A comprehensive review on metal based active sites and their interaction with O3 during heterogeneous catalytic ozonation process: Types, regulation and authentication

Accelerated tetracycline hydrochloride mineralisation by Fe@CeO2-x/MgO complex metal oxides via ozone-catalysed interfacial reactions: The role of oxygen vacancies and multivalent metal cycling

Heterogeneous catalytic ozonation (HCO) shows promising potential for degrading emerging contaminants, but its mineralisation rate needs further improvement due to insufficient electron transfer. To address this limitation, an efficient HCO system was developed by synthesising a Fe@CeO2-x/MgO multi-metal catalyst via an isomorphous substitution strategy, which was then coupled with ozone (O3) for efficient tetracycline hydrochloride (TCH) mineralisation. The results indicated that TCH mineralisation rate reached 0.0204 min-1 in the O3/0.5Fe@CeO2-x/MgO system, 2.43 fold times higher than that of O3 alone. This enhanced mineralisation performance can be attributed to iron substitution, introduction of numerous Lewis acid sites, and shortening of Ce-O bond length, which facilitated the migratory conversion between oxygen vacancies (OVs) and surface lattice oxygen, as well as improved adsorption and electron transfer between Fe@CeO2-x/MgO and O3. Mechanistic analysis revealed that OVs directly activate oxygen to form singlet oxygen and then reacted with O3 to generate superoxide radicals, that subsequently reacted with O3 to form hydroxyl radical (·OH) and recyclable OVs. In addition, O3 could oxidise Fe(Ⅱ) and Ce(Ⅲ) to obtain ·OH through electron transfer. Similarly, intermediate hydroperoxyl could reduce Fe(Ⅲ) and Ce(Ⅳ) to ensure continued free radical production. As a result of enhanced TCH mineralization performance, both toxicity of intermediates and disinfection by-products (DBPs) formation potential were gradually reduced. Notably, DBPs formation potential exhibited a positive linear correlation with total organic carbon. This study offers an effective HCO system to enhance TCH mineralisation through interfacial O3 catalysis rather than simple degradation, and this provided comprehensive insights to improve O3 utilisation and reduce energy consumption of catalytic ozonation processes.

High-Entropy Modulated High-Spin Localized Cobalt Sites Enhance Catalytic Ozonation for Efficient Odor Control

Catalytic ozonation technology is crucial for environmental remediation due to its exceptional efficiency and capability for complete mineralization of organic pollutants. However, hindered by spin-forbidden transitions, effective catalytic ozonation remains contingent upon the electronic properties and interfacial interactions of the catalyst. Recent studies identify interfacial atomic metal-oxygen species (*O) as a key descriptor in catalytic ozonation, determining the derivation of reactive species and subsEquationuent reactivity. Herein, we modulated the high-spin localized Co active sites in HE-Co3O4 via a high-entropy strategy, which selectively stabilizes *O surface species, thereby enhancing catalytic ozonation efficiency. HE-Co3O4 exhibits a five-fold higher degradation rate than Co3O4 for 50 ppm CH3SH elimination (63-fold the mass activity compared to commercial MnO2) while maintaining exceptional stability over 24 h at 298 K. Electron paramagnetic resonance (EPR) and magnetization hysteresis (M-H) measurements confirm the transition of Co3+ to high-spin states in HE-Co3O4. Density functional theory (DFT) calculations reveal that unpaired electrons enhance the hybridization of Co 3d with O 2p orbitals, thereby establishing a *O-mediated interfacial pathway. This mechanism is directly observed through in situ Raman spectroscopy. These findings provide insights into the targeted modulation of catalyst electronic structures for ozone-catalyzed environmental remediation.

Designing CuO@rGO-MoS2 Nanocomposite with Bird's-Nest Like Structure as Peroxymonosulfate Activator for the Efficient Degradation of Rhodamine B

