Oxidation Technology Research Articles

Synergistic effects of peroxydisulfate on UV/O3 process for tetracycline degradation: Mechanism and pathways

Tetracycline (TC) as a typical emerging pollutant is becoming a serious threat to the environment and human health. A combined advanced oxidation technology of UV/Ozone (O3)/peroxydisulfate (PDS) process was developed to explore an efficient and economic treatment process of TC in wastewater. Furthermore, the reactive sites and transformation pathways of TC were explored and the toxicity of the intermediates was quantified with a quantitative structure-activity relationship (QSAR) assessment. The degradation performance of TC was substantially enhanced in UV/O3/PDS process with a kobs of 0.0949 min−1, which was 2.3 times higher than UV/O3 and 3.2 times than sole UV. The results demonstrated that there was a superior synergistic effect of PDS on UV/O3 processes for the degradation of TC. Electron paramagnetic resonance (EPR) analysis and quenching experiments show that •OH, SO4•−, O2•− and 1O2 all contributed to TC degradation in the UV/O3/PDS process and exhibited a synergistic effect, which inhibited the generation of harmful products. In addition, the UV/O3/PDS system can effectively degrade TC in a wide range of substrate concentrations and pH, and also showed excellent adaptability to various concentrations of anions (Cl− and HCO3−). This study proves the feasibility of UV/O3/PDS process for treating TC contaminated wastewater with complicated water matrix.

Research Progress in the Treatment of High-Salinity Wastewater

The generation of high-salinity wastewater is closely associated with various industries, containing a plethora of dissolved salts such as chlorides, sulfates, and carbonates, which pose a significant threat to the environment and human health. Consequently, the treatment of high-salinity wastewater has emerged as a pivotal environmental challenge in contemporary society. This review aims to elucidate the sources and characteristics of high-salinity wastewater, as well as the current status and trends in the field of high-salinity wastewater treatment. First and foremost, we explore the means by which high-salinity wastewater is generated in different industries and the principal salt components it contains. We revisit conventional methods for high-salinity wastewater treatment, including chemical precipitation, ion exchange, evaporation-crystallization, and reverse osmosis, while emphasizing the application of biotechnological approaches. This includes the utilization of salt-tolerant microorganisms, biological adsorption, biodegradation processes, and various types of bioreactors. Advanced oxidation technologies also play a crucial role in high-salinity wastewater treatment. We introduce advanced oxidation techniques such as ozone oxidation, UV-catalyzed oxidation, and high-pressure water oxidation, emphasizing their potential in degrading organic compounds and reducing salt concentration. Furthermore, we discuss hybrid approaches, such as case studies combining biological treatment with advanced oxidation technologies, and the advantages and challenges associated with these integrated techniques. Finally, we provide an outlook on future trends, including research on novel and efficient biodegrading agents, advancements and innovations in advanced oxidation technologies, and the development of intelligent high-salinity wastewater treatment systems. Policy and industry trends will also influence the direction of high-salinity wastewater treatment field development. In summary, high-salinity wastewater treatment represents a complex and pressing environmental challenge. However, through the integration of diverse treatment technologies and ongoing research efforts, it is anticipated that more effective, cost-efficient, and environmentally friendly solutions can be developed to mitigate the impact of high-salinity wastewater on ecosystems and society.

Rapid Plasma Electrolytic Oxidation Synthesis of Intermetallic PtBi/MgO/Mg Monolithic Catalyst for Efficient Removal of Organic Pollutants.

