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Per- and polyfluoroalkyl substances (PFAS) are refractory anthropogenic chemicals and current treatment processes at municipal water resource recovery facilities (WRRFs) cannot efficiently degrade them, hence, these chemicals cycle through the environment. Certain PFAS can be concentrated in biosolids from WRRFs and are commonly land applied for beneficial reuse. Given recent advances in measurement of PFAS, documentation of the range of concentrations in pre-stabilized sludge and stabilized biosolids is critical to evaluating treatment best practices and assessing potential human health and ecological risks. In this study, pre-stabilized sludge and post-stabilized biosolids samples were collected from 12 major WRRFs across the United States. PFAS were analyzed using Environmental Protection Agency (EPA) Method SW846-3500C/537.1, and Draft EPA Method 1633, by one commercial laboratory and two university research laboratories, respectively. Results comparison among laboratories demonstrated statistical differences in PFAS concentrations among split samples. For example, 5:3 FTCA (fluorotelomer carboxylic acid) concentrations in post-stabilized sludge at Lab 1 were measured at 21 ng/g (dry), while they were detected at 151 ng/g (dry) in Lab 3. Further, higher PFAS concentrations were observed in post-stabilized biosolids compared to pre-stabilized sludges, regardless of the laboratory or analysis method, even when solids destruction through solids stabilization was considered. Further research is required to refine methods for analyses of PFAS in sludge and biosolids samples from WRRFs prior to being used for development of regulatory actions as well as understanding how various treatment protocols could impact concentrations of PFAS in land-applied biosolids.
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Domestic dogs have great potential to expand our understanding of the determinants of aging. To understand the aging pattern of domestic dogs and evaluate whether they can be used as an aging model, we performed RNA sequencing on white blood cells from domestic dogs aged 1-9 years and treated aged dogs with classical antiaging approaches. We obtained 30 RNA sequencing libraries and identified 61 age-associated genes with dynamic changes, the majority of which were related to metabolism and immune function, which may be predominant biomarkers for aging in dogs. We next treated aged dogs with canine mesenchymal stem cells (cMSCs), nicotinamide mononucleotide, and rapamycin to determine whether and how they responded to the antiaging interventions. The results showed that these treatments can significantly reduce the level of inflammatory factors (IL-6 and TNF-α). MSCs effectively improved the heart functions of aged dogs. Three key potential age-related genes (PYCR1, CCRL2, and TOX) were reversed by MSC treatment, two of which (CCRL2 and TOX) are implicated in immunity. Overall, we profiled the transcriptomic pattern of domestic dogs and revealed that they may be a good model of aging, especially in anti-inflammatory investigations.
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Transcriptoma , Animales , Perros , Transcriptoma/genética , Inflamación/genética , Envejecimiento/genética , Antiinflamatorios/farmacología , Células Madre Mesenquimatosas/metabolismoRESUMEN
This study systematically investigated the variable main electrooxidation mechanism of chlorophene (CP) and dichlorophen (DCP) with the change of reaction conditions at Ti4O7 anode operated in batch and reactive electrochemical membrane (REM) modes. Significant degradation of CP and DCP was observed, that is, CP exhibited greater removal efficiency in batch mode at 0.5-3.5 mA cm-2 and REM operation (0.5 mA cm-2) with a permeate flow rate of 0.85 cm min-1 under the same reaction conditions, while DCP exhibited a faster degradation rate with the increase of current density in REM operation. Density functional theory (DFT) simulation and electrochemical performance tests indicated that the electrooxidation efficiency of CP and DCP in batch mode was primarily affected by the mass transfer rates. And the removal efficiency when anodic potentials were less than 1.7 V vs SHE in REM operation was determined by the activation energy for direct electron transfer (DET) reaction, however, the adsorption function of CP and DCP on the Ti4O7 anode became a dominant factor in determining the degradation efficiency with the further increase of anodic potential due to the disappeared activation barrier. In addition, the degradation pathways of CP and DCP were proposed according to intermediate products identification and frontier electron densities (FEDs) calculation, the acute toxicity of CP and DCP were also effectively decreased during both batch and REM operations.
