Organic Contaminants Research Articles

Excellent bisphenol A removal performance triggered by electron-transfer regime on cobalt phosphide embedded in nitrogen, sulfur-doped carbon/MXene

The non-radical pathway dominated by the electron transfer process (ETP) has gained considerable attention for the removal of organic contaminants in persulfate-based advanced oxidation processes. Rationally designing new catalysts with optimized composition and structural merits and further elucidating the enhanced removal mechanism are of great importance. In this work, we successfully synthesized a nitrogen-sulfur co-doped carbon encapsulated cobalt phosphide (Co2P) on both sides of MXene nanosheets (MZPC) to degrade bisphenol A (BPA) from organic wastewater. The results indicated that BPA was degraded by 98.2 % in a mere 5 min using 0.1 g L-1 of peroxymonosulfate (PMS) and 0.05 g L-1 of the optimized catalyst (MZPC-9), exhibiting an excellent pseudo-first-order kinetics rate constant (k = 1.485 min−1). Uniformly dispersed Co2P nanoparticles (approximately 9.4 nm, calculated using the Scherrer equation) on both sides of MXene exhibited enhanced binding affinity with PMS, forming the MZPC-9-PMS* metastable complexes with potent oxidative capability. The resultant MZPC-9-PMS* complexes induced the polymerization reaction of BPA and achieved 81 % total organic carbon (TOC) removal. This study offers a novel perspective on the design of metal active centers to enhance the ETP-dominated non-radical pathway for pollutant degradation.

Molecular insights into pilot-scale selective removal of emerging contaminants in hospital wastewater

Advanced oxidation processes (AOPs) are a promising technology for removing emerging organic contaminants (EOCs) from wastewater, while the coexisting dissolved organic matter (DOM) significantly hinders effective oxidative removal of EOCs. Understanding the effects of DOM on EOCs removal in real water matrices is crucial for designing more efficient AOPs. Herein, a pilot-scale integrated in-situ ozonation/ultrafiltration process was conducted to remove EOCs from hospital wastewater. Furthermore, the ozonation reactivity of DOM and EOCs was contrastingly analyzed at the molecular level. Our integrated process selectively removed 85 % of EOCs at a relatively low oxidant dosage of 0.44 mg O3 per mg dissolved organic carbon (DOC). Using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), we reveal that ozone selectivity for EOCs arose from their overall reductive characteristics of being more aromatic and unsaturated in molecular composition compared to DOM. Additionally, specific DOM compounds potentially facilitate EOCs removal. This work provides pilot-scale experience in EOCs removal from hospital wastewater and in-depth understanding of DOM’s role in the integrated process, guiding the development of effective AOPs for selective removal of emerging contaminants.

Legacy and emergent contaminants in glaucous-winged gull eggs from Canada's Pacific coast: Spatial distribution, temporal trends, and risks for human consumers

Using glaucous-winged gull (Larus glaucescens) eggs from Canada's Pacific coast, we investigated spatial and temporal trends (2008–2022) of a suite of legacy and emergent contaminants, including 16 perfluoroalkyl substances (PFAS), 15 polybrominated diphenyl ethers (PBDEs), 7 alternative halogenated flame retardants (AHFRs), total mercury (THg), as well as stable isotopes of carbon (δ13C) and nitrogen (δ15N) to control for diet. Legacy organochlorines (OCs) were also measured in eggs in 2020 for a preliminary human health risk assessment (HHRA). Between 2008 and 2022, glaucous-winged gull eggs from more urban-influenced colonies (Mandarte Island) were up to ∼2x more contaminated with PFAS, PBDEs, AHFRs, and THg than eggs from the offshore colony (Cleland Island), suggesting different source regions and dietary exposures. Concentrations of Σ15PBDEs declined linearly among colonies (p < 0.001), consistent with several North American phase-outs and regulatory restrictions dating back to the early/mid 2000s. Conversely, temporal trends for PFOS, Σ12PFCAs, Σ7AHFRs, and THg were characterized by a combination of second-order declines and non-linear increases in recent years. After correcting THg for dietary shifts using δ15N, THg concentrations followed a U-shaped trend at Mandarte and Cleland Islands, while those at Mitlenatch Island remained relatively constant over time. Increasing trends for some contaminants coincided with both an increase in δ13C and δ15N. For the HHRA, all gull eggs collected in 2020 had hazard quotients (HQs) < 0.2, indicating no foreseeable risk or harm for First Nations consumers for certain contaminants. Our findings indicate that spatio-temporal trends of persistent organic contaminants and THg in Pacific glaucous-winged gull eggs are influenced by a combination of factors, including the impact of regulations on anthropogenic emissions, accompanied by changes in foraging behaviour and food-web structure.

