Efficient degradation of organic phosphorus in glyphosate wastewater by catalytic wet oxidation using modified activated carbon as a catalyst.
Glyphosate (PMG) wastewater, which is an organic phosphorus (OP) wastewater containing 200-3000 mg/L PMG, was treated via catalytic wet oxidation (CWO) to degrade PMG to orthophosphate ([Formula: see text]). The catalysts were activated carbons (ACs) modified by H2O2oxidation and thermal treatment with ammonia or melamine. The catalysts were characterized using N2adsorption/desorption, Boehm titration, and X-ray photoelectron spectroscopy. The CWO experiments were performed in a co-current upflow fixed-bed reactor at 110-130°C and under 1.0 MPa. The AC modified by H2O2and melamine had the highest catalytic activity and had excellent stability in the continuous 55-day test: 100% PMG removal and over 93% OP removal for different samples of real PMG wastewater. More pyrrolic nitrogen, pyridinic nitrogen, and graphitic nitrogen along with quinone oxygen functional groups on the surface of the AC showed higher catalytic activity according to linear fitting results. The identiﬁcation and quantiﬁcation of critical reaction intermediaries and the main end products of PMG degradation were possible, and a degradation pathway was proposed.
a Chengdu Institute of Organic Chemistry , Chinese Academy of Sciences , Chengdu , People's Republic of China.|b University of Chinese Academy of Sciences , Beijing , People's Republic of China.
Bo
B
Xing
a Chengdu Institute of Organic Chemistry , Chinese Academy of Sciences , Chengdu , People's Republic of China.
Honglin
http://orcid.org/0000-0002-2762-7589
H
Chen
a Chengdu Institute of Organic Chemistry , Chinese Academy of Sciences , Chengdu , People's Republic of China.
Xiaoming
X
Zhang
D002244:Carbon; D002384:Catalysis; D005998:Glycine / Q000031:analogs & derivatives; D006861:Hydrogen Peroxide; D010084:Oxidation-Reduction; D010758:Phosphorus / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D062065:Wastewater; D000097797:Glyphosate
D002244:Carbon; D005998:Glycine; D006861:Hydrogen Peroxide; D010758:Phosphorus; D062065:Wastewater; D000097797:Glyphosate
Glyphosate; catalytic wet oxidation; nitrogen-doped activated carbon; organic phosphorus; orthophosphate