The intermetallic PtBi/MgO/Mg monolithic catalyst was first prepared using non-equilibrium plasma electrolytic oxidation (PEO) technology. Spherical aberration-corrected transmission electron microscope (ACTEM) observation confirms the successful synthesis of the PtBi intermetallic structure. The efficiency of PtBi/Mg/MgO catalysts in catalyzing the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4 was demonstrated. The activity factor for the catalyst is 31.8 s-1 g-1, which is much higher than reported values. In addition, the resultant catalyst also exhibits excellent catalytic activity in the organic pollutant reaction of p-nitrobenzoic acid (p-NBA) and methyl orange (MO). Moreover, benefiting from ordered atomic structures and the half-embedded PtBi nanoparticles (NPs), the catalyst demonstrates excellent stability and reproducibility in the degradation of 4-NP. This study provides an example of a simple method for the preparation of intermetallic structures as catalysts for organic pollutant degradation.

Degradation of sulfonamide antibiotic via UV/MgO2 system: kinetic, application, and mechanism.

In response to antibiotic residues in the water, a novel advanced oxidation technology based on MgO2 was used to remediate sulfamethazine (SMTZ) pollution in aquatic environments. Upon appropriate regulation, the remarkable removal efficiency of SMTZ was observed in a UV/MgO2 system, and the pseudo-first-order reaction constant reached 0.4074 min-1. In addition, the better performance of the UV/MgO2 system in a weak acid environment was discovered. During the removal of SMTZ, the pathways of SMTZ degradation were deduced, including nitration, ring opening, and group loss. In the mineralization exploration, the further removal of residual products of SMTZ by the UV/MgO2 system was visually demonstrated. The qualitative and quantitative researches as well as the roles of reactive species were valuated, which revealed the important role of ·O2-. Common co-existing substances in actual wastewater such as NO3- HA, Cl-, Fe2+, Co2+, and Mn2+ can slightly inhibit the degradation of SMTZ in the UV/MgO2 system. Finally, the capacity of efficient degradation of SMTZ in actual wastewater by the UV/MgO2 system was proved. The results indicated that the innovative UV/MgO2 system was of great practical application prospect in antibiotic residue wastewater remediation.

Treatment of Monochlorobenzene from Polymers Process through Electrochemical Oxidation.

With the rapid development of the economy and the demands of people's lives, the usage amount of polymer materials is significantly increasing globally. Chlorobenzenes (CBS) are widely used in the industrial, agriculture and chemical industries, particularly as important chemical raw materials during polymers processes. CBS are difficult to remove due to their properties, such as being hydrophobic, volatile and persistent and biotoxic, and they have caused great harm to the ecological environment and human health. Electrochemical oxidation technology for the treatment of refractory pollutants has been widely used due to its high efficiency and easiness of operation. Thus, the electrochemical oxidation system was established for the efficient treatment of monochlorobenzene (MCB) waste gas. The effect of a single factor, such as anode materials, cathode materials, the electrolyte concentration, current density and electrode distance on the removal efficiency (RE) of MCB gas were first studied. The response-surface methodology (RSM) was used to investigate the relationships between different factors' conditions (current density, electrolyte concentration, electrode distance), and a prediction model was established using the Design-Expert 10.0.1 software to optimize the reaction conditions. The results of the one-factor experiments showed that when treating 2.90 g/m3 MCB gas with a 0.40 L/min flow rate, Ti/Ti4O7 as an anode, stainless steel wire mesh as a cathode, 0.15 mol/L NaCl electrolyte, 10.0 mA/cm2 current density and 4.0 cm electrode distance, the average removal efficiency (RE), efficiency capacity (EC) and energy consumption (Esp) were 57.99%, 20.18 g/(m3·h) and 190.2 (kW·h)/kg, respectively. The results of the RSM showed that the effects of the process parameters on the RE of MBC were as follows: current density > electrode distance > electrolyte concentration; the interactions effects on the RE of MBC were in the order of electrolyte concentration and current density > current density and electrode distance > electrolyte concentration and electrode distance; the optimal experimental conditions were as follows: the concentration of electrolyte was 0.149 mol/L, current density was 18.11 mA, electrode distance was 3.804 cm. Under these conditions, the RE achieved 66.43%. The response-surface variance analysis showed that the regression model reached a significant level, and the validation results were in agreement with the predicted results, which proved the feasibility of the model. The model can be applied to treat the CBS waste gas of polymer processes through electrochemical oxidation.

