Simultaneous removal of antibiotic resistance genes and improved dewatering ability of waste activated sludge by Fe(II)-activated persulfate oxidation.

Waste activated sludge properties vary widely with different regions due to the difference in living standards and geographical distribution, making a big challenge to developing a universally effective sludge dewatering technique. The Fe(II)-activated persulfate (S2O82-) oxidation process shows excellent ability to disrupt sludge cells and extracellular polymeric substances (EPS), and release bound water from sludge flocs. In this study, the discrepancies in the physicochemical characteristics of sludge samples from seven representative cities in China (e.g., dewaterability, EPS composition, surface charge, microbial community, relative abundance of antibiotic resistance genes (ARGs), etc.) were investigated, and the role of Fe(II)-S2O82- oxidation in enhancing removal of antibiotic resistance genes and dewatering ability were explored. The results showed significant differences between the EPS distribution and chemical composition of sludge samples due to different treatment processes, effluent sources, and regions. The Fe(II)-S2O82- oxidation pretreatment had a good enhancement of sludge dewatering capacity (up to 76 %). Microbial analysis showed that the microbial community in each sludge varied significantly depending on the types of wastewater, the wastewater treatment processes, and the regions, but Fe(II)-S2O82- oxidation was able to attack and rupture the sludge zoogloea indiscriminately. Genetic analysis further showed that a considerable number of ARGs were detected in all of these sludge samples and that Fe(II)-S2O82- oxidation was effective in removing ARGs by higher than 90 %. The highly active radicals (e.g., SO4-·, ·OH) produced in this process caused drastic damage to sludge microbial cells and DNA stability while liberating the EPS/cell-bound water. Co-occurrence network analysis highlighted a positive correlation between population distribution and ARGs abundance, while variations in microbial communities were linked to regional differences in living standards and level of economic development. Despite these variations, the Fe(II)-S2O82- oxidation consistently achieved excellent performance in both ARGs removal and sludge dewatering. The significant modularity of associations between different microbial communities also confirms its ability to reduce horizontal gene transfer (HGT) by scavenging microbes.

Quantitative Assessment of Ligand Substituent Effects on σ- and π-Contributions to Fe-N Bonds in Spin Crossover FeII Complexes.

The effect of para-substituent X on the electronic structure of sixteen tridentate 4-X-(2,6-di(pyrazol-1-yl))-pyridine (bppX ) ligands and the corresponding solution spin crossover [FeII (bppX )2 ]2+ complexes is analysed further, to supply quantitative insights into the effect of X on the σ-donor and π-acceptor character of the Fe-NA (pyridine) bonds. EDA-NOCV on the sixteen LS complexes revealed that neither ΔEorb,σ+π (R2 =0.48) nor ΔEorb,π (R2 =0.31) correlated with the experimental solution T1/2 values (which are expected to reflect the ligand field imposed on the iron centre), but that ΔEorb,σ correlates well (R2 =0.82) and implies that as X changes from EDG→EWG (Electron Donating to Withdrawing Group), the ligand becomes a better σ-donor. This counter-intuitive result was further probed by Mulliken analysis of the NA atomic orbitals: NA (px ) involved in the Fe-N σ-bond vs. the perpendicular NA (pz ) employed in the ligand aromatic π-system. As X changes EDG→EWG, the electron population on NA (pz ) decreases, making it a better π-acceptor, whilst that in NA (px ) increases, making it a better σ-bond donor; both increase ligand field, and T1/2 as observed. In 2016, Halcrow, Deeth and co-workers proposed an intuitively reasonable explanation of the effect of the para-X substituents on the T1/2 values in this family of complexes, consistent with the calculated MO energy levels, that M→L π-backdonation dominates in these M-L bonds. Here the quantitative EDA-NOCV analysis of the M-L bond contributions provides a more complete, coherent and detailed picture of the relative impact of M-L σ-versus π-bonding in determining the observed T1/2 , refining the earlier interpretation and revealing the importance of the σ-bonding. Furthermore, our results are in perfect agreement with the ΔE(HS-LS) vs. σp + (X) correlation reported in their work.

Nonionic detergent micelle aggregates: An economical alternative to protein A chromatography.

