Application In Wastewater Treatment Research Articles

Unearthing waste resources: Nano‐adsorbents from complex packaging waste for fluoride detoxification of water

AbstractThis study investigates the synthesis and characterization of Al2O3 nanoparticles derived from multilayered packaging (MLP) waste, specifically postconsumer coffee capsules, and evaluates their efficacy in fluoride adsorption from aqueous solutions. The nanoparticles were synthesized using a facile thermal degradation technique followed by leaching and precipitation processes. Characterization techniques, including inductively coupled plasma‐mass spectroscopy, XRF, Fourier transform infrared spectroscopy, X‐ray diffraction, and transmission electron microscope, confirmed the formation of γ‐Al2O3 nanoparticles with a cubic crystal structure. The adsorption process was found to be endothermic and spontaneous, with a maximum adsorption capacity of 9.60 mg/g. Kinetic studies revealed that the pseudo‐second order model best described the adsorption process, indicating a complex multistep mechanism involving both physisorption in the initial rapid adsorption and chemisorption in the latter slower phase. The Freundlich–Langmuir isotherm provided the best fit for equilibrium data suggesting a complex adsorption mechanism involving both homogeneous and heterogeneous surface interactions. The presence of competing anions, particularly carbonate and phosphate, significantly affected the adsorption efficiency. This research demonstrates the potential of upcycling MLP waste into valuable adsorbents for wastewater treatment applications, offering both environmental and economic benefits.

Mechanism of membrane fouling mitigation by microalgae biofilm formation for low C/N mariculture wastewater treatment: EPS characteristics, composition and interfacial interaction energy

Membrane fouling is considered one of the main limitations of membrane bioreactor (MBR) in wastewater treatment applications, including low C/N aquaculture wastewater. Although much research has focused on the integration of MBR with bacterial biofilm, there has been limited exploration into the mitigation mechanism of membrane fouling by microalgae biofilm. In this study, extracellular polymeric substances (EPS) before and after the formation of microalgae biofilm were compared, leading to the conclusion that the microalgae biofilm formation could reduce membrane fouling potential of EPS, thereby mitigating membrane fouling. EPS content and fluorescence components analysis indicated that microalgae biofilm formation could effectively reduce protein to polysaccharide ratios (PN/PS) of three types of EPS (soluble EPS (S-EPS), loosely bound EPS (LB-EPS), and tightly bound EPS (TB-EPS)), lowering the membrane fouling potential associated with protein substances, especially tryptophan-like protein. Moreover, the analysis of molecular weight (MW) suggested that microalgae biofilm could considerably decrease the MW of both S-EPS and LB-EPS, thus mitigating the influence of high MW substances on membrane fouling. Meanwhile, the precise composition of EPS revealed a reduction in hydrophobic alkanes and recalcitrant aromatics, which often lead to membrane fouling. Furthermore, the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory further highlighted that microalgae biofilm weakened the interfacial interaction energy between the three EPS and membrane to mitigate membrane fouling. Therefore, this study provides a comprehensive elucidation of how microalgae biofilm formation mitigates membrane fouling, offering theoretical support for utilizing microalgae biofilm MBR in treating low C/N mariculture wastewater.

Edge functionalized with benzenesulfonyl groups of g-C3N4 nanosheets as a highly efficient photocatalyst for water purification

Photocatalytic water purification is a promising method for environmental remediation, but it is greatly hindered by the rapid charge carrier recombination behavior of the photocatalysts. Herein, a simple wet-chemical method is developed for grafting electron-withdrawing benzenesulfonyl groups at the edges of g-C3N4 nanosheets. These exhibited a superior and versatile photocatalytic performance on the degradation of organic contaminant, as well as disinfected Escherichia coli (E. coli) bacteria under visible light illumination. Systematic studies reveal that the grafting of benzenesulfonyl groups led to the synergic effect in ultrathin g-C3N4 nanosheets of enhancing the photogenerated charge carrier separation on surface, improving light absorption, changing electronic band structure, and causing surface charge redistribution, all of which are beneficial for enhancing the photocatalytic performance. Notably, these edge-activated g-C3N4 photocatalysts also demonstrate remarkable photocatalytic activity in the real tap water and urban wastewater, indicating their promising potential for application in real wastewater treatment.

