Role of sorption energy and chemisorption in batch methylene blue and Cu2+ adsorption by novel thuja cone carbon in binary component system: linear and nonlinear modeling

Functionalized thuja cone carbon (FTCC) was synthesized thermochemically. It was carried out by carbonization (250 °C) and activation (320 °C), followed by surface functionalization in 0.5 M HAN (HNO and HCl 3 ) mixture and subsequent heating in H 2 SO 4 (95%) at 90 °C. This was used for methylene blue (MB) adsorption in single component system (SCS) and binary component system (BCS) with Cu 2+ . Maximum adsorption capacity of MB (83.4 mg/g) was achieved at pH 10 at 100 mg/L of adsorbate solution. MB and Cu 2+ adsorption onto FTCC obeyed pseudo-second-order model kinetics. Spontaneous and endothermic MB adsorption was noticed with negative Gibbs free energy change (− 6.34, − 9.20, and − 13.78 kJ/mol) and positive enthalpy change (133.91 kJ/mol). At low concentrations, Cu 2+ adsorption increased by 14 mg/g with least reduction of MB adsorption (