Emerging Contaminants Research Articles

Microplastic and associated emerging contaminants in marine fish from the South China Sea: Exposure and human risks

Microplastics can act as vectors of chemical contaminants in aquatic environments, but the extent to which this phenomenon contributes to chemical exposure in marine organisms remains poorly understood. We investigated the occurrence of microplastics and emerging contaminants (ECs), including antibiotics and per- and polyfluoroalkyl substances (PFAS) in 14 marine fish species. Microplastics were detected in all marine fish species, mainly in the gastrointestinal tract. Fluoroquinolones and tetracyclines were the dominant antibiotics in fish muscles with maximum concentrations of 24.84 and 26.95 ng g−1 ww, while perfluorooctanesulfonic acid (PFOS, 0.039–0.95 ng g−1 ww) was the dominant component in the PFAS profile. Fish with more microplastics had significantly higher concentrations of fluoroquinolones and perfluoroalkyl acids than fish with less microplastics (p < 0.05), but the correlation was not observed in other chemicals. Structural equation modeling revealed the contribution of microplastics in fish on the level of ECs contamination. The health quotient value indicated the low health risk of single compounds via fish consumption to humans; however, the combined risk of microplastics and ECs still needs to be considered. This work highlights the link between microplastics with associated ECs ingested by aquatic organisms and the human health risk of consuming polluted seafood.

Co-tracing of groundwater emerging and conventional contaminants in karst area of Southwest China: Distribution, source, and source-specific health risks

Groundwater pollution, especially the co-contamination of emerging contaminants (ECs) and conventional contaminants, is increasingly recognized as a critical global concern. Karst aquifers are found throughout the world, providing critical water sources and sustaining rivers and ecosystems, and are particularly vulnerable to pollution. In this study, the characteristics of the contamination, potential sources, and source-specific health risks related to ECs and trace elements (TEs) in groundwater were investigated in Guiyang (a typical karst city in southwest China). The distribution of TEs followed a descending pattern from urban to suburban to rural areas. Interestingly, the median concentrations (217 ng/L) of Caffeine (CAF) in rural areas surpassed those in urban areas (145 ng/L) and even exceeded these in densely populated areas. Additionally, ECs and TEs in groundwater are significantly influenced by population density and land use types within a 1000-meter buffer zone around the sampling sites. Hierarchical cluster analysis and positive matrix factorization suggested that five principal sources of contamination were identified: domestic wastewater (29.7 %), industrial production (25.2 %), agricultural activities (16.3 %), natural and industrial sources (14.9 %), and pharmaceuticals (13.9 %). Monte Carlo simulations revealed that the non-carcinogenic risks to children in urban areas are significant, with 30.0 % of these risks exceeding the safety threshold. Source-specific health risk assessments indicated that industrial production is the primary source of risk. Furthermore, this study introduces a co-tracing method to trace the sources of groundwater contamination in karst systems. The co-tracing method based on the ECs and TEs allows for a deeper understanding of contaminant transfer and its fate in karst groundwater.

Advancements in green-synthesized transition metal/metal-oxide nanoparticles for sustainable wastewater treatment: techniques, applications, and future prospects

Abstract In order to meet the demand for portable water and replenish depleting water resources caused by industrialization, urbanization, and population growth, wastewater purification has become crucial. Emerging contaminants (ECs), which include organic dyes, pesticides, pharmaceutical drugs, polyaromatic compounds, heavy metal ions, and fertilizers, among others, have caused significant disruptions to environmental balance and severe health complications. As a result, considerable effort has been devoted to the development of technologies that eliminate wastewater from effluents via adsorption, photocatalysis, and other means. However, considering the economic and environmental implications of the adopted technologies, green technology has gained significant attention owing to their eco-friendly approaches, cost-effectiveness, avoiding use of toxic and harmful chemicals and production of less-toxic by-products. Currently green-synthesized nanomaterials have seen tremendous growth in emerging as sustainable nanoadsorbents, nanocatalysts for the removal of the emerging contaminants from wastewater in highly efficient and eco-friendly manner. Thus, this review presents an overview of the various techniques utilized in wastewater treatment with a particular emphasis on the production and application of environmentally friendly transition metal/metal oxide nanoparticles as sustainable tools in wastewater treatment technology. This article also discusses the limitations and future potential of using green-synthesized transition metal/metal oxide based nanoparticles in advancing the technology on a broad scale.&amp;#xD;