An intriguing way to synthesize a TiO2–ZnO hybrid nanostructure for the pragmatic application as a photocatalyst

In an attempt to counter the problem of treating wastewater more efficiently, we report the study on photocatalytic properties of metal oxide nanostructures under different light sources. A novel sonication-assisted refluxing method was employed to synthesize a binary heterostructure consisting of TiO2 and ZnO. XRD and EDS analysis of synthesized materials confirm the presence of both TiO2 and ZnO. Also, the change in the intensity of XRD peaks and elemental composition are well observed with a change in molar concentration of Ti and Zn. HR-TEM micrographs show nanostructures having hybrid Janus and Core-shell type structures. The XPS spectra were probed to identify the surface chemical species associated with the prepared heterostructures. Raman spectra confirm the smaller ZnO particles attached over agglomerated TiO2 as a shell layer as depicted in TEM results. Optical studies exhibit the modification in the band structure of the materials due to the formation of the heterostructure. The synthesized hybrid catalyst shows impressive results in photocatalytic performance. The catalytic potency of the prepared heterostructures under UV light is reminiscent of Anatase while it gets convalescent with an increment of Zn content under visible light. The photocatalytic performance of synthesized materials under sunlight shows their potential to be utilized as commercial catalysts for direct application in wastewater treatment. The kinetic study of the degradation data reveals interesting facets of the catalysis. It suggests that the photo-corrosion of the catalyst inordinately changes the rate of photocatalytic reaction which ultimately affects the photocatalytic efficiency of the catalyst. The study also discusses the role of kinetic and validation parameters in the selection of the best-fitted kinetic model with realistic arguments.

The one-pot synthesis of defect-rich bimetallic MOFs for efficient photocatalytic Fenton degradation of organic pollutants

The efficient and straightforward treatment of organic contaminants in water remains a significant challenge. This study presents the synthesis of a defective NH2-MIL-88Fex/Cuy photo-Fenton catalyst via a simple one-pot hydrothermal method. The incorporation of the inexpensive metal Cu enhances the valence cycles of Cu2+/Cu+ and Fe3+/Fe2+ under the photo-Fenton system, thereby compensating for the rapid consumption rate of ·OH radicals. Degradation tests demonstrated that NH2-MIL-88Fe0.5/Cu0.5 can degrade 99.99 % of methylene blue within 30 min under visible light irradiation. Free radical trapping experiments and Electron Paramagnetic Resonance (EPR) confirmed that ·OH radicals play a predominant role in the catalytic system. Density Functional Theory (DFT) calculations verified the improved binding energy of the catalyst materials following the introduction of structural defects. The degradation pathway and mechanism of methylene blue were elucidated. This study offers a novel approach for designing photo-Fenton catalysts and holds significant promise for practical applications in wastewater treatment.

Green Removal of Basic Fuchsin Using Fibers from Reed Leaves

This study investigates the adsorptive capacity of a novel lignocellulosic material derived from reed leaves for the removal of Basic Fuchsin, a cationic dye, from aqueous solutions through batch adsorption experiments. The experimental data showed that the adsorbent demonstrated effective dye removal, with the adsorption kinetics following a pseudo-second-order model and the equilibrium data best described by the Freundlich and Temkin isotherm models. The Langumir model shows the maximum capacity adsorption was 37.59 mg.g-1 Moreover, thermodynamic analysis indicated that the adsorption process was non-spontaneous and exothermic, highlighting the potential for optimizing conditions to enhance dye uptake and sustainability in wastewater treatment applications. In addition, characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller surface area analysis (BET) confirmed that the adsorbent possessed an amorphous structure with a surface area of 2.42 m².g-1 and the presence of mesoporous features. Lignocellulosic materials such as reed leaf adsorbents, effectively remove hazardous dyes from wastewater offering a sustainable solution to pollution.