A straightforward, single-stage hydrothermal approach was utilized to synthesize a unique CuO@rGO-MoS2 nanocomposite, featuring a nest-mimicking architecture. It has highly efficient heterogeneous catalyzed property that can catalyze and activate the peroxymonosulfate (PMS) by means of radical (•OH, SO4•-, and O2•-) and nonradical (1O2) pathways to generate ROS for the rapid degradation of the organic dye rhodamine B (Rh.B). Graphene oxide, which has high specific surface, serves as an excellent carrier which achieves a homogeneous dispersion of the main catalyst component and gives a series of oxygen-containing functional groups that become active centers for nonradical route activation. Through experimental and DFT calculation, it was revealed that MoS2 as a cocatalyst accelerated the redox cycle of the Cu active center during the activation of PMS via catalysis, further enhancing the catalytic activity of the nanocomposites. And thus the CuO@rGO-MoS2/PMS system with bird's-nest like structure achieves rapid degradation of Rh.B in a short period, and the decomposition efficiency of Rh.B reaches 99% within 30 min duration of the reaction. Besides, this system exhibits excellent resistance to environmental interference, demonstrating commendable degradation efficiency across broad pH spectrum (pH 5-11) and high levels of common interfering ions (Cl-, NO3-, SO42-, etc.). To conclude, this study tried to propose and validate a catalyst design idea based on catalytic activation of peroxymonosulfate by selecting appropriate main catalysts, cocatalysts, and catalyst carriers to achieve improved catalytic performance and stability of the catalysts, and the synthesized catalysts CuO@rGO-MoS2 by this design strategy have shown good degradation performances in real wastewater.

Heterogeneous Peroxymonosulfate-Based Advanced Oxidation Mechanisms: New Wine in Old Bottles?

Heterogeneous persulfate-based advanced oxidation processes (PS-AOPs) have been gaining significant attention in water/wastewater treatment; however, the elucidation of mechanisms in PS-AOPs has become increasingly complex as the understanding of potential reactive pathways expands and the rigor of corresponding characterizations intensifies. As such, accurately illustrating system mechanisms with a robust and convincing methodology is crucial, while the influence of substrates must not be overlooked. In this Perspective, established techniques and critical issues are systematically compiled to serve as practical guidelines. Additionally, a newly proposed pathway, the direct oxidation transfer process (DOTP), is discussed in comparison to conventional mineralization processes by reactive oxidative species (ROS) in PS-AOPs. Overall, the investigation of PS-AOP mechanisms across various heterogeneous systems remains contentious and calls for standardization, for which this work aims to serve as a valuable reference.

Polarized electric field induced by piezoelectric effect of ozone micro-nano bubbles/spontaneously polarized ceramic to boost ozonolysis for efficient fruit sterilization

Ozone (O3) treatment is an environmentally friendly fruit sterilization strategy. However, the low O3 utilization rate and long-term oxidation lead to O3 waste and fruit damage, respectively. Herein, a sterilization system based on the synergy of O3 micro-nano bubbles (OMNB) and spontaneously polarized ceramic (SPC) was developed to piezoelectrically catalyze ozonolysis for efficient fruit sterilization. OMNB/SPC showed excellent sterilizing activity with 7 lg CFU/mL of E. coli and S. aureus inactivation within 20 min, together with significantly improved fruit quality in Kyoho grapes preservation. The excellent sterilizing performance of OMNB/SPC is attributed to that the piezoelectric SPC (d33 = 103.4 pm/V) formed a strong polarized electric field and rich reactive oxygen species (ROS) under OMNB collapse resulting in O3 absorption/decomposition. The electric field and rich ROS caused membranes in-situ electroporation and irreversible inactivation to the microorganisms on fruits successively. This system is important for more efficient long-term preservation of fruits.

Catalytic ozonation of dimethyl phthalate by Ti-MCM-41 in water

A Ti-MCM-41 mesoporous molecular sieve catalyst was prepared by a hydrothermal method. Nitrogen adsorption desorption, XRD, TEM and SEM characterization results showed that the catalyst had a large specific surface area, a regular hexagonal pore structure, and titanium doping was uniformly dispersed in MCM-41 molecular sieves. The amount of titanium doping, reaction temperature, and the initial solution pH had important effects on the catalytic ozonation of dimethyl phthalate (DMP) by Ti-MCM-41. In comparison to ozonation alone and MCM-41/O3, Ti-MCM-41/O3 exhibited the most effective degradation and mineralization of DMP, with a Si/Ti ratio of 80, a reaction temperature of 25 °C, and an initial solution pH of 5.4. Ozonation alone, MCM-41/O3, and Ti-MCM-41/O3 removed 94%, 96%, and 100% of DMP after 15 min of reaction. At 60 min of reaction, the TOC removal rate of the Ti-MCM-41/O3 process reached 36%, which was 2.4 times that of the O3 process and 1.9 times that of the MCM-41/O3 process. The experimental results of initial solution pH and hydroxyl radical capture showed that Ti-MCM-41 had the highest catalytic activity near the zero-charge point, and hydroxyl radicals were active oxygen species. Ti-MCM-41 catalytic ozonation of DMP had synergistic effects and is a promising environmental catalytic material.

