Notice of Retraction: Removal of Congo Red by Fixed Bed of Modified Wheat Straw: Effect of Flow Rate

The congo red (CR) adsorption from aqueous solutions has been investigated by means of a fixed bed of ethylenediamine modified wheat straw (MWS). Isothermal column experiments were performed under a constant inlet concentration and bed depth, and different flow rates. The experimental data confirmed that the flow rate affected the shape of breakthrough curves. The Yan model was applied to the experimental results by nonlinear regressive analysis. The predicted breakthrough curves have been obtained, and they are in agreement with the corresponding experimental data. When the flow rate is 4 ml/min and the influent concentration of CR was 50 mg/l, the adsorption quantity reached 55.1 mg/g according to Yan model. It is concluded that the MWS column can remove CR from solution.