Fenton's Reagent Research Articles

Removal of Methylene Blue dye from aqueous solution using Fenton-modified submerged aquatic plant Schoenoplectus species (Bulrush)

When dumping coloured effluent into the ecosystem, methylene blue dye contributes significantly to environmental health problems. In this investigation, Schoenoplectus species, commonly known as Bulrush, underwent modification using a Fenton reagent to enhance its effectiveness in adsorbing methylene blue (MB) from effluent. The Fenton-treated Bulrush was analysed using SEM, FTIR, BET, and TGA techniques, while various operational parameters were systematically explored to optimise the adsorbent. The FTIR results revealed an increase in the intensity of chemical compounds (–OH, C=C, and C–O, etc.) The FTIR data showed an increase in the intensity of chemical compounds (-OH, C=C, and C-O, among others) and aromatic structures on the exterior of the adsorbent, which aided in MB removal. The results exhibited conformity with the Langmuir model, with an R2 value of 0.9904 with an optimal adsorption capacity of 41.23 mg/g achieved for the Fenton-treated Bulrush. Kinetic analysis indicated adherence to the pseudo-second-order model (R2 = 1), with chemical bonding adsorption primarily governing the adsorption rate. Optimal adsorption conditions were determined to be 26°C, pH 8, a reaction time of 60 minutes, a dosing amount of 2 g, and a preliminary concentration of 100 mg/L. Enhanced pH and increased dosing of Fenton-treated Bulrush led to improved adsorption capacity. Crystal structural characteristics and surface functional groupings of Fenton-treated Bulrush emerged as crucial factors influencing adsorption, describing the three main processes that control MB absorption by the adsorbent: physical adsorption, electrostatic attraction, and π-π interaction. These processes demonstrated the economical, efficient, and environmentally friendly attributes of Fenton-treated Bulrush, which shows promise for eliminating dye contaminants from aquatic environments.

Persistence evaluation of fecal pollution indicators in dewatered sludge and dewatering filtrate of municipal sewage sludge: The impacts of ambient temperature and conditioning treatments

Sludge resource utilization is one of the important routines for transmitting fecal pollution to water and soil, and sludge dewatering is a crucial step for sludge resource utilization. However, it remains unclear the decay characteristics and persistence of fecal pollution indicators after sludge dewatering. In this study, the persistence of six fecal pollution indicators, namely E. coli (EC), human-specific HF183 Bacteroides (HF183), human adenovirus (HAdV), human JC and BK polyomavirus (JCPyV and BKPyV), and crAssphage, in dewatered sludge cake and dewatering filtrate deriving from raw sewage sludge, as well as three types of sludge conditioned with polyacrylamide (PAM), Fenton's reagent, or Fe[III] and CaO were analyzed. The quantitative polymerase chain reaction (qPCR) and viability-qPCR methods were used to analyze the variation in abundances and infectivity of fecal pollution indicators in dewatered sludge cake or dewatering filtrate over the storage time, respectively. Decay predications of fecal pollution indicators over time were modeled using either the first-order or the biphasic decay model. The qPCR results revealed that fecal pollution indicators in dewatered sludge cake persisted longer than those in dewatering filtrate at the same temperature. Increasing temperature can accelerate the decay of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Notably, sludge conditioning treatment may prolong the persistence of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Viability-qPCR results indicated that the fecal pollution indicators (except HAdV) in dewatered sludge cakes deriving from both raw sewage sludge and conditioned sludges remained infectious for up to 30 days. After a storage period of 40 days, the abundances of fecal pollution indicators (except for EC) in sludge conditioned with Fenton's reagent were effectively decreased and meanwhile the infectivity of EC was reduced, exhibiting the lowest levels of fecal pollution. Therefore, both ambient temperature and conditioning treatment greatly impacted the decay characteristics and persistence of fecal pollution indicators in dewatered sludge cake and dewatering filtrate, and selecting suitable conditioning method can minimize environmental risks associated with fecal pollution in sewage sludge.