We have recently described a non-chromatographic, ligand-free approach for antibody (Ab) purification based on specially designed [Tween-20:bathophenanthroline:Fe2+] aggregates. To assess the potential generality of this approach, a variety of detergents belonging to four nonionic detergent families (Tween, Brij, Triton and Pluronic) have now been studied. All surfactant aggregates led to high purity of the recovered Ab's (>95 %, by gel densitometry). Good overall Ab recovery yields were observed with Tween-20 (80-83 %), Brij-O20 (85-87 %) and Triton X-100 (87-90 %), while Pluronic F-127 was less efficient (42-53 %). Of additional importance is the finding that the process was performed by filtration rather than centrifugation, thereby allowing a continuous purification mode that led to the recovery of monomeric IgG, as determined by dynamic light scattering and preservation of Ab specificity as measured by ELISA. The amphiphilic chelator, bathophenanthroline (batho) was recycled almost quantitatively (95 %) by crystallization. Good IgG recovery yields of ∼80 % were also observed when Ab concentrations were increased from 1 mg/mL to 3-5 mg/mL. Potential advantages of the purification platform for industrial downstream processing of therapeutic monoclonal antibodies, are discussed.

A low-cost solvent-free method to synthesize α-Fe2O3 nanoparticles with applications to degrade methyl orange in photo-fenton system.

Hematite nanoparticles (α-Fe2O3 NPs) were successfully synthesized by a low-cost solvent-free reaction using Ferrous sulfate waste (FeSO4·7H2O) and pyrite (FeS2) as raw materials and employed for the decolorization of Methyl Orange by the photo-Fenton system. The properties of α-Fe2O3 NPs before and after photo-Fenton reaction were characterized by X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectrum and X-ray photoelectron spectroscopy (XPS), and the optical properties of α-Fe2O3 NPs were analyzed by UV-vis diffuse reflectance spectra (UV-vis DRS) and Photoluminescence (PL) spectra. The analytic results showed that the as-formed samples having an average diameter of ~50 nm exhibit pure phase hematite with sphere structure. Besides, little differences were found by comparing the characterization data of the particles before and after the photo-Fenton reaction, indicating that the photo-Fenton reaction was carried out in solution rather than on the surface of α-Fe2O3 NPs. A 24 central composite design (CCD) coupled with response surface methodology (RSM) was applied to evaluate and optimize the important variables. A significant quadratic model (P-value<0.0001, R2 = 0.9664) was derived using an analysis of variance (ANOVA), which was adequate to perform the process variables optimization. The optimal process conditions were performed to be 395 nm of the light wavelength, pH 3.0, 5 mmol/L H2O2 and 1 g/L α-Fe2O3, and the decolorization efficiency of methyl orange was 99.55% at 4 min.

Arsenic Contamination in Rice Grown Under Anaerobic Condition in Arid Agriculture: Assessment and Remediation.

Arsenic (As) concentrations in fine (2) and coarse (3) rice varieties belonging to Hafizabad, Gujranwala and Sheikhupura districts was assessed initially by means of field survey, followed by pot experiments. Bulk soil samples collected from same rice districts (Hafizabad and Gujtanwala) were spiked with As (0, 10, 20 mg kg-1) and each was amended with iron sulphate (0, 25, 50 g kg-1) to investigate their effect on plant growth and uptake under anaerobic conditions. Survey results revealed that mainly fine long grain (Super Basmati and KSK 515) and coarse long grain (Basmati 386 and Kainat) rice varieties were grown in the area. Overall, 16% rice grain samples were above the recommended permissible limit (RPL) of 300 mg kg-1. Among varieties, 24% grain samples of coarse and 12% of fine varieties had As concentration above the RPL. Results of pot experiments showed a significant decrease in straw and grain yield and increase in As concentration with increasing rates of As spiking. Paddy yield increased significantly when As spiked soils were amended with iron sulfate; and opposite was true for As concentration.

Technology for Triple Fortification of Salt with Folic Acid, Iron, and Iodine.

As many of the maternal and child health complications result from folic acid, iron, and iodine deficiencies; it makes sense to combat these simultaneously. We have developed cost-effective technology to deliver these three micronutrients simultaneously through salt. Our goal was to retain at least 70% of the micronutrients during 6 months of storage. The fortified salt was formulated by spraying a solution that contained 2% iodine and 0.5% or 1% folic acid onto salt and adding encapsulated ferrous fumarate. The formulated triple fortified salt contained 1,000 ppm iron, 50 ppm iodine, and 12.5 or 25 ppm folic acid. The spray solution and the salt were stored for 2 and 6 months respectively at 25, 35, and 45 °C 60 to 70% relative humidity. Even at 45 °C, over 70% of both iodine and folic acid were retained in the salt. The best formulation based on the color of the salt and stability of iodine and folic acid contained 12.5 ppm folic acid, 50 ppm iodine, and 1,000 ppm iron. These results indicate that iron, iodine, and folic acid can be simultaneously delivered to a vulnerable population through salt using the technology described. Also, the quality control of the process can be developed around pteroic acid that was detected as a primary degradation product of folic acid. PRACTICAL APPLICATION: The technology developed is already transferred to India for industrial scale up. When fully operational, the technology will simultaneously solve iron, iodine, and folic acid deficiencies in vulnerable populations at a very low cost.

