Adsorbents made from textile scraps: preparation, characterization and application for removal of reactive dye

Textile scraps from the clothing industry were used to prepare a low-cost adsorbent to remove anionic dye from textile effluents. Adsorbents were prepared through pyrolysis and chemical activation with K2CO3. These samples were characterized through thermogravimetric analysis, scanning electron microscopy, N-2 adsorption/desorption isotherms, Fourier transform infrared spectroscopy, point of zero charge, isoelectric point, elemental composition and proximate analysis. Batch kinetic experiments and adsorption isotherm modeling were conducted in different conditions. The surface properties of the adsorbents were significantly influenced by the activation process. The highest BET surface area (S (BET) = 358.55 m(2) g(-1)) was attributed to the sample with chemical treatment. The results indicate that activation process raised 700% the adsorption capacity. The adsorption was strongly dependent on the pH. For the activated adsorbent, 6 g L-1 was sufficient for the complete removal of 40 mg L-1 Reactive Black 5 (RB5) solution. The monolayer capacity was up to 10.3 mg g(-1) and was higher than a commercial activated carbon commonly used in textile sector, which was 9.7 mg g(-1).