Synthesis of nanocrystalline cellulose/hydroxyapatite nanocomposites for the efficient removal of chlortetracycline hydrochloride in aqueous medium

The presence of antibiotics in the water has potential impacts on the environment and consequently their removal is of great importance. In this article the possibility of chlortetracycline hydrochloride (CTC·HCl) removal from aqueous medium by using eco-friendly nanocrystalline cellulose-hydroxyapatite composites (NCC/HAPs) as adsorbents is reported. The NCC/HAPs were synthesized by a simple in-situ precipitation method and their structural properties were studied. The HAP nanoparticles were successfully incorporated on the surfaces of synthesized NCC/HAPs. A set of systematically designed experiments were carried out to determine the influences of the amount of NCC, pH, contact time, initial concentration, and adsorbent dosage on the adsorption behavior of NCC/HAPs. A high CTC·HCl removal rate of about 70.81% in 10 min was obtained, and NCC and HAP showed obviously synergistic effect on absorbing CTC·HCl. The structure analysis, kinetics, mechanistic studies, intraparticle diffusion model and Zeta potential tests demonstrated that the removal of CTC·HCl from aqueous media are attributed to van der Waals interaction, electrostatic interactions , cation-exchange, complexation and bridging, complexation and hydrogen bonding . Overall, the findings presented in this paper suggest that NCC/HAP has promising applicability for the removal of antibiotics from aqueous media as an alternative and eco-friendly adsorbent for environmental remediation.