Impact of titanium dioxide/graphene in polyvinylidene fluoride nanocomposite membrane to intensify methylene blue dye removal, antifouling performance, and reusability

AbstractThe development of efficient water purification technologies is a critical research focus driven by the crucial role of clean water sources for ecological sustainability. This study explores the strategic incorporation of nanoparticles within polyvinylidene fluoride (PVDF) membranes as a promising approach to enhance membrane performance for wastewater remediation. PVDF membranes containing varying ratios of graphene (GR) and titanium dioxide (TiO2) nanocomposites were fabricated via phase inversion method. Characterization techniques including XRD, FTIR, and FESEM‐EDX revealed that the 80% GR nanocomposite membrane exhibited desirable structural and functional properties with pronounced sponge‐like morphology and homogenous nanoparticle distribution. Fourier‐transform infrared spectroscopy and x‐ray diffraction analysis confirmed the 80% GR membrane retained PVDF crystallinity while uniquely eliminating TiO2 crystallinity. Subsequently, performance testing demonstrated the 80% GR nanocomposite membrane had the highest water flux and methylene blue dye rejection rates compared to other ratios and the pristine PVDF membrane. Both fabricated membranes exhibited sufficient reusability and antifouling properties. However, 80% GR ratio exhibited superior antifouling properties, indicating its potential as an optimal material for improving membrane hydrophilicity and overall water purification technologies. These findings underscore the strategic utility of GR‐TiO2 nanocomposites for enhancing PVDF membrane performance in sustainable wastewater treatment applications.

Anchoring cobalt dual-atom pairs on open hollow-structured carbon via a facile in-situ synthetic strategy for enhanced advanced oxidation processes

Atomically dispersed catalysts offer unprecedented opportunities for high-efficiency Fenton-like oxidation of organic pollutants in water. However, the hazardous metal leaching of atomically dispersed catalysts hinders their practical application for wastewater treatment, while the inaccessible interior active sites in carbon substrates have been commonly overlooked. Herein, we develop a straightforward approach for tightly anchoring cobalt dual-atom pairs on nitrogen-doped open hollow carbon structure (Co-NOHC) via an in-situ polyelectrolyte nanosphere-guided strategy. The unique open hollow carbon structure benefits the electron/mass transfer and maximizes the exposure of active sites. As a result, the as-synthesized Co-NOHC exhibits outstanding peroxymonosulfate activation activity and Fenton-like performance in oxidation by taking rhodamine B degradation as an example. Remarkably, the turnover frequency of the Co-NOHC is 6.5, 26.5, and 9.3 times higher than that of the Co2+, cobalt, and its oxides, respectively, and its catalytic activity also greatly outperforms the pristine zeolitic-imidazole frameworks derived Co-based atomically dispersed catalysts. More importantly, benefitted from the stable anchoring of cobalt dual atoms, the Co2+ leaching from the Co-NOHC is greatly alleviated, as low as 0.1 mg/L after the catalytic reaction, showing outstanding stability as compared to most atomically dispersed catalysts. Furthermore, the reactive active species, including SO4−, OH and O2− radicals, and electron-transfer mechanism are demonstrated to dominate the rhodamine B removal. This work offers a new consideration for promoting the development of the advanced catalysts and their potential applications in advanced oxidation process.

