Nitrogen doped bimetallic sludge biochar composite for synergistic persulfate activation: Reactivity, stability and mechanisms.

As a recycling use of waste activated sludge (WAS), we used high-temperature pyrolysis of WAS to support bimetallic Fe-Mn with nitrogen (N) co-doping (FeMn@N-S), a customized composite catalyst that activates peroxysulphate (PS) for the breakdown of tetracycline (TC). First, the performance of TC degradation was evaluated and optimized under different N doping, pH, catalyst dosages, PS dosages, and contaminant concentrations. Activating PS with FeMn@N-S caused the degradation of 91% of the TC in 120 min. Next, characterization of FeMn@N-S by XRD, XPS and FT-IR analysis highlights N doping is beneficial to take shape more active sites and reduces the loss of Fe and Mn during the degradation reaction. As expected, the presence of Fe-Mn bimetallic on the catalyst surface increases the rate of electron transfer, promoting the redox cycle of the catalyst. Other functional groups on the catalyst surface, such as oxygen-containing groups, accelerated the electron transfer during PS activation. Free radical quenching and ESR analysis suggest that the main contributor to TC degradation is surface-bound SO4•-, along with the presence of single linear oxygen (1O2) oxidation pathway. Finally, the FeMn@N-S composite catalyst exhibits excellent pH suitability and reusability, indicating a solid practicality of this catalyst in PS-based removal of antibiotics from wastewater.

[Determination of trace low molecular mass aldehydes in air by ultra-fast liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a rapid and accurate method for the determination of trace acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde in the air by ultra-fast liquid chromatography-tandem mass spectrometry(UFLC-MS/MS). METHODS: The air sample was concentrated and derivatived by 3-methyl-2(3 H)-benzothiazolonhydrazone(MBTH), and the effect of derivative conditions including the concentration of MBTH, the pH, the derivative time and temperature was investigated. The stability of derivatives, the cracking mechanism of mass spectrometry, the matrix effect of the method and air sampling efficiency were studied. The chromatographic separation was carried out on a Shim-pack XR-ODS II column(100 mm×2. 0 mm, 2. 2 µm) by using water/methanol solution as the mobile phase with the gradient elution. Detection was performed in positive multi-reaction monitoring(MRM) mode for quantification by using external standard method. RESULTS: The four analytes showed good linear relationship within the range of 1. 00-100 µg/L(calculated by aldehyde) with a correlation coefficient r≥0. 9990. The limits of quantitation(LOQs) of the method(concentrated with 10 L air) were 0. 5 µg/m~3 in air, for acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde. The recoveries of the method were 90. 6%-97. 8% at the three spiked levels, and the relative standard deviations(RSDs) were between 1. 9%-6. 4%(n=6), the average sampling efficiency was between 91. 0%-97. 1%. CONCLUSION: The developed method is simple, less interference and specificity, and is suitable for the simultaneous rapid determination of trace acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde in air of work place.

Understanding Mechanisms of Synergy between Acidification and Ultrasound Treatments for Activated Sludge Dewatering: From Bench to Pilot-Scale Investigation.

Enhancing activated sludge dewaterability is of scientific and engineering importance in the face of accelerated urbanization and stringent environmental regulations. In this study, we investigated the integration of acidification and ultrasound (A/US) treatment for improving sludge dewaterability at both bench- and pilot-scales. Our results showed that the A/US process exhibited significantly improved sludge dewatering performance, characterized by capillary suction time, cake moisture, and water/solid content of sludge cake. Synergistic dewatering mechanisms were elucidated with a suite of macro and spectroscopic evidence. Characterization of treated sludge revealed that US-induced thermal, mechanical shearing force, and radical oxidation effects disrupts floc cells and accelerates the decomposition of extracellular polymeric substances (EPS), releasing bound water into the bulk phase. In addition to enhancing hydrolysis of EPS, the acidic pH environment caused the protonation of functional groups on EPS, facilitating the reflocculation of US decomposed sludge for improved filterability. Our bench-scale and pilot-scale investigations provide a mechanistic basis for better understanding of the A/US process, and enable development of a viable and economical dewatering technology.

Rapid analysis of six trace trichlorophenols in seawater by magnetic micro-solid-phase extraction and liquid chromatography with tandem mass spectrometry.