Bimetal-organic framework derived single-atom-like Co/Fe catalysts for peroxydisulfate activation: The dual amplification of radical and nonradical pathways

A novel single-atom-like Co/Fe catalyst (i.e., Co/Fe-N-C) was synthesized by pyrolysis of a Zn/Co/Fe zeolitic imidazolate framework, and applied in peroxydisulfate (PDS) activation for removal of organic contaminants from wastewater. The isolated diatomic metal-nitrogen sites were detected by X-ray adsorption fine-structure. The degradation of four contaminants (i.e., phenol, bisphenol A, 2,4-dichlorophenol, and N-methyl-2-pyrrolidone) with a concentration of 100 mg/L could be degraded separately within 20 min by the Co/Fe-N-C system with 10 mmol/L of PDS, 0.5 g/L of catalyst dosage, and initial pH of 3. Besides, 79.2 % of phenol could be mineralized in 120 min, and the turn-over frequency value of the catalyst was calculated to be 27.17 min−1, which was higher than the commonly reported homogeneous PS-AOPs. Moreover, the Co/Fe-N-C exhibited high stability (mineralization rate over 70 % after 5 cycles), a wide initial pH range (3−9), and high catalytic performance at 5–20 mmol/L of PDS concentrations. Based on the analysis of radical scavenging experiments and electron spin resonance spectra, the radical and non-radical pathways for PDS activation were proved in the system, and the contribution of phenol degradation by each pathway was clarified.

Fabrication of Nanofiber Membranes from Waste-Expanded Polystyrene (EPS) Combined with Zinc Oxide Nanoparticles (ZnO NPs) and its Photocatalytic Activity

Society must face the challenge of creating high-value products from recycled waste polymers. This research focuses on the synthesis of nanofiber membranes from waste-expanded polystyrene (EPS) using electrospinning. Zinc oxide nanoparticles (ZnO NPs) enhance the photocatalytic activity of the fiber membrane. ZnO is a more useful alternative to TiO2 as a form of photocatalyst for degrading contaminants in water. This study systematically investigated the effects of varying amounts of ZnO NPs on fiber membrane nanostructure and photocatalytic activity. Methylene blue was used to measure the photocatalytic efficiency of fiber membranes, as they are commonly used in textile wastewater and exposed to ultraviolet light for 20 h. The results showed that the fiber membrane containing ZnO NPs with a concentration of 1 % effectively degraded methylene blue. HIGHLIGHTS The EPS/ZnO nanofiber produced using electrospinning was characterized using SEM-EDX, FTIR, and Raman spectroscopy UV-Vis spectrophotometer testing proves that the EPS/ZnO nanofiber has photocatalytic activity capabilities that can remove organic contaminants The EPS/ZnO 1 % shows the highest efficiency; 45 % of methylene blue was degraded within 20 h of irradiation GRAPHICAL ABSTRACT

Enhanced dye degradation using MIL-53(Fe)-Modified kraft lignin as a heterogeneous Fenton catalyst

