Valorisation of Posidonia oceanica leaf sheaths in removing synthetic dye from aqueous media using dynamic column system

Abstract

Packed columns were prepared using Posidonia oceanica fibres as adsorbent for the removal of a direct dye, Congo red (CR), from aqueous solution. The effects of flow rate, concentration of CR, pH solution and bed depth on breakthrough curves were investigated. The experimental results showed that the breakthrough time decreased with the increase of flow rate, influent concentration and the decrease of bed depth. The amount of sorbed dye decreased by increasing the flow rate and increased by increasing the dye concentration and bed height. The removal of CR by raw Posidonia fibres reached 80% with a dye concentration of 10 mg.l–1 at the flow rate of 0.47 ml.min–1 and at pH 6.5. Thomas, Yoon-Nelson, Adams-Bohart and bed depth/service time analysis (BDST) models were successfully used to analyse experimental data, to predict the breakthrough curves and to determine the characteristic parameters of the column useful for the process design.