Assessment of the antitumor activity of a cyclopalladated ferrocene compound assisted by a dual-targeting drug delivery system.

One cyclopalladated ferrocene compound CP was synthesized, which showed a good cell cytotoxicity. Assisted by a dual-targeting drug delivery system, the anticancer activity of CP to MDA-MB-468 remained unchanged, but the toxicity to non-tumorigenic cell line NIH3T3 was remarkably reduced. This provided a new path for the development of cyclopalladated ferrocene as an antitumor drug candidate.

A novel Fe(II)-Ca synergistic phosphorus removal process: process optimization and phosphorus recovery.

Phosphorus removal from wastewater is an important means to control eutrophication and to recover phosphorus from wastewater. In this study, a novel Fe(II)-Ca synergistic phosphorus removal process is developed using the complex of ferrous and calcium salts. The results showed that ferrous and calcium had an antagonistic effect at Fe(II)/Ca molar ratio of lower than 1:4, but a synergistic effect at Fe(II)/Ca molar ratio of higher than 1:4, with the strongest synergistic effect at Fe(II)/Ca molar ratio of 7:3. The optimal parameters of this novel process were as follows: Fe(II)/Ca = 3:1, ferrous-calcium complex/phosphorous (M/P) ≥ 1.5:1, pH = 7.0-8.0, and fast mixing speed (FMS) = 100-150 rpm. The cost of phosphorus removal agents was US$1.024 (kg P)-1, reduced by 30.39% compared with that of the traditional phosphorus removal process. The phosphorus content (by P2O5) in the precipitate produced in the new process was 32.70%, which had a high recycling value.

Some new nano-sized Cr(III), Fe(II), Co(II), and Ni(II) complexes incorporating 2-((E)-(pyridine-2-ylimino)methyl)napthalen-1-ol ligand: Structural characterization, electrochemical, antioxidant, antimicrobial, antiviral assessment and DNA interaction.

To estimate the biological preference of synthetic small drugs towards DNA target, new metal based chemotherapeutic agents of nano-sized Cr(III), Fe(II), Co(II) and Ni(II) Schiff base complexes having N,N,O donor system were synthesized and thoroughly characterized by physic-chemical techniques. The redox behavior of the Cr(III), Fe(II) and Co(II) complex was investigated by electrochemical method using cyclic voltammetry. IR results proven that the tridentate binding of Schiff base ligand with metal center during complexation reflects the proposed structure. Magnetic and spectroscopic data give support to octahedral geometry for Cr(III) and Fe(II) complexes and tetrahedral geometry for Ni(II) and Co(II) complexes. The activation thermodynamic parameters, such as, E(⁎), ΔH(⁎), ΔS(⁎) and ΔG(⁎) are calculated using Coats-Redfern method by analyzing the TGA data. The particle size of the investigated metal complexes was estimated by TEM. In addition to, the interaction of the nanosized complexes with CT-DNA was estimated by electronic absorption, viscosity and gel electrophoresis. These techniques revealed that the complexes could bind to CT-DNA through intercalation mode. Moreover, the in vitro cytotoxic and antiviral activities of the nanosized complexes were checked against Herpes Simplex virus and Tobacco Mosaic viruses. Moreover, investigation of antioxidant activities of the new nanosized compounds was done by ABTS assay. Among the compounds tested, Fe(II) complex showed the strongest potent radical scavenging activity with percent of 58.60%. Furthermore, the antimicrobial bustle of the prepared compounds was screened against different types of bacteria and fungi and the results show that all metal complexes have superior activity than its free ligand.

Macroscopic and Spectroscopic Assessment of the Cosorption of Fe(II) with As(III) and As(V) on Al-Oxide.