MIL-53(Fe), a metal–organic framework (MOF), is capable of degrading harmful organic contaminants, but it has relatively low Fenton catalytic efficiency. To enhance the degradation performance of MIL-53(Fe), we synthesized MIL-53(Fe)-MKL by incorporating modified kraft lignin (MKL) into pristine MIL-53(Fe). The as-prepared composite demonstrated Fenton activity, degrading 97 % of methylene blue (MB) within 50 min. Compared to pristine MIL-53(Fe) (which achieved 62.4 % MB degradation), the MIL-53(Fe)-MKL composite showed a 34.6 % improvement in MB degradation under identical reaction conditions. The incorporated MKL promotes Fe2+ regeneration from Fe3+ in the Fenton process, activating H2O2 to produce OH radicals, which were identified through scavenging experiments and chemical dosimetry with ESR analysis. The MIL-53(Fe)-MKL composite was reused for at least five cycles without a significant decrease in catalytic efficiency. This reported catalyst takes advantage of both MKL and MIL-53(Fe) to enhance catalytic activity, providing a basis for developing innovative catalysts for organic pollutant degradation.

Strong enhancement on diclofenac degradation in Cu(II)/H2O2 system by adding ascorbic acid: Efficiency, mechanism and influencing factors

Utilization of trace Cu(II) (at μM level) inherently existing in wastewater to activate hydrogen peroxide (H2O2) has exhibited significant potential to remove aqueous organic contaminants. Nevertheless, the Cu(II)/H2O2 system was only efficient under alkaline conditions. Herein, ascorbic acid (H2A), an environmentally benign and natural reductant, was introduced to broaden pH range of Cu(Ⅱ)/H2O2 process by expediting the Cu(II)/Cu(I) cycle. The H2A/Cu(Ⅱ)/H2O2 system performed well in degrading diclofenac across a wide pH range from 4.0 to 9.0, and its kinetic rate constant of diclofenac elimination was 247 times greater than its counterpart without H2A at the optimal pH of 6.0, outperforming the performance of most previously reported reductant-enhanced Cu(Ⅱ)/H2O2 system. Electron paramagnetic resonance analysis, periodate colorimetric method, and in situ Raman spectroscopy tests indicated that hydroxyl radical (HO), rather than Cu(III), was the dominant reactive species of diclofenac degradation. Thirteen degradation products of diclofenac were identified by LC-Q-TOF-MS, and five different elimination pathways were proposed. Furthermore, the presence of SO42− exerted an insignificant influence on diclofenac degradation, while the addition of Cl−, HCO3− and humic acid slightly suppressed the abatement of diclofenac. H2A/Cu(Ⅱ)/H2O2 system was still highly efficient in degrading diclofenac in actual water matrix (i.e., reservoir water and lake water). Overall, this study provided an eco-friendly approach to enhance the oxidation capacity of the Cu(II)/H2O2 system over a wide pH range, which might be a potential technology for degrading refractory organic pollutants in water treatment.

Predicting the spread of contamination in water distribution networks laid on sloping terrains

Contamination in domestic and drinking water during the conveyance process is one of the biggest health risks of all time. This is a very common hazard that is expected in the areas where water, sewer, and drainage pipes are laid in trenches near each other. The extent of the contamination spread in the case of intrusion through a pipe leak for water distribution networks (WDNs) laid on sloping terrain is not known. This article deals with the simulation and hydraulic analysis of organic contaminant intrusion in WDNs with significant consideration of the slope of the laid pipes. The source of organic contamination is considered to be the nearby leaking sewer water. The effects of sloping terrain on contaminant spread in the pipe network are studied in detail by injecting contaminant concentrations at eight different critical locations in the network. The results of contamination spread after a particular time at all nodes are compiled, and by using statistical techniques, a relation between the contaminant spread and pipe slope is proposed. The presented model is validated by comparing the actual values of the contaminant in water samples obtained at the site with the calculated ones, and it shows that the values deviate within the range of ±2% only, which is considered a good match. The research proves to be beneficial for the management of water distribution through pipe networks against contaminants to maintaining water quality and public health.

