Residuos agroindustriales y nanopartículas de óxido de hierro para la eliminación de cafeína y triclosán en procesos de adsorción por lotes y filtración/biofiltración.

Abstract

Emerging contaminants, characterized by their low concentration, limited regulation, and potential adverse effects on aquatic life, ecosystems, and human health, are a global concern. Prominent examples include caffeine (biomarker) and triclosan (endocrine disruptor). Traditional elimination methods rely on expensive activated carbon. This research explores the potential of combining agro-industrial residues with iron oxide nanoparticles to remove caffeine and triclosan from wastewater. The study focused on rice husks, peanut shells, coconut fibers, and corn cobs, which underwent conditioning processes. Iron oxide nanoparticles and compounds were synthesized through coprecipitation. Comprehensive physical-chemical and instrumental characterization of the adsorbents were conducted. Batch and fixed-bed adsorption processes were employed to determine optimal conditions for the removal of caffeine and triclosan. The study found that triclosan was easier to eliminate than caffeine, regardless of the selected residue, with an adsorption capacity up to 124.7 times higher. Particle size significantly impacted efficiency, with smaller particles yielding better results but posing challenges in filtration due to blockage. Impregnating nanoparticles into the agro-industrial residues significantly increased the adsorption capacity. Corn cobs emerged as a suitable filtration medium, achieving an efficiency of over 90% in the removal of caffeine and triclosan. Peanut shells also showed promise in biofiltration typologies.