MoS2 nanosheet assisted poly vinyl alcohol cross-linked with carboxylated acryl-amido-2-methyl-1-propanesulfonic acid in medium temperature proton exchange membrane fuel cell application

ABSTRACT Initially, the carboxylated-acryl amido propane sulfonic acid (C-AMPSA) was synthesized through the thiol-ene reaction using 2-acrylamido-2-methylpropane sulfonic acid and 3-mercapto propane sulfonic acid monomers. The C-AMPSA was cross-linked with polyvinyl alcohol to create a non-perfluorinated membranes were of these acid group-containing monomers. Using a cross-linking technique, a poly vinyl alcohol cross-linked C-AMPSA (PVA-C-AMPSA) polymer was prepared. Following that, the MoS2 nanosheets (NSs) were synthesized through the one-pot hydrothermal method, and their phase purity, functionality, and morphology were evaluated by p-XRD, FT-IR, and FE-SEM analyses. These nanosheets were then incorporated into PVA-C-AMPSA polymer nanocomposite membranes at various concentrations (0%, 1%, 2%, 3%, and 5% by weight). In addition, the physicochemical properties of bare and MoS2 nanosheets incorporated PVA-C-AMPSA polymer nanocomposite membranes were assessed, including water uptake, swelling ratio, and ion-exchange capacity. Remarkably, the membrane with 5% of MoS2 NSs in PVA-C-AMPSA displayed an ion-exchange capacity of 1.13 mmol g−1 and a proton conduction of 1.8 × 10−3 S cm−1 at 110°C. The Arrhenius plot indicated that the proton transport was involved in both Grotthuss and vehicular mechanisms. In the fuel cell testing, the PVA-C-AMPSA polymer nanocomposite membrane containing MoS2 NSs demonstrated superior performance, achieving a peak power density (PD) exceeding 0.7 W cm−2 and an open-circuit voltage (OCV) surpassing 0.93 V at 110°C. In contrast, the pure PVA-C-AMPSA membrane exhibited a peak PD of over 0.4 W cm−2 and an OCV of around 0.6 V at the same temperature. Additionally, the 5% of MoS2 NSs incorporated PVA-C-AMPSA polymer nanocomposite membrane exhibited outstanding oxidative stability with 87.7% of degradation when exhibited to a Fenton reagent at 80°C for 8 h.

The Degradation of Rhodamine B by an Electro-Fenton Reactor Constructed with Gas Diffusion Electrode and Heterogeneous CuFeO@C Particles

Compared with conventional Fenton processes, the electro-Fenton process consumes fewer chemicals and produces less sludge, as it can generate the required Fenton’s reagents in situ. In this work, an electro-Fenton reactor was constructed to treat synthetic rhodamine B (Rh B) wastewater, in which a gas diffusion electrode (GDE) was used as a cathode to produce H2O2, and heterogeneous CuFeO@C particles were used to generate Fe2+ in situ. The results indicated that the gas diffusion electrode made of elements N-S-B and r-graphene oxide (NSB-r-GO) composites produced more H2O2 than the one made from r-graphene oxide (r-GO), under the conditions of 0.1 mol ·L−1 Na2SO4 electrolyte, 10 mA·cm−2 current density, and 1.0 L·min−1 O2 flow rate, with the accumulated H2O2 production reaching 105.43 mg·L−1. Additionally, different iron morphologies, including octahedral Fe (II), octahedral Fe (III), and tetrahedral Fe (III), were found in the calcined CuFeO@C particles, approximately 1.0 mg·L−1 of iron ions dissolved in the electrolyte was detected, which worked simultaneously as conductive electrodes in a conceptual three-dimensional electrochemical reactor consisting of a gas diffusion electrode cathode, Ti/RuSn anode, and CuFeO@C particle electrodes. No external Fenton reagents were necessary.