Nanofabrication of Biochar from Cellulosic Waste for Bio-Sensing Application of Waste Water Treatment: Process, Challenges and Future Update

Nanofabrication of Biochar from Cellulosic Waste for Bio-Sensing Application of Waste Water Treatment: Process, Challenges and Future Update

Advancements in Biopolymer‐Derived Graft Copolymers: A Comprehensive Review on Their Application in Sustainable Wastewater Treatment

ABSTRACTRising concerns over water pollution and the depletion of non‐renewable resources have propelled the exploration of eco‐friendly and sustainable wastewater treatment alternatives. Biopolymer‐derived graft copolymers emerge as a promising solution, offering biodegradability, cost‐effectiveness, versatility, and enhanced functionality. This review provides a comprehensive overview of the latest developments in utilizing these copolymers as eco‐friendly flocculants for wastewater treatment. It covers synthesis methods for functionalized biopolymer‐based flocculants, diverse flocculation mechanisms, and their efficacy in solid–liquid separation. The article explores applications for removing pollutants, emphasizing biodegradability, cost‐effectiveness, and versatility. Special attention is given to the environmental impact, critically analyzing how these copolymers contribute to sustainable water treatment practices. The review also discusses potential future prospects and advancements in addressing global water pollution challenges using biopolymer‐derived graft copolymers.

Preparation of iron selenide decorated 1T/2H molybdenum disulfide catalysts for peroxymonosulfate activation: Effect of phase transition

The sulfate radical-based advanced oxidation process is recognized as an effective approach for acetaminophen (ACT) degradation. Modification of MoS2 through phase engineering can contribute to enhancing peroxymonosulfate (PMS) activation performance. In this work, we decorated MoS2 with FeSe2, aiming to alter the 1T/2H phase ratio of MoS2. Experiments and calculations suggested that the incorporation of FeSe2 increases the activation pathway through the Fe(III)/Fe(II) cycle and prompts a phase transition from 2H to 1T, providing active sites and boosting charge transfer between FeSe2 and MoS2. The optimum catalyst (FeSe2@MoS2-10) showed high efficiency in PMS activation, achieving complete removal of ACT within 20 min. The pseudo-first-order rate constant (kapp) on this catalyst is 17.7 times higher than that of the MoS2/PMS system. This study provides a new direction for promoting phase transition and improving the catalytic reactivity of MoS2-based catalysts, expanding their potential applications in pharmaceutical wastewater treatment.

Synthesis of MoS2@MoO3/(Cu+/g-C3N4) ternary composites with double S-scheme heterojunction for peroxymonosulfate activation exposing to visible light

The construction of semiconductor heterojunction is an effective way for charge separation in photocatalytic degradation of pollutants. In this study, a novel MoS2@MoO3/(Cu+/g-C3N4) ternary composites (MMCCN) was prepared via a simple calcination method. The as-prepared composites exhibited exceptional performance in activating peroxymonosulfate (PMS) for the degradation of rhodamine B (RhB). The activity testing results indicated that 99.41 % of RhB (10 mg·L−1, 10 mL) was effectively removed by the synergistic effect of composites photocatalyst (0.1 g·L−1) and PMS (0.1 g·L−1) under visible light irradiation for 40 min. Its reaction rate constant exceeded that of Cu+/g-C3N4, MoO3 and MoS2 by a factor of 3.56, 17.30 and 11.73 times, respectively. The crystal structure, band gap and density of states (DOS) of the semiconductors were calculated according to the density functional theory (DFT). Free radical trapping tests and electron spin resonance spectroscopy validated that 1O2, O2− and h+ are primary reactive species participating in the decomposition of RhB. The ternary composites demonstrated good stability and maintained excellent degradation efficiency even across four reaction cycles. Furthermore, the activation mechanism and the intermediates produced during the decomposition course of RhB by MMCCN/PMS/vis system were analyzed and elucidated. A double S-scheme heterojunctions was responsible for efficient separation of photo-induced electron-hole pairs. This work presents a novel method in the construction of double S-scheme heterojunctions for PMS activation which is expected to find wide applications in wastewater treatment and environmental remediation.

