Advanced Oxidation Processes Research Articles

Selective O2-to-H2O2 Electrosynthesis by a High-Performance, Single-Pass Electrofiltration System Using Ibuprofen-Laden CNT Membranes.

Producing H2O2 through a selective, two-electron (2e) oxygen reduction reaction (ORR) is challenging, especially when it serves as an advanced oxidation process (AOP) for cost-effective water decontamination. Herein, we attain a 2e-selectivity H2O2 production using a carbon nanotube electrified membrane with ibuprofen (IBU) molecules laden (IBU@CNT-EM) in an ultrafast, single-pass electrofiltration process. The IBU@CNT-EM can generate H2O2 at a rate of 25.62 mol gCNT-1 h-1 L-1 in the permeate with a residence time of 1.81 s. We demonstrated that an interwoven, hydrophilic-hydrophobic membrane nanostructure offers an excellent air-to-water transport platform for ORR acceleration. The electron transfer number of the ORR for IBU@CNT at neutral pH was confirmed as 2.71, elucidating a near-2e selectivity to H2O2. Density functional theory (DFT) studies validated an exceptional charge distribution of the IBU@CNT for the O2 adsorption. The adsorption energies of the O2 and *OOH intermediates are proportional to the H2O2 selectivity (64.39%), higher than that of the CNT (37.81%). With the simple and durable production of H2O2 by IBU@CNT-EM electrofiltration, the permeate can actuate Fenton oxidation to efficiently decompose emerging pollutants and inactivate bacteria. Our study introduces a new paradigm for developing high-performance H2O2-production membranes for water treatment by reusing environmental functional materials.

Deposition of Titanium Dioxide Particles on Kanthal Coils by Direct Heating Technique for Photodegradation of Methylene Blue Solution

Organic dyes are extensively used in textile and batik industry. Dispose of untreated dye effluent into water system is hazardous to human and environment. Advanced oxidation process (AOPs) based on heterogeneous TiO2 photocatalyst is proven for effluent treatment. Immobilization of TiO2 photocatalyst on supporting substrate is one of the research focuses to realize its application in industry to minimize the loss of TiO2 photocatalyst over time during effluent treatment. Many synthesis techniques have been used to grow TiO2 photocatalyst on supporting substrates. However, these synthesis techniques are either time- or cost-consuming. In this work, a novel direct heating (DH) technique has been developed for the first time to deposit TiO2 particles on kanthal coils. The optimum deposition of TiO2 particles was achieved in 15 min using 60 W. The TiO2 particles contained mixture of anatase (82.7%) and brookite (17.3%), with an average particle size of 167.36±15.37 nm. The surface coverage of TiO2 particles on kanthal wire was good, with minimum agglomeration. The TiO2 particles deposited on kanthal coils recorded 43.7% of photodegradation efficiency in methylene blue removal under UV light.

A Review of the Mechanisms of Single-Atom-Based Advanced Oxidation Processes for the Degradation of Persistent Organic Pollutants in Water Environments

A Review of the Mechanisms of Single-Atom-Based Advanced Oxidation Processes for the Degradation of Persistent Organic Pollutants in Water Environments

A Critical Review of Deep Oxidation of Gaseous Volatile Organic Compounds via Aqueous Advanced Oxidation Processes.

Volatile organic compounds (VOCs) are considered to be the most recalcitrant gaseous pollutants due to their high toxicity, diversity, complexity, and stability. Gas-solid catalytic oxidation methods have been intensively studied for VOC treatment while being greatly hampered by energy consumption, catalyst deactivation, and byproduct formation. Recently, aqueous advanced oxidation processes (AOPs) have attracted increasing interest for the deep oxidation of VOCs at room temperature, owing to the generation of abundant reactive oxygen species (ROS). However, current reviews mainly focus on VOC degradation performance and have not clarified the specific reaction process, degradation products, and paths of VOCs in different AOPs. This study systematically reviews recent advances in the application of aqueous AOPs for gaseous VOC removal. First, the VOC gas-liquid mass transfer and chemical oxidation processes are presented. Second, the latest research progress of VOC removal by various ROS is reviewed to study their degradation performances, pathways, and mechanisms. Finally, the current challenges and future strategies are discussed from the perspectives of synergistic oxidation of VOC mixtures, accurate oxidation, and resource utilization of target VOCs via aqueous AOPs. This perspective provides the latest information and research inspiration for the future industrial application of aqueous AOPs for VOC waste gas treatment.