High-Efficiency Catalytic Ozonation Degradation of Ni Complex Wastewater Using Mn-N Codoped Active Carbon Catalyst

With the rapid development of electroless nickel (Ni) plating industry, a large amount of Ni complex wastewater is inevitably produced, which is a serious threat to the ecological environment. Herein, a novel Mn-N codoped active carbon (Mn-N@AC) catalyst with high catalytic ozonation ability was synthesized by the impregnation precipitation method and was characterized by BET, XRD, Raman, SEM, FTIR, and TPR. Meanwhile, Mn-N@AC showed excellent catalytic ozonation ability, stability, and applicability. When Ni-EDTA (TOC = 400, Ni = 58.05 mg/L) was used as simulated wastewater, the removal efficiency of TOC and total Ni reached 97.8 and 92.7%, respectively, and after three cycles, the TOC removal efficiency was still up to 93.6%. When Ni-EDTA wastewater was replaced with Ni-citrate, Ni-tartaric, and Ni-malate, the TOC removal efficiency remained above 93%. In addition, mechanistic insights by quenching experiments and EPR verified the high removal efficiency of TOC mainly attributed to indirect oxidation of ·OH and ·O2-, and the potential mechanism was proposed. The work provides insights into the deep removal of Ni complex wastewater by catalytic ozonation with low cost and high efficiency.

Comparative study on CeO2 catalysts with different morphologies and exposed facets for catalytic ozonation: performance, key factor and mechanism insight

Morphology and facet effects of metal oxides in heterogeneous catalytic ozonation (HCO) are attracting increasing interests. In this paper, the different HCO performances for degradation and mineralization of phenol of seven ceria (CeO2) catalysts, including four with different morphologies (nanorod, nanocube, nanooctahedron and nanopolyhedron) and three with the same nanorod morphology but different exposed facets, are comparatively studied. CeO2 nanorods with (110) and (100) facets exposed show the best performance, much better than that of single ozonation, while CeO2 nanocubes and nanooctahedra show performances close to single ozonation. The underlying reason for their different HCO performances is revealed using various experimental and density functional theory (DFT) calculation results and the possible catalytic reaction mechanism is proposed. The oxygen vacancy (OV) is found to be pivotal for the HCO performance of the different CeO2 catalysts regardless of their morphology or exposed facet. A linear correlation is discerned between the rate of catalytic decomposition of dissolved ozone (O3) and the density of Frenkel-type OV. DFT calculations and in-situ spectroscopic studies ascertain that the existence of OV can boost O3 activation on both the hydroxyl (OH) and Ce sites of CeO2. Conversely, various facets without OV exhibit similar O3 adsorption energies. The OH group plays an important role in activating O3 to produce hydroxyl radical (∙OH) for improved mineralization. This work may offer valuable insights for designing Facet- and OV-regulated catalysts in HCO for the abatement of refractory organic pollutants.

Effect of impregnation strategy on structural characteristics of Ce-Mn/Al2O3 and its catalytic ozonation of benzoic acid

Ce-Mn binary oxides supported on Al2O3 (Ce-Mn/Al2O3), with enhanced activity and stability for catalytic ozonation of benzoic acid, were synthesized using a facile impregnation method. The competitive synergetic effects between cerium and manganese significantly influenced the structural characteristics and catalytic performance of the catalysts depending on the impregnation sequence. Catalysts prepared via the one-step impregnation process exhibited a higher concentration of homogeneous Ce3+ species on the catalyst surface. This led to an increase in surface oxygen vacancies, thereby enhancing catalytic activity. In contrast, the two-step impregnation process resulted in fewer oxygen vacancies due to reduced competitive effects between cerium and manganese. Overall, the optimized Ce-Mn/Al2O3 catalysts demonstrated improved catalytic performance in ozonation reactions, highlighting the importance of impregnation method and calcination conditions in tailoring catalyst properties for enhanced activity and stability. Oxygen vacancies play a crucial role as active sites for ozone adsorption and dissociation into *O2 and *O, facilitated by the reduction of Mn4+ to Mn3+ and the oxidation of Ce3+ to Ce4+. This process forms an electron closed loop that maintains electron balance. The synergistic interactions between cerium and manganese enable rapid electron transfer between Ce4+ and Mn3+, facilitating the regeneration of Ce3+ and Mn4+. Due to the increase of the dual redox conjugate pairs and the surface reactive oxygen species, the catalytic ozonation activity and stability of Ce-Mn/Al2O3 was enhanced.

