Green synthesis of CuO nanoparticles via Tulsi (Ocimum Sanctum) leaf extract for efficient adsorptive removal of doxycycline hydrochloride from aqueous solution

Abstract

Due to significant consumption and improper disposal, the increase in emerging broad-spectrum antibacterial pharmaceutical contaminants in water bodies leds to degradation of quality of water resources and aquatic life, causes water availability issues. Doxycycline hydrochloride belongs to the tetracycline antibiotic class of drug, exhibits a significant persistence of toxicity in the aquatic environment. In the present study, eco-friendly CuO nanoparticles were biosynthesized using ocimum sanctum leaf waste extract and an investigation was carried out for the efficient adsorptive removal of doxycycline hydrochloride from pharmaceutical waste with harmful impacts on the environment. UV–visible spectra, XRD, FTIR, EDX, BET, HRTEM and FESEM analysis were used to characterize surface modification of the biosynthesized nanoparticles. Drug concentration, contact time, pH, temperature and adsorbent dosage were among the main adsorption parameters that were examined in order to optimize the most effective removal results. Maximum adsorption capacity of 8.56 mg/g was achieved at optimum process parameter; 100 mg/L, 170 min., pH 6 at 298 K. Moreover, various isotherm models were examined in order to accurately describe the adsorption equilibrium experimental results. Although, the thermodynamic data and kinetic study showed that the sorption process was spontaneous and endothermic, followed second order kinetic model. The outcomes showed that green synthesized CuO nanoadsorbent can be effectively employed for the removal of antibiotic medications from actual wastewater.