Application In Wastewater Treatment Research Articles

Characterization and Optimization of Crustacean Shell-derived Activated Carbon for Wastewater Treatment Applications

Comparative studies of the Surface Chemistry, morphology, and physicochemical properties of crustacean shells activated chemically using acid (H2SO4) and base (KOH) were investigated. Following the activation, samples of acid and base activated Periwinkle shells (PSAAC and PSBAC), Clam shells (CSAAC and CSBAC), whelk shells (WSAAC and WSBAC), and a 1:1 Clam/Whelk composite Shells (CWSAAC and CWSBAC) were obtained. The properties investigated were moisture content, specific gravity, surface area, porosity, ash content, carbon yield, fixed carbon, FTIR, and SEM-EDX. The findings demonstrate the good physicochemical qualities of activated carbons made from Periwinkle, Clams, Whelks, and a Clam/Whelk composite by acid and base activation for the treatment of wastewater. Among them, the Clam acid-activated carbon (CSAAC) demonstrated exceptional physicochemical qualities with a surface area of 1277 m2/g, moisture content of 1.4%, ash content of 8.3%, carbon yield of 87%, and fixed carbon of 63.7%. On the other hand, the Clam Shell Base-Activated Carbon (CSBAC) exhibited a greater porosity of 0.88, indicating that it could be a more efficient option for adsorption in wastewater treatment. Both base- and acid-activated carbons generally showed modest ash contents; however, at 12.3%, Whelk Shell Base-Activated Carbon (WSBAC) had the highest ash concentration. The bulk densities of acid- and base-activated carbons were almost identical. The bulk densities, from highest to lowest, were CSBAC > CSAAC > CWSBAC > CWSAAC > PSBAC > PSAAC > WSBAC > WSAAC, with values ranging from 0.687 g/cm³ to 0.454 g/cm³. The porosity of the samples, ranked in descending order, was CSBAC > PSBAC > CSAAC > CWSAAC > PSAAC = CWSBAC > WSAAC > WSBAC, with values from 0.88 to 0.59. FTIR and SEM-EDX indicated that all samples were successfully converted to activated carbon. The results of this study demonstrate that it is possible to chemically activate crustacean shells using either an acid or a base without sacrificing the effectiveness of the activated sample that is produced, which can be used to remove adsorbates from wastewater samples. As a result, the selection of activation is widened since the natural abundance of precursors exists.

Design of ternary GO@AgNPs@g-C3N4 membranes for efficient dye removals in integrated photocatalysis-filtration reactors

Photocatalytic composite membranes (PCMs), which integrate the high degradation efficiency of photocatalysts and the physical separation properties of membranes, have emerged as a promising technology for wastewater treatment. Herein, the ternary GO@AgNPs@g-C3N4 PCM was fabricated through a facile vacuum-filtration assembly of graphene oxide (GO), graphitic phase carbon nitride (g-C3N4), and silver nanoparticles (AgNPs) onto commercial mixed cellulose ester (MCE) substrates. The effects of g-C3N4 synthesized from different precursors and various metal nanoparticles on the performance of PCM were systematically investigated. Interestingly, results show the addition of AgNPs not only significantly improves the photocatalytic performance of PCMs but also enhances the mechanical adhesion between the active layer and the MCE substrate. The resultant PCMs exhibit outstanding photocatalytic performance, maintaining dye removal above 89% even after 25 consecutive cycles. Moreover, dye degradation pathways over the PCMs were investigated through free radical scavenging experiments and electron spin resonance characterizations. This simple assembly method results in a 3–12 times increase in flux compared to the layer-by-layer assembly method. Accordingly, our designed PCMs exhibit significant potential for wastewater treatment and water purification applications.