Remediation of a non-steroidal anti-inflammatory drug from aqueous solutions using cobalt ferrite-photocatalytic membranes

CoFe2O4-PES photocatalytic membranes were assessed for Naproxen degradation in water. The degradation obeyed first-order reaction kinetics (Kapp: 1.25 × 10−3 min−1 - 3.90 × 10−3 min−1). Surface roughness altered the collision dynamics of reactive species. It enhanced the chances of successful collision between Naproxen and reactive radicals. Membrane hydrophilicity improved the generation of reactive radicals by minimizing the blockage of active sites. Intermediates detected by Quadrupole Time-of-Flight Mass Spectrometry showed that Naproxen degraded via demethylation, hydroxylation, and ring-opening reactions. Leaching studies investigated the stability of the prepared membranes. CoFe2O4-PES membranes can be used in advanced oxidation technologies for water treatment.

Sulfate Radical-Based Advanced Oxidation Technology to Remove Pesticides From Water A Review of the Most Recent Technologies

Sulfate Radical-Based Advanced Oxidation Technology to Remove Pesticides From Water A Review of the Most Recent Technologies

MOF-derived FeOx with highly dispersed active sites as an efficient catalyst for enchaning catalytic oxidation of VOCs

Highly efficient and stable catalysts serve as the crucial factor in VOCs catalytic oxidation technology. Iron-based materials are recognized as potential VOCs catalysts due to their cost-effectiveness and non-toxic nature. However, the limited catalytic performance of traditional iron oxide catalysts hinders their further industrial applications. A series of FeOx catalysts were synthesized via pyrolysis of Fe-based MOFs with diverse morphologies for toluene catalytic oxidation. Characterization results demonstrated that the FeOx-100 catalyst performed optimal characteristics, including the abundant specific surface area and smaller crystallite size, which offered highly dispersed active sites and defects for toluene oxidation. The catalytic activity of FeOx-100 was improved by adjusting the precursors and pyrolysis conditions, achieving a 50% toluene conversion at 223 °C and 90% conversion at 249 °C. The redox abilities of FeOx catalysts were carefully evaluated to assess their impact on catalytic activity. The results confirmed that FeOx-100 exhibited superior low-temperature reducibility, remarkable presence of surface active oxygen and lattice oxygen species, jointly facilitating the toluene oxidation performance at lower temperatures. The results of in situ DRIFTS provided evidence supporting a degradation pathway for toluene, likely proceeding as follows: toluene→ benzaldehyde→ benzoate→ anhydride → …→ CO2 and H2O.

Comparative study of Fe2+/H2O2 and Fe2+/persulfate systems on the pre-treatment process of real pharmaceutical wastewater.

Advanced oxidation technologies based on hydroxyl radical (•OH) and sulfate radical (SO4-•) are two common types of advanced oxidation technologies, but there are not many reports on the application of advanced oxidation methods in actual wastewater pretreatment. This article compares the pre-treatment performance of Fe2+/H2O2 and Fe2+/Persulfate systems in actual pharmaceutical wastewater, and combines EEM, GC-MS, and toxicity testing results to explore the differences in TOC, COD, and NH3-N removal rates, optimal catalyst dosage, applicable pH range, toxicity of effluent after reaction, and pollutant structure between the two systems. The results indicate that the Fe2+/H2O2 system has a higher pollutant removal rate (TOC: 71.9%, COD: 66.9%, NH3-N: 34.1%), but also requires a higher catalyst (Fe2+) concentration (6.0 g/L), and its effluent exhibits characteristic peaks of aromatic proteins. The Fe2+/Persulfate system has a wider pH range (pH ≈ 3-7) and is more advantageous in treating wastewater containing more cyclic organic compounds, but the effluent contains some sulfur-containing compounds. In addition, toxicity tests have shown that the toxicity reduction effect of the Fe2+/Persulfate system is stronger than that of the Fe2+/H2O2 system.

