Phosphonic Oxide Research Articles

An electrochlorination process integrating enhanced oxidation of phosphonate to orthophosphate and elimination: Verification of matrix chloridion-induced oxidation mechanism

Phosphonate used as scale inhibitor is a non-negligible eutrophic contaminant in corresponding polluted waters. Besides, its conversion to orthophosphate (ortho-P) is a precondition for realizing bioavailable phosphorus recovery. Due to the feeble degradation efficiency with less than 30 % from classical Fenton commonly used in industrial wastewater treatment and itself vulnerable to strong inhibition interference of matrix chloride ions, we proposed an electrochemical approach to transform the native salt in the solution into oxidizing substances, sort of achieving beneficial utilization of matrix waste, and enhanced the ortho-P conversion rate of 1-Hydroxyethane-1,1-diphosphonic acid (HEDP) to 89.2 % (± 3.6 %). In electrochlorination system, it was found that HEDP rapidly complexed with Fe(II) and then coordinated in-situ Fe(III) to release free HEDP via intramolecular metal-ligand electron transfer reaction. The subsequent degradation mainly rooted in the oxidation of pivotal reactive species HClO, FeIVO2+ and 1O2, causing C-P and CC bonds to fracture in sequence. Eventually the organically bound phosphorus of HEDP was recovered as ortho-P. This study acquainted the audiences with the rare mechanism of chloridion-triggered HEDP degradation under electrochemical way, as well as offered a feasible technology for synchronous transformation of organically bound phosphorus to ortho-P and elimination from phosphonates.

Rapid acceleration of Cu(II)/peroxymonosulfate oxidation of phosphonate by hydroxylamine

Developing simple and effective activation approaches to degrade phosphonate is crucial due to its potential aquatic environmental risks. Recently, Cu(II)-mediated activation processes provide a feasible method via nonradical oxidation mechanism to remove phosphonate, but is yet challenged under neutral conditions. Herein, a strategy for enhancing the Cu(II)/peroxymonosulfate (PMS) process by adding hydroxylamine (HA) could efficiently degrade 1-hydroxyethane1,1-diphosphonic acid (HEDP) at pH = 7.0. After 15-min reaction, 85.7% of total phosphorus (TP) in HEDP transformed into PO43− in the Cu(II)/PMS/HA process is observed, which is 3.4 times than that in the Cu(II)/PMS process. The results of multiple experiments confirm that the presence of HA accelerates the reduction of Cu(II) and the generation of reactive species, SO4•− and Cu(III) induced intramolecular electron transfer as the primary reactive species play a significant role in the degradation of HEDP. Additionally, the removal of HEDP is inhibited with the addition of Cl− and HCO3− in the Cu(II)/PMS/HA process. However, the Cu(II)/PMS/HA process demonstrates a superior removal effectiveness of HEDP in different actual wastewater samples compared to the Cu(II)/PMS process under neutral conditions. This study provides an effective method for removing phosphonate from actual wastewater.

Phosphorus recovery from phosphonate-contaminated wastewater by nonthermal plasma treatment prior to adsorption on granular iron-coated sand

Phosphonate contamination of water resources has drawn much attention. Advanced oxidation combined with phosphorus recovery is considered as a promising solution, but the development of a cost-efficient process remains challenging. This work demonstrates an effective two-step process including a plasma-based oxidation of phosphonate, followed by phosphate adsorption on granular iron-coated sand (ICS). In the first step, a tandem reactor configuration, which consists of a dielectric barrier discharge (DBD) plasma chamber and an ozonation chamber, was used to transform 1-hydroxyethane-1,1-diphosphonic acid (HEDP) to Ortho-phosphate (Ortho-P). When lava rock was added as a packing material in the ozonation chamber, the Ortho-P production was enhanced by 10–35%, due to an increased exposure of reactive species (O3,OH and O2•-) by 120%, 20% and 30%, respectively. The use of O2 as carrier gas in the plasma reactor resulted in the highest Ortho-P production efficiency (86%), followed by Ar (48%), N2 (21%) and air (13%). Humic acids present in the wastewater can compete with phosphonates for reactive species, decreasing the Ortho-P production efficiency by 30%. In the second step, ICS granules were used to adsorb the produced Ortho-P. The final recovery efficiency of Ortho-P from synthetic and real textile wastewater was 85% and 53%, respectively. The treatment performance of this novel two-step process is better compared to that of ozone-based AOPs, while the associated operational treatment costs are still somewhat higher. This indicates that optimizing energy consumption is still the biggest challenge for further industrial applications of nonthermal plasma-based AOPs.