High-strength TiO2/TPU composite fiber based textiles for organic pollutant removal

Effective integration of nanostructured photocatalysts into polymer matrices is crucial for the broad practical application of fiber-based photocatalytic composite textiles. Herein, highly durable TiO2/TPU composite fibers with high TiO2 content (>30 wt. %) were prepared through wet spinning using 1D electrospun TiO2 nanofibers (TNFs). Due to the fiber reinforcement principle, the TNF/TPU composite fibers exhibited superior mechanical properties compared with pure TPU fibers. Furthermore, the TNF/TPU composite fibers with a ratio of 1:2 process impressive degradation efficiency for rhodamine B (RhB). The orientation of 1D TNFs and stronger interface between TNF and TPU matrices not only enable the excellent load sharing and transfer effects following fiber pullout and crack bridging mechanisms, but also improve photogenerated charge transfer efficiency, resulting in high strength and high photocatalytic activity. In addition, enhanced TNF exposure on the fiber is due to the hollow and porous structures of composite fibers, which is advantageous for photocatalytic degradation. Notably, when the RhB concentration exceeded 15 ppm, the TNF/TPU composite fibers exhibited higher degradation efficiency than the TNF powder. Therefore, TNF/TPU composite fiber–based textiles with high photocatalytic activity and strength are promising for overcoming the separation and recovery issues of nanostructured catalysts in practical wastewater treatment applications.

High Salinity Tolerance of Zn-Rich g-C3N4 in the Photocatalytic Treatment of Chlorophenol Wastewater

Organic saline wastewater has become a concern in recent decades due to its resistance to biological treatment and potential harm to municipal wastewater treatment plants. While photocatalytic methods have been used for treatment, they often lead to catalyst deterioration. The use of salt-tolerant catalysts presents a viable solution for treating organic saline wastewater. In this study, a Zn-rich g-C3N4 was synthesized, demonstrating excellent performance in removing 2,4-DCP and its derivatives from saline wastewater. More than 75.6% of 2,4-DCP was effectively removed with the addition of Zn-rich g-C3N4, nearly doubling the removal rate compared to pure g-C3N4 and those doped with Co, Ag, Mo, and Bi. Notably, the removal efficiency of 2,4-DCP slightly increased as salinity rose from 0.1 to 2.3 wt.%. Adding 0.1 g L−1 of Zn-rich g-C3N4 resulted in the removal of 2,4-DCP, 2-chlorohydroquinone, chloroacetophenone, and 2-chloropropionic acid by 99.3%, 99.8%, 98.2%, and 99.9%, respectively, from a real saline wastewater sample with 2.2 wt.% salinity, corresponding to a 67.7% removal of TOC. The EPR results indicated that Zn-rich g-C3N4 generated more free radicals compared to pure g-C3N4, such as·OH and Cl, to degrade organic contaminants. The degradation pathway revealed that 2,4-DCP was first dechlorinated into p-phenol and catechol, which were subsequently degraded into maleic acid/fumaric acid, trihydroxyethylene, acetic acid, oxalic acid, and other products. Furthermore, Zn-rich g-C3N4 demonstrated excellent stability and holds promising potential for applications in saline wastewater treatment.

Prediction of Biochar Adsorption of Uranium in Wastewater and Inversion of Key Influencing Parameters Based on Ensemble Learning.

With the rapid development of industrialization, the problem of heavy metal wastewater treatment has become increasingly serious, posing a serious threat to the environment and human health. Biochar shows great potential for application in the field of wastewater treatment; however, biochars prepared from different biomass sources and experimental conditions have different physicochemical properties, resulting in differences in their adsorption capacity for uranium, which limits their wide application in wastewater treatment. Therefore, there is an urgent need to deeply explore and optimize the key parameter settings of biochar to significantly improve its adsorption capacity. This paper combines the nonlinear mapping capability of SCN and the ensemble learning advantage of the Adaboost algorithm based on existing experimental data on wastewater treatment. The accuracy of the model is evaluated by metrics such as coefficient of determination (R2) and error rate. It was found that the Adaboost-SCN model showed significant advantages in terms of prediction accuracy, precision, model stability and generalization ability compared to the SCN model alone. In order to further improve the performance of the model, this paper combined Adaboost-SCN with maximum information coefficient (MIC), random forest (RF) and energy valley optimizer (EVO) feature selection methods to construct three models, namely, MIC-Adaboost-SCN, RF-Adaboost-SCN and EVO-Adaboost-SCN. The results show that the prediction model with added feature selection is significantly better than the Adaboost-SCN model without feature selection in each evaluation index, and EVO has the most significant effect on feature selection. Finally, the correlation between biochar adsorption properties and production parameters was discussed through the inversion study of key parameters, and optimal parameter intervals were proposed to improve the adsorption properties. Providing strong support for the wide application of biochar in the field of wastewater treatment helps to solve the urgent environmental problem of heavy metal wastewater treatment.

