-order and pseudo-second-order were used to evaluate the rate of adsorption for kinetic modelling. As a result, the value of R2 for pseudo-second-order are closer to 1 and this model yields better fittings for the adsorption of MG dye compared to pseudo-first-order kinetic model. This research proves that kenaf core fiber can be applied as a low-cost attractive option for removal of MG from aqueous solution.