Development of high flux photocatalytic agcl-cooh-mwcnt/pes ultrafiltration membranes for enhanced waste water treatment and fouling mitigation

A structurally stable AgCl-COOH MWCNT/PES composite membrane was designed and fabricated by combining phase conversion and post-treatment techniques, which can solve the serious membrane fouling in industrial wastewater treatment. The carboxylation of MWCNTs not only enhanced their dispersion but also facilitated their binding with silver chloride, resulting in a stable composite structure that significantly improved contaminant degradation capabilities. The post-treatment technique increased the membrane’s water purification flux by 150 % (reaching 520 L·m2·h−1·bar−1) while maintaining a high BSA retention rate of 95 %. Additionally, the composite membrane demonstrated excellent photocatalytic antifouling properties, with a flux recovery rate of 91.8 % under UV irradiation, and exhibited more than 99 % inhibition of Escherichia coli. This method provides a scalable solution for enhancing the performance of PES membranes in wastewater treatment applications.

Enhanced Fenton-like process on Co9S8 catalyst with Mixed-Valence Cobalt(0)/Cobalt(Ⅱ)

Peroxymonosulfate (PMS)-based Fenton-like reactions have great potential to revolutionize wastewater treatment, but achieving highly efficient decontamination at low chemical input remains extremely challenging. In this study, a carbon carrier-supported Co9S8 catalyst with Mixed-Valence Cobalt(0)/Cobalt(Ⅱ) was prepared, which enables 70.72 % PMS decomposition-rate and complete, highly efficient tetracycline (TC) removal. Through the cyclic conversion pathways of polyvalent cobalt and the auto-decomposition of PMS, which produced SO4•-, 1O2, •OH, and high-valence metals, the material’s efficiency in degrading TC through PMS activation was effectively enhanced (99.92 %). S2-, as one of the active sites, not only promotes the participation of Co3+/Co2+/Co0 in the generation of reactive oxygen species but also significantly facilitates electron transfer to further increase the catalytic reaction rate. Through metal-chelating agents, it is illustrated that Co2+ directly activates PMS to produce reactive oxygen species (ROS), while Co3+ promotes cycling. The normalized kinetic constant of Co9S8/Co-C (105.6 min−1M−1) was even four times larger than that of Co9S8 (26.4 min−1M−1). Co9S8/Co-C exhibited rapid degradation over a wide pH range and extensive cycling experiments, demonstrating its versatility and stability in various environments. Possible degradation pathways were speculated using liquid chromatography-mass spectrometry (LC-MS). Toxicological evaluations and mung bean germination toxicity tests indicated that the Co9S8/Co-C+PMS system effectively reduced toxicity. It enables the complete degradation of TC while remarkably reducing the toxic intermediates, ensuring that the catalyst is suitable for wastewater treatment applications.

3D-printing bauxite residue/fly ash-containing geopolymers as promising metal sorbents for water treatment

Herein, we demonstrate for the first time the feasibility of employing significant amounts (up to 80 wt%) of unexplored industrial wastes (red mud and biomass fly ash) in the production of highly porous 3D-printed geopolymer lattices envisioned for wastewater treatment applications. This without compromising the mechanical performance of the geopolymers relative to those obtained using commercial precursors. The impact of the fly ash incorporation content in the fresh-state (calorimetric and reological characterization) and hardened-state (porosity and mechanical strength) properties of the produced structures was evaluated. Moreover, the influence of key printing parameters, including nozzle diameter and geometry alignment, on the resulting properties of the lattices was also evaluated. The most promising compositions were then evaluated as lead sorbents under continuous flow. The waste-based 3D-printed lattices showed remarkable adsorption ability reaching >95 % removal efficiency after 2 h. This sustainable strategy is in line with the United Nations sustainable development goals and the transition to a circular economy, reducing the consumption of natural resources and simultaneously contributing to reducing water pollution.

