Application In Wastewater Treatment Research Articles

A novel synthesis method of magnetic Janus particles for wastewater applications

HypothesisMagnetic particles are widely used in many adsorption and removal processes. Among the many types of magnetic colloids, magnetic Janus particles offer significant possibilities for the effective removal of several components from aqueous solutions. Nevertheless, the synthesis of structures integrating different types of materials requires scalable fabrication processes to overcome the limitations of the available methodologies. Herein, we hypothesized a fabrication process for dual-surface functionalized magnetic Janus particles. ExperimentsThe primary silica particles with surface-attached amine groups are further asymmetrically modified by iron oxide nanoparticles, exploiting Pickering emulsion and electroless deposition techniques. The dual surface functionality of the particles is designed for its versatility and demonstrated in two wastewater-related applications. FindingsWe show that our design can simultaneously remove chromium (VI) and phenol from aqueous solution. The fabricated magnetic-responsive Janus particles are also an effective adsorbent for genomic Deoxyribonucleic acid (DNA) and show superior performance to commercial magnetic beads. Thus, this study provides a novel platform for designing magnetic Janus particles with multifunctional surfaces for wastewater treatment applications.

Thermodynamic study and the development of a support vector machine model for predicting adsorption behavior of orange peel-derived beads in wastewater treatment

This study investigates the use of orange peels as a precursor for synthesizing sodium alginate-encapsulated beads for methylene blue (MB) removal. The prepared beads (BOP1 and BOP2) underwent characterization through FTIR, XRF, SEM and TGA. Subsequently, the impacts of various factors, including temperature, the initial pH, initial concentration, salt and humic acid, are studied. The adsorption isotherms show high adsorbed quantities of 764.92 and 659.78 mg/g for BOP1 and BOP2 respectively, while the obtained data are best described by the monolayer with two energies (MMTE) model, which is then used to perform a thermodynamic study of the MB adsorption mechanism. Additionally, the adsorption kinetics data are modeled using three models, with the PFO model identified as the most appropriate. The regenerated beads demonstrate the ability to be reused up to 7 cycles, The effects of NaCl and humic acid on MB adsorption reveal that NaCl inhibits adsorption due to competition with Na+, while humic acid has no effect. Finally, a support vector machine (SVM) model optimized by the Levy Flight Distribution Optimization (LFD) algorithm is developed and found to be capable of accurately predicting the adsorption behavior of the prepared beads. This model is then used in optimizing the process conditions for maximal MB removal. Overall, this study demonstrates that the prepared beads could be potential low-cost and environmentally friendly adsorbents for wastewater treatment applications.

Synthesis of aluminum alginate/graphene oxide/boehmite biopolymeric nanohybrid for the decontamination of Cu(II) and 2-chlorophenol

BackgroundSustainable biomaterials are crucial in wastewater treatment applications and are constantly in demand. Multifunctional nanohybrids can eliminate organic and inorganic pollutants from wastewater. MethodsHerein, aluminum alginate/graphene oxide/boehmite (Al-Alg/GO/AlOOH) has been synthesized and characterized using Fourier Transform Infrared Spectrophotometer (FT-IR), Transmission Electron Microscopy (TEM), and X-ray diffraction (XRD). The scavenging of 2-chlorophenol (2-CP) and copper (II)) onto synthesized hybrid biopolymer has been investigated as a function of reaction time, influence of pH, initial concentrations, and temperatures. Significant FindingsThe adsorption of Cu(II) onto Al-Alg/GO/AlOOH nanohybrid was more favorable than the 2-CP. The scavenging of Cu(II) and 2-CP was pH dependent and optimum adsorption capacity was found 83 mg/g for Cu(II) at pH 5.5 and 63 mg/g at pH 9.0 for 2-CP, respectively. The Cu(II) and 2-CP adsorption best fit the Redlich-Peterson (R-P) isotherm model. The equilibrium kinetic data for Cu(II) adsorption was fitted well to the Elovich model, and 2-CP adsorption was closely fitted to the pseudo-first-order (PFO) kinetic model. Cu(II) scavenging was spontaneous and endothermic, while, 2-CP adsorption was exothermic. Cu(II) and 2-CP adsorption mechanisms onto Al-Alg/GO/AlOOH have proposed mainly attraction forces, complexation, and hydrogen bonding. After five successive regenerations, Al-Alg/GO/AlOOH was considered a recyclable and promising adsorbent for removing organic and inorganic pollutants from the contaminated aquatic environment.

