Hydroxychloroquine Adsorption in Aqueous Medium Using Clinoptilolite Zeolite

The presence of drugs on a large scale in aquatic matrices raises concern and requires the study of efficient technologies to remove these compounds. This study investigated the adsorption capacity of the natural zeolite clinoptilolite (CP) in removing the drug hydroxychloroquine (HCQ). Zeolite was characterized by BET, XRD, FT-IR, SEM, and pH(pzc) techniques. The kinetic model that best fits the experimental data was the pseudo-first-order and the SIPS isotherm provided the best fit. The Langmuir isotherm RL separation factor (>0.01) indicated that the adsorption process was favorable and the Freundlich isotherm (n> 1) suggested that the adsorption mechanism occurred mainly by physisorption, with intraparticle diffusion as the step limiting the process. The process was spontaneous (Delta G(ads)degrees < 0), endothermic (Delta H-ads degrees > 0), and with increased randomness at the solid-solution interface (Delta S-ads degrees > 0). The initial pH variation of the effluent was not favorable for the adsorption process and the zeolite was easily regenerated for later use. The ecotoxicological tests with Artemia salina and Lactuca Sativa proved that the final effluent did not show toxicity after the adsorption treatment. Based on the results obtained in this work, clinoptilolite zeolite is a potential adsorbent for reducing HCQ toxicity in aquatic matrices.

Automated summary

This study investigated the adsorption capacity of natural zeolite clinoptilolite for removing the drug hydroxychloroquine. The results showed that clinoptilolite zeolite is a potential adsorbent for reducing HCQ toxicity in aquatic matrices. Additionally, the zeolite can be easily regenerated for repeated use.