Removal of organic materials from TNT red water by Bamboo Charcoal adsorption

Bamboo Charcoal (BC) was used as an adsorbent to remove organic materials from TNT red water. The studies were carried out by varying pH, dilution ratios of TNT red water, contact time and temperature. The characterizations of BC were analyzed by N2 adsorption, Boehm titration method, mass titration, the scanning electronic microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The functional groups of TNT red water was also determined by FTIR. The equilibrium adsorption data were analyzed using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) isotherms. It was observed that the Langmuir isotherm fitted the experimental results well and the adsorption involved a physical mechanism by the D–R models analysis. The pseudo-second-order kinetic model described the adsorption kinetics of the organic materials from TNT red water very well. The studies of external diffusion and intraparticle diffusion models showed that external as well as intraparticle diffusion also influenced on the actual adsorption process. Thermodynamic studies showed that the adsorption of organic materials from TNT red water on BC was a spontaneous, endothermic process and the randomness increases at the solid/solution interface. The mechanisms of adsorption were studied by electrostatic interactions, hydrogen bonding formation electron, donor–acceptor interaction and π–π dispersion interaction.

► Bamboo Charcoal (BC) was used as an adsorbent to adsorb organic materials from TNT red water.
► Many factors were found having great influence on adsorption.
► Adsorption fitted well to pseudo-second-order kinetics and the Langmuir model.
► Adsorption was a spontaneous, endothermic and the randomness increases physical process.
► The adsorption mass transfer and mechanisms were studied.