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Diclorofeno , Contaminantes Químicos del Agua , Adsorción , Oxidación-ReducciónRESUMEN
Poly- and perfluoroalkyl acids (PFAAs) are a large family of widespread contaminants of worldwide concern and well-known as "forever chemicals". Direct emission of PFAAs from the fluorochemical industry is a crucial source of PFAA pollutants in the environment. This study implemented nontarget analysis and comprehensive characterization for a category of new PFAA contaminants, i.e., iodinated PFAAs (IPFAAs), in fluorochemical industry wastewater and relevant contaminated river water by liquid chromatography-high-resolution mass spectrometry with a cascade precursor ion exclusion (PIE) strategy and in-house developed data extraction and processing algorithms. A total of 26 IPFAAs (including 2 isomers of an IPFAA) were found and identified with tentative molecular structures. Semiquantification of the IPFAAs was implemented, and the total concentrations of IPFAAs were 0.16-285.52 and 0.15-0.17 µg/L in wastewater and river water, respectively. The high concentrations in association with the predicted ecotoxicities and environmental behaviors demonstrate that these IPFAAs are worthy of more concern and further in-depth research. The cascade PIE strategy along with the data extraction and processing algorithms can be extended to nontarget analysis for other pollutants beyond IPFAAs. The nontarget identification and characterization outcomes provide new understanding on the environmental occurrence and pollution status of IPFAAs from a comprehensive perspective.
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Contaminantes Ambientales , Fluorocarburos , Contaminantes Químicos del Agua , Aguas Residuales , Ríos/química , Fluorocarburos/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , AguaRESUMEN
In this work, we demonstrate for the first time the abatement of sulfamethoxazole (SMX) induced by stabilized ortho-semiquinone radicals (o-SQâ¢-) in the MnO2-mediated system in the presence of humic acid. To evaluate the performance of different MnO2/mediator systems, 16 mediators are examined for their effects on MnO2 reactions with SMX. The key role of the bidentate Mn(II)-o-SQ⢠complex and MnO2 surface in stabilizing SQâ¢- is revealed. To illustrate the formation of the Mn(II)-o-SQ⢠complex, electron spin resonance, cyclic voltammetry, and mass spectra were used. To demonstrate the presence of o-SQ⢠on the MnO2 surface, EDTA was used to quench Mn(II)-o-SQâ¢. The high stability of o-SQâ¢- on the MnO2 surface is attributed to the higher potential of o-SQâ¢- (0.9643 V) than the MnO2 surface (0.8598 V) at pH 7.0. The SMX removal rate constant by different stabilized o-SQ⢠at pH 7.0 ranges from 0.0098 to 0.2252 min-1. The favorable model is the rate constant ln (kobs, 7.0) = 6.002EHOMO(o-Qred) + 33.744(ELUMO(o-Q) - EHOMO(o-Qred)) - 32.800, whose parameters represent the generation and reactivity of o-SQâ¢, respectively. Moreover, aniline and cystine are competitive substrates for SMX in coupling o-SQâ¢-. Due to the abundance of humic constituents in aquatic environments, this finding sheds light on the low-oxidant-demand, low-carbon, and highly selective removal of sulfonamide antibiotics.
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Sustancias Húmicas , Sulfametoxazol , Manganeso , Óxidos , Compuestos de ManganesoRESUMEN
Treatment of waters contaminated by per- and polyfluoroalkyl substances (PFAS) in large volumes remains a challenge to date. Treatment trains comprising separation and destruction technologies are promising to manage PFAS contamination. Foam fractionation (FF) and electrochemical oxidation (EO) are two cost-effective technologies for PFAS separation and destruction, respectively. This work systematically explored the performance of a treatment train of FF followed by EO (FF-EO) for treating PFAS in environmental water samples. For each treatment step, the dependence of the treatment performance on operational factors and other variables were analyzed statistically. The statistical analysis revealed PFAS enrichment and removal depend significantly on PFAS carbon chain length, solution conductivity, and PFAS concentration. Whether FF-EO treatment costs less energy than direct EO without FF mainly relies upon PFAS carbon chain length and TOC content in the sample. Both correlations were found to be linear. For all environmental water samples in this study, FF-EO is more energy-efficient than EO alone.