Z-Type Heterojunction MnO2@g-C3N4 Photocatalyst-Activated Peroxymonosulfate for the Removal of Tetracycline Hydrochloride in Water.

A Z-type heterojunction MnO2@g-C3N4 photocatalyst with excellent performance was synthesized by an easy high-temperature thermal polymerization approach and combined with peroxymonosulfate (PMS) oxidation technology for highly efficient degrading of tetracycline hydrochloride (TC). Analysis of the morphological structural and photoelectric properties of the catalysts was achieved through different characterization approaches, showing that the addition of MnO2 heightened visible light absorption by g-C3N4. The Mn1-CN1/PMS system showed the best degradation of TC wastewater, with a TC degradation efficiency of 96.97% following 180 min of treatment. This was an approximate 38.65% increase over the g-C3N4/PMS system. Additionally, the Mn1-CN1 catalyst exhibited excellent stability and reusability. The active species trapping experiment indicated •OH and SO4•- remained the primary active species to degrade TC in the combined system. TC degradation pathways and intermediate products were determined. The Three-Dimensional Excitation-Emission Matrix (3DEEM) was employed for analyzing changes in the molecular structure in TC photocatalytic degradation. The biological toxicity of TC and its degradation intermediates were investigated via the Toxicity Estimation Software Test (T.E.S.T.). The research offers fresh thinking for water environment pollution treatment.

Synthesis of CeO2-loaded composite catalysts of ZIF-67 for activation of persulfate degradation of Congo red dye

One of the most widely used and promoted synthetic dyes in the world is azo dyes, and the treatment of azo dyes wastewater is a hot issue. Currently, advanced oxidation technology is able to treat dye wastewater efficiently and the most critical means is to seek for suitable catalysts to activate the free radicals. In this study, ZIF-67@CeO2 composites were successfully synthesised by heating and refluxing and it degraded Congo red dye by activation of persulfate. The morphological structure of the composites was observed by using SEM, TEM, XPS, XRD, FT-IR and BET characterisation. In addition, the effects of different factors on the degradation of Congo red dye by the catalytic system were studied. And it was found that the best catalytic effect could be achieved at pH = 7, CeO2 loading of 0.3 g, and composite and potassium persulfate dosage of 10 mg and 0.3 g/L, respectively, and the degradation rate of the Congo red dye reached 98.8 %. Furthermore, the composite was able to maintain a better catalytic degradation effect after 4 cycles of regeneration experiments. Therefore, the ZIF-67@CeO2 composite as a new catalyst has a good application prospect in water treatment, which opens up a new avenue for the development of high-performance catalysts.

An Overview of the Progress made in Research on Odor Removal in Water Treatment Plants

Odor is one of the most intuitive indicators for assessing drinking water quality in waterworks. Removing odors is of great importance to improve the quality of tap water, ensure people’s health, and address public perception. The effective identification of odors in drinking water and the exploration of the source of the odor are the prerequisites for eliminating odors. Therefore, this article first discusses the sources and types of odors that are typical in current drinking water, focuses on reviewing the research progress of odor removal technologies in water treatment plants, including adsorption technology, chemical oxidation technology, biodegradation technology and combined technology, and explains the advantages, disadvantages, principles, research progress, practical application scenarios, considerations and application prospects of each odor-removal technology. It is expected to provide a reference for controlling odor pollution in drinking water.

