Removal of reactive dye Remazol Brilliant Blue R from aqueous solutions by using anaerobically digested sewage sludge based adsorbents

• Main Authors: Özçimen Didem, Salan Tufan
• Format: Article
• Language: English
• Published: Association of the Chemical Engineers of Serbia 2016-01-01
• Series: Chemical Industry and Chemical Engineering Quarterly
• Subjects: sewage sludge; carbonization; activated carbon; adsorption; Remazol Brilliant Blue R
• Online Access: http://www.doiserbia.nb.rs/img/doi/1451-9372/2016/1451-93721500029O.pdf

In this study, adsorbents were produced from sewage sludge via chemical and thermal activation processes. Experiments were carried out in a tubular furnace at the heating rate of 20˚C min-1 and temperature of 550 ˚C with a nitrogen flow rate of 400 mL min-1 for 1 h. Dye adsorption experiments were performed with Remazol Brilliant Blue R for its several concentrations under batch equilibrium conditions by comparing sewage sludge based adsorbents with raw material and a commercial activated carbon. Maximum adsorption capacities of carbonized sewage sludge (CSWS) and activated sewage sludge (ASWS) were found as 7.413 mg g-1 and 9.376 mg g-1 for 100 mg L-1 dye solution, whereas commercial activated carbon had a capacity of 11.561 mg g-1. Freundlich and Langmuir isotherms were used to explain the adsorption mechanism together with pseudo-first-order and pseudo-second-order kinetic models. Langmuir isotherm, which had adsorption capacities of 34.60 mg g-1 (CSWS) and 72.99 mg g-1 (ASWS), provided better fit to the equilibrium data than that of Freundlich isotherm. Pseudo second-order, model which had adsorption capacities of 7.451 mg g-1 (CSWS) and 9.319 mg g-1 (ASWS), was very favorable to explain the adsorption kinetics of the dye with high regression coefficients.