Uso y modificación química de residuos agrícolas para la remoción de Paracetamol, Diclofenaco y Cafeína utilizando columnas de lecho fijo

Abstract

In the present work, the adsorption process of caffeine, diclofenac, and paracetamol in aqueous solution was investigated using cocoa shell and maize cob as adsorbents. The work was conducted at the laboratory scale using fixed-bed columns, and breakthrough curves were constructed for each experiment. This allowed the examination of how variations in adsorbent dosage, inlet flow rate, and initial drug concentration influence column operation time, saturation time, bed utilization fraction (BUF), mass transfer zone (MTZ), and adsorption capacity.

Breakthrough curves were fitted to the mathematical models of Yoon-Nelson, Thomas, and Dose- Response, yielding results that described the kinetics in each case. The treatment of cocoa shell

and maize cob involved an acidic chemical process using 2N citric acid. The adsorbents were characterized with and without treatment using FTIR spectroscopy and BET analysis, identifying functional groups on the surface, particle surface area, and pore volume and radius. Furthermore, at the breakthrough point, the cocoa shell treated with acidic chemical treatment showed values of 0.30 mg/g for CNF, 0.30 mg/g for PRT, and 0.71 mg/g for DCF. For maize cob, the acidic treatment improved adsorption, reaching values of 0.71 mg/g for DCF, 0.13 mg/g for CNF, and 0.05 mg/g for PRT.