Enhanced Removal of Chiral Emerging Contaminants by an Electroactive Biofilter

50% of pharmaceuticals and 25% of herbicides used worldwide are chiral. Each enantiomer has a unique toxicity and biodegradation profile, affecting differently to organisms. Chirality plays a key role in the behavior of these emerging contaminants (ECs) in terms of their pharmacological or herbicidal activity, but this peculiarity is often overlooked in environmental research. The complexity of chiral ECs is underestimated, as the varying sensitivity of biological systems to enantiomers is rarely considered. Biofilters can promote the activity of specific microbial communities, facilitating the degradation of ECs, due to the greater interaction between water and microorganisms and their compact design. Here, we show that an electroactive biofilter can alter the chirality of drugs and herbicides in wastewater treatment, impacting their removal and toxicity. The electrochemical biofilter (BioeF) removed 80% of pharmaceuticals and 50–75% of herbicides, outperforming the conventional filter (ConF). BioeF also showed greater chiral alterations and lower ecotoxicity. This work provides the first evidence of a relationship between changes in contaminant chirality and detoxification capacity, enhanced by electroactive systems. The increased microbial activity observed in the BioeF suggests that bioelectrochemical systems offer a valuable advance for ECs removal and ecotoxicity reduction, addressing the environmental challenge posed by ECs.

Active and passive sampling techniques in headwater streams to characterize acesulfame-K, pharmaceutical and phosphorus contamination from on-site wastewater disposal systems in Canadian rural hamlets

On-site wastewater disposal systems have been identified as a source of contamination for nutrients and emerging contaminants (ECs), such as artificial sweeteners and pharmaceutical compounds. The passive sampling technique Polar Organic Chemical Integrative Sampler (POCIS) and phosphorus sampler (P-Trap) have been widely used for tracking polar organic contaminants and total dissolved phosphorus in environmental waters such as surface water and wastewater. However, limited studies have been conducted on application of passive sampling techniques to track contamination in headwater streams impacted by on-site wastewater disposal systems. In this study, active sampling (discrete samples) and passive sampling (P-Trap and POCIS) techniques were applied in upstream and downstream locations at three rural hamlets to compare and track the contamination of total dissolved phosphorus (TDP) and seven ECs, including six pharmaceuticals and one artificial sweetener acesulfame-K (ACEK), in the shallow headwater streams of rural hamlets in southern Ontario, Canada that exclusively rely on septic systems for wastewater disposal. Results show that POCIS and P-Trap yielded comparable time-weighted average (TWA) concentrations of target ECs and TDP, respectively, to mean concentrations of discrete samples during the seasonal (spring, summer, and fall) and two-week intensive study periods. Field-derived sampling rates (Rs-field) of target contaminants compared well to literature-reported values indicating POCIS and P-Trap were applicable in determining the concentrations of target contaminants in the investigated streams, even though some environmental factors, such as dry stream conditions and fouling, occurred during the sampling period. The low but stable Rs-field of ACE-K (~0.001 L d−1) from this study indicates consistency in application of POCIS for capturing ACEK. The results of this study provide insight into the confidence and limitations for using POCIS and P-traps to track ECs and TDP in shallow headwater streams impacted by septic systems.

Ciprofloxacin removal as an emerging contaminant using electrochemical advanced reduction process: Mechanism, degradation pathway and reaction kinetic

The introduction of emerging contaminants (ECs), particularly antibiotics to the water resources has grown in recent years. Due to its widespread application and their toxicity, the ECs are one of the major environmental concerns. The present study is to evaluate the electrochemical removal of ciprofloxacin (CIP) as an emerging contaminant through the advanced reduction process (ARP). Moreover, the degradation pathway, mechanism and its kinetics have provided. In this study, the impacts of main operating variables were evaluated including pH, current density, initial pollutant concentration, sodium sulfite (Na2SO3) concentration, and time on the CIP removal through electrochemical process based-ARP. The obtained results revealed the 94.15 % CIP degradation rate under optimal conditions, at the concentration of 20 mg/L and pH 5 during 60 min. The CIP reduction followed the first-order kinetics with the rate of 0.99. In addition, the ARP along with electrochemical systems as a novel process were suggested as suitable and high efficiency technique for the CIP removal.

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.

