Manganese-catalyzed degradation of phosphonic acids

Abstract

The non-biodegradable and chemically very stable phosphonates are used in a variety of industrial applications including cooling waters, oil production and textile industry. We show here that they are degraded in the presence of Mn(II) and oxygen. The half-life for the reaction is 9 min near neutral pH. The presence of other cations such as Ca(II) and Zn(II) considerably slows down the reaction by competition with Mn(II) for the phosphonate. The reaction involves the oxidation of complexed Mn(II) by oxygen to Mn(III) and the subsequent oxidation of phosphonate by Mn(III) thus yielding two stable phosphonic acid breakdown products. The oxidation also proceeds in the presence of the mineral manganite (Mn(III)OOH), and yields the same breakdown products. The use of a newly developed chromatographic method revealed the presence of the breakdown products in wastewater. The results show that manganese-catalyzed oxidation might be an important pathway for phosphonate degradation in natural waters.

Facile controlled preparation of phosphonic acid-functionalized gold nanoparticles

“…In the previous works, some investigations have indicated EDTMP could be oxidized to hydroxymethylene-phosphonic acid (HMP, shown in Scheme 1B), aminomethylene-phosphonic acid (AMP, shown in Scheme 1B) and iminodi(methylene-phosphonic acid) (IDMP, shown in Scheme 1B) in the presence of molecular oxygen and ozone [32][33][34]. Similarly, after HAuCl 4 is reduced by EDTMP, these oxidation products of EDTMP (i.e.…”

Phosphonic acid: preparation and applications

“…The bond angles at the phosphorus atom are ranging from 103.46(8)° to 112.86(7)° for methylphosphonic acid, indicating a distorted tetrahedral geometry around the phosphorus [ 9 ]. This function is very stable but under some oxidative conditions (e.g., Mn(II) with O 2 ) the rupture of the P–C bond can occur to produce phosphate [ 10 ]. The phosphonic acid function possesses two acidic protons featuring, for instance, when R is an aromatic moiety, a first p K a ranging from 1.1 to 2.3 and the second acidity which features a p K a ranging from 5.3 to 7.2 [ 11 ].…”

Humid Air Plasma Treatment of Birnessite Surface: Application to the Removal of Cochineal Red

“…Birnessite (Mn 7 O 13 •5H 2 O) contains manganese with two degrees of oxidation (Mn 4+ and Mn 3+ ) but Mn 4+ most oxidizing species which is supposed to react preferentially with pollutants [10]. In general, organic pollutants react with the manganese oxides via Mn(IV) ions which are reduced to Mn(II) in one step [27]- [29] or via a compound Mn(III) [30]. The determination of the average oxidation degree of manganese allows as to evaluate the Mn(III)/Mn(VI) of the different forms of manganese existing in the sheets of thin layers of birnessite.…”