Photocatalytic activity of barium titanate composites with zinc oxide doped with lanthanide ions for sulfamethoxazole degradation

This comprehensive study delves into the structural and optical characteristics of barium titanate (BT) and zinc oxide (ZnO) heterostructures doped with europium (Eu), erbium (Er), and ytterbium (Yb), alongside their application in the photodegradation of sulfamethoxazole antibiotic (SMX). The heterostructures, prepared via a hydrothermal process, exhibit a heterogeneous connection between doped ZnO nanoparticles and the BT dielectric material with crystalline nature and chemical composition. Moreover, a significant reduction in the bandgap of the doped BT@ZnO:Ln heterostructures compared to undoped counterparts, indicating successful dopant incorporation and the creation of new sub-bands within the bandgap. A minimal adsorption interaction between SMX and the nanomaterials was observed. While BT alone exhibited limited photocatalytic activity, doping with ZnO significantly enhanced performance. Notably, the BT@ZnO:Yb heterostructure exhibited exceptional SMX degradation (99%) within 60 minutes. Incorporation of rare-earth ions (Eu, Er, Yb) not only improved photocatalytic activity but also acted as electron scavengers, mitigating electron-hole recombination. Furthermore, the investigation into the reuse of BT@ZnO:Yb 5%mol showed sustained high efficiency over three cycles. Mechanistic insights into SMX degradation pathways highlight the predominant role of hydroxyl radicals and electron-hole processes. Overall, these findings contribute significantly to the advancement of photocatalytic materials based on composites doped with lanthanide ions for applications in environmental wastewater treatment.

Organic pollutants degradation by a superb MXene-based Z-scheme heterojunction Photocatalyst: Synthesize, delamination process, mechanism and toxicity assessment

In this study, a new CeO2/MXene-TiO2 photocatalyst was created using a simple and economical approach and thoroughly characterized by different techniques, including TEM, XPS, BET, XRD, Raman, and SEM. The focus of this research was to improve the degradation of tetracycline (TC), a commonly used antibiotic with known environmental and health risks. To optimize the degradation process, RSM- CCD method was used to systematically vary key parameters including initial TC concentration, photocatalyst dosage, pH and irradiation time. The trapping experiments were revealed that the hydroxyl (•OH) and superoxide anion (•O2-) radicals played a crucial role in this process. An impressive degradation efficiency of 96.60 % was achieved under optimal conditions, attributed to the Z-scheme electron transfer heterojunction, which enhances the generation and separation of oxidant species. LC-MS analysis was employed to elucidate the photodegradation pathway of TC by identifying the reaction intermediates. This analysis facilitated the proposal of a plausible mechanism for TC degradation. The demonstrated efficacy of the CeO₂/MXene-TiO₂ photocatalyst suggests its potential application in wastewater treatment for the significant degradation of persistent organic contaminants.

Phosphorylated chitin from shrimp shell waste: A robust solution for cadmium remediation

In this work, chitin (CT) was isolated from shrimp shell waste (SSW) and was then phosphorylated using diammonium hydrogen phosphate (DAP) as a phosphorylating agent in the presence of urea. The prepared samples were characterized using Scanning Electron Microscopy (SEM) and EDX-element mapping, Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA/DTG), conductometric titration, Degree of Substitution (DS) and contact angle measurements. The results of characterization techniques reveal the successful extraction and phosphorylation of chitin. The charge content of the phosphorylated chitin (P-CT) was 1.510 mmol·kg−1, the degree of substitution of phosphorus groups grafted on the CT surface achieved the value of 0.33. The adsorption mechanisms appeared to involve electrostatic attachment, specific adsorption (CdO or hydroxyl binding), and ion exchange. Regarding the adsorption of Cd2+, the effect of the adsorbent mass, initial concentration of Cd2+, contact time, pH, and temperature were studied in batch experiments, and optimum values for each parameter were identified. The experimental results revealed that P-CT enhanced the Cd2+ removal capacity by 17.5 %. The kinetic analyses favored the pseudo-second-order model over the pseudo-first-order model for describing the adsorption process accurately. Langmuir model aptly represented the adsorption isotherms, suggesting unimolecular layer adsorption with a maximum capacity of 62.71 mg·g−1 under optimal conditions of 30 °C, 120 min, pH 8, and a P-CT dose of 3 g·L−1. Regeneration experiments evidenced that P-CT can be used for 6 cycles without significant removal capacity loss. Consequently, P-CT presents an efficient and cost-effective potential biosorbent for Cd2+ removal in wastewater treatment applications.