The cosorption of Fe(II) with As(III) and As(V) in anoxic suspensions of γ-Al2O3 at pH 7.5 was investigated with batch kinetic experiments and synchrotron EXAFS analyses. Single-sorbate results showed that Fe(II) formed secondary Fe(II)-Al(III)-layered double hydroxide (LDH) phases during reaction with the Al-oxide sorbent, whereas As(III) and As(V) formed inner-sphere surface complexes. The kinetics and mechanisms of Fe(II) and As(III) sorption were identical in dual-sorbate and single-sorbate experiments, indicating that the processes involved operate independently. In contrast, As(V) and Fe(II) interacted strongly during cosorption. Fe(II) enhanced the rate and extent of As(V) removal from solution, but did not affect the mechanism of As(V) adsorption. Conversely, As(V) hindered the formation of Fe(II)-Al(III)-LDH, slowing down precipitation at low As(V) concentrations and preventing it at high concentrations. This was attributed to interference of adsorbed As(V) with the Al supply needed for Fe(II)-Al(III)-LDH precipitation, possibly combined with enhanced surface complexation of Fe(II) cations promoted by anionic As(V) surface species. No evidence was found for redox reactions between Fe(II) and As(V) or As(III), or for precipitation of Fe-arsenic phases. These results improve our understanding of the geochemistry of Fe(II) and arsenic in reducing environments, and demonstrate the utility of mechanistic studies on geochemically complex model systems.

Assessment of ferrous chloride and Portland cement for the remediation of chromite ore processing residue.

Chromite Ore Processing Residue (COPR) is an industrial waste containing up to 7% chromium (Cr) including up to 5% hexavalent chromium [Cr(VI)]. The remediation of COPR has been challenging due to the slow release of Cr(VI) from a clinker like material and thereby the incomplete detoxification of Cr(VI) by chemical reagents. The use of sulfur based reagents such as ferrous sulfate and calcium polysulfide to detoxify Cr(VI) has exasperated the swell potential of COPR upon treatment. This study investigated the use of ferrous chloride alone and in combination with Portland cement to address the detoxification of Cr(VI) in COPR and the potential swell of COPR. Chromium regulatory tests, X-ray powder diffraction (XRPD) analyses and X-ray absorption near edge structure (XANES) analyses were used to assess the treatment results. The treatment results indicated that Cr(VI) concentrations for the acid pretreated micronized COPR as measured by XANES analyses were below the New Jersey Department of Environmental Protection (NJDEP) standard of 20 mg kg(-1). The Toxicity characteristic leaching procedure (TCLP) Cr concentrations for all acid pretreated samples also were reduced below the TCLP regulatory limit of 5 mg L(-1). Moreover, the TCLP Cr concentration for the acid pretreated COPR with particle size ⩽0.010 mm were less than the universal treatment standard (UTS) of 0.6 mg L(-1). The treatment appears to have destabilized all COPR potential swell causing minerals. The unconfined compressive strength (UCS) for the treated samples increased significantly upon treatment with Portland cement.

Calorimetric assessment of Fe(2+) binding to α-ketoglutarate/taurine dioxygenase: ironing out the energetics of metal coordination by the 2-His-1-carboxylate facial triad.

The thermodynamic properties of Fe(2+) binding to the 2-His-1-carboxylate facial triad in α-ketoglutarate/taurine dioxygenase (TauD) were explored using isothermal titration calorimetry. Direct titrations of Fe(2+) into TauD and chelation experiments involving the titration of ethylenediaminetetraacetic acid into Fe(2+)-TauD were performed under an anaerobic environment to yield a binding equilibrium of 2.4 (±0.1) × 10(7) (Kd = 43 nM) and a ΔG° value of -10.1 (±0.03) kcal/mol. Further analysis of the enthalpy/entropy contributions indicates a highly enthalpic binding event, where ΔH = -11.6 (±0.3) kcal/mol. Investigations into the unfavorable entropy term led to the observation of water molecules becoming organized within the Fe(2+)-TauD structure.

Role of indigenous iron in improving sludge dewaterability through peroxidation.