A Combination of Adsorption and Photocatalysis Processes for the Removal of Direct Blue 71 (DB71) Dye on Fe-Doped Layered Double Hydroxides

Pollution in ecosystems has increased, especially in water, due to the pollutant agents that alter their chemical, physical and biological characteristics. This requires actions to resolve or at least reduce the harmful effects generated on the environment and people’s health. Many of the contaminants present in water come from the industrial sector, with the textile industry being one of the most impactful as it uses mostly synthetic dyes, which are characterized as being recalcitrant and toxic, so they cannot be degraded by conventional water treatment methods. Advanced oxidation processes have a great potential for application, especially those that use heterogeneous photocatalysis. The present research evaluates the efficiency in the adsorption and degradation of the triazoic Direct Blue 71 dye in aqueous mediums at concentrations of 600 ppm by the heterogeneous photocatalysis method. The photocatalysts used are layered double hydroxides (LDHs) with a Mg/Al = 3 ratio and are thermally activated and doped with Fe at 1, 3 and 5% w/w. The most efficient materials achieved removal percentages greater than 80% by means of a second-order kinetic model with a DB71 half-life decolorization of less than one hour; as shown by an HPLC study, the absence of intermediate products would confirm the mineralization of the dye.

Sustainable photodegradation of tetracycline by surface-functionalized carbon nitride: Mechanism insight and toxicity assessment

Here, we report the facile preparation of amino- and vacancies-abundant carbon nitride photocatalyst using acetone as a low-boiling-point solvent and describe its successful performance of environmental purification. As a demonstration of the notion, tetracycline (TC) antibiotic as an emerging aqueous contaminant has been used as a model substrate for assessing the photoactivity of the modified carbon nitride and clarifying its intrinsic mechanism. 96 % of TC can be photocatalytically removed within 30 min, accompanied by a discernible mitigation in ecotoxicological impact. Reactive species, including •OH, •O2-, and photogenerated holes, are considered the critical oxidants. Meanwhile, the possible intermediates and transformation pathways of TC degradation were investigated utilizing the LC-MS technique, the Fukui function, and the T.E.S.T. software. The comprehensive approach furnishes valuable insights for assessing the evolutionary dynamics of tetracycline in an advanced oxidation process (AOP). This study offers a sustainable, cost-effective, and eco-friendly approach to preparing carbon nitride material, which is believed to open an avenue for the facile design of heterogeneous environmental photocatalysts and to provide insights into the various environmental applications.

Decolorization of Acid Red 337 dye with hydroxyl and sulfate radical based advanced oxidation processes using different iron Catalyst: An experimental and statistical Investigation

The removal efficiencies of Acid Red 337 dye were investigated by combining advanced oxidation processes based on OH and SO4− radicals. The photocatalytic oxidation processes were carried out at the natural pH (5.4) and acidic pH (3.0) values of the dye solution. In the experiments, iron (II) sulfate (Fe2+) and potassium ferrioxalate (FeOx) were used as catalysts, hydrogen peroxide (H2O2) and peroxymonosulfate (PMS) were used as oxidants to compare dye removal efficiency and to determine the optimum doses. This comparison provided the opportunity to identify suitable catalysts and oxidants for dye removal. Furthermore, time-based comparisons were conducted from 2 to 10 min using the optimum catalyst doses. It was obtained that PMS was more effective as an oxidant in the presence of both iron catalysts for colour removal. The colour removal efficiency of 98.2 % was achieved in the PMS/Fe2+/UV process with doses of 1 mM PMS and 0.1 mM Fe2+ at pH 5.4 and an irradiation time of 10 min. In experiments using light-sensitive ferrioxalate (FeOx), colour removal was achieved in the PMS/FeOx/UV process with an efficiency of 97.8 %. Additionally, an artificial neural networks (ANNs) model effectively optimized the oxidation parameters, with predicted values closely matching the experimental data. The ANNs model yielded excellent statistical performance, with a root mean square error (RMSE) of 0.0317, 0.0223 and coefficient of determination (R2) of 0.9690 and 0.9854 for UV/Fe2+/H2O2-UV/FeOx/H2O2 and UV/Fe2+/PMS-UV/FeOx/PMS oxidation systems respectively.