Ultraviolet technology application in urban water supply and wastewater treatment in China: Issues, challenges and future directions

This study thoroughly explores the application of Ultraviolet (UV) water treatment technology in urban wastewater treatment and water supply in China, highlighting its crucial role in enhancing water quality safety. UV technology, with its environmentally friendly and low-carbon characteristics, is deemed more in line with the demands of sustainable development compared to traditional chemical disinfection methods. The widespread application of UV technology in urban wastewater treatment in China, particularly in the context of urban sewage treatment, is examined. However, to better promote and apply UV technology, there is a need to deepen the understanding of this technology and its application among a broad base of users and design units. The importance of gaining in-depth knowledge about the performance of UV water treatment equipment, the design calculation basis, and operational considerations, as well as the ongoing development of relevant standards, is underscored to ensure that the equipment used in projects complies with engineering design and production requirements. Furthermore, the positive trend of UV technology in the field of advanced oxidation, indicating a promising trajectory for engineering applications, is pointed out. Regarding the prospects of industrial development, a thorough analysis is conducted in the article, emphasizing the necessity for all stakeholders to collaborate and adopt a multi-level approach to promote the sustainable development and application of UV water treatment technology. This collaborative effort is crucial for providing effective safeguards for China's environment, ecology, and human health.

Isolation and characterization of Stenotrophomonas pavanii GXUN74707 with efficient flocculation performance and application in wastewater treatment.

The identification of microorganisms with excellent flocculants-producing capability and optimization of the fermentation process are necessary for the wide-scale application of bioflocculants. Therefore, we isolated and identified a highly efficient flocculation performance strain of Stenotrophomonas pavanii GXUN74707 from the sludge. The optimal fermentation and flocculation conditions of strain S. pavanii GXUN74707 was in fermentation medium with glucose and urea as the carbon and nitrogen sources, respectively, at pH 7.0 for 36 h, which treatment of kaolin suspension with 0.5 mL of the fermentation broth resulted in a flocculation rate of 99.0%. The bioflocculant synthesized by strain S. pavanii GXUN74707 was found mainly in the supernatant of the fermentation broth. Chemical analysis revealed that the pure bioflocculant consisted of 79.70% carbohydrates and 14.38% proteins. The monosaccharide components of MBF-GXUN74707 are mainly mannose (5.96 μg/mg), galactose (1.86 μg/mg), and glucose (1.73 μg/mg). Infrared spectrometric analysis showed the presence of carboxyl (COO-), hydroxyl (-OH) groups. The SEM images showed clumps of rod-shaped bacteria with adhesion of extracellular products. Furthermore, the strain decolored dye wastewater containing direct black, direct blue, and Congo red by 89.2%, 95.1%, 94.1%, respectively. The chemical oxygen demand (COD) and biological oxygen demand (BOD) removal rates after treatment of aquaculture wastewater with the fermentation broth were 68% and 23%, respectively. This study is the first to report the performance and application of strain Stenotrophomonas pavanii in wastewater flocculation. The results indicate that strain S. pavanii is a good candidate for the production novel bioflocculants and demonstrates its potential industrial practicality in biotechnology processes.