Improvement of sludge dewaterability is important for reducing the total costs for the treatment and disposal of sludge in wastewater treatment plants. In this study, we investigate the use of hydrogen peroxide as an oxidizing reagent for the conditioning of waste activated sludge. Significant improvement to sludge dewaterability was attained after the addition of hydrogen peroxide at 30 mg/g TS and 28 mg/g TS under acidic conditions (pH = 3.0), with the highest reduction of capillary suction time being 68% and 56%, respectively, for sludge containing an iron concentration of 56 mg Fe/g TS and 25 mg Fe/g TS, respectively. The observations were due to Fenton reactions between the iron contained in sludge (indigenous iron) and hydrogen peroxide. For the sludge with an insufficient level of indigenous iron, the addition of ferrous chloride was found to be able to improve the sludge dewaterability. The results firstly indicated that indigenous iron can be utilized similarly as the externally supplied iron salt to improve sludge dewaterability through catalyzing the Fenton reactions.

Factors influencing sorption of ciprofloxacin onto activated sludge: experimental assessment and modelling implications.

Many of the pharmaceuticals and personal care products occurring in municipal sewage are ionizing substances, and their partitioning behaviour is affected by ionic interactions with solid matrices. In activated sludge systems, such interactions have currently not been adequately understood and described, particularly for zwitterionic chemicals. Here we present an assessment of the effects of pH and iron salt dosing on the sorption of ciprofloxacin onto activated sludge using laboratory experiments and full-scale fate modelling. Experimental results were described with Freundlich isotherms and showed that non-linear sorption occurred under all the conditions tested. The greatest sorption potential was measured at pH=7.4, at which ciprofloxacin is speciated mostly as zwitterion. Iron salt dosing increased sorption under aerobic and, to a lesser extent, anoxic conditions, whereas no effect was registered under anaerobic conditions. The activated sludge model for xenobiotics (ASM-X) was extended with Freundlich-based sorption kinetics and used to predict the fate of ciprofloxacin in a wastewater treatment plant (WWTP). Scenario simulations, using experimental Freundlich parameters, were used to identify whether the assessed factors caused a significant increase of aqueous ciprofloxacin concentration in full-scale bioreactors. Simulation results suggest that a pH increase, rather than a reduction in iron salt dosing, could be responsible for a systematic deterioration of sorption of ciprofloxacin in the WWTP.

Mineralization of wastewater from the pharmaceutical industry containing chloride ions by UV photolysis of H2O2/Fe(II) and ultrasonic irradiation.

The mineralization of pharmaceutical wastewater containing chloride ions using a UV/H2O2/Fe(II) process was studied. The addition of Fe(II) to the UV/H2O2 system did not improve the degradation efficiency due to inhibition of the photo-Fenton reaction, at acid pH, in the presence of chloride ions in these wastewaters. The increase of pH from 2 to 7 increased the degree of mineralization under UV photolysis of H2O2 because more HO radicals are available by HOCl dissociation reaction. Under the selected operation conditions ([H2O2]o = 11,500 ppm, [Fe(II)] = 0 ppm, [TOC]o = 125 ppm and pH = 7), 100% of TOC removal was attained in 120 min. A significant synergistic effect of combining photolysis (UV/H2O2) and sonolysis was observed. Sonophotolysis (UV/H2O2/ultrasound) technique significantly increased the degree of mineralization (100% TOC removal in 90 min using 6500 ppm H2O2) when compared with each individual process. Sonochemical reaction was favored by the presence of chloride ions since the concentration of contaminants at the gas-liquid interface increased. Free radicals reaction was the controlling mechanism in the UV/H2O2/ultrasound system. HO radicals were the main oxidative intermediate species in the process, although hydroperoxyl radicals (HO2) also played a role. The contribution of thermal-pyrolytic reaction (in gas-phase) to sonophotolysis process was negligible.

Highly specific and sensitive non-enzymatic determination of uric acid in serum and urine by extended gate field effect transistor sensors.

A potentiometric non-enzymatic sensor using off-chip extended-gate field effect transistor (EGFET) with a ferrocenyl-alkanethiol modified gold electrode is demonstrated for determining the uric acid concentration in human serum and urine. Hexacyanoferrate (II) and (III) ions are used as redox reagent. This potentiometric sensor measures the interface potential on the ferrocene immobilized gold electrode, which is modulated by the redox reaction between uric acid and hexacyanoferrate ions. The device shows a near Nernstian response to uric acid and is highly specific. The interference that comes from glucose, bilirubin, ascorbic acid and hemoglobin is negligible in normal concentration range of these interferents. The sensor also exhibits excellent long term reliability. This extended gate field effect transistor based sensors can be used as a point of care UA testing tool, due to the small size, low cost, and low sample volume consumption.

Numerical study of magnetic and pairing correlation in a bilayer triangular lattice.