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Fluorocarburos , Contaminantes Químicos del Agua , Fluorocarburos/análisis , Contaminantes Químicos del Agua/análisis , Carbono , Biometría , AguaRESUMEN
Per- and polyfluoroalkyl acids (PFAAs) including polyfluoroalkyl carboxylic acids and polyfluoroalkyl sulfonic acids are a large category of crucial environmental pollutants of global concern. Besides known PFAAs, numerous unknown species may exist in the environment, urgently needing discovery and characterization. This study implemented nontarget analysis for a group of novel PFAA pollutants, viz., iodinated PFAAs (I-PFAAs) in wastewater from a fluorochemical manufacturing park by liquid chromatography-high-resolution mass spectrometry in combination with an iodine-specific data-processing algorithm. The algorithm took into account the diagnostic fragment iodine ion (I-) together with carbon and sulfur isotopologue distributions. In total, 18 I-PFAA formulas involving 21 congeners were identified. Semiquantification was conducted, and the total concentrations of I-PFAAs were 1.9-274.7 µg/L, indicating severe pollution of I-PFAAs in the wastewater. The determined concentrations along with predicted environmental behaviors and toxicities demonstrate that I-PFAAs merit further in-depth investigation. The analytical method including the instrumental analysis and data-processing algorithm can be extended to screening and identification of I-PFAAs in other matrices. Furthermore, the analysis results for the first time provide recognition on the occurrence, distribution features, and pollution status of I-PFAAs in the environment.
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Treatment of large volumes of waters contaminated by per- and polyfluoroalkyl substances (PFAS) remains a challenge. This work presented a systematic study on PFAS removal by foam fractionation (FF). Experiments were conducted on both laboratory-spiked and environmental water samples containing PFASs. It is found that higher air flow, greater ionic strength, and addition of thickener boosted PFAS removal in the defoamed bottom solutions and intensified enrichment in the collected foam. FF treatments of a landfill leachate, a groundwater contaminated by aqueous film-forming foams, and a wastewater treatment plant effluent sample were evaluated. The removal reached above 70% for most monitored PFASs, except the ones of short alkyl chains. PFAS concentrations in the final collected foams were up to over 30 × than that in the original samples. Analysis using high-resolution mass spectrometry revealed enrichment of non-target PFASs by FF. The results of this study demonstrate great effectiveness of FF in removing most PFASs from waters, producing low-volume, highly concentrated solutions of PFASs in all tested environmental samples.
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Formation of chlorate (ClO3-) and perchlorate (ClO4-) as by-products in electrooxidation process has raised concern. In the present study, the formation of ClO3- and ClO4- in the presence of 1.0 mM Cl- on boron doped diamond (BDD) and Magneli phase titanium suboxide (Ti4O7) anodes were evaluated. The Cl- was transformed to ClO3- (temporal maximum 276.2 µM) in the first 0.5 h on BDD anodes with a constant current density of 10 mA cm2, while approximately 1000 µM ClO4- was formed after 4.0 h. The formation of ClO3- on the Ti4O7 anode was slower, reaching a temporary maximum of approximately 350.6 µM in 4.0 h, and the formation of ClO4- was also slower on the Ti4O7 anode, taking 8.0 h to reach 780.0 µM. Compared with the BDD anode, the rate of ClO3- and ClO4- formation on the Ti4O7 anode were always slower, regardless of the supporting electrolytes used in the experiments, including Na2SO4, NaNO3, Na2B4O7, and Na2HPO4. It is interesting that the formation of ClO4- during electrooxidation was largely mitigated or even eliminated, when methanol, KI, and H2O2 were included in the reaction solutions. The mechanism of the inhibition on Cl- transformation by electrooxidation was explored.
