31P NMR Investigations on Roundup Degradation by AOP Procedures

Abstract

The reactions of (N-(PhosphonoMethyl)Glycine) PMG with H2O2 in homogenous systems were investigated using 31P NMR (Nuclear Magnetic Resonance). These reactions were carried out in two reaction modes: without UV radiation and under UV radiation. The reactions of PMG with H2O2 without UV radiation were carried out in two modes: the degradations of PMG (0.1 mmol) by means of 5–10 molar excess of hydrogen dioxide (PMG-H2O2 = 1:5 and 1:10) and the degradation of PMG (0.1 mmol) in homogenous Fenton reactions (PMG-H2O2-Fe2+ = 1:10:0.05 and 1:10:0.1). All reactions were carried out at ambient temperature, at pH 3.5, for 48 h. The reactions of PMG (in Roundup herbicide composition, 12 mmol) with H2O2 under UV radiation (254 nm) were carried out using 5 × molar excess of H2O2 (60 mmol), in the pH range of 2 ≤ pH ≤ 12, for 6 h. In this mode of PMG oxidation, the splitting of C-P was observed in the ratios dependent on the applied pH of the reaction mixture.

Photocatalytic Hydrogels with a High Transmission Polymer Network for Pollutant Remediation

“…NMR analysis further indicates the existence of an intermediate at 19.3 ppm, which is likely to be (aminomethyl)phosphonic acid. 72 To investigate the time-dependent degradation, kinetic measurement of the photodegradation of glyphosate was conducted via 31 P NMR spectroscopy, where a near-linear degradation of glyphosate was observed (Figures 2b and S30). Previously, degradation has been achieved using TiO 2 nanoparticles in a photoreactor.…”

“…The reaction progression was analyzed via 31 P NMR with a glyphosate shift of 16.9 ppm, and the main degradation product, phosphate, emerges at 2.5 ppm. NMR analysis further indicates the existence of an intermediate at 19.3 ppm, which is likely to be (aminomethyl)­phosphonic acid . To investigate the time-dependent degradation, kinetic measurement of the photodegradation of glyphosate was conducted via 31 P NMR spectroscopy, where a near-linear degradation of glyphosate was observed (Figures b and S30).…”

Decomposition of glyphosate in water by peroxymonosulfate activated with CuCoFe‐LDH material

“…At higher pH, glyphosate exists in the major forms of H2L -(pH 3.5), HL 2-(pH = 7), HL 2and L 3-, (pH 9-11), and L 3-(pH ≥ 12). [32] Hence, solution pH affects the adsorption and decomposition of glyphosate on the surface of the catalyst, as demonstrated in figure 7. Figure 7 depicts a strong effect of initial pH on glyphosate decomposition.…”