Bioavailability of Endocrine Substances in Aquatic Ecosystems, Emerging Contaminants (ECs) and Impact on Agricultural Water Reuse

Bioavailability of Endocrine Substances in Aquatic Ecosystems, Emerging Contaminants (ECs) and Impact on Agricultural Water Reuse

Synergistically enhanced heterogeneous activation of dissolved oxygen for aqueous carbamazepine degradation over S(III) coupled with siderite

The wide occurrence of emerging contaminants (ECs) was drawing more attention due to the potential hazard and threat on human and environment. Carbamazepine (CBZ) is a widely prescribed medication that has garnered considerable research interest with the exposures exceeding the environmental carrying capacity. We have established the innovative heterogeneous advanced oxidation process (AOPs) based on the activated dissolved oxygen (DO) coupled with S(III) and natural iron ore (siderite). In S(III)/O2/siderite system, we investigated the degradation efficiency, reactive species generation mechanism, and degradation pathway of CBZ. CBZ degradation and mineralization rate were 90% above and ∼15% with the reaction time of 40 min. The degradation of CBZ conformed to a pseudo-first-order kinetic model, with an activation energy determination of 76.36 kJ/mol. The optimal initial solution pH was the weak acid condition (pH = 4–6) for CBZ degradation. Moreover, the inhibition effects of coexisting substance including Cl−, HCO3−, and natural organic matter (NOM) on CBZ removal were observed, while the coexisted SO42− exhibited no significant influence. In addition, the reactive species generated in S(III)/O2/siderite system were predominantly identified as sulfate radical (SO4∙-) and hydroxyl radical (∙OH). The crucial intermediate complexes, Fe(III)S(IV)O3(+) and Fe(II)HS(IV)O3(+), was proposed to form in the initial stages of the reaction, which upon decomposition, yielded SO4∙- along with other reactive species. The degradation pathway of CBZ primarily involved deamination, oxidative ring-opening, hydroxylation, decarboxylation, and ketone degradation processes. This work provides the effective approach for the CBZ degradation with the mild reaction conditions and the sustainable technology for ECs treatment and control.

Fate of emerging contaminants in an advanced SBR wastewater treatment and reuse facility incorporating UF, RO, and UV processes

A critical factor for widescale water reuse adoption is the capability of advanced wastewater treatment facilities to consistently produce high-quality water by efficiently removing various pollutants, including emerging contaminants (ECs). This study monitored the fate of seventeen ECs (which included pesticides, antibiotics and other pharmaceutically active compounds) over six months in an advanced wastewater reuse facility situated in the United Arab Emirates. The facility integrates a sequencing batch reactor (SBR) based sewage treatment plant (STP) with a water recycling facility featuring ultrafiltration (UF), reverse osmosis (RO), and ultraviolet (UV) disinfection. ECs were detected and quantified at the influent and effluents of the various treatment stages, using an ultra-high-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS). The STP exhibited variable removal efficiencies, achieving >90 % removal for compounds like caffeine and acetaminophen, while others, such as carbamazepine and thiabendazole, displayed poor removal (<10 %). UF treatment broadly resulted in limited removal, with ECs in permeate typically persisting in the 1–10 ng/L range. Subsequently, after undergoing RO treatment, eight ECs were still detected in the RO permeate, albeit at <1 ng/L, except for imidacloprid (2.5 ng/L). Conversely, the final UV disinfection step led to concentration increases of certain ECs, namely imidacloprid, thiabendazole, sulfamethoxazole, sulfamethazine and caffeine. Overall, the total EC concentration levels decreased considerably from 2300 ng/L in the STP influent to 5.2 ng/L in the RO permeate. However, a subsequent increase to 27.5 ng/L was observed after UV disinfection. While the study underscores the effectiveness of advanced treatment processes, notably RO, in reducing EC concentrations, it also demonstrates the importance of continuous EC monitoring in such facilities as many compounds persist post treatment. Additionally, the potential for processes like UV disinfection to increase certain EC concentrations highlights the need to optimize treatment trains to minimize EC concentration rebound.

Adsorption of Ciprofloxacin and Lidocaine by Non-Fibrous Raw Mg-Clays: The Role of Composition and Texture

This study evaluated non-fibrous Mg-clays as potential adsorbents of emerging contaminants (ECs) from water. The materials were characterized, and their textural and structural properties were related to their ability to remove two model EC molecules: ciprofloxacin (CPX) and lidocaine (LID). The results showed that Ad-6 and Ad-7 are mixed-layer kerolite/stevensite, while Ad-5 and Ad-8 are mainly composed of smectite minerals like stevensite and saponite, respectively. Ad-8 exhibited the highest CPX-adsorption capacity (0.91 mmol·g−1 clay), likely due to its saponite content. Mixed-layer materials also performed well, with Ad-6 and Ad-7 achieving an adsorption capacity of 0.8 and 0.55 mmol·g−1 clay, respectively. Adsorption studies suggested that CPX is adsorbed through ion exchange in materials with high smectite content (Ad-8 and Ad-5), while interstratified materials showed enhanced retention due to kerolite presence, which improves their porous structures. Similar findings were observed for LID, indicating a cationic-exchange mechanism for LID adsorption in all the materials and suggesting that the molecular size of the EC could regulate the removal capacity of these materials. This work showed that the studied Mg-clays could be effectively used for the removal of pharmaceutical pollutants, expanding their commercial possibilities.