Architecting side chain grafted poly (vinylidene fluoride) based graphene oxide composite polyelectrolyte membranes for hydrogen and direct methanol fuel cells

Chemically modified poly (vinylidene fluoride) (PVDF) as polyelectrolyte has generated immense interest due to its high efficiency in electrochemical energy devices. Herein, the design of a polymer electrolyte membrane (PEM) is formulated by the synergistic fusion of graphene oxide (GO) into chemically grafted PVDF with 2-acrylamido-2-methylpropane sulfonic acid (AMPS) by solution phase intercalation producing GO@PVDF-g-PAMPS composite membranes. Ozone-induced graft copolymerization technique is employed to prepare PVDF-g-PAMPS with 18.3% (w/w) degree of grafting. Incorporation of GO into the polymeric membrane generates appropriate hydrophilic-hydrophobic phase separation and constructs well-organized sub-nano slit-like pathways that elevate the proton conduction. PAG-0 membrane without any filler shows a proton conductivity (κ) of 15.1 mS/cm at 80°C whereas PAG-2 membrane (with 2% w/w GO loading) shows a κ of 25.9 mS/cm under similar conditions. The presence of a perfluorinated backbone furnishes excellent oxidative stability to the PEMs by retaining 95% of total mass and 97.3% of κ after dipping in harsh Fenton's reagent at 60°C for 6 h. Representative PAG-2 shows a peak power density of 152.9 mW/cm2 with a maximum current density of 480.6 mA/cm2 (fuel cell operating conditions: 75°C at 100% RH) in hydrogen fuel cell and a peak power density of 37.7 mW/cm2 in methanol fuel cell. Moreover, PAG-2 retains 91% of its initial OCV after 50 h of the durability test.

Treatment of Organic Pollutant by Advanced Oxidation Processes

The investigation involved the oxidation of urea (UR) in a batch reactor, employing Fenton's reagent. Various parameters, namely reaction time, pH level, ferrous ion dose, and hydrogen peroxide dose, were scrutinized. The reaction time spanned from 30 minutes to 3 hours, revealing a notably positive impact. An optimal pH of 3 was identified for the medium. The concentrations of ferrous ions ranged from 0.2 g/l to 0.53 g/l, with hydrogen peroxide levels ranging from 1 g/l to 2.65 g/l. The impact of hydrogen peroxide was notably significant at a ferrous ion concentration of 0.3 g/l and a pH of 3. Evaluating urea removal efficiency through chemical oxygen demand (COD) calculations showed a maximum efficiency of 86.8%, with a minimum ammonia yield of 6%. Overall, the outcomes underscored the efficacy of the Fenton process in urea treatment.

Adsorptive removal of naproxen onto nano magnesium oxide-modified castor wood biochar: Treatment of pharmaceutical wastewater via sequential Fenton's-adsorption process.

This current investigation explored the thermal conversion process of castor wood into biochar, which was subsequently harnessed for removing naproxen from pharmaceutical industrial effluent via adsorption. Surface composition analyses conducted through scanning electron microscopy-energy dispersive X-ray, laser-induced breakdown spectroscopy, and Fourier-transform infrared studies unveiled the presence of nano MgO particles within the adsorbent material. Employing optimization techniques such as response surface methodology facilitated a refined approach to batch study. The optimized conditions for batch naproxen sodium (NPX) adsorption on nano-MgO-modified biochar were identified as pH 4, 1.5 g/L adsorbent dosage, and a 120-min contact time maintaining a constant NPX concentration of 10 mg/L. The adsorption capacity was calculated to be 123.34 mg/g for a nano-magnesium oxide-modified castor wood biochar (modified biochar) and 99.874 mg/g for pristine castor wood biochar (pristine biochar). Fenton's reagents comprising 15 mM of FeSO4 (7H2O) and 25 mM of H2O2 have been scrutinized under conditions of pH 3.0, a reaction time of 30 min, a temperature of 30°C, and stirring at 120 rpm, followed by batch adsorption treatment. The COD, NH3-N, NO3 -, PO4 3-, and NPX removal percentages was found to be 90%, 87%, 79%, 80%, and 90%, respectively. Thus nano MgO-modified biochar holds promise of treatment of pharmaceutical effluent.

