Removal of chlortetracycline from spiked municipal wastewater using a photoelectrocatalytic process operated under sunlight irradiations

The degradation of chlortetracycline in synthetic solution and in municipal effluent was investigated using a photoelectrocatalytic oxidation process under visible irradiation. The N-doped TiO2 used as photoanode with 3.4 at.% of nitrogen content was prepared by means of a radiofrequency magnetron sputtering (RF-MS) process. Under visible irradiation, higher photoelectrocatalytic removal efficiency of CTC was recorded using N-doped TiO2 compared to the conventional electrochemical oxidation, direct photolysis and photocatalysis processes. The photoelectrocatalytic process operated at 0.6A of current intensity during 180min of treatment time promotes the degradation of 99.1±0.1% of CTC. Under these conditions, removal rates of 85.4±3.6%, 87.4±3.1% and 55.7±2.9% of TOC, TN and NH4+ have been recorded. During the treatment, CTC was mainly transformed into CO2 and H2O. The process was also found to be effective in removing indicator of pathogens such as fecal coliform (log-inactivation was higher than 1.2 units). •PECO process is a feasible technology for the treatment of MWW contaminated by CTC.•99.1%±0.1% of CTC was degraded by PECO using N-doped TiO2.•85.4%±3.6% of TOC removal and 97.5%±1.2% of COD removal were achieved.•87.4%±3.1% of TN removal and 55.7%±2.9% of NH4+ removal were recorded.•More than 94% of fecal coliform was removed (abatement >1.2-log units).