This work proposed to use waste steel slag as bed material of circulating fluidized bed (CFB) to reduce N2O emission. The steel slag was modified by using the mechanochemical method with its effect on N2O emission was studied in a horizontal tube furnace combustion experimental device under the combustion temperature of CFB. The effect of mechanochemical method modification condition and combustion parameter on N2O emission was investigated. Combing with steel slag characterization including Brunauer-Emmett-Teller (BET), X-Ray diffraction (XRD), scanning electron microscope (SEM)-mapping, and X-ray photoelectron spectroscopy (XPS), the mechanism of modified steel slag inhibiting N2O emission was concluded. The result showed that raw steel slag has very little effect on N2O emission of lignite combustion, but after addition of modified steel slag, the N2O emission concentration was significantly reduced. Under the optimal modification conditions (wet method, 600 r/min ball milling speed, 3 h milling time), with the ratio of lignite to steel slag setting at 1:10 and steel slag size selecting 200 mesh, the maximum removal rate of N2O reached 88.78%. With combustion temperature increased from 750 °C to 900 °C, the N2O emission concentration increased continuously, and addition of modified steel slag effectively inhibited N2O formation at different combustion temperature. O2 not only improved N2O formation but also promoted N2O removal after addition of modified steel slag. Characterization analysis indicated that mechanochemical modification significantly improved the pore structure and specific surface area of steel slag. Moreover, other active metal oxides (Fe2O3 and Al2O3 etc) wrapped in iron oxide were exposed on the surface of steel slag after modification. The exposed active metal oxides can reduce the energy barrier of N2O decomposition and promote the cleavage of N-O bond. The mechanochemical modified steel slag was a promising material to control N2O emission in CFB.

Herein, carbon quantum dots (CQDs) are facilely recovered from commercial black liquor in high yield via a rapid and mild acid-induced strategy. Upon acidification with 60 wt% H2SO4 solution at 60 degrees C for 5 min, black liquor derived from a poplar/reed mixture (PR), a poplar/eucalyptus mixture (PE), and cornstalk (CS) afforded CQD yields of 22.0 wt%, 21.8 wt%, and 31.1 wt%, respectively. In addition, black liquor from PR produced 48.8 wt% lignin, resulting in a maximum combined CQD and lignin yield of 70.9 wt%. All synthesized CQDs exhibited excellent water dispersibility, favorable photoluminescence properties, and abundant surface functional groups, with quantum yields ranging from 8.09% to 15.04%. The photocatalytic application of CQDs was evaluated using modified TiO2 and g-C3N4 composites. The 1% CQDs-PE/TiO2 composite achieved a methylene blue (MB) degradation efficiency of 77% within 120 min, while CQDs/g-C3N4 composites also exhibited enhanced degradation of the antibiotic ofloxacin (OFX). Furthermore, the Ru/CQD catalyst demonstrated good electrocatalytic activity in the hydrogen evolution reaction (HER), requiring an overpotential of only 76.46 mV to reach a current density of 10 mA cm-2. This work provides a green, scalable, and economically viable approach for the valorization of black liquor, enabling the high-yield production of high-quality CQDs under mild conditions.

The development of thermally efficient and environmentally friendly thermal energy storage materials is crucial for ensuring the continuity and stability of renewable energy systems. In this study, a medium-temperature shape-stabilized phase change material (NCPCM) was fabricated via a cold-press sintering method, using coal fly ash (CFA) as the supporting matrix, a NaNO3-KNO3 eutectic mixture as the phase change material (PCM), and expanded graphite (EG) as a thermal conductivity enhancer. Among the prepared samples with different CFA types and PCM fractions, NCPCM50-A with 50 wt% NaNO3-KNO3 eutectic exhibited the most favorable morphological stability and thermal storage performance, achieving a latent heat of 53.17 J/g. With the addition of 5 wt% EG, the optimized NCPCM50-A-EG5 retained a latent heat of 52.08 J/g, while its thermal conductivity reached 1.77 W/(m & sdot;K), corresponding to an improvement of approximately 205% compared to the EG-free NCPCM50-A. After 200 thermal cycles, NCPCM50-A-EG5 maintained good thermal stability, with a mass loss of only 3.81% and a retained latent heat of 51.19 J/g. To evaluate the environmental viability of NCPCMs, a cradle-to-gate life cycle assessment (LCA) was conducted in comparison with three thermal storage counterparts, including conventional magnesia bricks, MgO-based composite PCM, and Al2O3-based composite PCM. The CFAbased NCPCM showed lower impacts across the six selected indicators, mainly owing to the substitution of energy-intensive ceramic supports with industrial fly ash and the simplified low-temperature process. These findings indicate that CFA-based shape-stabilized PCMs have promising potential for sustainable mediumtemperature thermal energy storage while promoting industrial solid-waste valorization.