Industrial Pollution in Patna City : Physico-Chemical Analysis of Effluents and Their Effects on Water and Soil

Industrial pollution is a significant concern in Patna City, with rapid urbanization and industrial growth contributing to the degradation of natural resources. This study focuses on the physico-chemical analysis of industrial effluents and their effects on the water and soil quality in and around Patna. Effluents from various industries, including textile, sugar, rice mills, and small-scale manufacturing units, are released into nearby water bodies and soils, posing serious environmental risks. The research aims to assess the levels of pollutants by analysing key physico-chemical parameters such as pH, total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), heavy metals (lead, chromium, cadmium), and organic contaminants in industrial effluents. Samples were collected from various locations near industrial zones and water bodies. The study also evaluated the impact of these pollutants on soil and groundwater quality. It was found that prolonged exposure to industrial effluents led to the accumulation of toxic metals in soil, reducing its fertility and altering its structure. Additionally, groundwater sources were contaminated with hazardous chemicals, making them unfit for drinking and irrigation purposes. The implementation of advanced treatment technologies and sustainable industrial practices is crucial for safeguarding the environment and public health in Patna City.

Urban Groundwater in the cities of Europe: hidden challenges in a changing climate

In European cities, groundwater remains an issue of significant concern, largely because it is “out of sight and out of mind.” The general public, and even decision-makers, possess only a limited understanding of the state and characteristics of this vital resource. As a consequence, problems related to groundwater quality or changing water tables/piezometric surfaces may persist for years, or even decades, without being adequately addressed-or worse, without being noticed at all before resulting in land subsidence,saltwater intrusion, deep migration of persistent organic contaminants like PFAS (Le monde, 2023) or other irreversible consequences. The urban water cycle is central to ensuring the supply of clean, safe drinking water, effective sanitation, and wellfunctioning drainage systems for millions of residents. The impacts of human activities, such as land use change, excessive water abstraction and mismanagement, and the discharge of wastewater can exert a far greater influence on groundwater systems and hydrogeology than climate change. These activities alter the quantity and quality of both surface and groundwater, raising complex scientific, technical, socio-economic, cultural, and ethical challenges in urban water management. It is important to address the many challenges associated with ensuring water security and safety in cities (Quevauviller et al., 2024), as well as for development of effective climate change mitigation and adaptation strategies for urban areas (IPCC, 2024). Groundwater plays a critical role in the green transition and is an integral component of most climate change mitigation and adaptation strategies (Ingemarsson et al., 2022), and for meeting the increasing demand for freshwater in cities due to accelerating urbanization (United Nations, 2022). Many urbanized areas in Europe already face poor chemical and quantitative status (EEA, 2024; Sentek et al., 2024), and global change including increasing populations and sea level rise pose a tremendous challenge for safe and secure water supply especially in coastal European cities. Open access to digital subsurface data e.g. through the European Geological Data Infrastructure supports societal needs and UN sustainable development goals (Hinsby et al., 2024). This special issue demonstrates some of the important issues that the water supply of European cities are facing in times of increasing competing use of the subsurface (Volckko et al., 2020), projected climate change impacts on the hydrological cycle (Henriksen et al., 2023) and with freshwater now being among the transgressed planetary boundaries (Richardsson et al., 2023). [...]

Groundwater resilience, security, and safety in the four largest cities in Denmark

Denmark's complete reliance on groundwater for water supply presents a unique case study in management of natural resources, urban planning, and water resilience in the face of climate change. This paper examines the groundwater management strategies in Denmark in general, focusing on Denmark's four largest cities—Copenhagen, Aarhus, Odense, and Aalborg— each facing distinct challenges due to their demographic, geographical, hydrogeological, and economic characteristics. Through analysis of these cities' approaches to groundwater management, this research contributes to the global discourse on sustainable urban water supply systems. As coastal groundwater cities (CGC), these urban areas must navigate the complexities of sustaining growing populations, mitigating climate change impacts, and coastal processes while ensuring the long-term viability of their groundwater resources. Copenhagen and Aalborg, built atop semi-confined fractured and locally karstic carbonate rocks, highlights the specific challenges associated with karstic groundwater systems, while, Aarhus, and Odense built on glaciofluvial aquifers faces different issues. The different groundwater challenges in these cities underscores the importance of integrating urban development with water resource management and environmental sustainability, offering valuable insights and lessons learned for other regions facing similar challenges. This study, thus not only sheds light on Denmark's groundwater management practices, but also emphasizes the need for innovative solutions to ensure the resilience of urban water supply systems in a changing climate and increasing pressures of emerging organic contaminants and elevated concentrations of geogenic elements induced by water abstraction and fluctuating water tables. Advanced Danish monitoring and modelling tools applied to support decision-making and innovation within the water sector are continuously developed and improved to support resilient and sustainable management of the available water resources.