A new facile, rapid, inexpensive, and sensitive method for the analysis of six trace trichlorophenols in seawater samples was developed by magnetic micro-solid-phase extraction coupled to liquid chromatography with tandem mass spectrometry. Core-shell covalently functionalized ferroferric oxide coated with aminated silicon dioxide and decorated with multiwalled carbon nanotubes was applied as an adsorbent to perform the extraction process. The effect of factors including solution pH, contact time, adsorbent amount, and ionic strength were investigated in detail. The obtained results revealed that the proposed adsorbent was a highly effective and low-cost magnetic micro-solid-phase extraction material for the enrichment of 2,3,4-trichlorophenol, 2,3,5-trichlorophenol, 2,3,6-trichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, and 3,4,5-trichlorophenol from seawater. Under the optimized conditions, the recoveries ranged from 88.0 to 99.5% at the three spiking levels, the limits of detection and the limits of quantification were 0.002 and 0.007 µg/L for the six trichlorophenols, respectively. The intra- and interday relative standard deviations were 2.0-6.7 and 4.5-8.9%, respectively. The calibration curves showed a good linearity in the range of 0.02-5.0 µg/L. The routine run analyses showed that the developed method was fast, simple, accurate, solvent-saving and high resolution, and it was suitable for the determination of trace trichlorophenols in seawater.

Silica enhanced activation and stability of Fe/Mn decorated sludge biochar composite for tetracycline degradation.

In this study, SiO2-composited biochar decorated with Fe/Mn was prepared by co-pyrolysis method. The degradation performance of the catalyst was evaluated by activating persulfate (PS) to degrade tetracycline (TC). The effects of pH, initial TC concentration, PS concentration, catalyst dosage and coexisting anions on degradation efficiency and kinetics of TC were investigated. Under optimal conditions (TC = 40 mg L-1, pH = 6.2, PS = 3.0 mM, catalyst = 0.1 g L-1), the kinetic reaction rate constant could reach 0.0264 min-1 in Fe2Mn1@BC-0.3SiO2/PS system, which was 12 times higher than that in the BC/PS system (0.00201 min-1). The electrochemical, X-ray diffractometer (XRD), Fourier transform infrared spectrum (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis showed that both metal oxides and oxygen-containing functional groups provide more active sites to activate PS. The redox cycle between Fe(II)/Fe(III) and Mn(II)/Mn(III)/Mn(IV) accelerated the electron transfer and sustained the catalytic activation of PS. Radical quenching experiments and electron spin resonance (ESR) measurements confirmed that surface sulfate radical (SO4•-) play a key role in TC degradation. Three possible degradation pathways of TC were proposed based on high-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC-HRMS) analysis, the toxicity of TC and its intermediates was analyzed by bioluminescence inhibition test. In addition to the enhanced catalytic performance, the presence of silica also improved the stability of the catalyst, as confirmed by cyclic experiment and metal ion leaching analysis. The Fe2Mn1@BC-0.3SiO2 catalyst, derived from low-cost metals and bio-waste materials, offer an environmentally friendly option to design and implement heterogenous catalyst system for pollutant removal in water.

Cationic polyacrylamide (CPAM) enhanced pressurized vertical electro-osmotic dewatering of activated sludge.

Pressurized vertical electro-osmotic dewatering (PVEOD) has been regarded as a feasible method to achieve sludge deep-dewatering, but the dewatering efficiency is still challenged by high electric resistance. This study employed cationic polyacrylamide (CPAM) as a skeleton builder to enhance electro-osmotic flow in PVEOD. The sludge dewatering efficiency and synergistic effect of CPAM and PVEOD were elucidated. The sludge morphology, surface property, extracellular polymeric substances (EPS) destruction and migration, spatial distributions of proteins and polysaccharides, and current changes were investigated. After the addition of optimal CPAM dose, the sludge formed a uniform and porous structure that provided water channels and enhanced electric transport, thus promoting EPS destruction. The sludge moisture content (MC) analysis indicated the more liberation of bound water due to EPS destruction. Besides, the re-flocculation of disintegrated sludge flocs improved the sludge filtration and thus dewaterability. Instantaneous energy consumption (Et,0.5) was optimized and two-step synergistic mechanism was thus proposed. These findings indicated that the combination of CPAM and PVEOD is a promising strategy to broaden the scope of industrial application of sludge deep-dewatering.