Methods for eliminating micropollutant from wastewater: A review

The amount of suspended solid and medicinal micropollutants, such as fungicides, personal care products, contraceptive medications, antibiotics and aromatic hydrocarbons are increasing daily and has reached an alarming level. The micropollutant present in wastewater must be treated before its release because it forms adverse effect on mortal health. Because some harmful micropollutants are incredibly difficult to remove from WWTPs because of their nonbiodegradability, poor adsorption capability, complex nature and traditional wastewater treatments are precious or insufficient for decontamination. For the micropollutant declination some of the conventional physicochemical has been used. The use of powdered activated carbon (PAC) for water purification has been proven to be effective without harming the environment. Advanced oxidation technologies (AOTs), typically applied after natural processes have recently emerged as effective tertiary treatments for the withdrawal of micropollutants at high concentrations. Various methods have been developed and studied for the removal of these micropollutants from wastewater. This review aims to provide a comprehensive overview of the different methods employed, including physical, chemical, and biological processes, highlighting their effectiveness and limitations in micropollutant removal. As well as improving treatment efficiency, they can also remove any accumulation of dangerous byproducts produced during treatment.

Comparison of methods for enhancing gold recovery from double refractory concentrates using the technology of autoclave oxidation

The study aims to investigate the most efficient method for significant minimization of the impact of organic carbon on gold recovery from double refractory raw materials. We tested three double refractory gold-sulfide concentrates from different deposits with the content of gold from 23.5 to 40.9 g/t and total carbon from 1.2 to 9.5 wt %. Thermal treatment was carried out in a tubular rotary furnace that provided permanent temperature setting and rotation speed in the reactor. The initial concentrate was grinded as pulp in a Fritsch planetary mono mill Pulverisette 6. Autoclave oxidation was performed in Premex and Büchi titanium autoclaves. The technology of autoclave oxidation with the addition of a secondary oxidizer was found to be the most efficient, since it can increase gold recovery up to 97%. Another technology – hightemperature autoclave oxidation – also proved high performance; however, a significant increase in the residence time of the material in the autoclave (up to 120 min) at elevated temperatures is required to achieve this performance. According to the results, thermal treatment in general can provide a small increase in gold recovery (up to 4%). Due to this, it can be used as an additional processing with other methods analyzed in this article rather than as a self-sufficient technological solution. The studies revealed that the preliminary thermal treatment of concentrates entering autoclave oxidation shows a positive effect; high-temperature autoclave oxidation of concentrates with different carbon content provides high gold recovery for high-carbon concentrates; the use of a secondary oxidizer (in the form of nitric acid) also benefits the gold recovery. The high efficiency of the technology for concentrates with different carbon content allows us to recommend it for further research.

Photocatalytic activation of peroxymonosulfate (PMS) by CNN@NH2-MIL-101(Fe) Z-scheme heterojunction for phthalates degradation under visible light irradiation

Phthalates (PAEs) are known to pose a serious threat to the environment and human health duo to their endocrine disrupting effects, thus a great deal of effort has been made to develop destruction technologies for PAEs treatment in the water environment, such as peroxymonosulfate (PMS)-based advanced oxidation technology. Here we prepared an environmentally friendly visible light catalyzer, a heterojunction of carbonitride nanosheets (CNN) doped with NH2-iron metal organic frameworks (NH2-MIL-101(Fe)), for the activation of PMS to efficaciously remove two representative PAEs—diisobutyl phthalate (DIBP) and diethyl phthalate (DEP)—from the aquatic environment. The CNN@NH2-MIL-101(Fe) photocatalyst possesses an excellent visible light harvesting performance with a narrow band gap (1.66 eV), low recombination ratio of photoinduced carriers, and long charge lifetime. The pore volume and surface area of the composite material was increased compared with any single component. The optimum CNN@NH2-MIL-101(Fe) catalyst manifested the high performance to activate PMS to degrade DIBP and DEP under visible irradiation with maximum removal of 94.5 ± 2.2 % and 83.4 ± 0.9 %, respectively. Four main active species (•OH, O2−•, SO4−•, and h+) were involved in PAEs photodegradation, with h+ and SO4−• playing a key role in the degradation of DIBP, and h+ in the degradation of DEP. The degradation mechanism of DIBP and DEP mainly involved the ester bond cleavage and oxidationby active species. Additionally, the CNN@NH2-MIL-101(Fe) heterojunction exhibited high and stable catalytic performance to activate PMS for PAEs destruction under pH 3 – 9. Therefore, this study provides a new strategy for designing and selecting environment-friendly treatment approach for the effective eradication of PAEs via a PMS-based advanced oxidation process.