Design plasmonic nanostructure of silicon dioxide and titanium dioxide loaded on a nano surface for clean water production through photocatalysis and electrochemical techniques

The work is targeted to rebuild the framework of a nanocatalyst (NCat) that depends on the n/p-type heterojunction through the plasmonic structure of reduced graphene oxide (rGO), silicon oxide nanoparticles (SiO2 NPs), polyvinyl alcohol (PVA NPs), and titanium dioxide (TiO2 NPs). The removal of medical and organic contaminants occurs via photocatalysis operation which follows through the electrochemical technique and UV-spectrophotometer under visible light with nanocatalyst (rGO@SiO2@PVA@TiO2) for clean water and a safe medical environment. The Z-Scheme mechanism explains the development of electron maps in fabricated nanocatalyst engineering to increase the efficiency of the photocatalytic activity. The high activity of the NCat appeared, after 160 min, and the photocatalytic efficiency for methylene blue (MB), methyl orange (MO), rhodamine B (RhB), moxifloxacin (MFX), and colchicine, was 90 %, 76 %, 88 %, 84 %, and 91 % respectively. The stability of NCat was confirmed via the recyclability process, with the efficiency at 58 % after the fifth cycle. The high stability of NCat was proved by the electrochemical technique performed after 100 cycles. The safety of the NCat for the generation of clean water was highlighted by the cytotoxicity test using normal mouse liver cells. It is suggested to use the new NCat design because of its distinctive optical characteristics, which make it a viable candidate for use as a revolutionary nanomaterial with high efficiency and safety for clean water and removal of medical contaminants.

One-pot hydrothermal synthesis of g-C3N4/BiOBr/Bi2MoO6 as a Z-scheme heterojunction for efficient photocatalytic degradation of ciprofloxacin (CIP) antibiotic and Rhodamine B (RhB) dye

Photocatalytic degradation of toxic organic pollutants using natural sunlight is a rapidly advancing area of research, particularly involving binary or ternary component photocatalysts with Z-type heterojunctions. In this study, ternary g-C3N4/BiOBr/Bi2MoO6 photocatalysts were fabricated using a simple one-pot solvothermal method. The morphology and physicochemical properties of the samples were characterized using various techniques, including X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), confirming the presence of BiOBr, Bi2MoO6, and g-C3N4 components. The inclusion of g-C3N4 increased the BET surface area of the composite up to 46 m2/g, compared with BiOBr. In addition, g-C3N4 also enhanced the light absorption capability of the composite into the visible light range, while BiOBr and Bi2MoO6 significantly improved separation of electron-hole pairs, as evidenced by photoluminescence (PL) intensity. Under visible light illumination (LED lamp), the prepared photocatalyst showed high efficiency, achieving 94 % degradation of ciprofloxacin (CIP) antibiotic in 180 min and 92 % degradation of Rhodamine B (RhB) dye in 240 min. Moreover, under natural sunlight irradiation, the photocatalyst achieved degradation efficiencies of approximately 91 % for CIP and 100 % for RhB within 180 minutes. The photodegradation of the pollutants followed first-order kinetics with a Z-scheme type heterojunction. The photogenerated electrons played a crucial role as the main active species involved in detoxification of the organic contaminants. The photocatalyst exhibited excellent structural stability and good cycling ability, maintaining its original photocatalytic performance even after five cycles of use. This work demonstrates a promising strategy for developing sunlight-active ternary heterojunctions for environmental remediation.