Exploring the role of domesticated resistors in batch-mode microbial desalination cell

Microbial Desalination Cells (MDCs) are an electrochemical process that harnesses microbial reactions to simultaneously treat wastewater, generate power, and desalinate water. By utilizing microbial decomposition of organic pollutants in wastewater, MDCs offer a sustainable and energy-efficient alternative to conventional desalination technologies. The technical framework of MDCs emphasizes the integration of water-electricity principles, making them promising for future applications in seawater desalination, wastewater treatment, resource recovery, and water softening. This study investigates the impact of acclimation resistance, represented by four different domesticated resistors values of 1 kΩ, 100Ω, 51Ω, and 10Ω, on the performance of MDCs. Larger acclimation resistors exhibit higher power performance, with the case of 100Ω achieving a power density of 0.33 mA/m2 and the case of 1 kΩ achieving the highest current density of 1.90 mA/m2. Furthermore, the case with an acclimation resistance of 1 kΩ exhibits superior performance in terms of chemical oxygen demand (COD) removal, achieving a removal rate of 76.3% on day 1. Conversely, the case with an acclimation resistance of 10Ω demonstrates the best desalination performance, achieving a desalination rate of 9.0%. It should be noted that the optimal performance in terms of COD removal and desalination capacity varies due to the various operational mechanisms involved. . The findings of this study provide valuable insights for enhancing the performance of MDCs in future applications, enabling further improvements in their efficiency and effectiveness.

Harnessing the Potential of Extracellular Polymeric Substances in Enhancing ANAMMOX Processes: Mechanisms, Strategies, and Perspectives

Anaerobic ammonium oxidation (ANAMMOX) has emerged as a promising sustainable nitrogen removal technology that offers significant advantages over conventional nitrification–denitrification processes, such as reduced energy consumption, a 60% reduction in oxygen demand, and a 90% reduction in sludge production. However, the practical application of ANAMMOX is hindered by several challenges, including the slow growth of ANAMMOX bacteria, long start-up periods, and high sensitivity to environmental disturbances. Recent studies have highlighted the crucial role of extracellular polymeric substances (EPSs) in the formation, activity, and stability of ANAMMOX biofilms and granules. An EPS is a complex mixture of high-molecular-weight polymers secreted by microorganisms, mainly composed of polysaccharides, proteins, nucleic acids, and lipids. The diverse physicochemical properties and functional groups of EPSs enable them to serve as a structural scaffold, protective barrier, sorption site, electron shuttle, and nutrient source for ANAMMOX bacteria. This review aims to provide an overview of the latest research progress on harnessing the potential of EPSs to enhance the ANAMMOX process. The characteristics, compositions, and extraction methods of ANAMMOX-derived EPSs are summarized. The mechanisms of how EPSs facilitate the enrichment, immobilization, aggregation, and adaptation of ANAMMOX bacteria are elucidated. The strategies and effects of EPS supplementation on improving the performance and robustness of ANAMMOX reactors under various stresses are critically reviewed. The challenges and future perspectives of the EPS-mediated optimization of the ANAMMOX process are also discussed. This review sheds new light on exploiting EPSs as a renewable bioresource to develop more efficient and stable ANAMMOX applications for sustainable wastewater treatment.

A novel membrane-aerated biofilm reactor using flexible and adjustable plate membrane modules: Treatment of wastewater containing anionic surfactants

Membrane-aerated biofilm reactors (MABRs) are a promising biofilm technology for wastewater treatment; however, achieving high pollutant removal in MABR systems with a low specific membrane surface area, low air-based aeration pressure and flexible aeration control remains a substantial challenge. In this study, a flexible and adjustable plate membrane module was developed and applied in an air-based plate MABR (PMABR) for treating anionic surfactant wastewater. The plate membrane module achieved high oxygen mass transfer under a low air-based membrane aeration pressure. When the influent linear alkylbenzene sulfonate (LAS) load was 0.559±0.010 kg/m3·d and a gradient-pressure membrane aeration scheme of (8,7,6) kPa was adopted, the LAS removal rate reached 99.2±0.1%, and the LAS removal load per unit membrane area reached 14.08±0.25 g/m2·d. The bacteria participating in the degradation of LAS were mainly Parvibaculum, Pseudomonas, Desulfovibrio, Flavobacterium and Holophagaceae. The dominant microbial communities of different biofilms in the PMABR played an important role in ω-oxidation, β-oxidation, benzene ring breaking and sulfonic acid group shedding in the degradation of LAS. The developed plate membrane module and PMABR provide a clean, energy-saving and flexible technical solution for MABR applications in wastewater treatment.