Catalytic ozonation of reverse osmosis concentrate from coking wastewater reuse by surface oxidation over Mn-Ce/γ-Al2O3: Effluent organic matter transformation and its catalytic mechanism

Degradation of organics in high-salinity wastewater is beneficial to meeting the requirement of zero liquid discharge for coking wastewater treatment. Creating efficient and stable performance catalysts for high-salinity wastewater treatment is vital in catalytic ozonation process. Compared with ozonation alone, Mn and Ce co-doped γ-Al2O3 could remarkably enhance activities of catalytic ozonation for chemical oxygen demand (COD) removal (38.9%) of brine derived from a two-stage reverse osmosis treatment. Experimental and theoretical calculation results indicate that introducing Mn could increase the active points of catalyst surface, and introducing Ce could optimize d-band electronic structures and promote the electron transport capacity, enhancing HO• bound to the catalyst surface ([HO•]ads) generation. [HO•]ads plays key roles for degrading the intermediates and transfer them into low molecular weight organics, and further decrease COD, molecular weights and number of organics in reverse osmosis concentrate. Under the same reaction conditions, the presence of Mn/γ-Al2O3 catalyst can reduce ΔO3/ΔCOD by at least 37.6% compared to ozonation alone. Furthermore, Mn-Ce/γ-Al2O3 catalytic ozonation can reduce the ΔO3/ΔCOD from 2.6 of Mn/γ-Al2O3 catalytic ozonation to 0.9 in the case of achieving similar COD removal. Catalytic ozonation has the potential to treat reverse osmosis concentrate derived from bio-treated coking wastewater reclamation.

Performance evaluation and optimization of a suspension-type reactor for use in heterogeneous catalytic ozonation

Packed fixed-bed reactors are traditionally used for heterogeneous catalytic ozonation. However, a high solid-to-liquid requirement, poor ozone dissolution, ineffective utilization of catalyst surface area, and production of large amounts of catalyst waste impede application of such reactors. In this study, we designed a suspension catalytic ozonation reactor and compared the performance of this reactor with that of a traditional fixed-bed catalytic ozonation reactor employing oxalic acid (OA) as the target contaminant. Our results showed that total O3 dissolved into the suspension reactor (117-134 mg.L-1) was much higher compared to that measured in the fixed-bed reactor (53 mg.L-1) due to a higher O3(g) interphase mass transfer rate in the suspension reactor. In accordance with the higher O3(g) interphase mass transfer, we observed a much higher proportional OA removal (32 %) compared to that achieved in the fixed-bed reactor (10%) employing an Fe-oxide catalyst supported on Al2O3 (Fe-oxide@Al2O3) in both reactors. Use of a double-layered Cu-Al hydroxide (Cu-Al LDHs) catalyst in the suspension reactor further enhanced the performance with nearly 90 % OA removal observed. Given the superior performance of the suspension reactor, we investigated the impact of operating conditions (catalyst dosage, hydraulic retention time and ozone dosage) employing Cu-Al LDHs as the catalyst. We also developed a mathematical kinetic model to describe the performance of the suspension reactor and, through use of the kinetic model, showed that O3(g) interphase transfer rate was the rate-limiting step in OA removal. Thus, improvement in ozone gas diffuser design is required to improve the performance of the suspension reactor. Overall, the present study demonstrated that suspension reactors were more effective than fixed-bed reactors for oxidation of surface-active organic compounds such as OA due to the higher ozone interphase mass transfer rate and effective utilization of the catalyst surface area that can be achieved. As such, further research on suspension reactor design and development of catalysts suitable for use in suspension reactors should facilitate large-scale application of catalytic ozonation processes by the wastewater treatment industry.