One-step hydrothermal synthesis of ternary heterostructure stannic sulfide - bismuth sulfide - bismuth oxychloride (SnS2-Bi2S3-BiOCl) composite loaded on carbon felt for highly efficient piezocatalytic degradation of organic dyes and antibiotics

The piezoelectric catalysis technique harnesses naturally occurring vibrational energy to remove organic pollutants from water in an environmentally friendly manner. In this study, a ternary heterostructure SnS2-Bi2S3-BiOCl (S-B-B) composite was successfully synthesized via a one-step hydrothermal method and simultaneously deposited on the surface of carbon felt. The S-B-B heterojunction exhibits significantly enhanced piezoelectric catalytic activity compared to SnS2, Bi2S3, and BiOCl, achieving a k value of 2.26 × 10⁻² min⁻¹ and a degradation efficiency of 89.9 % towards methyl orange (MO) dye after 100 min of ultrasonic degradation. This performance is markedly superior to the individual components, with k values of 3.80 × 10⁻⁴ min⁻¹ for SnS2, 1.16 × 10⁻² min⁻¹ for BiOCl, and 1.31 × 10⁻² min⁻¹ for Bi2S3. Moreover, in addition to levofloxacin (LV), it demonstrates high removal efficiency for Congo red (CR), methylene blue (MB), tetracycline hydrochloride (TC-HCl), and sulfanilamide (SN). Furthermore, it can be loaded onto carbon felt for use in piezoelectric catalytic degradation of dyeing wastewater, highlighting its potential for practical applications. Trapping experiments suggest that singlet oxygen non-radicals and hydroxyl radicals play a critical role in the piezocatalytic degradation of organic contaminants. Based on LC-MS results, a possible degradation pathway for MO dye is proposed. Furthermore, DFT calculations confirm electron transfer from Bi2S3 to SnS2 and BiOCl at the interfaces between SnS2/Bi2S3 and BiOCl/Bi2S3. The piezoelectric mechanism of the S-B-B composite is also elucidated, highlighting the interaction and electron dynamics within the heterostructure.

Cation-Doped Nanocarbons for Enhanced Perfluoroalkyl Substance Removal: Exotic Bottom-Up Solution Plasma Synthesis and Characterization.

Perfluorinated alkyl substances (PFAS), such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are pervasive organic contaminants that are widespread in aquatic environments, posing significant health risks to humans and wildlife. Due to their persistent nature, urgent removal is necessary. Conventional adsorbents are inefficient at removing PFOS and PFOA, highlighting the need for alternative materials. Herein, we present a synthetic method for quaternary ammonium cation-doped carbon nanoparticles (QACNs) using a solution plasma process for the efficient removal of PFOS and PFOA. QACN is formed simultaneously through a one-step discharge of nonequilibrium plasma at the interface of benzene and pyridinium chloride. The resulting material exhibited a high surface electrical charge and enhanced hydrophilicity as well as an amorphous structure of a nonporous nature, involving nanoparticles with an undefined shape. The obtained adsorbent demonstrated high adsorption efficiency and stability, adsorbing 998.45 and 889.37 mg g-1 of PFOS and PFOA, respectively, exceeding the efficiencies of conventional carbon-based adsorbents (80.89-313.15 mg g-1). The adsorption performance was dependent on the adsorbent dosage, pH of the solution, and the coexisting ionic species. Adsorption studies, including adsorption kinetics, isotherms, and thermodynamics, revealed that PFOS and PFOA were chemisorbed to the QACN surface, forming multilayers endothermically and spontaneously. Experimental and computational analyses revealed that adsorption primarily occurs via electronic interactions between the PFAS active sites and the quaternary ammonium group in the carbon framework. The slightly lower adsorption potential of the PFOS and PFOA fluorocarbon chains on the adsorbent was elucidated. Furthermore, the dispersibility of the adsorbent in solution significantly affected the adsorption performance. These findings highlight the potential of the novel synthetic method proposed in this study, offering a pathway for the development of highly effective carbon adsorbents for environmental remediation.