Enhanced Synergistic performance of ZnO@BiOX (X=Cl, Br, I) heterojunction for photocatalytic degradation of emerging pollutants under visible light

In this work, we study the influence of the proportion and halogen type present in heterojunctions of zinc oxide and bismuth oxyhalides ZnO@BiOX (Where X=Cl-, Br-, I- and several binary combinations of them) on the photocatalytic activity in the degradation of rhodamine-B (Rh-B) under visible light, as well as in two important emergent contaminants resorcinol and sulfadiazine. The materials were synthesized by a solvothermal process at 130 °C, starting from ZnO nanoparticles and BiOX precursors (Bi+ and X=Cl-, Br-, I- ions). It was found that the best combination of halogens was 75 % Br- and 25 % Cl- (ZnO@BiOBrCl bromine-chlorine ratio 3:1) forming a Z-type heterojunction with a time constant of τ = 5.6067 min (κ = τ-1 = 0.1784 min−1) in the degradation of Rh-B (C0 = 30 ppm, VRxn = 250 mL). The same composite degraded totally resorcinol in 250 min, and 85.2 % of sulfadiazine in 150 min.

Research on the removal efficiency and membrane fouling analysis of nanofiltration membranes under the combined pollution of emerging contaminants

Based on the research background of five emerging contaminants (ECs)— sulfadiazine (SD), sulfamethoxazole (SMZ), malathion, hexachlorobenzene (HCB), and bisphenol A (BPA)—which can be detected in trace amounts in a river basin in southern China, a spiking experiment was conducted to effectively address the potential impact risks of these contaminants. The experiment aimed to investigate the removal efficiency and membrane fouling of nanofiltration membranes (NF) under the combined pollution of these ECs. The experimental results show that under the combined pollution of these ECs, the NF exhibits good removal efficiency for all five ECs, with removal rates of approximately 83 ± 2 %, 84 ± 3 %, 76 ± 3 %, 73 ± 6 %, and 80 ± 5 % for SD, SMZ, malathion, HCB, and BPA, respectively. Additionally, NF also has high efficiency in removing other pollutants, with removal rates for chromaticity, CODMn, and total hardness at 80 ± 2 %, 60 ± 3 %, and 62 ± 2 %, respectively, and over 80 % of fluorescent substances were removed. Analysis of the key operating indicators of the NF under the combined pollution of ECs revealed that the membrane flux decreased slightly faster compared to without the combined pollution of ECs, and both the membrane fouling index and membrane resistance increased to a certain extent. Furthermore, the analysis of the NF chemical cleaning solutions showed that these ECs can be detected in both alkaline and acid cleaning solutions. Analysis of membrane dissection on NF revealed that severe cake layer contamination formed on the membrane surface both under and without the combined pollution of ECs, the presence of ECs is worse than the absence of ECs.

Septic tanks as a pathway for emerging contaminants to the aquatic environment–Need for alternative rural wastewater treatment?

Septic tanks (STs) as a decentralised approach to community wastewater treatment were investigated as a pathway for emerging contaminants (ECs) entering the aquatic environment. A broad range of ECs were examined in five community STs (population equivalents 217–475) and receiving rivers in Scotland over 12 months. All 68 studied ECs were detected at least once in ST influent or effluent at a broad concentration range from ng L−1 – μg L−1 which can surpass freshwater predicted no-effect concentrations. Pharmaceuticals with acute use, such as antibiotics and antifungals, had high monthly variability and concentrations can exceed those previously found in centralised wastewater treatment works. Differences between the STs demonstrate the impact of localised prescription and population behaviour on EC concentrations. The similarities in concentrations between influent and effluent, suggest limited or no removal of ECs in STs. Hence, dilution of the discharges is required to mitigate environmental risk. Although the contribution of ECs sorbed to suspended solids to the total EC concentration was generally small (<10%), higher contributions (>30%) were observed for fluoroquinolone antibiotics (ofloxacin and ciprofloxacin), antidepressants (fluoxetine), and antifungals (clotrimazole). A wide range of ECs were also detected in rivers upstream and downstream of the ST discharge points, and concentrations increased by up to 95% downstream. In general, risk quotients (RQs) in the rivers were low, indicating small risk for the environment. However, higher RQs (>1) were found for ibuprofen, diclofenac and ciprofloxacin in a few samples. Therefore, reducing their concentration by improving ST performance or through sustainable medicines use may be needed at low dilution locations to mitigate any risk.