Iron–Cobalt Bimetallic Metal–Organic Framework-Derived Carbon Materials Activate PMS to Degrade Tetracycline Hydrochloride in Water

Organic pollutants entering water bodies lead to severe water pollution, posing a threat to human health. The activation of persulfate advanced oxidation processes using carbon materials derived from MOFs as substrates can efficiently treat wastewater contaminated with organic pollutants. This research uses NH2-MIL-101(Fe) as a substrate, doped with Fe2+ and Co2+, to prepare Fe/Co-CNs through a one-step carbonization method. The surface morphology, pore structure, and chemical composition of Fe/Co-CNs were investigated using characterization techniques such as XRD, SEM, TEM, XPS, FT-IR, BET, and Raman. A comparative study was conducted on the performance of catalysts with different Fe/Co ratios in activating PMS for the degradation of organic pollutants, as well as the effects of various influencing factors (the dosage of Fe/Co-CNs, the amount of peroxymonosulfate (PMS), the initial pH of the solution, the TC concentration, and inorganic anions) on the catalyst’s activation of persulfate for TC degradation. Through radical quenching experiments and post-degradation XPS analysis, the active radicals in the FeCo-CNs/PMS system were investigated to explain the possible mechanism of TC degradation in the Fe/Co-CNs/PMS system. The results indicate that Fe/Co-CNs-2 (with a Co2+ doping amount of 20%) achieves a degradation rate of 93.34% for TC (tetracycline hydrochloride) within 30 min when activating PMS, outperforming other Co2+ doping amounts. In addition, singlet oxygen (1O2) is the main reactive species in the reaction system.

High-efficiency and stable Z-scheme heterojunction of Co9S8 anchored by g-C3N4 for peroxymonosulfate activation

Photocatalytic technology and peroxymonosulfate (PMS) based advanced oxidation technology have been proven to be simple and effective strategies for recalcitrant organic pollutants degradation. In this work, we designed and prepared a coupled photocatalytic and advanced oxidation system for sulfamethazine (SMR) antibiotics degradation. Firstly, a series of Z-scheme Co9S8/g-C3N4 heterojunction photocatalysts are prepared by a simple two-step method and further work as PMS activators. The prepared Co9S8/g-C3N4 photocatalysts exhibit a great improvement in electron-hole pairs migration and visible-light response due to heterojunction formation. In addition, the g-C3N4 acts as a substrate to anchor the Co9S8 nanoparticle, which suppresses the Co9S8 leaching and prevents the Co9S8 oxidation. Consequently, the Co9S8/g-C3N4/PMS system displayed an improved SMR degradation ability (93 % for Co9S8/g-C3N4/PMS vs. 86 % for Co9S8/g-C3N4). After the fourth cyclic degradation experiment, the Co9S8/g-C3N4/PMS system still maintained a comparatively high degradation rate. Considering its good properties and better degradation performance, we propose that the synergistic effect of photocatalytic technology and PMS possess a promising prospect for application in environmental treatment.

Effect, Fate and Remediation of Pharmaceuticals and Personal Care Products (PPCPs) during Anaerobic Sludge Treatment: A Review.

