N-doped carbon achieved by pyrolyzing urea and active carbon for the capacitive deionization coupled PMS oxidation system.

Tetracyclines are among the most widely used antibiotics, and the saline organic wastewater generated during their production has caused serious environmental problems. Thus, it is imperative to develop effective methods for treating this antibiotic wastewater. In this study, we examined the structural characteristics and electrochemical performance of nitrogen-doped carbon materials and assessed the effects of nitrogen doping on the performance of a peroxymonosulfate (PMS)-coupled membrane capacitive deionization (MCDI) system for removing tetracycline (TC) and salt. Having optimized the carbonization temperature and system operating parameters, we observed that in response to an increase in carbonization temperature, there was an increase in the abundance of surface functional groups in the material, which promoted the ion migration capacity of the electrode and PMS activation sites. In addition, we observed that nitrogen doping can alter the electrical properties of carbon materials, provide a larger number of adsorption sites, and enhance the interactions between carbon structures and salt ions, thereby improving material properties. Under optimal operating conditions, the salt adsorption and tetracycline removal rates reached 30.2 % and 61.8 %, respectively. Our findings in this study provide a feasible method for the treatment of saline tetracycline wastewater. [Display omitted] • MCDI coupled PMS treatment system for TC wastewater were constructed firstly. • Preparation of electrode materials by simple doping urea as a nitrogen precursor. • The couple system effectively remove TC (61.8 %) and ions (30.2 %), simultaneously. • The operation mechanism of the system has been fully analyzed. [ABSTRACT FROM AUTHOR]