Electrochemical production of sulfate radicals for degradation of Tenofovir in aqueous solution

This work concerns the treatment of Tenofovir (TEN) in aqueous medium by electro-persulfate (EPS) process. The influence of current intensity, persulfate concentration, solution pH and initial TEN concentration on the degradation of TEN and chemical oxygen demand (COD) removal were studied. The concentration of TEN and COD were analyzed by HPLC and spectrophotometrically method, respectively. The biodegradability was assessed by the measurement of biological oxygen demand (BOD5). The optimization of the COD removal was studied by the surface response methodology, following the Box Behnken design (BBD). The results showed 99.0% of degradation was attained at 30 min of electrolysis and 99.2% of COD abatement was achieved at 90 min at pH 3. The kinetic study of the degradation and COD removal showed that both follows the pseudo-first order law with maximum apparent kinetics constants equal to 0.129 and 0.041 min−1, respectively. The biodegradability of the initial solution was highly improved after 30 min of electrolysis. The model equation based on investigation of BBD shows a good adequacy and able to explain the COD removal during the electrochemical treatment of TEN. These findings contribute significantly to exhibit the potential of combination of electrochemistry with biological treatment for emerging pollutants removal from aqueous media.