Biomass energy recovery from sewage sludge through anaerobic treatment is vital for environmental sustainability and a circular economy. However, large amounts of pharmaceutical and personal care products (PPCPs) remain in sludge, and their interactions with microbes and enzymes would affect resource recovery. This article reviews the effects and mechanisms of PPCPs on anaerobic sludge treatment. Most PPCPs posed adverse impacts on methane production, while certain low-toxicity PPCPs could stimulate volatile fatty acids and biohydrogen accumulation. Changes in the microbial community structure and functional enzyme bioactivities were also summarized with PPCPs exposure. Notably, PPCPs such as carbamazepine could bind with the active sites of the enzyme and induce microbial stress responses. The fate of various PPCPs during anaerobic sludge treatment indicated that PPCPs featuring electron-donating groups (e.g., ·-NH2 and ·-OH), hydrophilicity, and low molecular weight were more susceptible to microbial utilization. Key biodegrading enzymes (e.g., cytochrome P450 and amidase) were crucial for PPCP degradation, although several PPCPs remain refractory to biotransformation. Therefore, remediation technologies including physical pretreatment, chemicals, bioaugmentation, and their combinations for enhancing PPCPs degradation were outlined. Among these strategies, advanced oxidation processes and combined strategies effectively removed complex and refractory PPCPs mainly by generating free radicals, providing recommendations for improving sludge detoxification.

Trimetallic MOF–derived Fe–Mn–Sn oxide heterostructure enabling exceptional catalytic degradation of organic pollutants

Developing efficient and environmentally benign heterogeneous catalysts that activate peroxymonosulfate (PMS) for the degradation of persistent organic contaminants remains a challenge. Metal–organic frameworks (MOFs)–derived metal oxide catalysts in advanced oxidation processes (AOPs) have received considerable attention research fraternity. Herein, we report an innovative magnetic trimetallic MOF-derived Fe-Mn-Sn oxide heterostructure (FeMnO@Sn) with adjustable morphology, size and Sn content, prepared through an impregnation–calcination strategy. The formation of a novel magnetic Fe2O3/Fe3O4/Mn3O4 heterostructure induces the generation of abundant Fe2+ and Mn2+ sites on the FeMnO@Sn surface. Meanwhile, the introduction of SnO2 into the Fe2O3/Fe3O4/Mn3O4 heterostructure facilitates the cleavage of the OO bond in adsorbed PMS. The synergy among the different functionalities of each metal oxide plays a vital role in the swift and effective degradation of pollutants. In addition, the uniquely designed catalyst exhibits magnetic properties that facilitate easy recycling and repeated use, thereby meeting environmental protection requirements. Overall, this research highlights the design of heterogeneous catalysts for the effective activation of PMS and provides valuable insights for the advancement of future environmental catalysts.

Unveiling the heterojunction of Fe3O4@MXene nanocatalyst for ultrafast degradation of antibiotics via non-radical pathway

The transfer of advanced oxidation processes (AOPs) to real-world applications faces several technology challenges involving oxidation performance, catalyst cost, poor reactive oxygen species (ROS) yield, and long-term stability. This work aims to develop a reactive, efficient, and stable MXene-based nanocatalyst, namely Fe3O4@Ti3C2Tx, for ultrafast removal of the selected sulfonamide antibiotics. As revealed by extensive nanocatalyst characterization, the MXene surface not only anchors Fe/Fe3O4 nanoparticles (NPs) but also prevents NP agglomeration. Notably, the conductive interface between MXene and Fe3O4 promotes the Fe(II)/Fe(III) redox cycle and accelerates peroxymonosulfate (PMS) activation. The Fe3O4@Ti3C2Tx demonstrates excellent catalytic activity by achieving complete sulfamethoxazole (SMX) degradation within 6 min and maintained its catalytic activity after 5 continuous cycles. In the Fe3O4@Ti3C2Tx/PMS system, multiple ROS (e.g., •OH, SO4•-, O2•-) are involved but 1O2 was found to be the primary ROS for SMX degradation. The presence of co-exiting inorganic impurities and pH changes may hinder SMX degradation. Finally, elucidating possible degradation pathways of SMX would greatly aid in treating antibiotic-containing wastewater.

