New low-cost nanoporous carbonaceous adsorbent developed from carob (Ceratonia siliqua) processing industry waste for the adsorption of anionic textile dye: Characterization, equilibrium and kinetic modeling

Carob (Ceratonia siliqua) processing industry waste (an) has been applied as an abundant, cheap and available precursor to produce a new nanoporous carbon (CWNC) for removal of an anionic textile dye, Reactive Black 5 (RB5), which is frequently used in the textile industry, from aqueous phase. CWNC was characterized by BET, FTIR, SEM, and XRD techniques, proximate and ultimate analyses, Boehm titration Method, pH(pzc), measurement iodine and Methylene blue numbers. Its surface area, total pore volume, average pore diameter was found as 921.07 m(2)g(-1), 0.571 cm(3) g(-1) and 2.482 nm, respectively. The influences on RB5 adsorption of various experimental factors such as adsorbent dose, solution pH, initial RB5 concentration, temperature and ionic strength were investigated. Adsorption kinetics was found to be best represented by the pseudo-second order model. The isotherm analysis indicated that the adsorption data could be represented by the langmuir model. The maximum adsorption capacity for RB5 was 36.90 mg g(-1) at 50 degrees C. Thermodynamic parameters showed that the process was spontaneous and endothermic. (C) 2015 Elsevier B.V. All rights reserved.