Enhanced photocatalytic degradation of Cr (VI) and organic pollutants using novel 3D/2D MoS2/SnS2 heterostructures for water remediation

In this study, 3D flower-like MoS2 nanostructures were synthesized using a hydrothermal technique to form heterostructures with 2D porous SnS2 nanosheets. The resulting 3D/2D MoS2/SnS2 heterostructures were evaluated for their photocatalytic abilities in removing Cr (VI), tetracycline (TC), and methylene blue (MB) under simulated solar irradiation. The results demonstrate that the MoS2/SnS2 heterostructures significantly outperformed pristine MoS2 and SnS2 in photocatalytic efficiency. Specifically, the MoS2/SnS2 photocatalysts achieved 99.9% degradation of Cr (VI) within 50 min, 96% degradation of TC in the same timeframe, and 99.9% elimination of MB in just 10 min. The reduction rate constant for Cr (VI) reduction by MoS2/SnS2 photocatalysts was 0.117 min−1, surpassing that of pure SnS2 (0.007 min−1) and MoS2 (0.0034 min−1) by 16 and 30 times, respectively. This outstanding performance is attributed to the heterojunction formation between SnS2 and MoS2, which suppresses the recombination of photogenerated charge carriers and provides abundant reactive sites due to their large specific surface area. The proposed photodegradation mechanism illustrates the facilitated migration of photogenerated charge carriers under light irradiation, enabled by the energy band alignment at the MoS2/SnS2 interface. These findings represent a significant advancement in the development of photocatalysts based on 3D flower-like MoS2 and porous SnS2 nanostructures, offering promise for applications in wastewater treatment and environmental remediation.

SnO2QDs: Photophysical properties, photocatalytic activity, mineralization financial cost and recycling process during industrial effluent treatment

This study investigates the synthesis, characterization, and photocatalytic performance of pure and titanium-doped tin dioxide quantum dots (SnO2QDs) prepared via a sonochemical method. The structural and morphological properties were thoroughly examined using XRD, FTIR, SEM-EDX, HRTEM, UV-DRS, and BET surface area analysis. XRD confirmed the formation of tetragonal SnO2 with high phase purity and average crystallite sizes of 2.95 nm for SnO2QD1 (calcined at 270 °C) and 8.36 nm for SnO2QD2 (calcined at 480 °C). Titanium doping was achieved without altering the SnO2 crystalline structure, as evidenced by FTIR spectra showing characteristic vibrational modes and hydroxyl groups. HRTEM images revealed spherical nanoparticles with diameters of 3.2 nm for SnO2QD1 and 9.7 nm for SnO2QD2, supported by SAED patterns confirming their polycrystalline nature. The photocatalytic efficiency was evaluated through the degradation of Reactive Yellow 145 dye under Xenon lamp irradiation. SnO2QD1 exhibited superior photocatalytic activity with a rate constant (k) of 6.94 × 10−3 s−1, achieving 80 % dye degradation in 105 min, compared to SnO2QD2 with a k of 4.50 × 10−3 s−1 and 83 % degradation in 120 min. Titanium doping further enhanced the photocatalytic performance, with SnO2QDT1 (1 % Ti) showing a k of 9.89 × 10−3 s−1 and 80 % degradation in just 90 min, three times more efficient than SnO2QDT2 (9 % Ti). BET analysis indicated a significant reduction in surface area with increased calcination temperature, from 154 m2/g for SnO2QD1 to 86 m2/g for SnO2QD2. The bandgap energies, determined via UV-DRS, were 3.30 eV for SnO2QD1 and 3.34 eV for SnO2QD2, slightly reduced in Ti-doped samples, enhancing visible light absorption. The SnO2QDs demonstrated excellent recyclability, maintaining photocatalytic activity over eight reuse cycles. Economic analysis based on Saudi Arabian electricity tariffs highlighted the cost-effectiveness of SnO2QD1, offering a 5.2 % reduction in energy consumption compared to SnO2QD2. These findings position SnO2QDs as highly efficient and sustainable photocatalysts for industrial wastewater treatment applications.

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.