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Percloratos , Contaminantes Químicos del Agua , Boro , Cloratos , Diamante , Electrodos , Peróxido de Hidrógeno , Metanol , Oxidación-Reducción , Titanio/farmacología , Contaminantes Químicos del Agua/análisisRESUMEN
Following juice crushing for sugar or bioethanol production from sugarcane, bagasse (SCB) is generated as the main lignocellulosic by-product. This study utilized SCB generated by a hydraulic press as feedstock to evaluate sugar extraction as well as adsorption potential. Total soluble sugar (sucrose, glucose, and fructose) of 0.4 g/g SCB was recovered with H2O extraction in this case. Insoluble sugar, that is, cellulose in SCB, was further hydrolyzed into glucose (2%-31%) with cellulase enzyme, generating a new bagasse residue (SCBE). Persulfate pretreatment of SCB slightly enhanced saccharification. Both SCB and SCBE showed great potential as adsorbents with 98% of methylene blue (MB) removed by SCB or SCBE and 75% of Cu2+ by SCBE and 80% by SCB in 60 min. The maximum adsorption amount (q m) was 85.8 mg/g (MB by SCB), 77.5 mg/g (MB by SCBE), 3.4 mg/g (Cu2+ by SCB), and 1.2 mg/g (Cu2+ by SCBE). The thermodynamics indicated that the adsorption process is spontaneous, endothermic, and more random in nature. The experimental results offer an alternative to better reutilize SCB.
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Electrooxidation (EO) has been shown effective in degrading per- and polyfluoroalkyl substances (PFASs) in water, but concurrent formation of chlorate and perchlorate in the presence of chloride is of concern due to their toxicity. This study examined EO treatment of three representative PFASs, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and 6:2 fluorotelomer sulfonate (6:2 FTS), in chloride-containing solutions on pristine and surface-fluorinated Ti4O7 anodes having different percentage of surface fluorination. The experiment results indicate that surface fluorination of Ti4O7 anodes slightly inhibited PFAS degradation, while significantly decreased the formation of chlorate and perchlorate. Further studies with spectroscopic and electrochemical characterizations and density functional theory (DFT) computation reveal the mechanisms of the impact on EO performance by anode fluorination. In particular, chlorate and perchlorate formation were fully inhibited when fluorinated Ti4O7 anode was used in reactive electrochemical membrane (REM) under a proper anodic potential range (<3.0 V vs Standard Hydrogen Electrode), resulting from slower intermediate reaction steps and short residence time of the REM system. The results of this study provide a basis for design and optimization of modified Ti4O7 anodes for efficient EO treatment of PFAS while limiting chlorate and perchlorate formation.
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Ácidos Alcanesulfónicos , Fluorocarburos , Contaminantes Químicos del Agua , Cloratos , Cloruros , Electrodos , Fluorocarburos/análisis , Hidrógeno , Percloratos , Titanio , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
The effect of electrochemical degradation on Magnéli phase Ti4O7 anode combined with UV irradiation on the removal of PFOS was systematically evaluated in the present study. A synergistic effect of electrolysis and UV irradiation rather than a simple additive effect for PFOS degradation was demonstrated experimentally and theoretically. The short wavelength irradiation within 400â¯nm is the main contribution to enhance the electrochemical degradation of PFOS, while the initial pH of the solution has little effect on the PFOS degradation. The increase of current density accelerates the removal of PFOS either by electrolysis treatment or the joint process. The time-dependent density functional theory (TD-DFT) calculation indicates that the synergistic effect of the electrolysis and UV irradiation is most likely due to the involvement of the excited PFOS induced under UV irradiation in the electrochemical reaction. This study provides the first mechanistic explanation for the electrochemical degradation of PFOS enhanced by UV irradiation.
