Experimental and theoretical insight into the adsorption of 2,4-dichlorophenol on low-cost bamboo sheath activated carbon

The present research reports the development of cost-effective adsorbent as bamboo sheath activated carbon (BSAC) for removal of 2,4-dichlorophenol (DCP) from wastewater. Batch experiments were carried out under varying initial concentration, adsorbent dosage, temperature, contact time, and pH (2–12) to understand the effects of different operating parameters on the removal efficiency for DCP from wastewater. The prepared bamboo sheaths activated carbon has attained maximum removal efficiency of 95.5% for DCP under optimal conditions of 0.35g adsorbent dose, 40 min contact time and 100 mg/L DCP initial concentration. The equilibrium isotherm study for DCP adsorption was suitably fitted to the Langmuir model with the qe (adsorption capacity) of 37.29 mg/g. The adsorption kinetics was well described by pseudo second order adsorption kinetics model with R2 value of 0.99. Thermodynamic data indicated a negative ΔG° (spontaneous) and positive ΔH° process (endothermic). Theoretical studies using DFT (Density Functional Theory) simulations suggested that various interactions for DCP adsorption are possible on functionalized activated carbon surfaces such as (-CHO, -CO-, –CCO,-OH and –COOH). Hydroxyl functional (-OH) groups attached to the surface of activated carbon have a greater negative value of −103.44 kJ/mol adsorption energy, according to this theoretical research. This study suggested that the bamboo sheath biomass of Dendrocalamus hamiltonii can be utilized to produce activated carbon (AC) for removing DCP from wastewater.