Antibacterial activity of biogenic and chemically synthesized silver nanoparticles and its application in wastewater treatment

The present work reports the synthesis of silver nanoparticles (Ag NPs) by chemical as well as biological approaches. Ag NPs have been synthesized using different plant extracts such as Aloe vera, Syzygium aromaticum (clove), Musa (banana leaf), and Citrus X Sinensis (orange peel). The effect of various reducing agents has been examined on the shape and morphology of the synthesized Ag NPs. The synthesized Ag NPs have been characterized using UV–visible spectrophotometer, Dynamic Light Scattering (DLS), and Transmission Electron Microscopy (TEM). The average size of the synthesized Ag NPs has been confirmed by DLS characterization as 64 ± 11 nm, 106 ± 8 nm, 500 ± 14 nm, 281 ± 9 nm and 105 ± 7 nm, respectively. when synthesized using Aloe vera, Syzygium aromaticum, Musa, Citrus X Sinensis, and trisodium citrate (TSC), respectively. The synthesized Ag NPs have been used for screening antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis. The synthesized Ag NPs have also been evaluated for their bactericidal property against wastewater from polluted rivers and other water sources and have been found appropriate for use in bacteriological and wastewater treatment.

Development of two-dimensional amyloid fibril/carboxymethyl cellulose hybrid membranes for effective adsorption of hexavalent chromium

Amyloid fibrils (AFs) are protein aggregates with highly ordered fibrillar structures and can be formed via self-assembly of proteins under appropriate conditions. Owing to the unique properties of AFs, e.g., high surface-to-volume ratio and versatile functional groups, they offer abundant binding sites for the efficient adsorption of hexavalent chromium (Cr(VI)). This study was aimed at examining the performance of two-dimensional AF-based hybrid membranes for adsorbing Cr(VI). First, AF/carboxymethyl cellulose (AF/CMC) hybrid membranes were synthesized via chemical crosslinking coupled with phase inversion, followed by investigating the synthesis mechanism using Fourier transform infrared spectroscopy. Our results revealed that the surface microstructures and mechanical properties of the hybrid membranes could be affected by the AF:CMC mass ratio of the membrane. The porosity and ζ-potential of hybrid membranes were found to be dependent on both pH value and membrane composition. Analyses of the kinetics and thermodynamic behavior of Cr(VI) adsorption on the AF/CMC hybrid membranes revealed that the initial adsorption rate and maximum adsorption capacity were determined to be ∼149.20 mg g–1 h–1 and ∼311.11 mg g–1, respectively. The Cr(VI) removal percentage of hybrid membrane with high CMC content was found to remain at >75 % after five successive adsorption-desorption cycles. Finally, the mechanism and interactions involved in the adsorption of Cr(VI) on the hybrid membrane were further investigated via thermodynamic analysis and X-ray photoelectron spectroscopy. This study provides an excellent example of harnessing AF-based membranes in water remediation, highlighting the potential of AF-based hybrid materials for wastewater treatment applications.

Appraisal of Characterization and Adsorption Isotherm in the Bioremediation of Cu and Zn Ions from Aqueous Solutions Exploiting Unmodified Corn and Coconut Husk

Environment is contaminated by heavymetals has emerged as a substantial globaly. Conventional remediation methods have proven inadequate and costly in addressing this issue. Hence, there is a pressing need to discover bio-remediation as a cost effective, effectual, and environmentally, a substitute for heavymetal removal. This work investigates the adsorption behaviour of Corn Husk (CH) and Coconut Husk (CCH), an inexpensive adsorbent, towards Cu and Zn ions for potential application in wastewater treatment. The physico-chemical variables of unmodified CH and CCH were appraised, and batch experimental methods were employed to study variables like pH, contact time, size of particle, and preliminary content of metals. The impact of solution pH on metals uptake by the adsorbent was investigated on the pH range of 3 to 8, revealing optimal removal efficiencies at pH 6 for Cu and pH 5 for Zn. Equilibrium adsorption times were determined to be 80 minutes for Cu and 60 minutes for Zn ions onto CH and CCH. adsorption volumes is conforming to mono-layer coverage, attained from the Langmuir plots were 4.792 mg/g and 4.594 mg/g respectively for Cu and Zn metals onto the CH and 4.771 mg/g and 4.400 mg/g for their adsorption onto CCH. Experimental values were confirmed to the Langmuir model and Freundlich model, with the Langmuir model providing the best fit. The CH based adsorbent was generally found to have an increased capacity of adsorption of the metal contents than Coconut husk (CCH). These findings underscore the strength of Corn husk as an active adsorbent to extract cationic heavymetal contents from industrial effluents.