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Ácidos Alcanesulfónicos , Fluorocarburos , Contaminantes Químicos del Agua , Fluorocarburos/análisis , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
Traditional composting is a well-suited biotechnology for on-farm management of livestock manure (LM) but still leads to the release of toxic micropollutants and imbalance of nutrients. One in situ exoenzyme-assisted composting has shown promise to ameliorate the agronomical quality of end products by improving humification and polymerization. The naturally occurring extracellular laccase from microorganisms belongs to a multicopper phenoloxidase, which is verified for its versatility to tackle micropollutants and conserve organics through the reactive radical-enabled decomposition and polymerization channels. Laccase possesses an indispensable relationship with humus formation during LM composting, but its potential applications for the harmless disposal and resource utilization of LM have until now been overlooked. Herein, we review the extracellular laccase-aided humification mechanism and its optimizing strategy to maintain enzyme activity and in situ production, highlighting the critical roles of laccase in treating micropollutants and preserving organics during LM composting. Particularly, the functional effects of the formed humification products by laccase-amended composting on plant growth are also discussed. Finally, the future perspectives and outstanding questions are summarized. This critical review provides fundamental insights into laccase-boosted humification that ameliorates the quality of end products in LM composting, which is beneficial to guide and advance the practical applications of exoenzyme in humification remediation, the carbon cycle, and agriculture protection.
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Compostaje , Animales , Sustancias Húmicas/análisis , Lacasa , Ganado , Estiércol , SueloRESUMEN
Managing per- and polyfluoroalkyl substance (PFAS) contamination has gained worldwide attention due to their ubiquitous occurrence in water systems. Anion exchange resins (AERs) have been proven effective in removing both long-chain and short-chain PFASs. In this study, an explicit model was developed to describe the breakthrough behavior of an individual PFAS as a single solute onto anion exchange resin in a column filtration process. The model was further modified to predict the breakthrough curve of co-existing PFASs on AER in multi-solute systems by incorporating a separation factor describing the competitive adsorption and a blockage factor describing the loss of adsorption sites. Rapid small-scale column tests (RSSCTs) were performed with six AERs of various properties and three model PFASs in both single- and multi-solutes systems. The breakthrough behaviors of RSSCTs for both single- and multi-solute systems were found adequately described by the models developed in this study. The experiments and accompanied model simulations reveal some important relationships between the AER performance and the properties of both the AERs and the PFASs.
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Fluorocarburos , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Resinas de Intercambio Aniónico , Fluorocarburos/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
Primordial black holes (PBHs) might form from the collapse of over-densed regions generated by large scalar curvature perturbations in the radiation dominated era. Despite decades of various independent observations, the nature of dark matter (DM) remains highly puzzling. Recently, PBH DM have aroused interest since they provide an attracting explanation to the merger events of binary black holes discovered by LIGO/VIRGO and may play an important role on DM. During the formation of PBH, gravitational waves will be sourced by linear scalar perturbations at second-order, known as the scalar induced gravitational waves (SIGWs), which provides a new way to hunt for PBH DM. This topic review mainly focuses on the physics about SIGWs accompanying the formation of PBH DM.
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This study examined the feasibility of a novel treatment train that combines electrocoagulation (EC) with electrooxidation (EO) treatment to remove and degrade per- and polyfluoroalkyl substances (PFASs) from water. Electrocoagulation with a zinc anode could effectively remove PFASs from water, and long-chain PFASs (C7-C10) tended to have a higher removal rate. Foam was generated when a relatively high current density (>1 mA cm-2) was applied to a relatively high PFAS concentration (each PFAS > 0.1 µM) during EC, which promoted the separation of PFASs from the bulk solution, especially for long-chain PFASs. Isotherm-like adsorption results indicated that competitive adsorption on floc occurred between PFASs when no foam was produced in a solution containing 10 different PFASs. Acid dissolution methods could recover and concentrate 10 PFASs in controlled volumes from both the floc and the foam, and it was also successfully applied in groundwater collected from a contaminated site. The concentrated PFASs in the acid solutions were efficiently destructed using EO treatment with a Ti4O7 anode at 10 mA cm-2, and no supplement of electrolyte was needed for the floc dissolved solution. This electrochemical-based process can economically separate, concentrate and destroy PFASs in groundwater and wastewater.
