Degradation of trimethoprim by advanced oxidation process using UV/TiO2 and H2O2: Kinetic and economic aspects

Trimethoprim (TMP) is an effective antibiotic for treating many different infections, but it can lead to water pollution and pose a threat of generating antibiotic‐resistant bacteria through waste in the drug manufacturing process, use, and excretion of humans as well as animals. Due to its strong and non‐selective oxidizing ability, advanced oxidation processes (AOPs) utilizing UV/TiO2 and H2O2 are more efficient in removing them than conventional wastewater treatment. This work investigates TMP degradation in different water substrates by AOPs using UV/TiO2 and H2O2. The results show that the apparent reaction rate constant to the TMP's degradation in the de‐ion water matrix is 0.0379; 0.1937; and 0.209 min−1 for UV/TiO2, UV/H2O2, and UV/TiO2/H2O2 processes. The rate of degradation of TMP in hospital wastewater is lower than that of lake water and de‐ion water. The major intermediate products obtained from the degradation of TMP in de‐ion water by UV/TiO2/H2O2 process were recognized as C14H19O4N4 (m/z: 307), C5H7ON4 (m/z: 139), and C5H6O2N4 (m/z: 155). Finally, the cost of TMP treatment in de‐ion water by several AOPs using photocatalyst and hydrogen peroxide was calculated, it is 0.88 $/m3 for UV/H2O2; 33.01 $/m3 for UV/TiO2 process, and 18.77 $/m3 for UV/TiO2/H2O2 process.