An Yttrium-sensitized luminescence system and its application for the determination of trace chlorophacinone in serum.

Chlorophacinone (CPN) is an extensively used anticoagulant rodenticide in China. A simple, rapid, and sensitive method is necessary for the determination of CPN in clinical emergency rescue. In this study, a novel fluorimetric method for the determination of CPN in human serum was developed. This proposed method is based on luminescence produced by a formation of a ternary CPN-europium-dl-histidine complex system. The fluorescence intensity was enhanced by adding yttrium and polyvinylpyrrolidone colloid-type suspension at pH 9.0. All of the important methodological achievements, such as working wavelengths, pH for optimal yttrium fluorescence enhancement, and the method recovery, limit of detection, limit of quantification, and relative standard deviation together with its linearity range, are discussed in detail. The developed method was successful in the determination of CPN in actual human serum in both clinical and forensic specimens. In comparison with the liquid chromatography tandem mass spectrometry method, this method is fast, simple, and less expensive.

An enhancement of europium-/gadolinium- diphacinone -DL-histidine- cetylpyridine bromide system for the determination of diphacinone in serum.

As one of the first generation anticoagulant rodenticide, diphacinone (DPN) was extensively used in China, and often occurred accidental and intentional intoxications. To meet the needs of clinical emergency rescue, a simple, rapid and sensitive method was necessary for the determination of DPN in serum. In this paper, a fluorimetric method using a ternary europium-gadolinium-DPN-DL-histidine-cetylpyridine bromide system was developed. The fluorescence intensity was measured with a 1 cm quartz cell at 335 nm excitation wavelength and 612 nm emission wavelength. The fluorescence intensity of the europium-DPN- DL- histidine complex system was further enhanced by using gadolinium ion (Gd(3+)) in a cetylpyridine bromide (CPB) colloid-type suspension. By adding Gd(3+) at pH 8.5 to 9.5 in the presence of an ammonia-ammonium chloride buffer solution, about a 100-fold enhancement of the fluorescence intensity was achieved. The enhanced fluorescence intensity showed a good linear relationship with the DPN concentration from 0.01 mg/L to 5.0 mg/L. The limit of detection was 0.001 mg/L in serum. The established method was used to determine DPN in real human serum in clinical specimens. The luminescence mechanism was discussed in detail. In the fluorescence system of the europium-gadolinium-DPN-DL-histidine-CPB, the CPB not only acted as the surfactant but also acted as the energy donor.

[Study on the enhancement diphacinone-europium fluorescence system and application for determination of the residue in urine].

OBJECTIVE: To establish an accurate, convenient and sensitive quantitative fluorescence method for the determination of diphacinone (DPN) in urine. METHODS: Diphacinone was complexed with europium ion (Eu3+) at the presence of DL-histidine, polyvinylpyrrolidone (PVP) and ammonia-ammonium chloride (NH3 -NH4 Cl) buffer solution to form a multiple complex of DPN-Eu(3+) -DL-histidine-NH3-PVP fluorescence system, and the fluorescence sensitivity was greatly enhanced by the rare earth element of yttrium ion (Y3+ ). The excitation and emission wavelengths were 330 nm and 612 nm, respectively. RESULTS: The optimum conditions were Eu3+ 10.0 mg/L,Y3+ 20.0 mg/L, DL-histidine 0.01%, PVP 0.05% at pH 9.0. Under the optimum conditions, fluorescence intensity of the system was a linear function of the concentration of diphacinone in the range of 0.2 - 10.0 mg/L, the limit of quantification was 0.2 mg/L. The spiked recoveries for DPN in urine were 87.0% - 97.3%, the intra-and inter-day RSDs were between 3.4% - 4.7% and 4.8% - 6.6%, respectively. CONCLUSION: The established method is simple, accurate and reliable, and it is satisfactory for the determination of DPN in urine and can be used for DPN poisoned patients for the rapid clinical diagnosis.

Manganese doped iron-carbon composite for synergistic persulfate activation: Reactivity, stability, and mechanism.