Impact of Fenton aging on the incipient motion of microplastic particles in open-channel flow

Upon entering the environment, Microplastics (MPs) experience aging processes that modify their properties and integrity. Previous methods for predicting the incipient motion of MPs have been validated using pristine plastics, which do not account for the effects of aging. This can lead to uncertainties in both quantification and characterization. This study investigates the effect of aging on the incipient motion of MPs with different bed roughness (smooth and rough beds) and MP properties (e.g., grain sizes and densities) in an open-channel flow. Five types of MPs were subjected to four different degrees of aging using the Fenton reagent, and their incipient velocities were tested on beds with two distinct roughness. The results suggest that the incipient velocity of MPs increases linearly with aging. However, this increase is not uniform across different particles and bed roughness. Upon comparing various commonly employed sediment incipient velocity equations, experimental results are in agreement with Ruijin Zhang's equation as the most precise. The parameters in Ruijin Zhang's equation are modified to enhance its applicability for predicting the incipient velocity of aged MPs. This study provides novel insights into the incipient motion of aged MPs in an open-channel flow, highlighting the intricate interaction between aged MP characteristics and bed roughness.

Synthesis and characterization of micro-/nano-α-Fe2O3 for photocatalytic dye degradation.

Photocatalytic activity using micro-/nano-α-Fe2O3 on a large scale was carried out using a sol-gel autocombustion method. A degradation time of 60 min was noted for 50 mg of the catalyst. Post characterization, this catalyst system showed a degradation of about 53% (rate = 2.60 × 10-3 min-1) and 17% (rate = 1.38 × 10-2 min-1) under sunlight and up to 45% (rate = 1.13 × 10-3 min-1) and 7% (rate = 1.20 × 10-2 min-1) under a 400 W UV lamp for rhodamine 6G (R6G) and crystal violet (CV), respectively. Sunlight has a broad spectrum of light; it greatly accelerates the degradation process and creates ideal conditions for the reaction to occur. The rate of photocatalytic dye degradation of α-Fe2O3 without Fenton's reagent was found to be 7.84 × 10-3 min-1 in the presence of external air provided (in the photocatalytic setup) through a bubbler and 3.23 × 10-3 min-1 in the absence of the bubbler.

Autophagic cell death induced by pH modulation for enhanced iron-based chemodynamic therapy

Iron-based chemodynamic therapy (CDT) exhibits commendable biocompatibility and selectivity, but its efficacy is constrained by the intracellular pH of tumors. To overcome this obstacle, we constructed a silica delivery platform loaded with autophagy-inducing reagents (rapamycin, RAPA) and iron-based Fenton reagents (Fe3O4). This platform was utilized to explore a novel strategy that leverages autophagy to decrease tumor acidity, consequently boosting the effectiveness of CDT. Both in vitro and in vivo experiments revealed that RAPA prompted the generation of acidic organelles (e.g., autophagic vacuoles and autophagosomes), effectively changing the intracellular pH in the tumor microenvironment. Furthermore, RAPA-induced tumor acidification significantly amplified the efficacy of Fe3O4-based Fenton reactions, consequently increasing the effectiveness of Fe3O4-based CDT. This innovative approach, which leverages the interplay between autophagy induction and iron-based CDT, shows promise in overcoming the limitations posed by tumor pH, thus offering a more efficient approach to tumor treatments.