Multi-metal-doped transition metal compounds for high-performance asymmetric capacitive deionization

To address the limited ion adsorption capacity of carbon-based capacitive deionization (CDI) which primarily relies on double-layer mechanism, recent efforts have focused on the rational design and development of efficient Faradaic materials for CDI applications. In this study, we synthesized and applied Co- and Mn-doped transition metal compounds (Cu₂O@MCF) as the electrodes for asymmetric CDI using a simple hydrothermal method. The synthesized electrodes were analyzed using various characterization techniques, to confirm the successful doping and structural integrity. Electrochemical performance assessments revealed significant improvements in ion-capture capacity and overall desalination efficiency. Specifically, the optimized asymmetric CDI cell configuration, consisting of Cu₂O@MCF(Cl) as an anode and Cu₂O@MCF(Na) as a cathode, led to a significant increase in salt adsorption capacity (27.42 mg/g) over conventional symmetric carbon electrode (11.22 mg/g), an increase of over 2.4 times. Furthermore, the synthesized electrodes demonstrated effective phosphate ion removal, highlighting their potential applicability in wastewater treatment. The findings suggest that multi-metal doping significantly enhances electrode performance by synergistically combining electric double-layer capacitance and pseudocapacitance effects, due to their unique morphological and electrochemical properties. These results contribute to sustainable water treatment and resource recovery efforts, showcasing the effectiveness of the materials in improving CDI performance and opening new avenues for their application in environmental cleanup and resource management.

Engineering mineralized interlayers for enhanced nanofiltration: Synergistic modulation of polyamide layer structure and catalytic self-cleaning performance

High permselectivity and antifouling/self-cleaning nanofiltration (NF) membranes are ideal materials for water treatment, and this vision is expected to be reached through the design of multifunctional self-cleaning interfaces. In this study, we employed metal - polyphenol network (MPN) to mediate in situ mineralization of porous substrates, enabling simultaneous modulation of interfacial polymerization (IP) and catalytic self-cleaning. The findings demonstrate that the mineralized layers employ an interlayer modulation strategy to produce a polyamide (PA) layer that is more hydrophilic, thinner, and structurally denser. As a result, the resulting PA-Fe3O4-PSF membrane exhibited a 2.5-fold increase in permeance (19.2 L m−2 h−1 bar−1) and a 7.3-fold enhancement in Cl−/SO42− selectivity (66.4), compared to the control membrane (PA-PSF). Additionally, its highly polarized membrane surface significantly improved its antifouling performance. Compared to membranes with mineralized layers on the surface (Fe3O4-PA-PSF), PA-Fe3O4-PSF constructs a confined space that facilitates more efficient regeneration through in situ catalytic self-cleaning and ensures greater stability during multiple fouling-regeneration cycle operations. This study paves the way for fabricating multifunctional NF membranes with sustainable applications in material concentration, wastewater treatment, and environmental remediation.

Superior photocatalytic degradation of pharmaceuticals and antimicrobial Features of iron-doped zinc oxide sub-microparticles synthesized via laser-assisted chemical bath technique

Addressing the dual challenges of antimicrobial resistance and pharmaceutical contamination in wastewater is crucial for global health and environmental preservation. Predictions estimate up to 10 million annual deaths by 2050 due to antimicrobial resistance, underscoring the urgent need for innovative solutions. This study explores the potential of zinc oxide Sub-Microparticles (ZnO SMPs) doped with iron (Fe) to enhance the photocatalytic degradation of pharmaceutical compounds in water and improve antimicrobial efficacy. A green laser-assisted chemical bath synthesis method created ZnO SMPs with varying Fe dopant concentrations (1 %, 1.5 %, and 3 %). The synthesized Sub-Microparticles underwent rigorous structural analysis using X-ray diffractometry, SEM, EDX, FTIR, and UV–visible spectrophotometry techniques. Their photocatalytic performance was evaluated in the degradation of paracetamol under blue laser light, and their antimicrobial properties were assessed following CLSI guidelines. Structural analyses confirmed the hexagonal wurtzite structure of ZnO SMPs, with noticeable changes due to Fe doping, including a transition from sub-microrods to sub-microsheets and a redshift in the optical band gap. Photocatalytic tests revealed a significant enhancement in paracetamol degradation efficiency, increasing from 53.41 % with pure ZnO to 98.99 % with 3 % Fe-doped ZnO in 50 min. Antimicrobial assays demonstrated an increased inhibitory effect against pathogens, with Fe-doped ZnO outperforming control discs. This study substantiates the potential of Fe-doped ZnO SMPs in wastewater treatment and antimicrobial applications, showcasing significant improvements in photocatalytic degradation of pharmaceutical compounds and antimicrobial efficacy. The findings underscore the importance of continuing research in this domain for environmental and public health benefits.

