Assessment of isotherm and kinetic adsorption modelling for dye removal using banana stem as green alternative adsorbent

Abstract

Abstract Wastewater effluent from the batik industry which contain dyes such as Methylene Blue (MB) will cause pollution to the adjacent water bodies if not treated effectively. A batch adsorption experiment using banana stem was conducted for various dosage (0.2 g – 1.4 g) and various contact time (15 to 120 minutes). Adsorption isotherm was employed to understand the nature of the sorption process. Feasibility of the sorption process of MB were evaluated by developing kinetics adsorption modelling, while error function suggested the best-fitted sorption model on sorption data. From isotherm analysis, the adsorption process fits the Freundlich better than other models due to r2 value, 0.917 even though Langmuir Type IV is relatively higher. In Langmuir Type IV model, the negative sign of b value signifies the surface of banana stem has heterogeneous coverage instead of homogeneous coverage. For the adsorption kinetic models, it reveals that Pseudo-Second-Order model fitted well with r2 value of 0.996. The adsorption of MB is dominated by multi-layer adsorption on the heterogeneous surface of banana stem adsorbent which influenced by chemisorption process. Therefore, banana stem has the potential as an alternative, eco-friendly adsorbent media for effective removal of dyes in textile effluents.