Carbon dioxide (CO2) emissions in the cement production approximately make up 7% of worldwide anthropogenic greenhouse gas emissions. Currently, reducing the CO2 emissions of cement industry has become an urgent problem. Oxy-fuel combustion technology possesses significant application prospects, which increases the CO2 concentration in flue gas remarkably, and simplifies the capture process. However, current research primarily focuses on the thermal transfer characteristics of pulverized coal, with limited systematic studies addressing combustion behavior, flow field, species field, and the mechanisms of pollutant formation. This study conducts a comparative analysis of the heat transfer and combustion characteristics of pulverized coal using the computational fluid dynamics (CFD) methods, thoroughly investigates flow, temperature, species, and NOx distribution in cement rotary kiln under the 21%O2/79%N2 and 21%O2/79%CO2 atmospheres, thereby addressing the current gap in multi-physics field coupling research. Results show that the transformation of combustion atmosphere from 21%O2/79%N2 atmosphere to 21%O2/79%CO2 atmosphere does not significantly alter the flow field structure, although it reduces gas velocity. Meanwhile, notable changes occur in temperature field, species field, and NOx distribution. Specifically, it has a great impact on temperature, species, and NOx. The ignition of pulverized coal delays, the flame length becomes shorter, CO2 concentration at the kiln outlet increases significantly, and NOx emissions are markedly reduced. Consequently, adjusting the combustion environment to 21%O2/79%CO2 facilitates the efficient recovery and utilization of exhaust gas from the kiln outlet. This strategy not only effectively lowers the cost of carbon capture but also significantly reduces pollutant emissions, thereby contributing to the green and sustainable development of the cement industry.

The selective cleavage of beta-O-4 linkages in lignin under mild conditions remains a major challenge for the sustainable production of aromatic chemicals. In this work, CdZnS photocatalysts were synthesized via coprecipitation (CP), hydrothermal (HT), and template-assisted solvothermal ion-exchange (TP) methods and applied to the photocatalytic cleavage of the beta-O-4 linkage in 2-phenoxy-1-phenylethanol (PP-ol). Cd0.5Zn0.5S-CP exhibited outstanding photocatalytic performance under visible-light irradiation, achieving complete conversion of PP-ol with high molar yields of phenol and acetophenone reaching 92.2% and 86.6%, respectively. Comprehensive characterizations revealed that the superior activity of Cd0.5Zn0.5S-CP originates from the synergistic interplay between its suitably negative conduction band potential (-1.26 eV) and a mesoporous structure with a large accessible surface area. In contrast, Cd0.5Zn0.5S-HT showed lower activity mainly because of its limited accessible surface area. Cd0.5Zn0.5S-TP also exhibited inferior performance, which was mainly attributed to its overly positive conduction band potential (-0.60 eV) and insufficient reductive driving force for C-O bond cleavage. Mechanistic investigations demonstrate that the reaction proceeds via a self-hydrogen transfer pathway, with photogenerated electrons playing a dominant role in driving C beta-O bond cleavage. This study provides fundamental insights into the rational design of efficient photocatalysts for lignin valorization under mild conditions.

As a typical industrial solid waste, red mud exhibits low utilization rates and poses serious ecological threats due to its high alkalinity. Meanwhile, tetracycline pollutions in water are difficult to degrade naturally, presenting numerous challenges to conventional water treatment methods. This study utilized red mud and granulated blast furnace slag as raw materials to prepare geopolymer microspheres (RGGMs) through suspension polymerization. BiOX (X = Cl, Br, I)-RGGMs were synthesized via in-situ growth, with BiOX nanoparticles uniformly dispersed on the RGGMs surface. BiOI-RGGMs, with the narrowest bandgap, achieved a 79.70% removal rate for 50 ppm tetracycline within 180 min, demonstrating excellent degradation performance. Additionally, BiOI-RGGMs maintain high stability, exhibiting only a 7.77% efficiency loss after five cycles. center dot O2-and h+ dominated the partial mineralization of tetracycline through three pathways due to their high reactivity, ultimately transforming it into CO2 and H2O. The CO2 emissions from electricity consumption during in-situ growth of BiOX on RGGMs accounted for only 11.59%, confirming the low-carbon characteristics of this process. This study proposes a low-carbon in-situ synthesis strategy that realizes high-value utilization of alkaline solid waste while efficiently treating tetracycline pollution in water.

