Novel CuO/Cu2(V2O7)/V2O5 composite membrane as an efficient catalyst for the activation of persulfate toward ciprofloxacin degradation

Abstract

In this work, a novel nanocomposite of CuO/Cu2(V2O7)/V2O5 was successfully synthesized via a thermal conversion method. The prepared nanocomposite demonstrated a high efficiency with a degradation rate constant of 0.07 min−1 for ciprofloxacin (CIP) compared to 0.014 min−1 for CuO and 0.03 min−1 for V2O5 in the presence of persulfate (PS). Meanwhile, the nanocomposite was employed in fabricating a membrane to solve the recycling and reuse issue of nanomaterials. The nanomaterial-decorated membrane (NDM) represented an abundant pore structure with a relatively high surface area of 12 m2/g. Response surface methodology was applied to investigate the effects of different operational parameters on CIP degradation using the NDM/PS system. The results revealed the following order of importance for the different parameters: membrane weight > PS concentration > CIP concentration > initial pH. The degradation mechanisms indicated that singlet oxygen is a crucial activated species for CIP degradation. It was also discussed and suggested that the synergistic effect between Cu and V played a key role in the activation of PS. Furthermore, eight degradation products were identified using ultrahigh-performance liquid chromatography combined with high-resolution mass spectrometry (UHPLC-QTOF-MS). The results also led to the identification of possible degradation pathways. Finally, the toxicity of intermediates was evaluated by ECOSAR calculation. This study develops a novel catalytic membrane with high efficiency and stability for the degradation of CIP in the presence of PS, which can be used to overcome issues regarding the collection and reuse of the materials in real wastewater treatment applications.