Self-Enhanced Selective Oxidation of Phosphonate into Phosphate by Cu(II)/H2O2: Performance, Mechanism, and Validation.

Phosphonate is an important category of highly soluble organophosphorus in contaminated waters, and its oxidative transformation into phosphate is usually a prerequisite step to achieve the in-depth removal of the total phosphorus. Currently, selective oxidation of phosphonate into phosphate is urgently desired as conventional advanced oxidation processes suffer from severe matrix interferences. Herein, we employed 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) as a model phosphonate and demonstrated its efficient and selective oxidation by the Cu(II)/H2O2 process at alkaline pH. In the presence of trace Cu(II) (0.020 mM), 90.8% of HEDP (0.10 mM) was converted to phosphate by H2O2 in 30 min at pH 9.5, whereas negligible conversion was observed by UV/H2O2 or a Fenton reaction (pH = 3.0). The oxidation of HEDP by Cu(II)/H2O2 was insignificantly affected by natural organic matters (10.0 mg TOC/L) and various anions including chloride, sulfate, and nitrate (10.0 mM). The complexation of Cu(II) with HEDP coupling Cu(III) produced in situ enabled an intramolecular electron transfer process, which features high selective oxidation. Selective degradation of HEDP was further validated by adding stoichiometric H2O2 into an industrial effluent, where the existing Cu(II) could serve as the catalyst. This study also provides a successful case to trigger selective oxidation of trace pollutants of concern upon synergizing with the nature of the contaminated water.

Directed Multistep Biocatalysis for the Synthesis of the Polyketide Oxytetracycline in Permeabilized Cells of Escherichia coli

We report on tailored regeneration modules for the essential cofactors ATP and NADPH as well as for SAM supply, adapted to support biocatalytic multistep synthesis of oxytetracycline (OTC) in permeabilized cells of E. coli. ATP is regenerated from ADP and AMP by the use of polyphosphate. The efficiency of this system was proven with permeabilized cells producing flaviolin. NADPH is regenerated from NADP+ by oxidation of phosphonate. A constant level of 0.7 mg/L of SAM is provided by the ligation of ATP and methionine. OTC is synthesized at a rate of 2.05 ng/(h (g of the combined biocatalyst)), reaching a final concentration of 0.9 mg/L.

Corrigendum: Fluorescent Mimetics of CMP-Neu5Ac Are Highly Potent, Cell-Permeable Polarization Probes of Eukaryotic and Bacterial Sialyltransferases and Inhibit Cellular Sialylation

In this Communication, reference compound 1-Ac and intermediate 5-p were used. While both compounds were reported initially in reference 12b as cited, the detailed experimental protocols and spectroscopic data were published subsequently in reference 12c, which has to be added. The application of chiral oxaziridines for the stereoselective oxidation of phosphonates was published originally in reference 15a as cited. The method has been applied to allyl phosphonates in another reference 15b, which has to be added. References 12 and 15 should read as follows:

New chiral P-ligands: P-amino- and P-cycloalkoxy dibenzo[ c. e][1,2]oxaphosphorines

The reaction of racemic chloro-dibenzo[ c. e][1,2]oxaphosphorine with ( S)-(−)-α-methyl-benzylamine and (1 R,2 S,5 R)-(−)-menthol led to a mixture of optically active diastereomers of the corresponding phosphonous derivatives. The isomers were separated in a diastereomeric excess of 71–93% at the phosphonic oxide and/or at the phosphonous borane stage. The P(III) boranes are suitable precursors of the P-ligands. The absolute P-configuration in one of the menthyl phosphonates isolated was determined by single crystal X-ray analysis.

