Application of advanced oxidation processes for removing salicylic acid from synthetic wastewaters

In this study, advanced oxidation processes (AOPs) such as anodic oxidation (AO), UV/H_2O_2 and Fenton processes (FP) were investigated for the degradation of salicylic acid (SA) in lab-scale experiments. Boron-doped diamond (BDD) film electrodes using Ta as substrates were employed for AO of SA. In the case of FP and UV/H_2O_2, most favorable experimental conditions were determined for each process and these were used for comparing with AO process. The study showed that the FP was the most effective process under acidic conditions, leading to the highest rate of SA degradation in a very short time interval. However, the results showed that Ta/BDD films had high electrocatalytic activity for complete degradation of S A; even if it employs more time for complete elimination of the S A respect to FP. Additionally, AO led to a sixfold acceleration of the oxidation rate compared with the UV/H_2O_2 process. Finally a rough comparison of the specific energy consumption shows that AO process reduced the energy consumption by at least 90% compared with the UV/H_2O_2 process.