Enhanced humification attributed by the integration of Fenton reagent and oxalic acid during a co-composting of swine manure and corn straw: Impacts and the possible mechanisms

To illustrate the role and mechanism of using oxalic acid (OA) and Fenton reagent to enhance carbon transformation and humification in the co-composting of swine manure and corn straw, four different treatments, SW1 (Control), SW2 (Fenton reagent), SW3 (10 % OA), and SW4 (Fenton reagent + 10 % OA) were set up for an 80-day pilot-scale composting. Compared with the Fenton pretreatment, the contents of Fe (II) and hydroxyl radicals (·OH) in the SW4 treatment increased by 20.25 %-54.55 % and 6.39 %-71.00 %, respectively. This confirmed the role of OA in protecting Fe (II) and maintaining the generation of ·OH during the composting. Compared with Control, Fenton-like reagent amendment facilitated decomposition of dissolved organic carbon and total organic matter by 20.53 % and 25.37 %, respectively, which led to a higher content of humic substances (141.81 mg/g) and a higher degree of polymerization (3.51) in SW4. Among all, the dissolved organic carbon in the compost substrate of SW4 treatment showed the highest level of aromatization and more refractory organic matter decomposition. The compact microbial co-occurrence network analysis exhibited the high-metabolic activity in Fenton-like treatment (SW4). Therefore, the probable mechanism of humification facilitation by Fenton-like reagent amendment in co-composting could be controlled by several processes: 1) generation of ·OH for facilitating the decomposition of organic matter, 2) disintegration of refractory lignocellulose substances by promoting the lignin pathway of humification, and 3) increasing the quantity and activity of microbes (i.e., Proteobacteria, Actinobacteriota, Chloroflexi, Ascomycota and Basidiomycota) involved in humification. This study provided a profound understanding of Fenton-like reagent amendments in co-composting of agricultural solid wastes and proposes a solution for enhancing the humification degree of compost products for agricultural use.

Phosphomolybdic acid functionalized nano silica for enhanced anti-biofouling effect in polymer electrolyte membranes for microbial fuel cell application

Microbial fuel cells (MFCs) represent a promising technology for simultaneous electricity generation and wastewater treatment. In this study, a single-chambered MFC was fabricated utilizing a novel polymer electrolyte membrane synthesized from sulfonated polyether ether ketone grafted with styrene sulfonic acid (SPEEK/SSA) as the base polymer, and silica decorated with phosphomolybdic acid (SPMA) as a functionalized nanofiller. Various concentrations of SPMA (2.5 %, 5 %, 7.5 %, and 10 %) were incorporated into the SPEEK/SSA membranes and characterized physicochemically. The SPEEK/SSA membrane with 5 wt% SPMA demonstrated the highest proton conductivity (3.75×10−2 S cm−1) and ion exchange capacity (1.68 meq g−1). This PEM also exhibited superior tensile strength (20 MPa) and excellent chemical durability, as evidenced by Fenton's reagent test. Performance evaluation revealed that this membrane achieved a maximum power density of 196.6 mW m−2 at a maximum of 180 mA m−2 current density. Additionally, antibiofouling tests indicated that the 5 % SPMA-incorporated membrane possessed significant antibacterial properties against both gram-positive and gram-negative bacteria and exhibited high biofilm inhibition. The wastewater treatment efficacy of the MFC with the 5 % SPMA membrane was confirmed by a chemical oxygen demand (COD) removal efficiency of 81.49 %, indicating its potential for effective wastewater treatment. Phylogenetic analysis through 16S rRNA sequencing identified major bacterial phyla including Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes, with predominant genera such as Pseudomonas and Acidovorax. This study emphasises the potential of nanocomposite membranes to enhance the performance and durability of MFCs while mitigating biofouling, thereby paving the way for future research and development in this field.