The heterogeneous catalytic process has been under development for aqueous pollutant degradation, yet electron transfer efficiency often limits the effectiveness of catalytic reactions. In this study, a novel composite material, manganese doped iron-carbon (Mn-Fe-C), was tailor designed to promote the catalytic electron transfer. The Mn-Fe-C composite, synthesized via a facile carbothermal reduction method, was characterized and evaluated for its performance to activate persulfate (PS) and degrade Rhodamine Blue (RhB) dye under different pH, catalyst dosages, PS dosages, and pollutant concentrations. Electron spin resonance, along with quenching results by ethanol, tert-butanol, phenol, nitrobenzene and benzoquinone, indicated that surface bounded SO4•- was the main contributor for RhB degradation, while the roles of aqueous SO4•- and •OH were very minor. Through characterization by XRD, XPS and FTIR analysis, it was determined that the electron transfer during activation of PS was accelerated by the oxygen functional groups on catalyst surface and the promoted redox cycle of Fe3+ and Fe2+ by Mn. Finally, the Mn-Fe-C composite catalyst exhibited an excellent reusability and stability with negligible leached Fe and Mn ions in solutions. Results of this study provide a promising design for heterogeneous catalysts that can effectively activate PS to remove organic pollutants from water at circumneutral pH conditions.

[Rapid qualitative analysis of indandione rodenticides by high-performance liquid chromatography coupled with ion trap mass spectrometry].

OBJECTIVE: To establish a method for the simultaneous qualitative analysis of four indandione rodenticides by high-performance liquid chromatography coupled with ion trap mass spectrometry (LC-IT/MS). METHODS: After the indandione rodenticides in bait were extracted by acetone, and cleaned by solid-phase extraction (SPE), the liquid chromatographic separation and the MS/MS cracking were performed in the optimal instrument conditions by LC-IT/MS. Qualitative detection were carried out by the principle of mass spectrometry analysis of three qualitative ions. RESULTS: The MS/MS fragment ions had good characteristics and stability, the cracking ways to the parent ions and fragment ions were clear. Qualitative ion pairs were m/z 339-->167 and m/z 339-->145 for diphacine, m/z 373-->201 and m/z 373-->145 for chlorophacinone, m/z 229-->145 and m/z229-->187 for valone, and m/z 229-->172 and m/z229-->145 for pindone. CONCLUSION: This established method is simple, accurate and reliable for the qualitative analysis of indandione rodenticides.

Simultaneous measurement of indandione-type rodenticides in human serum by liquid chromatography-electrospray ionization- tandem mass spectrometry.

Measurement of indandione rodenticides is important in the diagnosis and treatment of accidental rodenticide ingestion. Current assays lack effective measurements for simultaneous analysis of the indandiones, especially the isomers. The intent of this study was to establish a novel and selective method for the simultaneous determination of indandione-type rodenticides (diphacinone, chlorophacinone, valone, and pindone) in human serum by liquid chromatography-electrospray ionization-tandem mass spectrometry. After addition of internal standard, the sample was extracted with 10% methanol in acetonitrile and cleaned by solid-phase extraction (SPE). The analytes were separated on a C(18) rapid column and infused into an ion trap mass spectrometer in the negative electrospray ionization mode. The multiple-reaction monitoring ion pairs were m/z 339 --> 167, m/z 373 --> 201, m/z 229 --> 145, m/z 229 --> 172, and m/z 307 --> 161 for diphacinone, chlorophacinone, valone, pindone, and IS, respectively. Recoveries were between 81.5 and 94.6%, and the limits of quantification were 0.2 to 0.5 ng/mL. Intra- and interday RSDs were less than 7.9 and 11.5%, respectively. The assay was linear in the range of 0.5-100.0 ng/mL with coefficients of determination (r(2) > 0.99) for all analytes. The proposed method enables the unambiguous confirmation and quantification of the indandiones in both clinical and forensic specimens.

Rapid identification and determination of the rodenticide valone in serum by high-performance liquid chromatography-tandem mass spectrometry.