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In this study, effects of polystyrene microplastics (MPS) on Euglena gracilis were investigated via examination on its photosynthesis and motility, two typical properties of the protozoan. No adverse effects were observed after 4-d exposure except for decrease in motility at two high MPS concentrations (5 and 25 mg/L). After 8-d duration, MPS at 1 mg/L had no obvious effects on E. gracilis, but two higher concentrations (5 and 25 mg/L) of MPS inhibited protozoan growth, motility, and photosynthesis. The reduced protozoan photosynthetic activity was reflected by changes in Fv/Fm (the maximum photochemical yield of PSII), ΔFIP (difference between FP and FI) and PIABS (the performance index), indicative of reduced quantum yield of electron transport and enhanced energy dissipation. A dose-dependent effect of MPS on E. gracilis was found in protozoan growth, photosynthesis and motility, especially photosynthetic indices. MPS of small size (75 nm) seemed more toxic to the protozoa than large size (1000 nm). Internalization of MPS in the cells and chloroplasts was observed clearly for the first time, likely responsible for their toxicity. Analysis on photosynthetic process and motility of E. gracilis could provide more comprehensive understanding of MPS toxicity in the aquatic environment, and may potentially serve as a biomonitoring tool.
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Microplásticos/toxicidad , Poliestirenos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Transporte de Electrón , Euglena gracilis/efectos de los fármacos , Fotosíntesis/efectos de los fármacos , Plásticos/toxicidadRESUMEN
This is the first comprehensive overview of laccase-triggered anabolism from fundamental theory to biotechnology applications. Laccase is a typical biological oxidordeuctase that induces the one-electronic transfer of diverse substrates for engendering four phenoxy radicals with concomitant reduction of O2 into 2H2O. In vivo, laccase can participate in anabolic processes to create multifarious functional biopolymers such as fungal pigments, plant lignins, and insect cuticles, using mono/polyphenols and their derivatives as enzymatic substrates, and is thus conducive to biological tissue morphogenesis and global carbon storage. Exhilaratingly, fungal laccase has high redox potential (E° = 500-800 mV) and thermodynamic efficiency, making it a remarkable candidate for utilization as a versatile catalyst in the green and circular economy. This review elaborates the anabolic mechanisms of laccase in initiating the polymerization of natural phenolic compounds and their derivatives in vivo via radical-based self/cross-coupling. Information is also presented on laccase immobilization engineering that expands the practical application ranges of laccase in biotechnology by improving the enzymatic catalytic activity, stability, and reuse rate. Particularly, advances in biotechnology applications in vitro through fungal laccase-triggered macromolecular biosynthesis may provide a key research direction beneficial to the rational design of green chemistry.
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Biotecnología , Lacasa , Catálisis , Hongos/metabolismo , Lacasa/metabolismo , Lignina/metabolismo , Oxidación-ReducciónRESUMEN
This study for the first time investigated the advanced treatment of bio-treated landfill leachate effluent using a novel reactive electrochemical membrane (REM) technology at the laboratory and pilot scales. At the laboratory scale, RuO2-Ir-REM, Ti4O7-REM, and ß-PbO2-REM featured similar properties in pore size and water flux. Although RuO2-Ir-REM holds more reactive sites than the other two REMs, ß-PbO2-REM and Ti4O7-REM featured higher oxidation ability than RuO2-Ir-REM, causing their high yield of hydroxyl radical. Consequently, ß-PbO2-REM and Ti4O7-REM performed better than RuO2-Ir-REM, which removed total organic carbon and ammonia nitrogen by 70%-76% and 100%, respectively, after 45 minutes of treatment. Fluorescence spectroscopy analysis showed that humic acid-like substances were oxidized by the REM treatment. Using the ß-PbO2-REM in the lab-scale setup with the solutions circulated, we observed a greater removal of chemical oxygen demand (COD) at a higher applied current or a faster water flux. The pilot system with four large size of ß-PbO2-REMs modules in series was developed based on the lab-scale setup, which steadily treated landfill leachate in compliance with the disposal regulations of China, at an energy consumption of 3.6 kWh/m3. Also, a single-pass REM can effectively prevent the transformation of chloride to chlorate and perchlorate. Our study showed REM technology is a powerful and promising process for the advanced treatment of landfill leachate.