Polycyclic aromatic hydrocarbons (PAHs) in crude oil-contaminated water and soil and their removal using locally available plant materials

ABSTRACT The presence of polycyclic aromatic hydrocarbons (PAHs) in water and soil can be harmful to human life when ingested. PAHs are determined in the water and soil of the B-Dere community of Rivers State, Nigeria. The extent of risk and source identification were carried out. The water samples were treated with garlic and Moringa seed extracts, while the soil samples were treated with garlic and Fenton oxidation reagents. PAHs were extracted before and after treatment. The gas chromatograph mass spectrometer analyses showed 13 PAHs in the water and 10 PAHs in thesoil. The highest concentration in water was recorded for benzo(ghi)perylene, with a mean value of 27.7 ± 0.25 ngL−1, while that of soil was recorded for benz(a)anthracene, with a mean value of 14.4 ± 0.631 ngkg−1. The source of PAHs in water was pyrogenic, while that of soil was petrogenic. Garlic extract removed 100% of benz(a)anthracene and benzo(b)fluorothane from the water, while Moringa removed 100% biphenylene from the water. However, garlic extract removed 2.59% of acenaphthylene, while Fenton reagents removed 100% of anthracene, phenathrene, and chrysene from the soil. Moringa seed and garlic extracts can be used in PAH's polluted water treatment.

Boron removal from wastewater via coordinative adsorption assisted by Fenton-Induced Oxoprecipitation/Flocculation

Chemical precipitation is widely used for boron removal from water in industrial-scale processes, though a following post treatment is generally required to meet the concentration set by current international standards.In this work, chemical precipitation of boron (B) in water by different precipitating agents was combined with Fenton treatment to enhance the boron removal effectiveness. This approach achieved residual boron concentration of less than 0.5 mg/L, hard to achieve through conventional precipitation methods.Batch tests were performed at different dosage of Fenton reagents, and selected Fe2+/H2O2 weight ratios were evaluated with or without adding precipitating agents. The effect of pH on the process was also investigated, to assess the optimal conditions to maximize boron removal. At the end of the process, barium hydroxide was used to remove effectively excess sulfate ions.The sludge produced was characterized by XRD, SEM and FTIR analysis, and the mechanism of boron removal was investigated.An oxoprecipitation mechanism was induced by the Fenton process: boron-based species were converted into borate ion, thus predisposing them to a coordination-type adsorption on the surface of iron and calcium hydroxide, assisted by aluminum sulfate at pH 12.5.The process was then successfully tested on real boron −contaminated wastewater, thus confirming the effectiveness of the process while simultaneously decreasing the organic content.

Trace silver doping improved the efficiency of copper-based Fenton-like catalysts cathode for wastewater treatment

The treatment of highly concentrated and recalcitrant organic pollutants in industrial wastewater has garnered significant attention, with Fenton oxidation emerging as a promising approach. However, traditional iron-based Fenton reagents present certain limitations, and copper-based Fenton systems are often less efficient. Thus, it is necessary to develop innovative copper-based Fenton catalytic materials. In this study, Cu₂O and Ag-modified activated carbon fibers (Cu₂O-Ag@ACF) were synthesized via liquid-phase reduction. The composition, structure, and morphology of Cu₂O-Ag@ACF were systematically characterized. The Cu₂O-Ag@ACF was employed as a functionalized cathode in the electro-Fenton process to degrade a highly concentrated organic pollutant solution, with methylene blue serving as a model contaminant. The loading of Cu₂O and Ag not only enhances the electrochemical performance of ACF but also improves its Fenton oxidation efficiency. Cu₂O-Ag@ACF exhibited less than 1 % performance degradation after five cycles of use, highlighting its potential for industrial applications under simulated realistic conditions. Moreover, the electro-Fenton system parameters, including current density, pH, electrode spacing, and solution temperature, were optimized. Under the optimal conditions, the degradation rate of methylene blue by Cu₂O-Ag@ACF reached 92.8 % within 120 minutes. Kinetic analysis indicated that the reaction followed a first-order kinetic model, with a rate constant of 0.253 min⁻¹. Furthermore, this study revealed that trace silver doping significantly accelerated the generation of reactive oxygen species, thereby enhancing the efficiency of the Cu-based Fenton-like catalysts. In conclusion, this work presents a convenient strategy for the sustainable and efficient purification of industrial wastewater, contributing to the improvement of human life quality.

