Continuous adsorption study of congo red using tea waste in a fixed-bed column

In this paper, continuous fixed-bed studies were carried out to investigate the feasibility of using tea waste (TW) as a low-cost adsorbent for the removal of Congo red (CR) from aqueous solution. Effects of various parameters, such as mass of the adsorbent, flow rate, influent dye concentration, and initial pH were investigated. It was found that the amount of the column adsorption capacity was at about 3mg/g. Three commonest models, namely Adams-Bohart, Thomas, and Yoon-Nelson models have been employed to predict the adsorption breakthrough curves of CR onto TW. The Adams-Bohart model satisfactorily predicts the initial parts of the adsorption process with the correlation coefficient at about 0.9. The Thomas and Yoon-Nelson models were found to be in reasonable agreement with the experimental data. In addition, the bed depth service time (BDST) model was applied at different bed depths. The results revealed that the experimental data greatly described using BDST model. It was concluded that the fixed-bed adsorption column with TW adsorbent can be used as a wastewater treatment for the removal of CR.