By using the determinant Quantum Monte Carlo method, the magnetic and pairing correlation of the NaxCoO2⋅yH2O system are studied within the Hubbard model on a bilayer triangular lattice. The temperature dependence of the spin correlation function and pairing susceptibility with several kinds of symmetries at different electron fillings and interlayer coupling terms are investigated. It is found that the system shows antiferromagnetic correlation around half filling, and the fn-wave pairing correlation dominates over other kinds of pairing symmetry in the low doping region. As the electron filling decreases from half filling, both ferromagnetic correlation and the f-wave pairing susceptibility are enhanced and tend to dominate. It is also shown that both the magnetic susceptibility and pairing susceptibility decrease as the interlayer coupling increases.

The facile assembly of bis-, tris- and poly(triazaphosphole) systems using "click" chemistry.

Uncatalysed 1,3-dipolar cycloaddition reactions between two phosphaalkynes, P≡CR (R = Bu(t) or Me), and a series of di-, tri- and poly-azido precursor compounds have given very high yields of a range of triazaphosphole substituted systems. These comprise the 1,1'-bis(triazaphosphole)ferrocenes, [Fe{C5H4(N3PCR)}2], the tris(triazaphosphole)cyclohexane, cis-1,3,5-C6H9(N3PCBu(t))3, and the poly(allyltriazaphosphole)s, {C3H5(N3PCR)}∞. Electrochemical studies on the 1,1'-bis(triazaphosphole)ferrocenes reveal the compounds to undergo reversible 1-electron oxidation processes, at significantly more positive potentials than ferrocene itself. Attempts to chemically oxidise one 1,1'-bis(triazaphosphole)ferrocene with a silver salt, Ag[Al{OC(CF3)3}4] were not successful, and led to the formation of a silver coordination complex, [{Fe[µ-C5H4(N3PCBu(t))]2(µ-Ag)}2][Al{OC(CF3)3}4]2, thereby demonstrating the potential the reported triazaphosphole substituted systems possess as novel ligands in coordination chemistry.

Residence time as a key for comprehensive assessment of the relationship between changing land use and nitrates in regional groundwater systems.

In this study, an approach is put forward to study the relationship between changing land use and groundwater nitrate contamination in the Sanjiang Plain. This approach emphasizes the importance of groundwater residence time when relating the nitrates to the changing land use. The principles underlying the approach involve the assessment of groundwater residence time by CFCs and the Vogel age model and the reconstruction of the land use at the groundwater recharge time by interpolation. Nitrate trend analysis shows that nitrates have begun to leach into the aquifers since agricultural activities boomed after the 1950s. Hydrochemical analysis implies that the possible process relating to the nitrate reduction in the groundwater is the oxidation of Fe(ii)-silicates. However, the chemical kinetics of the oxidation of Fe(ii)-silicates is slow, so this denitrification process contributes little to the nitrate variations. Stepwise regression shows that the nitrate concentrations of samples had no direct relationship with the land use at the groundwater sampling time, but had a relatively strong relationship with the land use at the groundwater recharge time. Dry land is recognized as the dominant factor contributing to the elevated concentration of nitrates. The nitrogen isotope for nitrate (δ(15)N-NO3) gives a more direct result of the identification of nitrate sources: the use of manure in agricultural activities. Principle component (PC) regression shows that the process of the dry land exploitation is the major process that controls the nitrate contamination in the Sanjiang Plain.

Comprehensive insights into the structural and chemical changes in mixed-anion FeOF electrodes by using operando PDF and NMR spectroscopy.

In-depth analysis of operando X-ray pair distribution function (PDF) data is combined with Li NMR spectroscopy to gain comprehensive insights into the electrochemical reaction mechanism of high-performance iron oxyfluoride electrodes. While the full discharge capacity could be recovered upon charge, implying reversibility of the electrochemical reaction, the atomic structure of the electrode formed after cycling (discharge-charge) differs from the pristine uncycled electrode material. Instead, the "active" electrode that forms upon cycling is a nanocomposite of an amorphous rutile phase and a nanoscale rock salt phase. Bond valence sum analysis, based on the precise structural parameters (bond lengths and coordination number) extracted from the in situ PDF data, suggests that anion partitioning occurs during the electrochemical reaction, with the rutile phase being F-rich and the rock salt phase being O-rich. The F- and O-rich phases react sequentially; Fe in a F-rich environment reacts preferentially during both discharge and charge.