Removal of hydroxychloroquine from an aqueous solution using living microalgae: Effect of operating parameters on removal efficiency and mechanisms

Wastewater contaminated with hydroxychloroquine (HCQ) poses a serious threat to the environment and human life. This study aimed to evaluate the ability of living microalgae to remove HCQ from an aqueous solution. Batch mode experiments were conducted under different conditions to investigate the effect of operating parameters on HCQ removal efficiency and mechanisms. Equilibrium, kinetic and thermodynamic study was also carried out to better describe the interactions between HCQ and microalgae. The maximum HCQ removal was 92.101.25% obtained under optimal pH of 9.90.1, a contact time of 45min, a stirring speed of 300rpm, an initial HCQ concentration of 20mg/L, and a microalgae dose of 100mg/L. The Langmuir isotherm and the pseudo-second-order kinetic model were best suited for the biosorption experiments, and the maximum biosorption capacity was 339.02mg/g. The thermodynamic study showed that the biosorption process was exothermic and spontaneous. Experiments on real wastewater showed that the HCQ removal was not significantly affected by the presence of other contaminants in the water. Practitioner Points The best HCQ removal was 92.10 +/- 1.25% obtained under optimal conditions. The Langmuir isotherm and the pseudo-second-order kinetic model were best suited for the biosorption experiments. The maximum biosorption capacity was 339.02 mg/g. The thermodynamic study showed that the biosorption process was exothermic and spontaneous. The microalgae studied can be successfully used in HCQ removal from water.

Automated summary

The ability of living microalgae to remove hydroxychloroquine (HCQ) from contaminated wastewater was evaluated in this study. Experimental results showed that microalgae can effectively remove HCQ under optimal conditions. The Langmuir isotherm and the pseudo-second-order kinetic model were found to be suitable for describing the biosorption of HCQ by microalgae.