LaCuMnOx perovskite activating persulfate for the degradation of bisphenol A: excellent tolerance to hypersaline environment

AbstractBackgroundLaCuMnOx (LCMO) perovskite was designed as an effective catalyst to activate peroxydisulfate (PDS) to remove bisphenol A (BPA) in hypersaline wastewater.ResultsIn the LCMO/PDS system, BPA (10 mg/L) was removed completely and the mineralization degree reached 74.9% in the presence of 0.12 g/L catalyst and 1.2 mM PDS. The BPA removal efficiency was still almost 100% even after five cycles. Metal ion leakage also indicated the stability of the catalytic system. •OH, SO4•−, 1O2, and O2•− all contributed to BPA removal, and O2•− accounted for the greatest contribution. The presence of oxygen vacancies (Vo··) on the surface of the catalyst was important for PDS activation and the formation of active species. In addition, the system could still maintain outstanding performance even when [Cl−] and [SO42−] were 100 g/L. CO32− and HCO3− inhibited BPA degradation greatly, even at very low concentrations. The inhibitory effect was related to changes in the pH of the solution caused by the addition of CO32− and HCO3−. This effect could be eliminated by adjusting the pH.ConclusionThe system showed excellent catalytic performance, stability, and inorganic anion tolerance, indicating its potential for application in hypersaline wastewater treatment. © 2024 Society of Chemical Industry (SCI).

Mechanically durable tri-composite polyamide 6/hematite nanoparticle/tetra-n-butylammonium bromide (PA6/α-Fe2O3/TBAB) nanofiber based membranes for phosphate remediation.

Essential properties for a Point of Use (POU) water filter include maintaining high removal capacity and rate, with excellent mechanical properties to withstand pressure drop. Herein, mechanically robust tri-composite polyamide 6/iron oxide nanoparticles/tetra-n-butylammonium bromide (PA6/α-Fe2O3/TBAB) nanofiber composite membranes were electrospun for phosphate (P) remediation, where the diameter and composition were tuned by controlling solution compositions and electrospinning conditions. Tri-composite composition and morphology affect phosphate uptake where the adsorption capacity followed Langmuir isotherm whereas the adsorption kinetics followed pseudo second order behavior. Mechanical properties (i.e., Young's Modulus (E) and toughness) were significantly influenced by the composition and morphology of the tri-composite, as well. Although additional TBAB and iron oxide decreased toughness, there are optimum composition ranges which resulted in maximum Young's Modulus. Of the synthesized nanofiber membranes, PA6/α-Fe2O3/TBAB nanofibers with 17% α-Fe2O3 and 2% TBAB showed excellent phosphate uptake capacity [i.e., 8.9mg/g (52mg of P/g of α-Fe2O3)] while it is bendable, stretchable, and able to plastically deform without fracturing (i.e., Young's modulus of 2.06 × 108Pa and Toughness of 1.35 × 106Jm-3). With concerns over the impact of P on water resources and the long-term availability of limited P resources, this tri-composite membrane is well suited for applications in both wastewater treatment and resource recovery.