Two C-P lyase operons in Pseudomonas stutzeri and their roles in the oxidation of phosphonates, phosphite, and hypophosphite.

DNA sequencing and analysis of two distinct C-P lyase operons in Pseudomonas stutzeri WM88 were completed. The htxABCDEFGHIJKLMN operon encodes a hypophosphite-2-oxoglutarate dioxygenase (HtxA), whereas the predicted amino acid sequences of HtxB to HtxN are each homologous to the components of the Escherichia coli phn operon, which encodes C-P lyase, although homologs of E. coli phnF and phnO are absent. The genes in the htx operon are cotranscribed based on gene organization, and the presence of the intergenic sequences is verified by reverse transcription-PCR with total RNA. Deletion of the htx locus does not affect the ability of P. stutzeri to grow on phosphonates, indicating the presence of an additional C-P lyase pathway in this organism. To identify the genes comprising this pathway, a Deltahtx strain was mutagenized and one mutant lacking the ability to grow on methylphosphonate as the sole P source was isolated. A ca.-10.6-kbp region surrounding the transposon insertion site of this mutant was sequenced, revealing 13 open reading frames, designated phnCDEFGHIJKLMNP, which were homologous to the E. coli phn genes. Deletion of both the htx and phn operons of P. stutzeri abolishes all growth on methylphosphonate and aminoethylphosphonate. Both operons individually support growth on methylphosphonate; however, the phn operon supports growth on aminoethylphosphonate and phosphite, as well. The substrate ranges of both C-P lyases are limited, as growth on other phosphonate compounds, including glyphosate and phenylphosphonate, was not observed.

Manganese-catalyzed degradation of phosphonic acids

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.

Uptake and utilisation of phosphonate ions by Phytophthora citrophthora and Nectria haematococca in relation to their selective toxicity

AbstractPhosphonate ions, which are degradation products of aluminium tris‐O‐ethyl phosphonate (fosetyl‐aluminium) in plant tissues, had more effect in vitro against Phytophthora citrophthora than against Nectria haematococca.Both fungi were able to take up phosphonate ions. This uptake was realised against a concentration gradient and was affected by metabolic inhibitors. When examined over a 0.5 to 6.0 mm concentration range, phosphonate was carried by a single transport process obeying Michaelis‐Menten kinetics, with a low affinity (high K′m). Further analysis by means of Hofstee plots indicated a somewhat faster phosphonate uptake by N. haematococca than by P. citrophthora, so it appears clearly that uptake was not involved in the selective toxicity of this compound.The continuous uptake of phosphonate by N. haematococca is correlated with an important utilisation of this ion by the fungal cells. This fact could be explained by a detoxification process corresponding to the oxidation of phosphonate to phosphate which could account for the low sensitivity of this fungus.Phosphonate uptake by P. citrophthora reached a maximum level after 20 min and then decreased to a constant level over the following period. During the incubation period phosphonate was incorporated directly without oxidation into phosphate. This incorporation could lead to a disturbance of the cell metabolism.

Recherches sur la formation et la transformation des esters XLIV. Sur l'action de l'oxyde phénylphosphonique sur des alcools non saturés, des hydroxy‐éthers, des alcools cycliques et le phénol

AbstractEthenic alcohols, ethynic tertiary alcohols, hydroxy ethers, cyclic alcohols, araliphatic alcohols, and phenol react very easily with phenyl phosphonic oxide to yield the corresponding phosphonic monoesters.

Recherches sur la formation et la transformation des esters XL. Sur la phosphonylation d'alcools divers par l'oxyde p‐fluorophénylphosphonique

Abstractp‐Fluorophenyl phosphonic oxide reacts with different type of alcohols, and with tertiary alcohols in the presence of a tertiary base, to yield the corresponding p‐fluorophenyl phosphonic monoesters.