In situ generation of H 2 O 2 using MWCNT-Al/O 2 system and possible application for glyphosate degradation

• Published in: The Science of the total environment 2019-02, Vol.650 (Pt 2), p.2567
• Main Authors: Tan, Ni, Yang, Zhao, Gong, Xiao-Bo, Wang, Zhen-Ran, Fu, Tao, Liu, Yong
• Format: Article
• Language: English
• ISSN: 1879-1026
• DOI: 10.1016/j.scitotenv.2018.09.353

Hydrogen peroxide (H O ), as a green oxidant, has been widely applied into advanced oxidation processes (AOPs) for the degradation of toxic organic pollutants. The in situ generation of H O can not only improve the storage and transportation safety of H O but also reduce the capital and operation costs. In the present work, a novel system, i.e., multi-walled carbon nanotube‑aluminum (MWCNT-Al) composite was used to in situ generate H O through micro-electrolysis. The MWCNT-Al composite was characterized and optimized. The accumulation concentration of H O reached 947 mg/L at the initial pH of 9.0, the MWCNT-Al composite dosage of 8 g/L and oxygen gas flow rate of 400 mL/min after 60 min. The in situ generation of H O was achieved by MWCNT-Al/O system, mainly owing to the direct contact between Al and MWCNT in MWCNT-Al composite, which accelerated the transfer of electrons from Al to O , as well as the excellent electrocatalytic activity of MWCNT toward the two-electron reduction of oxygen. When H O in situ generation technology was used in peroxone process (O /H O process) to degrade glyphosate in aqueous solution, the removal efficiency of TOC and total phosphorus was 68.35% and 73.27%, respectively. Finally, the possible mechanism of in situ generation of H O in MWCNT-Al/O system was temporarily proposed.