Valone is a chronic anticoagulant rodenticide that has come into wide use in China. Current literature lacks analytical methods for the determination of valone. In this paper, a sensitive and selective assay was established for the identification and quantification of valone in serum by liquid chromatography-tandem mass spectrometry. After addition of the internal standard, warfarin, serum samples were extracted with 10% methanol in acetonitrile and cleaned using Oasis HLB solid-phase extraction (SPE) cartridges. The compounds were separated on an Agilent SB C18 column with a mobile phase of methanol/acetic acid-ammonium acetate (5 mmol/L, pH 6.3) (75:25, v/v). Detection was performed by electrospray ionization ion trap mass spectrometry in the negative multiple reaction monitoring mode. The transition ions of m/z 229 --> 145 and m/z 307 --> 161 were selected for quantification of valone and the internal standard, respectively. The overall extraction efficiency was between 81.1% and 91.1%. The limit of quantification was 0.5 ng/mL. Regression analysis of the calibration data revealed good correlation (r(2) > 0.99) for valone. Intra- and interday precisions for quality-control samples were less than 7.8% and 12.8%, respectively. This method combines a rapid SPE procedure with an extremely fast chromatographic analysis, which is especially advantageous or clinical laboratories.

Ion chromatography tandem mass spectrometry for simultaneous confirmation and determination of indandione rodenticides in serum.

This paper describes a simple method for the simultaneous determination and confirmation of the indandione rodenticides in serum. After samples were extracted with 10% (v/v) methanol in acetonitrile and cleaned by solid-phase extraction, chromatographic separation was performed on an IonPac AS11 analytical column (250 x 4.0 mm) using gradient KOH eluent with 10% (v/v) methanol as organic modifier. Confirmation was depended on the extensive fragmentation of the indandione molecule under MS/MS conditions which provides sufficient structural information. Quantification was performed by negative electrospray ionization in multiple reaction monitoring mode. All the method parameters were validated. It was confirmed that this method could be used in clinical diagnosis and forensic toxicology.

Retracted: Rapid and effective sample cleanup based on graphene oxide-encapsulated core-shell magnetic microspheres for determination of fifteen trace environmental phenols in seafood by liquid chromatography-tandem mass spectrometry.

This article has been retracted at the request of the Editor after the corresponding author pointed the Editor to comments from an anonymous reader. The article reports electron micrographs of different preparations while showing identical images as used in previous publications by the same authors. The particles in Fig. 4C (SEM image of Fe3O4@SiO2) are identical to each other and the corresponding author confirmed that these have been copy-pasted. In addition, these particles have previously been communicated as different substances in Fig. 1B from Pan et al., J. Mater. Chem. A, 2015,3, 23042-23052 (DOI: 10.1039/C5TA05840F) and Fig. 3F from Pan et al., Anal. Methods, 2017,9, 5281-5292 (DOI: 10.1039/C7AY01444A). Furthermore, the curves in Fig. 7, especially the baseline, shows a remarkable similarity to Fig. 8 from Pan et al., J. Mater. Chem. A, 2015,3, 23042-23052 (DOI: 10.1039/C5TA05840F) and Fig. 5F from Pan et al., J. Mater. Chem. A, 2014,2, 15345-15356 (DOI: 10.1039/c4ta02600d). The manipulation of images and data in this way is a serious offense to the integrity of the scientific community and casts doubts on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).

Development and validation of a liquid chromatography coupled with atmospheric-pressure chemical ionization ion trap mass spectrometric method for the simultaneous determination of triptolide, tripdiolide, and tripterine in human serum.

A sensitive method has been developed and validated for the simultaneous determination of triptolide, tripdiolide, and tripterine in human serum using hydrocortisone as an internal standard (IS). After triptolide, tripdiolide, and tripterine in human serum were extracted with ethyl acetate, the extracts were separated on an XDB C(18) column (30 mm x 2.1-mm i.d., 3 microm) using a mobile phase of acetic acid/ammonium acetate (5 mmol/L, pH 4.5)/acetonitrile/methanol in gradient elution. Detection was performed by high-performance liquid chromatography coupled with atmospheric-pressure chemical ionization ion trap mass spectrometry in negative multiple reaction monitoring mode. The transition ions m/z 359 --> 340, m/z 375 --> 357, m/z 449 --> 405, and m/z 419 --> 329 were selected for the quantification of triptolide, tripdiolide, tripterine, and IS, respectively. The linear range was 1.0-100.0 ng/mL, the absolute recoveries were between 78.3 and 89.2%, the relative recoveries were between 88.1 and 94.6%, and the limits of quantification in human serum were 0.5-1.0 ng/mL for the three target compounds. The intra- and interday relative standard deviations were less than 11.9% and 13.0%, respectively. This method was found to effectively and simultaneously determine trace triptolide, tripdiolide, and tripterine in human serum and can be suitable for clinical and toxicological studies.