Background: Carbon-based materials have emerged as promising catalyst supports for selective catalytic reduction with NH3 (NH3-SCR) due to their high specific surface area, splendid porous structure, abundant oxygenfunctional groups, and low-temperature adaptability. Methods: Mn-Fe modified carbon-based catalysts (Mn-Fe/HAC) were prepared by using a combined method of nitric acid oxidation, solution impregnation and controlled atmosphere calcination. The effects of reaction temperature and flue gas components (O2, CO, SO2, H2O, etc.) on NO reduction and Hg0 removal in NH3-SCR over as-prepared catalysts were investigated. The rection mechanisms were discussed by using characterizations of N2 adsorption-desorption, FT-IR, SEM-EDS, XRD, XPS, in-situ DRIFTS and Hg-TPD. Significant findings: Fe doping promoted the uniform distribution of Mn on the surface of Mn-Fe/HAC, increased Mn4+ contents and surface chemisorbed oxygen (O alpha), and shifted the operation temperature window of NO reduction to 120 degrees C. NO reduction efficiency over 7Mn0.5Fe/HAC reached 95% at 160-220 degrees C, and Hg0 removal efficiency was basically stable at 100%. The presence of oxygen had a significant promoting effect on NO reduction over 7Mn/HAC and 7Mn0.5Fe/HAC catalysts, but CO had a certain inhibitory effect. Individually adding SO2 or H2O in flue gas had a significant inhibitory effect on NO reduction, but the presence of moisture could help to reduce the irreversible deactivation caused by SO2. NO reduction of 7Mn0.5Fe/HAC was better than that of 7Mn/HAC, achieving 84% at 180 degrees C in the presence of 30-100 ppm SO2 and 6% H2O. NO in flue gas promoted Hg0 oxidization to a certain extent, but NH3 had obviously inhibition. NO reduction over 7Mn0.5Fe/ HAC catalyst followed two possible pathways of Eley-Rideal (E-R) mechanism and Langmuir-Hinshelwood (L-H), but Hg0 oxidization possibly followed L-H mechanism to form HgO, Hg(NO3)2 and HgSO4.

Nitrogen oxides (NOx) constitute the principal air pollutants, and the sintering process serving as the predominant source of NOx emissions in the iron and steel sector. Selective catalytic reduction (SCR) denitrification technology is widely used for flue gas denitrification, but due to the low temperature of the sintering flue gas and the uneven internal flow field, it brings challenges to SCR technology. In this study, numerical simulations were performed to analyze the impact of various deflectors configurations on flue gas velocity distribution and system resistance characteristics in the SCR denitrification system, based on its specific dimensions and operational data. Results show that introducing four deflectors at the initial bend yields the optimal performance, with a velocity standard deviation of 12.93% at the inlet of the first catalyst layer and an overall pressure drop of 641.5 Pa. And compared to other deflectors shapes, the straight-arc deflectors exhibit the lowest velocity standard deviation at 10.85%. The lowest relative velocity standard deviation of 10.8% was achieved when the deflectors at the second bend are parallel to the outer wall. And uniform-length deflectors at the second bend exhibited the lowest velocity standard deviation of 8.69%.

Background: Carbon-based materials (CMs) derived from metal-organic frameworks (MOFs) have garnered significant attention in activating peroxymonosulfate (PMS) to remediate dye wastewater pollution. However, the catalytic activity of MOFs-derived CMs for PMS activation through conventional methods still needs to be further improved. Methods: A novel Co/N-doped carbon material (BM-Fe/Co@N-C) was synthesized via ball milling combined with pyrolysis. Briefly, Co-doped MIL-101(Fe) precursor was prepared by adding a specific amount of Co (NO3)2 & sdot;6H2O during MIL-101(Fe) synthesis. The as-prepared Co-doped MIL-101(Fe) and urea were then ball-milled together for 1 h, followed by pyrolysis of the mixed powder at 600 degrees C for 2 h under N2 atmosphere to obtain BM-Fe/Co@N-C. Significant findings: The novel material of BM-Fe/Co@N-C exhibited outstanding PMS activation performance, achieving a Rhodamine B (Rh B) degradation efficiency of 97.4% within just 10 min. Quenching experiments and electron paramagnetic resonance (EPR) tests revealed that SO4 center dot- and center dot OH were the main reactive species in the BM-Fe/Co@N-C/PMS system. DFT calculations confirmed the cobalt/nitrogen doping significantly augmented charge transfers from BM-Fe/Co@N-C to PMS, thereby promoting the cleavage of the O-O bond in PMS.