Fabrication of 3D-printed GNP/TiO2/epoxy composites: an investigation on mechanical and photocatalytic properties

PurposeThree-dimensional (3D) printing is popular for many applications including the production of photocatalysts. This paper aims to focus on developing of 3D-printed photocatalyst-nano composite lattice structure. Digital light processing (DLP) 3D printing of photocatalyst composites was performed using photosensitive resin mixed with 0.5% Wt. of TiO2 powder and varying amounts (0.025% Wt. to 0.2% Wt.) of graphene nanoplatelet powder. The photocatalytic efficiency of DLP 3D-printed photocatalyst TiO2 composite was investigated, and the effects of nano graphite powder incorporation on the photocatalytic activity, thermal and mechanical properties were investigated.Design/methodology/approachMethods involve 3D computer-aided design modeling, printing parameters and comprehensive characterization techniques such as structural equation modeling, X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared (FTIR) and mechanical testing.FindingsResults highlight successful dispersion and characteristics of TiO2 and graphene nanoplatelet (GNP) powders, intricate designs of 3D-printed lattice structures, and the influence of GNPs on thermal behavior and mechanical properties.Originality/valueThe study suggests applicability in wastewater treatment and environmental remediation, showcasing the adaptability of 3 D printing in designing effective photocatalysts. Future research should focus on practical applications and the long-term durability of these 3D-printed composites.Graphical abstract

Low toxicity of magnetite-based modified bionanocomposites with potential application for wastewater treatment: Evaluation in a zebrafish animal model

In recent years, the escalating concerns surrounding environmental pollution and the need for sustainable wastewater treatment solutions have underscored the significance of developing technologies that can efficiently treat wastewater while also reducing negative ecological effects. In this context, our study aims to contribute to the advancement of sustainable technologies for wastewater treatment, by investigating the effects that bare magnetite nanoparticles and those functionalized with the enzyme laccase could have in an aquatic animal, zebrafish, at various life cycle stages. Exposure to magnetite nanoparticles shows some effects on embryo hatching, survival rates, or larval behavior at higher concentrations. For both treatments, the hatching percentages were close to 80% compared to 93% for the control group. At the end of the observations in larvae, survival in all the evaluated groups was higher than 90%. Additionally, we evaluated the accumulation of nanoparticles in various stages of zebrafish. We found that, although there was accumulation during embryonic stages, it did not affect normal development or subsequent hatching. Iron levels in different organs such as gills, muscles, gastrointestinal tract, and brain were also evaluated in adults. Animals treated with a mix of food and nanoparticles at 10 μg/mL (Food group) presented a higher concentration of iron accumulation in muscle, gastrointestinal tract, and gills compared to the untreated control group. Although iron levels increased depending on the dose and exposure method applied, they were not statistically significant from the control groups. Our findings suggest that bionanocomposites evaluated here can be considered safe for removal of contaminants in wastewater without toxic effects or detrimental accumulation fish's health.

Fabrication of high-flux PTFE hollow fiber membranes through nonionic surfactant infiltration coupled with mussel-inspired chemistry coating

Polytetrafluoroethylene (PTFE) hollow fiber membrane holds tremendous potential for the treatment of complex wastewater due to its outstanding chemical and thermal stability. However, its treatment efficiency is often hindered by the low water permeate flux arising from the inherent hydrophobicity of PTFE. Here, we present a gentle and convenient hydrophilic modification method that involves immersion in a nonionic surfactant aqueous solution, followed by dopamine self-polymerization. The nonionic surfactant facilitated the penetration of the dopamine solution into the membrane, where dopamine self-polymerized to form a hydrophilic layer on the surface and inner pores of the membrane. The hydrophilicity-modified PTFE hollow fiber membranes demonstrated an impressive increase in water permeate flux, reaching 10231.4 L m−2 h−1, nearly ten times that of the original membrane. Even after prolonged exposure to a strong acid solution (pH = 1) or an oxidant solution (1000 mg L−1 NaClO) for two weeks, this membrane still maintained its favorable water permeability. Furthermore, the modified PTFE membranes also exhibited remarkable resistance to fouling by humic acid. These results showcased a straightforward method for designing a hydrophilic layer on PTFE hollow fiber membranes, underscoring their significant potential for real wastewater treatment applications.

