An effective calix[4]arene-based adsorbent for tetracycline removal from water systems: Kinetic, isotherm, and thermodynamic studies

This study aims to investigate the adsorption characteristics of tetracycline from polluted waters using C-4-hydroxyphenylcalix[4]resorcinarene as an adsorbent. The adsorptive efficiency is optimized by adjusting various operational parameters such adsorbent dosage, pH, contact time, temperature, and initial adsorbate concentration. most efficient remediation 96% at 10.0 mg/L concentration, 0.05 C-4-hydroxyphenylcalix[4]resorcinarene, a time 30 min, pH 5.6, ambient temperature. ability toward also investigated in water with different characteristics, including solutions without addition background salts. results show that can effectively remove aqueous capacity ca. 36.9 mg/g. finds removal process followed pseudo-second order kinetics Freundlich isotherm models. Moreover, spontaneous exothermic, suggesting thermodynamically favorable chemisorption process. In addition, method successfully applied real natural systems.