Enhancing the degradation of microplastics through combined KMnO4 oxidation and UV radiation

The pervasive issue of microplastics in aquatic environments presents a formidable challenge to traditional water treatment methodologies, including those utilizing KMnO4. This study pioneers advanced oxidation processes (AOPs) method aimed at improving the degradation of PE microplastics by employing a dual treatment strategy that combines KMnO4 oxidation with UV irradiation. Detailed analysis of the surface modifications and chemical functional groups of the treated PE microplastics revealed the establishment of Mn-O-Mn linkages on their surfaces. Weight reductions of 3.9%, 4.9%, and 7.5% were observed for the KMnO4/UVA, KMnO4/UVB, and KMnO4/UVC treatments over seven days, respectively. The emergence of carboxyl and hydroxyl groups played a crucial role in accelerating the degradation process. Notably, the combined application of UVC rays and KMnO4 resulted in the most effective degradation of PE microplastics observed in our study. The process significantly enhanced the formation of MnO2 particles from KMnO4 oxidation, with concentrations ranging from 0.036 to 0.070 mM for KMnO4/UVA, 0.066–0.097 mM for KMnO4/UVB, and 0.086–0.180 mM for KMnO4/UVC. Furthermore, the influence of varying pH levels, KMnO4 concentrations, and different water sources on the degradation efficacy was investigated. The pivotal role of free radicals and reactive manganese species in promoting the degradation of PE microplastics was identified. A comparative evaluation with treatments solely utilizing KMnO4 or UV light highlighted the enhanced effectiveness of the combined approach, demonstrating its potential as an efficient solution for reducing microplastic contamination in aquatic systems.

In-depth analysis of the roles and mechanisms of sulfate radical and hydroxyl radical in the degradation of metal-cyanide complexes

Persulfate-based advanced oxidation processes (PS-based AOPs), characterized by the coexistence of SO₄•⁻ and HO•, have been proven effective in treating a series of cyanide-bearing pollutants. However, the mechanisms of these reactive species in the degradation of cyanides, especially metal-cyanide complexes, remain unclear or contradictory. The degradation behavior of representative cyanides (including potassium cyanide and potassium ferricyanide) at different pH conditions (2, 7 and 12) in thermally activated persulfate system (T = 60 °C) was explored, and the roles of SO₄•⁻ and HO• in cyanide degradation were explored by leveraging the distinct characteristics of reactive species under different pH conditions. The study found that both HO• and SO₄•⁻ can react with free cyanide (CN⁻ and HCN). However, the reaction barrier between CN⁻ and HO• is lower than that between HCN and SO₄•⁻, resulting in a higher removal rate of free cyanide under alkaline conditions compared to acidic and neutral conditions. For complexed cyanide, the complex bonds in ferricyanide were completely broken within 24 h by thermally activated persulfate at pH 2, releasing free cyanide, indicating the effectiveness of SO₄•⁻ in breaking the Fe-C bonds in ferricyanide. In contrast, ferricyanide was barely decomposed at pH 12, implying the inefficacy of HO• in breaking the Fe-C bonds. This study also innovatively found that SO₄•⁻ breaks the Fe-C bonds by oxidizing Fe(Ⅲ) in ferricyanide to Fe(Ⅳ) or Fe(Ⅴ), releasing CN⁻, which is then converted to CNO⁻ by SO₄•⁻ and HO•. CNO⁻ is further mineralized to NO₃⁻, NH₄⁺, and N₂ through hydrolysis or oxidation reactions. This research clarifies, for the first time, the activity of SO₄•⁻ and HO• toward cyanide degradation in PS-based AOPs.

