Desenvolvimento de hidrogel adsorvente para tratamento de efluente sintético contendo fármaco

Abstract

The present study consisted of developing a cellulose-sludge-based hydrogel for the treatment of the pharmaceutical compound bromazepam. For the characterization of the sludge, Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) were performed to measure the amount of cellulose available in the sludge, and X-Ray Fluorescence (XRF) analysis was used to obtain information on its chemical composition. After this stage, the cellulose-sludge and alginate hydrogel adsorbent was prepared. To determine the material’s operational pH range, the point of zero charge (pHpzc) was analyzed. With the hydrogel adsorbent prepared, experimental design was used to determine the optimal conditions of pH, adsorbent dosage, and pharmaceutical concentration. A kinetic study was also conducted to define the adsorption equilibrium time. The sludge characterization results confirmed the presence of cellulose, with its decomposition range occurring between 250°C and 400°C. The chemical analysis showed the presence of several metal oxides, as well as a high loss on ignition (LOI) of 71.4%, suggesting the presence of organic matter and indicating the material’s adsorptive potential. The hydrogel’s pHpzc was 8.04. For the adsorption tests using the hydrogel adsorbent, the best condition was pH 6 and a dosage of 20 g of hydrogel. The equilibrium time obtained from the kinetic study was 180 minutes. The results obtained in this stage of the work demonstrated the potential of the hydrogel for use as an adsorbent in the removal of the pharmaceutical bromazepam.