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.

A novel sulfur-based fiber carrier fixed-bed reactor for nitrate-contaminated wastewater treatment: Performance, operational characteristics and cold-tolerant mechanism

In the view of the serious prejudice of nitrates, sulfur-based autotrophic denitrification filter (SADF) has been widely used for deep nitrate removal from electron-donor-deficient water. However, it faces many challenges like slow start-up, reliance on backwashing, and poor low-temperature tolerance. For these challenges, a novel sulfur-based fiber carrier fixed bed reactor (SFFR) was developed in this study. It was found that SFFR had great film-forming ability and flow field characteristics, which promoted it to obtain superior denitrification performance, and the maximum nitrogen removal rate of 0.53 kg-N/m3/d. Meanwhile, SFFR shows significant cold tolerance, and alleviating the acidification problem of effluent to a certain extent. To sum up, the SFFR possesses the potential to be widely used in real-world wastewater treatment applications, especially as a promising solution for nitrate removal in cold regions. This study can provide an important reference for the improvement of the elemental sulfur autotrophic denitrification process.

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.

Enhancing water purification efficiency with zirconium-mercaptosuccinic acid metal-organic framework integrated mixed matrix membranes: Synthesis, comprehensive characterization, and performance insights

The development of metal-organic framework (MOF) based membranes has shown great potential to address the bottlenecks in industrial wastewater treatment. This study emphasized a novel approach involving a zirconium-based MOF (Zr-MA-MOF) with mercaptosuccinic acid (MA) as a ligand for fabricating mixed matrix membranes (MMMs). These MMMs were fabricated using a polyethersulfone (PES) matrix embedded with different nanofiller loadings of 0.25, 0.5, 0.75, and 1.0 wt%. Consequently, this study investigated the impact of Zr-MA-MOF loadings on the membrane morphology and functional performance, particularly focusing on pure water flux, rejection of salts, heavy metals, and dyes, antifouling properties, and long-term stability. The MMM with a loading of 0.75 wt% Zr-MA-MOF emerged as a standout performer, delivering an exceptional water flux of 71 Lm−2h−1 and rejection efficiencies of 80, 74, and 99 % for divalent magnesium sulfate (MgSO4), monovalent sodium chloride (NaCl), and dyes (including methylene blue, congo red, and rose bengal), respectively. The heavy metal rejection capabilities of the Zr-MA-MOF membrane were equally remarkable, with rejection rates of 90, 92, and 94 % for arsenic, chromium, and aluminum ions, respectively. Furthermore, a flux recovery ratio of 92 % showcased the great potential for sustainable industrial applications. These findings revealed that the integration of Zr-MA-MOF into membrane technology holds great potential for water treatment processes, catering to both human consumption and industrial applications for diverse wastewater treatment needs.

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.

Periodate-driven efficient degradation of diverse pharmaceuticals with iodine-doped MnO2

This research investigated the development of a novel catalyst for contaminant remediation. The strategy involved enhancing the catalytic effectiveness of MnO2 by strategically incorporating iodine, resulting in I-MnO2. Electron paramagnetic resonance (EPR) spectroscopy confirmed an augmentation in oxygen vacancies upon iodine inclusion, leading to increased catalytic activity. I-MnO2 was evaluated as an efficient catalyst within an advanced oxidation process for ciprofloxacin removal through periodate activation. The system achieved a 91.2 % degradation of 20 ppm ciprofloxacin within 9 min, demonstrating a strong correlation between catalyst and oxidant dosages. The I-MnO2/IO4¯ system exhibited remarkable stability across a broad pH range and minimal susceptibility to ionic strength variations, water anions, and humic acid presence. Quenching experiments coupled with EPR analysis suggested the involvement of singlet oxygen (1O2) and iodate radicals (IO3•) generated from the interaction of the metastable Mn(IV)-O-IO3 species with ciprofloxacin. X-ray photoelectron spectroscopy analysis of Mn 2p and O 1s orbitals, performed before and after reactions, further corroborated the role of I-MnO2 in facilitating periodate activation by promoting the conversion of Mn(II) and Mn(III) to Mn(IV) species. This innovative catalyst demonstrates exceptional efficiency in eliminating high concentrations of organic pollutants, suggesting its potential for practical and cost-effective 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.