Study on Fenton-based discoloration of reactive-dyed waste cotton prior to textile recycling

The aim of this study is to investigate the feasibility of an alternative Fenton-based advanced oxidation process for the discoloration of reactive-dyed waste cotton as a pre-treatment for textile recycling. For that, pre-wetted dark-colored (black and blue) knitted samples of 300 cm2 are treated in 1200mL Fenton-solution containing 14 mM Fe2+ and 280mM H2O2 at 40 °C. Characterization of the textiles before and after the treatments are performed by UV VIS-spectrophotometry measuring color strength, microscopy, FTIR spectroscopy, thermal analysis and tensile testing measuring tenacity and elongation. Afterwards, the cotton is mechanically shredded for qualitative analysis of the recyclability. The color-strength measurements of the black and blue cotton led to discoloration-efficiencies of respectively 61.5 and 72.9%. Microscopic analysis of discolored textile fabric also showed significant fading of the colored textiles. Mechanical analysis resulted in reduced tensile strength after treatment, indicating oxidation of the cellulosic structure besides the degradation of the dye-molecules, also confirmed by reductions in thermal stability found after thermal analysis. Shredding of the fabric resulted in enhanced opening, but shorter remaining fibers after treatment. The findings of this study provide a proof-of-concept for an alternative color-stripping treatment concerning a Fenton-based advanced oxidation process as a pre-treatment for textile recycling.

Broad spectrum catalysis using Ca3Sn2S7 Ruddlesden-Popper perovskite under multi-stimulus

Advanced oxidation processes emerged as effective alternatives to traditional approaches. The efficacy of these methods significantly depends on the intrinsic properties of a catalyst material. Semiconductor materials with robust photo absorption alongside inherent polarization emerged as subjects of great interest. In this study, we synthesized two-dimensional Ca3Sn2S7 nanosheets oriented as Ruddlesden-Popper type perovskite structure. The optimal compositions of these nanosheets exhibit excellent physical and optical characteristics while varying Sn ratios significantly impact the properties. Impressively, these compositions boast a wide optical window that spans from the visible to the far infrared region, featuring a narrow bandgap of approximately 0.6 eV. Band potentials in a positive regime make it highly favorable for the oxidation process. The electrochemical analysis further validates high mobility with low resistance in both compositions. The catalytic efficiency of the synthesized nanosheets is evaluated using rhodamine-B. Three energy sources, i.e., visible light, laser, and ultrasound vibrations, decomposed 96 %, 90 %, and 78 %, respectively, in 30 min. Remarkably accelerated degradation rates are achieved under each stimulus, owing to the presence of oxidative optical bands, large surface area, and potential internal polarization within the nanosheets. Preliminary findings strongly indicate the immense potential of this compound in catalytic and photovoltaic applications.

Evaluation of the acute phytotoxicity of phototreated textile effluent using cucumber (Cucumis sativus) and radish seeds (Raphanus sativus)

Water, as a vital resource, plays a crucial role in human activities, notably in the textile industry, whose operations can significantly impact the quality of this resource. It is imperative to explore solutions, such as the adoption of advanced oxidative processes, which encompass the degradation of dyes present in effluents through the action of hydroxyl radicals. To evaluate the effectiveness of this treatment, acute phytotoxicity tests are carried out to analyze the responses of plant organisms to the effluents. Therefore, this study aimed to assess the acute phytotoxicity of a natural textile effluent subjected to heterogeneous photocatalysis and homogeneous photo-fenton treatments. Acute phytotoxicity tests were performed with cucumber (Cucumis sativus) and radish (Raphanus sativus) seeds, both for the treated effluent and in natura. The results revealed a sensitivity of cucumber seeds to effluent in natura and resistance to radish seeds. Regarding the phototreated effluents, the results showed an increase in seed germination rate and contributed to enhance this germination. Phytotoxic tests were also carried out with sodium chloride and sodium sulfate, and the toxicity of these substances to cucumber and radish seeds was confirmed.

