Paracetamol and Atenolol mitigation by Fenton and adsorption in-simultaneous process – Adsorbent regeneration and QSAR eco-toxicity prediction

Abstract

This study aims to study the adsorption and oxidation of Paracetamol (PAR) and Atenolol (ATL) for application in water treatment. The pharmaceutical concentrations were monitored over time to assess the efficiency of the simultaneous process. The pH, contact time, and activated carbon (GAC) concentration were the variables evaluated in the adsorption process. While to the Fenton reaction, the proportion of Fe²⁺/H₂O₂ was the variable studied. Outcomes show that the most suitable conditions in the adsorption process to treat 40 mg/L of each pharmaceutical were achieved at 3 g of activated carbon (GAC) and 60 min. To the Fenton reaction, a ratio of 0.5 Fe²⁺/H₂O₂ was the most suitable condition. The results obtained in the simultaneous process were 17 % of mineralization, and 100 and 73.3 % of degradation of ATL and PAR. respectively. The formation of degradation products also decreased after treatment, suggesting the potential environmental safety of the combined treatment. A regeneration study was conducted to recuperate the GAC. The results showed that a GAC regeneration of 98 % was achieved after 4 cycles by the Fenton process, maintaining the degradation of pollutants evaluated at ∼ 99–98 %. Finally, a toxicity Quantitative Structure-Activity Relationship (QSAR) study was carried out to predict its potential toxicity, showing that it is feasible to conclude that the method has positive implications for environmental safety.