New insights into toxicity reduction and pollutants removal during typical treatment of papermaking wastewater

Papermaking wastewater contained various of toxic and hazardous pollutants that pose significant threats to both the ecosystem and human health. Despite these risks, limited research has addressed the detoxification efficiency and mechanism involved in the typical process treatment of papermaking wastewater. In this study, the acute toxicity of papermaking wastewater after different treatment processes was assessed using luminousbacteria, zebrafish and Daphnia magna (D. magna). Meanwhile, the pollution parament of the corresponding wastewater were measured, and the transformation of organic pollutant in the wastewater was identified by three-dimensional fluorescence and other techniques. Finally, the possible mechanism of toxicity variation in different treatment processes were explored in combination with correlation analyses. The results showed that raw papermaking wastewater displayed high acute toxicity to luminousbacteria, and exhibited slight acute toxicity and acute toxicity effect to zebrafish and D. magna, respectively. After physical and biochemical processes, not only the toxicity of the wastewater to zebrafish and D. magna was completely eliminated, but also the inhibitory effect on luminousbacteria was significantly reduced (TU value decreased from 11.07 to 1.66). Among them, the order of detoxification efficiency on luminousbacteria was air flotation > hydrolysis acidification > IC > aerobic process. Correlation analyses revealed a direct link between the reduced of Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) and the detoxification efficiency of the different processes on the wastewater. In particular, the removal of benzene-containing aromatic pollutant correlated positively with decreased toxicity. However, the Fenton process, despite lowering TOC and COD, increased of the acute toxicity of the luminousbacteria (TU value increased from 1.66 to 2.33). This may result from the transformation generation of organic pollutant and oxidant residues during the Fenton process. Hence, oxidation technologies such as the Fenton process, as a deep treatment process, should be more concerned about the ecological risks that may be caused while focusing on their effectiveness in removing pollutant.

Preparation of metal organic frame derived MgO-porous carbon composite and its high catalytic activity in ozonation with excellent stability

BackgroundOzone-based advanced oxidation technology has been extensively studied so far, but is hardly successfully used in treating actual wastewater. Preparation of a catalyst with high activity and stability, and insensitivity to quencher is still a big challenge in this field. MethodThe calcination of MOF-74 in inert gas resulted in a composite of the MgO-porous carbon, in which 2 nm MgO nanoparticles were uniformly distributed in porous carbon. Significant findingsThe specific surface area of MgO-PC composite (531.16 m²/g) was about 15 times that of MgO. The results of MgO-PC catalytic ozonation indicated it had not only high activity in ozonation of different organic but also excellent stability. The constant rate of p-CBA degradation in O3/MgO-PC only decreased from 11.63 × 10−2 min−1 to 9.36 × 10−2 min−1 after consecutive 15 cycles of the catalyst owing to the coating of porous carbon on nano particles of MgO. The most important thing is that O3/MgO-PC is a little insensitive to the free radical quenchers, which is an amazing result in progress of heterogeneous catalytic ozonation.