Synergetic pretreatment of waste activated sludge by hydrodynamic cavitation combined with Fenton reaction for enhanced dewatering.

The dewatering of waste activated sludge by integrated hydrodynamic cavitation (HC) and Fenton reaction was explored in this study. We first investigated the effects of initial pH, sludge concentration, flow rate, and H2O2 concentration on the sludge dewaterability represented by water content, capillary suction time and specific resistance to filtration. The results of dewatering tests showed that acidic pH and low sludge concentration were favorable to improve dewatering performance in the HC/Fenton system, whereas optimal flow rate and H2O2 concentration applied depended on the system operation. To reveal the synergism of HC/Fenton treatment, a suite of analysis were implemented: three-dimensional excitation emission matrix (3-DEEM) spectra of extracellular polymeric substances (EPS) such as proteins and polysaccharides, zeta potential and particle size of sludge flocs, and SEM/TEM imaging of sludge morphology. The characterization results indicate a three-step mechanism, namely HC fracture of different EPS in sludge flocs, Fenton oxidation of the released EPS, and Fe(III) re-flocculation, that is responsible for the synergistically enhanced sludge dewatering. Results of current study provide a basis to improve our understanding on the sludge dewatering performance by HC/Fenton treatment and possible scale-up of the technology for use in wastewater treatment plants.

Comparison of the reactivity of ibuprofen with sulfate and hydroxyl radicals: An experimental and theoretical study.

Hydroxyl radical (•OH) and sulfate radical anion (SO4•-) based advanced oxidation technologies (AOTs) are effective methods to treat trace organic contaminants (TrOCs) in engineered waters. Although both technologies result in the same overall removal of TrOCs, the mechanistic differences between these two radicals involved in the oxidation of TrOCs remain unclear. In this study, we experimentally examined the degradation kinetics of neutral ibuprofen (IBU), a representative TrOC, by •OH and SO4•- at pH3 in UV/H2O2 and UV/persulfate systems, respectively. The second-order rate constants (k) of IBU with •OH and SO4•- were determined to be 3.43±0.06×109 and 1.66±0.12×109M-1s-1, respectively. We also theoretically calculated the thermodynamic and kinetic behaviors for reactions of IBU with •OH and SO4•- using the density functional theory (DFT) M06-2X method with 6-311++G** basis set. The results revealed that H-atom abstraction is the most favorable pathway for both •OH and SO4•-, but due to the steric hindrance SO4•- exhibits significantly higher energy barriers than •OH. The theoretical calculations corroborate our experimental observation that SO4•- has a smaller k value than •OH in reacting with IBU. These comparative results are of fundamental and practical importance in understanding the electrophilic interactions between radicals and IBU molecules, and to help select preferred radical oxidation processes for optimal TrOCs removal in engineered waters.

Rapid decolorization of dye Orange G by microwave enhanced Fenton-like reaction with delafossite-type CuFeO2.

Bimetallic oxide CuFeO2 as a new heterogeneous catalyst has shown much higher catalytic ability for activating peroxide than single-metal oxides. The present work demonstrated a synergistic microwave (MW) enhanced Fenton-like process with CuFeO2 for rapid decolorization of azo dye Orange G (OG). The MW irradiation dramatically enhanced the OG degradation efficiency, achieving 99.9% decolorization within 15min at pH5. The XRD analysis of reused CuFeO2, together with metal leaching tests, indicated merits of recycling for CuFeO2. The subsequent surface element analysis by XPS for fresh and used CuFeO2 showed a complex network for reactions between copper-iron redox pairs and surface hydroxyl groups, leading to a synergistic Fenton-like system accelerated by MW irradiation. In the CuFeO2 initiated Fenton-like reactions, several oxidant species (i.e., OH, O2-, electron hole, and FeIVO) responsible to the OG oxidation were identified by quenching experiments, showing the MW generated high temperature and "hot spots" enhanced the yield of OH by generation of electron-hole pairs. Further, the 26 detected degradation products confirmed the OH dominant oxidation of OG. This study shows that the MW-enhanced Fenton-like reaction using CuFeO2 has potential applications for rapid decolorization of dye effluent.