Source identification, characteristics, and spatial distribution of airborne microplastic deposition in Lahore City, Pakistan.

A large volume of atmospheric microplastics (MPs) has been observed worldwide and is considered an emerging global environmental issue. Nevertheless, no significant assessment of the atmospheric deposition of MPs in Pakistan has been reported yet. The present study was designed to highlight the source, type, and spatial distribution of MPs in atmospheric fallout in Lahore, Pakistan. A total of 23 sites were sampled in Lahore with a heterogeneous background of human activities. All samples were collected in a box with a one-foot depth fitted with a steel tray of 0.1 m2 at the bottom. Fenton's reagent and hydrogen peroxide were used to remove organic matter, and sodium chloride for density separation, while the MPs were quantified through a stereomicroscope, and polymers were identified through ATR-FTIR spectroscopy. The highest deposition rate (particles/m2/day) was observed at Badami Bagh, i.e., 6819, followed by Mall Road 4414, and Chung 4263, while the lowest was in Sabzazaar (i.e., 524) and Township (1047) with an average deposition rate of 2340 ± 1392. Among the MPs, the major portion was fiber, i.e., 96%, while fragment was 1.9%, sheets 0.78%, foams 1.12%, beads 0.04%, and other MPs 0.06%. At all sampling sites, 20 different types of polymers were identified with different percentages, of which polyester fibers were predominant with an abundance of 96.09% associated with clothes and textiles. A high frequency of MPs was found in populated areas with dense traffic, plastic wastes, household plastic materials, and mismanagement of wastes, which accelerates the atmospheric deposition of airborne microplastics. Evaluation and characterization of MP help assess health and environmental impacts, cleanup efforts, and guiding regulations. It also provides valuable information for waste management innovation to reduce plastic pollution.

A High-Methanol-Permeation Resistivity Polyamide-Based Proton Exchange Membrane Fabricated via a Hyperbranching Design.

Four non-fluorinated sulfonimide polyamides (s-PAs) were successfully synthesized and a series of membranes were prepared by blending s-PA with polyvinylidene fluoride (PVDF) to achieve high-methanol-permeation resistivity for direct methanol fuel cell (DMFC) applications. Four membranes were fabricated by blending 50 wt% PVDF with s-PA, named BPD-101, BPD-102, BPD-111 and BPD-211, respectively. The s-PA/PVDF membranes exhibit high methanol resistivity, especially for the BPD-111 membrane with methanol resistivity of 8.13 × 10-7 cm2/s, which is one order of magnitude smaller than that of the Nafion 117 membrane. The tensile strength of the BPD-111 membrane is 15 MPa, comparable to that of the Nafion 117 membrane. Moreover, the four membranes also show good thermal stability up to 230 °C. The BPD-x membrane exhibits good oxidative stability, and the measured residual weights of the BPD-111 membrane are 97% and 93% after treating in Fenton's reagent (80 °C) for 1 h and 24 h, respectively. By considering the mechanical, thermal and dimensional properties, the polyamide proton-exchange membrane exhibits promising application potential for direct methanol fuel cells.

Purification and tailored functionalities in detonation nanodiamond

Abstract Nanodiamonds (NDs) offer immense potential in various fields, but graphitic or metal-based impurities hinder their widespread adoption. Conventional purification methods often employ harsh chemicals or high temperatures, raising concerns about ND integrity and surface properties. Herein, we compared various strategies to purify and tailor the surface functional groups in the detonation-derived NDs. A facile 2-step purification strategy combining salt-assisted air oxidation (SAAO) and Fenton chemistry is particularly interesting for efficient and selective removal of graphitic impurities while preserving the diamond lattice structure. SAAO selectively burns off graphitic impurities at 450 °C under controlled oxygen flow, minimizing damage to the diamond core. Subsequently, Fenton's reagent (H2O2/Fe2+) introduces hydrophilic functional groups onto the ND surface, further enhancing diamond purity and promoting subsequent functionalization. This synergistic approach enables (i) highly efficient removal of graphitic impurities while preserving ND morphology and crystal structure, (ii) controlled introduction of surface functionalities, and (iii) improved colloidal stability of purified NDs. This green and efficient purification protocol is beneficial for tailoring ND properties and unlocking their full potential in diverse applications ranging from biomedicine and electronics to catalysis and quantum technologies.