Prospects for refractory gold-sulfide ore processing

Cyanide-refractory ores constitute 30 % of the world’s gold mineral resource base. With the global decrease in the availability of high-grade and free-milling ores, low-quality ores, including those rich in sulfur and arsenic, are increasingly being processed. The authors have conducted an assessment of the primary factors complicating the leaching process of refractory gold. These factors include the influence of gold distribution within the ore, the presence of preg-robbing effects, and the impact of cyanicidal minerals, notably pyrrhotite, on the leaching process. Sulfide minerals significantly affect the kinetics of gold leaching and associated reagent costs. The behavior of Fe5S6 is elucidated through the concept of “chemical depression”. Under cyanide leaching conditions, pyrrhotite actively and directly reacts with NaCN/KCN, undergoing surface oxidation by dissolved oxygen in the pulp. This leads to the formation of ferrocyanide complexes and rhodanides, which are unable to leach gold. Presently, there are two approaches to enhance the process parameters of refractory ore processing technology. The first approach involves the inclusion of preparation operations for cyanidation, aimed at liberating gold from the sulfide matrix (including hydrometallurgical and pyrometallurgical oxidation technologies and mechanical activation). An alternative approach is to use alternative reagents as leaching agents (notably thiourea, sodium and ammonium thiosulfates, and halides). The article explores means of modifying the technological process for gold extraction when ores contain substantial amounts of pyrrhotite or concentrates.

Mechanistic insights and DFT analysis of bimetal doped styrofoam-like LaFeO3 perovskites with in-built dual redox couples for enhanced Photo-Fenton degradation of Tetracycline

The rising number of contaminants released into the environment and the inadequacies of traditional wastewater treatment techniques have led to the demand for enhanced oxidation technologies like photo-Fenton. In this study, bimetal co-doped lanthanum orthoferrite (BixLa1-xCuyFe1-yO3 (x = 0, 0.01, 0.05, 0.1; y = 0, 0.01, 0.05, 0.1, 0.15)) based photo-Fenton catalysts with the in-built redox couples Fe3+/Fe2+, Cu2+/Cu+ and oxygen vacancies have been successfully synthesised via a facile one-pot solution combustion route. Systematic studies show that the Bi0.05La0.95Cu0.1Fe0.9O3 (LFOBC) exhibits an optimal photo-Fenton degradation rate of 0.0497/min for Tetracycline (TC) removal, being ∼ 1.8 and ∼ 6.2 times greater than Bi0.05La0.95FeO3 (LFOB) and pristine LaFeO3 (LFO) respectively. DFT analysis confirmed the better adsorption and dissociation of H2O2 on a bimetal co-doped catalyst and identified the electron density difference in LFOBC, which can induce the H2O2 dissociation. A detailed investigation of various influencing reaction parameters is explored. The degradation pathway for the LFOBC catalyst with the toxicological characteristics of each intermediate is analysed. This study presents the Bi0.05La0.95Cu0.1Fe0.9O3 as a potential photocatalyst for enhanced photo-Fenton degradation with excellent efficiency observed for the degradation of various harmful pollutants for environmental remediation.

Synthesis of Cu/Mn/Ce polymetallic oxide catalysts and catalytic ozone treatment of wastewater.

Non-homogeneous ozone-catalyzed oxidation technology is one of the effective ways of treating wastewater, the core of which lies in the development of efficient ozone oxidation catalysts. This work proposes the design and synthesis of an efficient Cu/Mn/Ce multi-metal composite oxide catalyst by metal salt precursor mixing-direct granulation. The effect of metal doping on the catalyst properties was compared using Density function theory (DFT) calculations, and the Cu/Mn/Ce co-doping showed significant charge accumulation effect with a low ozonolysis energy barrier, which is more favorable for the generation of reactive oxygen species. The successful loading of the main active metal components, such as Mn, Cu, and Ce, was clarified by systematic characterization by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Brunauer-Emmett-Teller's test (BET), and the chemical oxygen demand (COD) removal could reach more than 60% for the simulated wastewater. The electron paramagnetic resonance (EPR) characterization clarified that the degradation of organic pollutants was mainly dominated by the combination of single-linear oxygen and superoxide radicals in the catalytic process, and the possible catalytic oxidation mechanism was proposed. This work advances the development of non-homogeneous ozone oxidation technology.