Carboxymethyl cellulose/activated carbon/hydroxyapatite composite adsorbent for remediation of methylene blue from water media

In the present study, activated carbon (AC), activated carbon/hydroxyapatite (AC/HAp), and carboxymethyl cellulose/activated carbon/hydroxyapatite (CMC/AC/HAp) composite adsorbents were prepared to remediation of methylene blue (MB) from water media. The pyrolysis method used the Pine cone as a natural precursor to synthesize AC. FTIR, XRD, Raman, BET, TEM, and SEM-Dot mapping techniques were applied to characterize synthesized adsorbents. Experimental results demonstrated that the maximum removal efficiency of AC, AC/HAp, and CMC/AC/HAp adsorbents under optimum conditions of pH 8, adsorbent dose 1 g/L, contact time 60 min, initial concentration 10 mg/L, and temperature 25 °C was computed to be 98.75, 98.86, and 98.93 %, respectively. Kinetic and equilibrium data were well-fitted with pseudo-second-order and Langmuir models, respectively. The maximum monolayer adsorption capacity of AC, AC/HAp, and CMC/AC/HAp was determined to be 40, 44.248, and 43.86 mg/g, respectively. FTIR results showed that hydrogen bonding and electrostatic interactions are the main mechanisms of the adsorption process. Results of the thermodynamic study showed that the adsorption process is spontaneous and exothermic. Finally, AC, AC/HAp, and CMC/AC/HAp composite adsorbents can be used as promising adsorbents for the remediation of MB from wastewater.