Comparative Study on Removal of Textile Dyes in Aqueous Medium by Adsorption Using Modified Drinking Water Treatment Sludge

The adsorption study of anionic reactive blue 19 (RB19) and cationic methylene blue (MB) dyes from synthetic water was investigated using a new adsorbent. It was prepared from drinking water treatment sludge (DWTS) modified by iron nitrate. The surface area Brunauer, Emmett, and Teller BET increased from 15.58 to 106.12 m(2)/g after the iron incorporation. The adsorption of RB19 and MB on Fe-DWTS was carried out in a batch system to evaluate the effect of contact time (0-30 min), initial solution pH (2-8), Fe-DWTS dosage (0.5-2.5 g/L), and initial dye concentration (10-200 mg/L). The second-order kinetic model and Langmuir isotherm model provided the best fit to the experimental data for RB 19 and MB. The maximum adsorption capacities were found to be 40.16 and 46.08 mg/g for RB19 and MB, respectively.