Cu-Co binary metal-organic framework nanosheets for highly efficient degradation of norfloxacin using the Fenton-like process

Efficient catalyst development for hydrogen peroxide activation is crucial in advanced oxidation processes (AOPs) technology. In this study, we successfully synthesized a bimetallic organic framework incorporating Cu-Co MOF nanosheets via a one-pot strategy. The subsequent Cu-Co MOF nanosheets demonstrated outstanding oxidative activity, achieving a remarkable 95.37 % removal of norfloxacin (NOR), surpassing the efficacy of Cu MOF/H2O2 or Co MOF/H2O2 nanosheets alone by 1.34 and 2.59 times, respectively. Density functional theory (DFT) calculations revealed that the bimetallic MOF nanosheets: firstly, enhanced optimization of the adsorption energy for H2O2 activation; and secondly, facilitated the cleavage of the O–O bond in H2O2. Furthermore, electrochemical impedance spectroscopy (EIS) analysis demonstrated a significant improvement in interfacial electron transfer once dual-reaction centers were introduced into the Cu-Co MOF nanosheets. Electron paramagnetic resonance analysis and quenching tests confirmed that 1O2, ·O2− and ·OH were involved in NOR degradation. Reasonable NOR degradation pathways were proposed by analysing the results of LC-MS and DFT calculations. Moreover, the synthesized nanosheets exhibited excellent reusability, with more than 90.00 % NOR removal achieved using the Cu-Co MOF nanosheets/H2O2 system after reuse on 3 occasions. These findings underscore the effectiveness of bimetallic MOF construction in developing highly efficient MOF-based Fenton-like catalysts. Also highlighted here is the promising role of Cu-Co MOF nanosheets in wastewater treatment, particularly for the removal of antibiotics.

Construction and evaluation of electrophotocataltic tubular reactor in phenol degradation

Contamination of the environment is one of the main threats to achieving sustainability. Even though there have been significant legal efforts to regulate parameters for effluent disposal, conventional treatment methods often prove to be ineffective, resulting in the incomplete removal of pollutants. This inefficiency leads to serious environmental issues, such as the toxicity of biomes, which is closely related to the bioaccumulation of harmful substances. In response to this challenge, this study aimed to develop and optimize an electrophotocatalytic reactor for the remediation of a synthetic phenol solution using advanced oxidative processes (AOPs). By applying these processes, we observed that the characteristics of the reaction medium allowed for a maximum pollutant removal yield of 54.73% over a 3-hour operation period in a continuous recirculation regime. Despite the promising results, the study revealed the influence of additional factors that were not considered, which are likely important in further optimizing the reactor's efficiency for real-world applications.

Ultrasound-Assisted Advanced Oxidation Process Using Perovskite-Type LaMnO3 Nanospheres.

Among the perovskite oxide community, La-based perovskites have garnered considerable interest due to their remarkable properties including catalytic, electrocatalytic, photocatalytic, sensing, electrical, magnetic, and optical characteristics. Herein, rhodamine-B (RB) dye has been reported to be sono-catalytically decomposed by an ultrasound-assisted advanced oxidation process (AOP) using perovskite-type LaMnO3 (LMO) nanospheres synthesized via ultrasonic approach. Several physiochemical characterizations such as XRD, FT-IR, XPS, SEM, TEM, and SEM-EDS investigations were used to investigate the LMO perovskite nanospheres. Then, LMO potential for adsorption and the sonocatalytic decolorization of RB dye in an aqueous solution are examined. With LMO perovskites, the adsorption and removal kinetics of RB correspond to the pseudo-first-order model. Furthermore, by utilizing the pseudo-first-order, the RB dye process is removed with improved efficacy in the following sequence: Agitation alone: 3.76×10-4 min-1<US only: 5.02×10-3 min-1<LMO only: 5.85×10-3 min-1<LO@MO + US: 1.38×10-2 min-1<LMO + US: 1.75×10-2 min-1, accordingly. Perovskite-type LMO, which has significant reusability and stability, is an ensuring sonocatalyst for dye decomposition in wastewater, enabling faster decolorization. A prospective mechanism has been suggested for the sonocatalytic decomposition of RB.