The Removal of Organic Contaminants from Condensed Wastewater Using Electrolysis Combined with Ozonation: A Pilot-Scale Study

A pilot-scale investigation of ozonation combined with electrolysis (E-O3) was performed to treat concentrated wastewater from a reverse osmosis system from the printing and dyeing industry. It was found that E-O3 only exhibits an efficiency advantage after the removal of carbonate ions. The synergy of ozone and electrolysis lies not only in the generation of hydroxyl radicals, but also in the degradation of organic compounds. Moreover, the combination of electrolysis and ozonation has an inhibitory effect on the decrease in pH, which plays an important role in the synergistic generation of hydroxyl radicals. This pilot-scale study holds reference significance for the engineering applications of the E-O3 technology.

Modified PVDF ultrafiltration membrane with host–guest supramolecular trapping for efficient separation of multiple organic contaminants

In our modern lifestyle, the cocktail of organic pollutants from everyday items, such as hair dyes, cloth dyes, food colours, hair oils, cooking oils, and agricultural proteins, enters water streams through household pipelines. This unnoticed contamination, growing alarmingly, poses a serious challenge beyond the scope of conventional separation techniques, calling for a comprehensive solution. While membrane technology offers a promising solution, it grapples with persistent surface fouling issues. This study introduces a novel approach through the development of extraordinary Polyvinylidene fluoride-Montmorillonite-Cucurbit[6]uril (PVDF-M-CB[6]) mixed matrix membranes, presenting a potential breakthrough in overcoming surface fouling challenges and offering a versatile solution for the separation of an array of organic contaminants. Powered by the synergistic host–guest supramolecular complexation of CB[6] onto montmorillonite (M) clay support, these membranes demonstrate swift and selective encapsulation, leading to superior cationic dye rejection. Adding to the allure, CB[6]’s structure encourages favorable carbonyl interactions with bovine serum albumin (BSA), effectively repelling the protein away from the membrane, while also promoting seamless oil–water emulsion separation with an underwater oil contact angle of 150 ± 3°, displaying its superoleophobic nature and enhancing remarkable antifouling properties. The PV-M-CB[6] membranes showcased 2x removal of cationic dyes, 1.3x removal of anionic dyes, 1.4x oil–water emulsion separation, and 2x BSA separation compared to the pristine polyvinylidene fluoride (PVDF) membrane. These membranes displayed 98.3 % efficiency in oil–water emulsion separation and sustained a flux recovery ratio of over >75% after seven cycles. Overall, PV-M-CB[6] membranes represent an innovative solution with heightened hydrophilicity, remarkable antifouling performance, and exceptional proficiency in delivering one-stop organic foulant separation.

Fish Health Altered by Contaminants and Low Water Temperatures Compounded by Prolonged Regional Drought in the Lower Colorado River Basin, USA.

The goal of this study was to assess health of male Common Carp (carp, Cyprinus carpio) at four sites with a wide range in environmental organic contaminant (EOC) concentrations and water temperatures in Lake Mead National Recreation Area NV/AZ, US, and the potential influence of regional drought. Histological and reproductive biomarkers were measured in 17-30 carp at four sites and 130 EOCs in water per site were analyzed using passive samplers in 2010. Wide ranges among sites were noted in total EOC concentrations (>10Xs) and water temperature/degree days (10Xs). In 2007/08, total polychlorinated biphenyls (tPCBs) in fish whole bodies from Willow Beach (WB) in the free-flowing Colorado River below Hoover Dam were clearly higher than at the other sites. This was most likely due to longer exposures in colder water (12-14 °C) and fish there having the longest lifespan (up to 54 years) for carp reported in the Colorado River Basin. Calculated estrogenicity in water exceeded long-term, environmentally safe criteria of 0.1-0.4 ng/L by one to three orders of magnitude at all sites except the reference site. Low ecological screening values for four contaminants of emerging concern (CEC) in water were exceeded for one CEC in the reference site, two in WB and Las Vegas Bay and three in the most contaminated site LVW. Fish health biomarkers in WB carp had 25% lower liver glycogen, 10Xs higher testicular pigmented cell aggregates and higher sperm abnormalities than the reference site. Sperm from LVW fish also had significantly higher fragmentation of DNA, lower motility and testis had lower percent of spermatozoa, all of which can impair reproduction. Projections from a 3D water quality model performed for WB showed that EOC concentrations due to prolonged regional drought and reduced water levels could increase as high as 135%. Water temperatures by late 21st century are predicted to rise between 0.7 and 2.1 °C that could increase eutrophication, algal blooms, spread disease and decrease dissolved oxygen over 5%.