Textile wastewater contains both dyes and heavy metals, forming binary composite pollution that is difficult to remove using conventional single-functional materials. To overcome this limitation, a dual-functional MC@SAPEI composite material with excellent adsorption and catalytic properties was fabricated for simultaneous removal of binary contaminants. The adsorption and degradation performances of the MC@SA-PEI were systematically investigated in single and binary pollutant systems. In the single Sb(V) system, the composite exhibited a theoretical maximum adsorption capacity of 99.6 mg/g according to the Langmuir isotherm model. The adsorption process fitted with the pseudo-second-order kinetic model. For the single crystal violet (CV) system, the composite activated peroxymonosulfate (PMS) to realize 99.2% degradation efficiency within 60 min at pH 5. SO4 center dot- and center dot OH were identified as the primary reactive oxygen species responsible for CV degradation. In the binary systems of Sb(V) and CV, the composite showed excellent synergistic removal performance, achieving 89.6% Sb(V) removal and 93.6% CV degradation efficiency. The presence of an appropriate Sb(V) concentration could promote CV degradation, while CV had a slight inhibitory effect on Sb(V) adsorption. After five consecutive cycling tests, the removal efficiencies of Sb(V) and CV still remained above 82.5% and 90.7%, respectively. The leaching concentrations of Fe and Co ions were far below the national standard limit. This work provides a promising technical strategy for the efficient remediation of textile wastewater co-contaminated with organic dyes and heavy metal ions.

Conventional methods for antibiotic removal often suffer from poor mineralization efficiency, harsh reaction conditions, or secondary pollution. To address these issues, this study developed a nitrogen-doped single-atom cobalt catalyst (Co-N@ZIF-8) for highly efficient peroxymonosulfate activation and rapid degradation of ofloxacin (OFX). Characterization by XRD, SEM, and TEM confirmed that the as-prepared catalyst possesses a mesoporous structure with highly dispersed cobalt single atoms and Co-Nx coordination sites. In the PMS-activated OFX degradation system, the catalyst exhibited excellent catalytic performance, achieving a degradation efficiency of 94.4 % for 100 mg/L OFX within 10 min. XPS analysis revealed that in the Co-N@ZIF-8/PMS system, the single-atom cobalt sites serve as key active centers for PMS activation through the Co2+/Co3+ redox cycle. Quenching experiments demonstrated that O2 center dot- and 1O2 were the primary reactive species responsible for OFX degradation. A possible degradation pathway involving five intermediate products was proposed. Moreover, five consecutive recycling tests and degradation experiments on four other organic pollutants confirmed the outstanding reusability and broad applicability of the material, with degradation efficiencies exceeding 93.5 % and 94.2 %, respectively. This work provides a new strategy for designing highly efficient and stable PMS catalysts for the removal of antibiotics from water.

Biomass co-firing is considered a promising pathway for reducing carbon emissions in existing coal-fired power systems; however, its large-scale application is significantly constrained by chlorine-related issues, including slagging, fouling, high-temperature corrosion, and hazardous emissions. This review provides a comprehensive and integrated analysis of chlorine behavior throughout the entire biomass combustion lifecycle, encompassing its sources, speciation, transformation, and engineering impacts. Chlorine in biomass is primarily present as water-soluble inorganic salts and organically bound compounds, with their relative distribution strongly dependent on biomass type. During thermal conversion, chlorine exhibits a temperature-dependent release pattern: organic chlorine is mainly volatilized as HCl and CH3Cl at 200–500°C, whereas inorganic chlorine is predominantly released as gaseous HCl and alkali metal chlorides at temperatures above 700°C. These processes are further influenced by interactions with alkali metals, sulfur, and mineral phases. Importantly, this review highlights that slagging, fouling, and corrosion are interconnected phenomena governed by the formation, transport, and deposition of alkali chlorides along boiler temperature gradients. Current mitigation strategies, including fuel pretreatment, additive injection, and material protection, are critically evaluated, revealing inherent trade-offs between efficiency and practicality.

