Compósitos sustentáveis a base de quitosana e resíduos agroindustriais para remoção de fármacos.

Abstract

Contamination of water by pharmaceuticals arises from inadequate practices in the disposal of medications and hospital waste, as well as deficiencies in water treatment systems. Adsorption emerges as a promising solution to mitigate these impacts, offering an effective and sustainable approach to combat pollution. Moreover, advocating for the adsorption of pharmaceuticals aligns with the Sustainable Development Goals (SDGs), especially SDG 6 (Clean Water and Sanitation), aiming to ensure sustainable water management and preserve aquatic ecosystems. The use of composites as drug adsorbents (dipyrone, paracetamol, and sodium diclofenac) using chitosan, a polysaccharide derived from chitin, is highlighted. Chitosan, with its functional groups, promotes the adsorption of pollutants, while agro-industrial residues such as coconut husks, sawdust, and coffee grounds confer unique properties to the chitosan composite, enhancing its effectiveness in adsorbing contaminants. These residues can be employed as sustainable raw materials in adsorbent production, supporting sustainability and waste reduction. The primary objective of this study was the development and characterization of sustainable composites based on chitosan and agro-industrial residues (coffee ground powder, coconut husk powder, and sawdust) for the removal of pharmaceuticals from water. Three drugs were studied: dipyrone, paracetamol, and sodium diclofenac. The research also evaluated the efficiency of the composites in drug removal, studying the kinetics and adsorption isotherms. During the research, the adsorption method was used to evaluate the effectiveness of the composites in removing drugs such as dipyrone, paracetamol, and diclofenac from aqueous solutions. This method was conducted in two stages: initially, with the three drugs and the four synthesized composites (QGBC, QGPS, QGPC, and QG); subsequently, it focused specifically on paracetamol, which demonstrated the highest removal, and on QGBC, which exhibited the highest drug adsorption capacity. Additionally, the physical and chemical characterization of the composites was performed using techniques such as FTIR (Fourier Transform Infrared Spectroscopy) and SEM (Scanning Electron Microscopy). The QGBC composite (Chitosan, glycerol, coffee grounds) stands out, demonstrating an adsorption efficiency of 76%, with emphasis on the paracetamol drug, especially under pH 6 conditions. The QGBC composite also removed a significant amount of the other two drugs compared to the other three composites. The process demonstrated efficiency and sustainability, valorizing agro-industrial substrates and contributing to the reduction of environmental pollution. The production of sustainable composites proved to be simple and economical, with effective drug removal.