Modelling of chemical kinetics in the presence of hydrodynamic cavitation for wastewater treatment applications

The reaction rate of hydroxyl radicals with organic pollutants is about 108−1011 /mol-s, can degrade a wide range of pollutants. Intense bubble collapse during hydrodynamic cavitation can produce hydroxyl radicals, making it suitable for wastewater treatment. The current study introduces a numerical method of predicting the performance of a hydrodynamic cavitation reactor. Unlike most literature that considers cavitation volume as an indicator of effectiveness of hydrodynamic cavitation, the present approach considers local pressure variation, cavitation volume fluctuation, radical production and their inter-relations. The findings show that though an initial increase in the extent of cavitation, marked by a rise in cavity volume, leads to higher OH. radical production, the radical generation declines below an optimal cavitation number. The downstream recovery pressure also influences radical production. This numerical methodology, providing complete picture of radical production and its locations, will be very helpful for designing a new and more efficient cavitation reactor.

Production of Mycelium-Based Papers from Carrot Pomace and Their Potential Applications for Dye Removal

AbstractThe Current study aimed at valorizing carrot pomace (CP), an abundant waste from the juice industry. A water-soluble fraction of CP was separated from solid fraction of CP (SFCP) and employed as feedstock for producing fungal biomass (FB) in bench-scale bioreactors. FB combined with SFCP were used to develop mycelium-based papers (MBP) using the wet-laid method. The potential and capacity of FB, SFCP and MBP to remove dye (methylene blue) from wastewater was then investigated. The maximum achieved dye removal was 92% when using a mixture of SFCP and FB in their suspended forms. The MBP with the lowest density (549 kg/m3) reached 83% dye elimination. The findings of this study support the valorization of carrot pomace, through environmentally benign processes, to mycelium-based papers with potential application in wastewater treatment.

Construction of BiOCl/bismuth-based halide perovskite heterojunctions derived from the metal-organic framework CAU-17 for effective photocatalytic degradation

The designed synthesis of an S-scheme heterojunction has possessed a great potential for improving photocatalytic wastewater treatment by demonstrating increased the photoredox capacity and improved the charge separation efficiency. Here, we introduce the fabrication of a heterojunction-based photocatalyst comprising bismuth oxychloride (BiOCl) and bismuth-based halide perovskite (BHP) nanosheets, derived from metal-organic frameworks (MOFs). Our composite photocatalyst is synthesized through a one-pot solvothermal strategy, where a halogenation process is applied to a bismuth-based metal-organic framework (CAU-17) as the precursor for bismuth sourcing. As a result, the rod-like structure of CAU-17 transforms into well-defined plate and nanosheet architectures after 4 and 8 h of solvothermal treatment, respectively. The modulation of the solvothermal reaction time facilitates the establishment of an S-scheme heterojunction, resulting in an increase in the photocatalytic degradation efficiency of rhodamine B (RhB) and sulfamethoxazole (SMX). The optimized BiOCl/BHP composite exhibits superior RhB and SMX degradation rates, achieving 99.8% degradation of RhB in 60 min and 75.1% degradation of SMX in 300 min. Also, the optimized BiOCl/BHP composite (CAU-17-st-8h sample) exhibited the highest rate constant (k = 3.48 × 10−3 min−1), nearly 6 times higher than that of the bare BHP in the photocatalytic degradation process of SMX. The enhanced photocatalytic efficiency can be endorsed to various factors: (i) the in-situ formation of two-components BiOCl/BHP photocatalyst, derived from CAU-17, effectively suppresses the aggregation of pristine BHP and BiOCl particles; (ii) the S-scheme heterostructure establishes a closely-knit interfacial connection, thereby facilitating efficient pathways for charge separation/transfer; and (iii) the BiOCl/BHP heterostructure enhances its capacity to absorb visible light. Our investigation establishes an effective strategy for constructing heterostructured photocatalysts, offering significant potential for application in photocatalytic wastewater treatment.