Defluorination of perfluorooctanoic acid and perfluorooctane sulfonic acid by heterogeneous catalytic system of Fe-Al2O3/O3: Synergistic oxidation effects and defluorination mechanism

In this study, catalytic ozonation by Fe-Al2O3 was used to investigate the defluorination of PFOA and PFOS, assessing the effects of different experimental conditions on the defluorination efficiency of the system. The oxidation mechanism of the Fe-Al2O3/O3 system and the specific degradation and defluorination mechanisms for PFOA and PFOS were determined. Results showed that compared to the single O3 system, the defluorination rates of PFOA and PFOS increased by 2.32- and 5.92-fold using the Fe-Al2O3/O3 system under optimal experimental conditions. Mechanistic analysis indicated that in Fe-Al2O3, the variable valence iron (Fe) and functional groups containing C and O served as important reaction sites during the catalytic process. The co-existence of 1O2, OH, O2- and high-valence Fe(IV) constituted a synergistic oxidation system consisting of free radicals and non-radicals, promoting the degradation and defluorination of PFOA and PFOS. DFT theoretical calculations and the analysis of intermediate degradation products suggested that the degradation pathways of PFOA and PFOS involved Kolbe decarboxylation, desulfonation, alcoholization and intramolecular cyclization reactions. The degradation and defluorination pathways of PFOA and PFOS consisted of the stepwise removal of -CF2-, with PFOS exhibiting a higher defluorination rate than PFOA due to its susceptibility to electrophilic attack. This study provides a theoretical basis for the development of heterogeneous catalytic ozonation systems for PFOA and PFOS treatment.

Electric field-enhanced heterogeneous catalytic ozonation (EHCO) process for sulfadiazine removal: The role of cathodic reduction

In this work, an electric field-enhanced heterogeneous catalytic ozonation (EHCO) was systematically investigated using a prepared FeOx/PAC catalyst. The EHCO process exhibited high sulfadiazine (SDZ) and TOC removal efficiency compared with electrocatalysis (EC) and heterogeneous catalytic ozonation (HCO) process. Almost 100% of SDZ was removed within 2 min, and the TOC removal reached approximately 85% within 60 min. Quenching experiments and EPR analysis suggested that the prominent SDZ and TOC removal performance is supported by the enhanced ·OH generation ability. Further study proved that H2O2 formed by O2 electrochemical reduction, peroxone reaction and electrochemical reduction of ozone contributed to improving ·OH generation. Furthermore, the EHCO system showed satisfactory stability and recyclability compared to conventional HCO systems, and the SDZ and TOC removal rates were maintained at ≥95% and ≥70% in 16 consecutive recycles, respectively. Meanwhile, XPS analysis and Boehm's titration for the FeOx/PAC catalyst used in HCO and EHCO process confirmed that the external electron supply could restrain the oxidation of surface functional groups of PAC and maintain a balance of the Fe(II)/Fe(III) ratio, which proved the critical role of cathode reduction in catalyst in situ regeneration during long consecutive recycles. In addition, the EHCO system could achieve more than 80% SDZ removal within 2 min in different water matrices. These results confirmed that the EHCO process has a wide application perspective for refractory organics removal in actual wastewater.

Efficient catalytic activity of NiO and CeO2 films in benzoic acid removal using ozone

This research focuses on the synthesis of NiO and CeO2 thin films using spray pyrolysis for the removal of benzoic acid using ozone as an oxidant. The results indicate that the addition of CeO2 films significantly enhances the mineralization of benzoic acid, achieving a rate of over 80% as the CeO2 films react with ozone to produce strong oxidant species, such as hydroxyl radicals, superoxide radicals, and singlet oxygen as demonstrated by the presence of quenchers in the reaction system. The difference in catalytic activity between NiO and CeO2 films was analyzed via XPS technique; specifically, hydroxyl oxygen groups in the CeO2 film were greater in number than those in the NiO film, thus benefitting catalytic oxidation as these species are considered active oxidation sites. The effects of nozzle-substrate distances and deposition time during the synthesis of the films on benzoic acid removal efficiency were also explored. Based on XRD characterization, it was established that the NiO and CeO2 films were polycrystalline with a cubic structure. NiO spherical nanoparticles were well-distributed on the substrate surface, while some pin holes and overgrown clusters were observed in the CeO2 films according to the SEM results. The stability of the CeO2 films after five consecutive cycles confirms their reusability. The retrieval of films is easy because it does not require additional separation methods, unlike the catalyst in powder form. The obtained results indicate that the CeO2 films have potential application in pollutant removal from water through catalytic ozonation.

