Complete and rapid degradation of glyphosate with FeCeO catalyst for peroxymonosulfate activation at room temperature.

Glyphosate, a common broad-spectrum herbicide, is a serious environmental pollutant that causes a significant threat to humans. Hence, there is a pressing task to remove glyphosate from the environment. Here, we report an excellent FeCeO catalyst synthesized via the one-step co-precipitation method for activating peroxymonosulfate (PMS) to degrade glyphosate at 25 °C. As a result, glyphosate is completely degraded with a high degradation rate of 400 mg L·h, and the TOC and TN removals are 85.6% and 80.8%, respectively. As proven by systematic characterizations, the Fe-Ce synergistic effect plays a significant role in promoting PMS activation. The main reactive oxygen species for glyphosate oxidation are surface-bound SO· and ·OH, produced by activating PMS by electron transfer between Fe/Fe and Ce/Ce of FeCeO. In light of the products determined, the possible degradation process of glyphosate is also speculated: C-N and C-P bonds of glyphosate molecules are attacked to form aminomethylphosphonic acid (AMPA) and orthophosphate (PO) by surface-bound SO· and ·OH that continuously mineralize and dephosphorylate AMPA to generate small molecules and inorganic ions, such as HO and PO. The results of this work suggest that FeCeO/PMS could provide a potential candidate for efficiently removing organic compounds containing nitrogen or phosphorus from wastewater.