Fixed-bed adsorption of atrazine onto microwave irradiated Aegle marmelos Correa fruit shell: Statistical optimization, process design and breakthrough modeling

Abstract

In this study, the feasibility of using microwave irradiated Aegle marmelos Correa fruit shell was investigated in a fixed-bed column towards sorptive removal of Atrazine from aqueous solutions. Characterizations of adsorbent such as SEM, point of zero charge (6.5), surface functional groups, BET surface area (910.31m2g−1), thermal and elemental analysis were carried out. Box-Behnken response surface methodology was utilized to optimize the process parameters such as influent flow rate (2.5–4.5mlmin−1), initial atrazine concentration (20–60mgl−1), adsorbent particle size (0.082–0.20mm), and fixed-bed height (5–10cm). The highest equilibrium adsorption capacity of atrazine at optimum conditions viz. bed height 9.46cm, initial atrazine concentration 43.29mgl−1, flow rate 4.41mlmin−1 and adsorbent particle size 0.2mm were estimated to be 12,303.3mgg−1. Single stage batch adsorber was designed using BBD quadratic model for desired purification. Fixed-bed adsorption data obtained at optimum conditions and at different bed heights were fitted into different kinetic models to predict the applicable break-through curve model. Dose-response model best suited model for mathematical description of atrazine removal in fixed bed column over other selected models.