Single atom catalyst-mediated generation of reactive species in water treatment

Water is one of the most essential components in the sustainable development goals (SDGs) of the United Nations. With worsening global water scarcity, especially in some developing countries, water reuse is gaining increasing acceptance. A key challenge in water treatment by conventional treatment processes is the difficulty of treating low concentrations of pollutants (micromolar to nanomolar) in the presence of much higher levels of inorganic ions and natural organic matter (NOM) in water (or real water matrices). Advanced oxidation processes (AOPs) have emerged as an attractive treatment technology that generates reactive species with high redox potentials (E0) (e.g., hydroxyl radical (HO˙), singlet oxygen (1O2), sulfate radical (SO4˙-), and high-valent metals like iron(IV) (Fe(IV)), copper(III) (Cu(III)), and cobalt(IV) (Co(IV))). The use of single atom catalysts (SACs) in AOPs and water treatment technologies has appeared only recently. This review introduces the application of SACs in the activation of hydrogen peroxide and persulfate to produce reactive species in treatment processes. A significant part of the review is devoted to the mechanistic aspects of traditional AOPs and their comparison with those triggered by SACs. The radical species, SO4˙- and HO˙, which are produced in both traditional and SACs-activated AOPs, have higher redox potentials than non-radical species, 1O2 and high-valent metal species. However, SO4˙- and HO˙ radicals are non-selective and easily affected by components of water while non-radicals resist the impact of such constituents in water. Significantly, SACs with varying coordination environments and structures can be tuned to exclusively generate non-radical species to treat water with a complex matrix. Almost no influence of chloride, carbonate, phosphate, and NOM was observed on the performance of SACs in treating pollutants in water when nonradical species dominate. Therefore, the appropriately designed SACs represent game-changers in purifying water vs. AOPs with high efficiency and minimal interference from constituents of polluted water to meet the goals of water sustainability.

Enhancing water purification through F and Zn-modified Fe-MCM-41 catalytic ozonation

Due to its low interfacial electron migration ability and highly hydrophilic, Fe-MCM-41 (FeM) had poor activity and stability during catalytic ozonation. To this end, the secondary metal Zn and Si-F group were introduced into the framework of FeM to create surface potential difference and hydrophobic sites. Comparative characterizations showed that there existed rich acid sites with great potential difference on F-Fe-Zn-MCM-41 (FFeZnM). Additionally, because of the existence of hydrophobic and electron-withdrawing Si-F unit, the electron migration ability, hydrophobicity and acidity of FFeZnM were enhanced. The greater O3 mass transfer was induced by Si-F group and O3 was directly activated at Fe and Zn Lewis acid sites into •OH, •O2- and 1O2. With •OH acting as main species, FFeZnM/O3 achieved the superior IBP removal (93.4%, 30 min) and TOC removal (46.6%, 120 min) over those of sole O3 and F-FeM/O3 processes, respectively. HCO3-, Cl-, NO3- and SO42- hindered IBP degradation by FFeZnM/O3, but high concentration humic acid (HA) exhibited promotion by forming HA-IBP complex. IBP degradation by FFeZnM/O3 was enhanced with tap water, river water, and effluent from the secondary sedimentation tank of the sewage plant acting as medium. This study proposed an innovative approach to catalyst design for catalytic ozonation.

Mn-doped carbon-Al2SiO5 fibers enable catalytic ozonation for wastewater treatment: Interface modulation and mass transfer enhancement

Heterogeneous catalytic ozonation is an efficient approach to remove hazardous and refractory organic contaminants in wastewater. It is crucial to design an ozone catalyst with high catalytic activity, high mass transfer and facile separation properties. Herein, easily separable aluminosilicate (Al2SiO5) fibers were developed as carriers and after interface modulation, Mn-doped carbon-Al2SiO5 (Mn-CAS) fibrous catalysts were proposed for catalytic ozonation. The growth of carbon shells on Al2SiO5 fiber surface and the introduction of metal Mn provided abundant Lewis acid sites to catalyze ozone. The Mn-CAS fiber/O3 system exhibited superior reactivity to degrade oxalic acid with a rate constant of 0.034 min-1, which was about 19 times as high as Al2SiO5/O3. For coal gasification wastewater treatment, Mn-CAS fibers also demonstrated high catalytic activity and stability and the COD removal was over 56%. Computational fluid dynamic simulations proved the high mass transfer properties of fibrous catalysts. Hydroxyl radicals (•OH) were identified as the predominant active species for organic degradation. Particularly, the catalytic pathways of O3 to •OH on Mn-O4 sites were revealed by theoretical calculations. This work provides a novel fibrous catalyst with high reactivity and mass transfer as well as easy separation characteristics for catalytic ozonation and wastewater purification.