Green polycaprolactone/sulfonated kraft lignin phase inversion membrane for dye/salt separation

Exploring environmentally friendly, renewable, and cost-effective raw materials is essential in sustainable membrane fabrication. This study presents a facile and scalable method for fabricating a green and biodegradable tight ultrafiltration membrane for dye/salt separation. This involves simply blending biodegradable polycaprolactone (PCL) with the low-cost biobased sulfonated kraft lignin (SKL) additive. Additionally, we employed acetic acid as a green alternative solvent to enhance the sustainability of the membrane fabrication process. The incorporation of hydrophilic SKL into the PCL matrix resulted in increased hydrophilicity (water contact angle changed from 72° to 56°), surface roughness (increased from 29 nm to 43.5 nm), and enhanced negative electrostatic charge of the membrane (−40 mV to −45 mV). The optimized PCL/SKL membrane (M3) exhibited excellent water flux (∼45 LMH) under 40 psi hydraulic pressure coupled with ∼98 % and ∼10 % rejection rates for reactive red (RR) dye and NaCl, respectively. Moreover, the M3 membrane maintained its exceptional dye/salt fractionation performance while separating the mixtures at low salt concentrations. However, with increasing salt concentration (1–50 g/L), the membrane's RR dye rejection declined from ∼90 % to ∼50 %, with a significant reduction in NaCl and Na2SO4 salts rejection (from ∼14 % to ∼1 % and ∼22 % to –∼1 %, respectively). The M3 membrane exhibited remarkable antifouling properties during dye and humic acid filtration with a high flux recovery ratio (>98 %) and low flux decline rate (<7 %). The PCL/SKL membrane also showed excellent stability and maintained consistent separation performance over a long period. Overall, the novel biodegradable PCL/SKL membrane prepared in this study presents a promising avenue toward sustainable membrane fabrication for wastewater treatment applications.

Hierarchical 0D CuO Wrapped by Petal-like 2D ZnO: A Strategic Approach of Superhydrophobic Melamine Sponge toward Wastewater Treatment.

In addressing the pressing environmental challenges posed by frequent oil spills, this work presents a novel approach of synthesizing a superhydrophobic three-dimensional (3D) porous melamine sponge (MS). CuO and ZnO nanoparticles were grown on the MS via a hydrothermal method to create MS/CuO/ZnO with multiscale hierarchical nanostructures. The resulting material exhibited a stable water contact angle of 155° through various tests. MS/CuO/ZnO demonstrated exceptional oil absorption capacities (40-145 g/g and 0.83-0.99 mL.cm-3), surpassing 98% efficiency in oil separation, and retained reusability for 10 cycles. Impressively, the sponge achieved successful separation of oil/water emulsions with a permeation flux of 14870 L m-2 h-1. The composite sponge, distinguished by its high photodegradation ability, can degrade both water- and oil-targeted pollutants under visible light irradiation from light-emitting diode (LED). With its remarkable attributes including superior oil absorption, excellent oil/water separation, mechanical resistance, and excellent photocatalytic ability, it exhibits considerable potential for applications in both wastewater treatment and large-scale marine oil spill response. The easily prepared MS/CuO/ZnO emerges as a versatile solution capable of addressing pressing challenges and marking a significant leap toward sustainable and impactful environmental remediation.

Structural, dielectric and magnetic properties of MnFe2O4/ MWCNTs based nanocomposites for technological applications

In this paper, the manganese ferrite/MWCNTs nanocomposites were prepared by functionalizing with MWCNTs in various wt% from x = 0 to x = 25. First the nanoparticles of manganese ferrites have been composed by means of sol-gel self-combustion route. Nanocomposites with manganese ferrite/MWCNTs were synthesized by ultra-sonication. The crystalline structures of the nanocomposites were confirmed using the x-ray diffraction techniques (XRD). The crystallite size of the prepared nanocomposites was determined and found in the range of 9.1 to 9.4 nm. FTIR analysis assisted to get the vibration bands at tetra- and octahedral sites. Furthermore, confirmation of the linkage between MnFe2O4 and MWCNTs and morphology of the prepared was investigated through transmission electron microscopy (TEM). The relaxation mechanism of the prepared nanocomposites for the applied frequency range from 1 MHz to 3 GHz has been investigated. The relaxation behavior due to hopping of electrons in GHz are the interest for this research work. The dielectric constant at high frequency is useful for the nanocomposites that can be used in high frequency devices. The magnetic properties of the prepared nanocomposites were also investigated with applying magnetic field. The soft magnetic nature of the prepared nanocomposites makes the excellent choice for the waste water treatment application.