Degradation of Procion Golden Yellow H-R Dye Using Ultrasound Combined with Advanced Oxidation Process

The current study aims to degrade Procion Golden Yellow H-R through ultrasound-induced cavitation coupled with various oxidants. A comprehensive investigation was conducted to examine the impact of parameters, specifically pH, power, and frequency, on the extent of degradation. The primary aim was to optimize degradation by solely utilizing a cavitation reactor where only 23.8% degradation was observed under the established optimum conditions of pH 2.5, frequency of 22 kHz, and power of 200 W. The investigation of the combined process of cavitation with H2O2, Fenton reagent (H2O2/Fe2+), NaOCl, and potassium persulphate (KPS) was subsequently conducted under optimized conditions. The combined operations greatly enhanced degradation with the use of H2O2 loading of 0.1 g/L leading to 53.3% degradation and the H2O2/Fe2+ ratio of 1:0.25 resulting in 94.6% degradation, while the NaOCl quantum of 0.075 g/L yielded 90% degradation and the KPS quantity of 2 g/L resulted in 97.5% degradation in the specific combinations. A toxicity test on two bacterial strains, Staphylococcus aureus and Escherichia coli, was carried out using the original dye solution and after treatment. The various individual and combination processes were compared using the parameters of cavitational yield and total treatment cost. The study elucidates that combining ultrasonic cavitation with KPS is an effective method for treating wastewater containing Procion Golden Yellow H-R dye, especially when implemented at a larger scale of operation.

Innovating Ferro-sonication approach for extracting microplastics from wastewater

For accurate and reliable analysis of microplastics (MPs) in wastewater (WW), it is imperative to comprehend the significance of pre-treating WW before analysis. The suspended solids (SS) in the matrix tend to adhere to the MPs during filtration, which interferes with the detection of the MPs. In this regard, the present study aims to develop and optimize a pretreatment method to improve the extraction efficiency of MPs from WW by reducing the SS. A combination of the Fenton reaction and ultrasonication, ferro-sonication (Fe-UlS), was proposed to digest and eliminate the SS from WW. This hybrid pretreatment, Fe-UlS, was optimized for ultrasonication amplitude, treatment time, and hydrogen peroxide dose using response surface methodology (RSM) with a Box-Behnken design, achieving a desirability of 0.984. The optimum conditions for the Fe-UlS, such as the (1:1) Fenton reagent ratio (0.05 M FeSO4: 30 % H2O2), ultrasonication amplitude (31 %), and total process time (30 min) were found to be statistically significant (p < 0.05). The developed method was then employed for the extraction of spiked polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) MPs in real WW and found efficient in removing 83 % of the TSS present in the primary influent were in 30 min at a temperature of 45 °C. Also, the method did not affect the physio-chemical characteristics of the MPs; however, the thermal analysis of PE and PP MPs showed a statistically significant decrease in the melting temperature, as proven by paired t-test analysis. Further, a non-targeted liquid chromatography-mass spectrometry (LC-MS) analysis proved that Fe-UlS is a stable process, as it did not cause any leaching of MPs under the optimum pretreatment conditions. Finally, Laser Direct-Infrared Imaging (LD-IR) analysis was conducted to validate the developed Fe-UlS pretreatment approach for MP analysis in real WW. About 3434 MPs were detected in 100 mL of WW primary influent, within the size range of 9 to 500 μm. This hybrid pretreatment approach not only streamlines WW sample processing but also reduces the required concentration of Fenton reagent and processing time, yielding accurate and reliable results for monitoring MPs in WW.