A combined strategy integrating mechanical ball milling pretreatment with a ternary deep eutectic solvent (DES) system was developed to enable efficient lignin isolation under mild conditions while preserving reactive structural motifs. Ball milling significantly disrupted the hierarchical structure of biomass, altering micromorphology, crystallinity, surface roughness, and specific surface area, thereby enhancing lignin accessibility. Under identical DES extraction conditions (ChCl/EG/10% OA, 90 degrees C, 6 h), birch premilled at 800 rpm for 1 h achieved a lignin recovery of 44.1%, approximately 4 times higher than that of untreated birch. When applied to six representative hardwood, softwood, and herbaceous biomasses, the ball milling-DES strategy increased lignin recovery by 1.2-4.5 times, with more pronounced improvements observed for woody biomass than for herbaceous biomass owing to their intrinsically more compact cell wall structures. The isolated lignin from birch retained 56 beta-O-4 linkages per 100 aromatic units and afforded a monophenol yield of 19.2 wt % upon Ru/C catalyzed depolymerization at 240 degrees C for 4 h. Mechanistic insights are proposed to illustrate how ball milling enhances DES penetration and lignin extraction. Overall, this strategy helps alleviate the common trade-off between high lignin extraction efficiency and preservation of beta-O-4 linkages, enabling the recovery of lignin with both high yield and high structural integrity.

The low energy efficiency, high heat loss, and insufficient dynamic load matching of district heating systems (DHS) restrict its low‐carbon transition. This paper reviews the research progress of source‐network‐load modeling and optimization in DHS system, focusing on the key technologies of heat source modeling, pipe network modeling, load forecasting, and system optimization. The research covers thermoelectric decoupling techniques in heat source modeling and multi‐energy flow coupling energy hubs (EHs), mechanism‐based and data‐driven modeling methods of pipe network, as well as long‐ and short‐term applications of load forecasting algorithms. As for system optimization, the effectiveness of MILP, PSO, NSGA‐II algorithms in multi‐objective scheduling and planning is compared and analyzed. Finally, some future directions are proposed for developing DHS into a fully autonomous intelligent, zero‐carbon, and digital twin ecological heating system in the future.

Using isopropanol as an in situ hydrogen source, lignin-derived phenolics were effectively hydrodeoxygenated to cyclohexanol and cyclohexane over RuMo/NC bimetallic catalysts, which were prepared via a facile in situ pyrolysis strategy. Catalyst screening showed that Ru0.75Mo0.25/NC achieved complete conversion of 4-propylguaiacol at 240 degrees C, producing 70.4% 4-propylcyclohexanol and 20.4% propylcyclohexane as the major products. Physicochemical characterizations, including N2 sorption, high-resolution transmission electron microscopy, X-ray diffraction, NH3 temperature-programmed desorption, and X-ray photoelectron spectroscopy, revealed that the uniform dispersion of nanoscale, electron-deficient Ru species and electron-enriched Mo species, anchored on a micromesoporous N-doped carbon matrix, is responsible for the excellent catalytic transfer hydrodeoxygenation (CTHDO) activity of Ru0.75Mo0.25/NC. Isopropanol, as a secondary alcohol, demonstrated significantly superior in situ hydrogen-donating capabilities than primary alcohols, effectively promoting the CTHDO of phenolic compounds. The CTHDO of 4-propylguaiacol followed a sequential reaction pathway consisting of dehydroxylation to form 4-propylphenol, aromatic hydrogenation to yield 4-propylcyclohexanol, and further dehydroxylation to generate propylcyclohexane. CTHDO of other phenolic compounds confirmed the general applicability of Ru0.75Mo0.25/NC. Moreover, the catalyst exhibited high stability and retained its activity after five cycles, highlighting its potential for sustainable applications in green fuel production.

A FeCl3 modified wood chips hydrochar sorbent (Fex-HC) was prepared via hydrothermal carbonization method for removing gas phase elemental mercury from simulated flue gas. The mercury adsorption capability of the Fex- HC sorbent was evaluated in a fixed bed system. The characterization of the Fex-HC sorbent was implemented to determine its physicochemical properties. Combined with Hg-TPD analysis, mercury adsorption mechanism of the Fex-HC sorbent was ascertained. Results indicated that the modified hydrochar prepared from cohydrothermal carbonization of wood chips with FeCl3 possessed high mercury removal capability at 50-250 degrees C. Addition of FeCl3 significantly promoted the mercury capture rate of the hydrochar increasing from 10 % to more than 90 %. The optimal mass ratio of FeCl3 & sdot;6H2O to wood chips was 1.3:1, and the optimum hydrothermal temperature was 180 degrees C. With SO2 existing in flue gas, the modified hydrochar still owned a mercury capture rate of 99.3 %, proving it high SO2 tolerance. The characterization results indicated that hydrothermal treatment and addition of FeCl3 elevated the specific surface area of the Fe1.3-HC sorbent to 269.3 m2/g, constructing an abundant porous structure. The Fe1.3-HC sorbent surface possessed a considerable amount of Fe3+, which can promote mercury adsorption by oxidizing Hg0 to Hg2+. A large number of chemically adsorbed oxygen (O*) and active C-Cl functional groups were also detected on the Fe1.3-HC sorbent surface, both of which acted as active sites for mercury adsorption. Combing Hg-TPD and XPS analysis, it displayed that Hg0 was adsorbed onto the Fe1.3-HC sorbent in the form of HgO and HgCl2.