Visible-light induced effective and sustainable remediation of nitro organics pollutants using Pd-doped ZnO nanocatalyst

Nitroaromatic compounds represent a class of highly toxic pollutants discharged into aquatic environments by various industrial activities, posing significant threats to ecological integrity and human health due to their persistent and hazardous nature. In this study, Pd-doped ZnO nanoparticles were investigated as a potential solution for the degradation of nitro organics, offering heightened photocatalytic efficacy and prolonged stability. The synthesis of Pd-doped ZnO NPs was achieved via the hydrothermal method, with subsequent analysis through XRD spectra and XPS confirming successful Pd doping within the ZnO matrix. Characterization through FESEM and HRTEM unveiled the heterogeneous morphologies of both undoped and Pd-doped ZnO nanoparticles. Additionally, UV–vis and PL spectroscopy provided insights into the optical properties, chemical bonding, and defect structures of the synthesized Pd-doped ZnO NPs. Pd doping induces a redshift in ZnO’s absorption spectra, reducing the bandgap from 3.12 to 2.94 eV as Pd concentration rises from 0 to 0.2 wt.%. The photocatalytic degradation, following pseudo-first-order kinetics, achieved 90% nitrobenzene abatement (200 µg/L, pH 7) under visible light within 320 min with a catalyst loading of 16 µg/mL. The photocatalytic efficacy of 0.08 wt% Pd-doped ZnO (k = 0.058 min⁻1) exhibited a 25-fold enhancement compared to bare ZnO (k = 3.1 × 10–4 min-1). Subsequent quenching and ESR experiments identified hydroxyl radicals (OH•) as the predominant active species in the degradation mechanism. Mass spectrometry analysis unveiled potential breakdown intermediates, illuminating a plausible degradation pathway. The investigated Pd-doped ZnO nanoparticles demonstrated reusability for up to five successive treatment cycles, offering a sustainable solution to nitro organics contamination challenges.

First principles calculations of double perovskite RbX2Y3O10 (X = Ca, Ba: Y[dbnd]Cd, Ta) materials for photocatalytic applications

Production of oxygen and hydrogen energy through suited photocatalysts by water splitting is the main issue in the modern age. In this regard, the double perovskite Dion-Jacobson materials RbX2Y3O10 (X = Ca, Ba: YCd, Ta) for photocatalytic activity are investigated by using the CASTEP package. The plane-wave (PW) pseudo-potential in the context of the generalized gradient approximation (GGA)-Perdew Burke Ernzerhof (PBE) and local density approximation (LDA) exchange-correlation functional technique is used to investigate the compounds. According to the results, compounds have a tetragonal (a = b≠c) structure with space group 123 (p4/mmm). Compounds Mullikan bond populations were estimated in order to comprehend the bonding characteristics that found a mixed ionic and covalent bonding. According to electronic characteristics, RbBa2Ta3O10, RbBa2Cd3O10, and RbCa2Cd3O10 have semiconductor behavior with indirect bandgap of 2.11 eV, 2.27 eV, and 1.51 eV, respectively, and respond under visible region light. DOS and PDOS are studied to inspect the distinct atom's contribution to electronic band structure. The compounds are mechanically brittle (1.55, 1.39), ductile (1.97), and stable in their natural form, according to elastic constant values. The optical characteristics simulation indicates that compounds have the potential to decompose or oxidize organic contaminants. According to the results, these compounds are suitable for the water-splitting photocatalytic process to produce oxygen and hydrogen.