Three-dimensional electrocatalytic oxidation (3D-ECO) has garnered significant attention in recent years as an advanced wastewater treatment technology. This paper systematically reviews the oxidation mechanisms, key electrode materials and their reactor designs, operational parameters, and specific applications of 3D-ECO. Compared to traditional two-dimensional electrocatalytic oxidation (2D-ECO) systems, 3D-ECO significantly enhances the reaction interface area and mass transfer efficiency by incorporating particle electrodes (PEs), demonstrating superior pollutant removal capabilities. Furthermore, the use of PEs not only reduces energy consumption but also improves treatment efficiency. This paper also explores the importance of composite materials in enhancing electrocatalytic performance and electrode stability, along with an analysis of the key operational parameters affecting system performance. Despite its excellent performance in terms of current density and energy efficiency, high costs and complex operations continue to limit the industrial application of 3D-ECO. To address these challenges, the paper proposes future research directions, including the development of novel electrode materials, reactor designs, machine learning to optimize operating parameters, and the integration of multiple technologies. Through these efforts, 3D-ECO has the potential for broader application, contributing to the sustainable development of wastewater treatment technologies.

This review systematically summarizes the current research status of materials for CO2 capture and storage. The research background is introduced, detailing the impact of CO2 as a greenhouse gas on climate change and the urgency of reducing CO2 emissions. In the realm of materials for CO2 capture and sequestration, liquid-phase materials include ionic liquids and liquid amine detergents, while solid-phase materials encompass alkali/alkaline earth metal compounds, carbon-based materials, molecular sieves, aerogels, MOFs, and COFs. For each material, we discuss its working principle, advantages and disadvantages, and the latest research progress, demonstrating the potential and application prospects in CO2 capture and storage. This paper provides a comprehensive overview of the latest research developments in these fields, offering important references for further research and applications. Future research directions include optimizing the performance of existing materials, developing new high-efficiency materials, and exploring integrated solutions for CO2 capture and storage. These efforts aim to provide technical support and a scientific basis for combating climate change and achieving carbon neutrality.

Background: MIL-101(Fe), an eco-friendly catalyst in sulfate radical based advanced oxidation processes (SRAOPs) for treating textile wastewater, faces limitations in peroxymonosulfate (PMS) activation due to its fully coordinatively saturated state and the slow conversion of Fe III to FeII. Methods: Three co-modified MIL-101(Fe) catalysts of CUS-FeII-MIL-101(Fe), CUS-CuII-MIL-101(Fe) and CUS-CoII- MIL-101(Fe) were successfully synthesized by combining metal-doping (Fe2+, Cu2+ and Co2+) and thermal activation (300 degrees C). The physiochemical properties of as-synthesized catalysts were characterized by powder Xray diffraction (PXRD), field emission electron microscope coupled with energy dispersive spectroscopy (FESEMEDS), Brunauer-Emmett-Teller (BET) and Fourier transform infrared spectroscopy (FTIR). The effects of catalyst dosage and type, PMS concentration, solution pH and co-existing anions on methylene blue (MB) degradation in SR-AOPs systems were analyzed, and the degradation mechanisms was discussed by quenching tests with scavengers of Methanol (MeOH), tertbutyl alcohol (TBA), p-benzoquinone (BQ) and L-histidine (L-his). Significant findings: Compared to the MB degradation efficiency of original MIL-101(Fe) (92.5 %), three co- modified catalysts shown higher MB degradation efficiencies of 97.5 %, 98.1 % and an outstanding 100 %, respectively. Free radicals quenching tests indicated that SO 4 center dot- and center dot OH played key roles in MB degradation mechanism. Promisingly, the three catalysts also demonstrated high degradation efficiencies above 94.0 % for four additional dyes.