Advances and future directions of environmental risk research: A bibliometric review

Environmental risk is one of the world’s most significant threats, projected to be the leading risk over the next decade. It has garnered global attention due to increasingly severe environmental issues, such as climate change and ecosystem degradation. Research and technology on environmental risks are gradually developing, and the scope of environmental risk study is also expanding. Here, we developed a tailored bibliometric method, incorporating co-occurrence network analysis, cluster analysis, trend factor analysis, patent primary path analysis, and patent map methods, to explore the status, hotspots, and trends of environment risk research over the past three decades. According to the bibliometric results, the publications and patents related to environmental risk have reached explosive growth since 2018. The primary topics in environmental risk research mainly involve (a) ecotoxicology risk of emerging contaminants (ECs), (b) environmental risk induced by climate change, (c) air pollution and health risk assessment, (d) soil contamination and risk prevention, and (e) environmental risk of heavy metal. Recently, the hotspots of this field have shifted into artificial intelligence (AI) based techniques and environmental risk of climate change and ECs. More research is needed to assess ecological and health risk of ECs, to formulize mitigation and adaptation strategies for climate change risks, and to develop AI-based environmental risk assessment and control technology. This study provides the first comprehensive overview of recent advances in environmental risk research, suggesting future research directions based on current understanding and limitations.

Monitoring of ketamine-based emerging contaminants in wastewater: a direct-injection method and fragmentation pathway study

The ketamine (KET) and its analogs consumed by humans are becoming emerging contaminants (ECs), as they at present in surface waters after being carried through wastewater systems. Drugs in wastewater can be analyzed using the direct-injection method, a simple wastewater analysis (WWA) method that can provide objective, continuous and nearly to real-time findings. This article describes an ultra-high-pressure liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for the simultaneous quantification and confirmation of seven KET-based ECs in wastewater by direct injection. After optimization of the UPLC–MS/MS and sample pretreatment conditions, the method was validated and applied to samples (n = 157) collected from several wastewater treatment plants (WWTPs) in southern China in which KET had the highest detection rate. The established direct-injection method was not only simple to perform but also had better sensitivity, shorter detection times, and analyzed more KET-based ECs than currently published methods, meeting the requirements for the monitoring and high-throughput analysis of common KET-based ECs. We also analyzed the fragmentation pathway of KET-based ECs to obtain product ion information on other unknown substances. Additional studies are needed to establish a comprehensive direct-injection screening method of ECs in wastewater on model-based assessment.

Potential application of SDSO-layered double hydroxide in wastewater treatment: Synergy between hydrophobicity and activation activity

The hydrophobic surface properties of catalysts, generally overlooked in the field of sulfate radical-based advanced oxidation processes (SR-AOPs), have significant potential in enhancing the applicability of catalysts in realistic wastewater treatment. The conflicting nature of hydrophobicity and activation activity presents considerable challenges in developing heterogeneous oxidation. To overcome such limitation, herein, different surfactants were employed to regulate the surface properties of CoCu-layered double hydroxides (LDH) for the activation of peroxymonosulfate (PMS). Our results demonstrated that by comparison with sodium dodecyl sulfate (SDS) and sodium laurate (SLA), sodium dodecyl sulfonate (SDSO) regulated LDH (SDSO-LDH) exhibited the most effective interpolation of organic anions into the interlayer space, simultaneously showing efficient ability for PMS activation and hydrophobicity. The SDSO-LDH/PMS system exhibited excellent degradation performance of various emerging contaminants (ECs), with Co(IV) = O and SO4•- species identified as the dominant oxidative intermediates. Density functional theory (DFT) calculations further confirmed the thermodynamic feasibility of these reactions. Moreover, the effective degradation of intrinsic organic substances in realistic wastewater and sustained hydrophobicity establishes SDSO-LDH a competitive candidate catalyst for SR-AOPs. The synergy between activation activity and hydrophobicity offers a novel perspective for the application of SR-AOPs in wastewater treatment.

Picolinic acid-mediated Mn(II) activated periodate for ultrafast and selective degradation of emerging contaminants: Key role of high-valent Mn-oxo species

The utilization of periodate (PI, IO4-) in metal-based advanced oxidation processes (AOPs) for the elimination of emerging contaminants (ECs) have garnered significant attention. However, the commonly used homogeneous metal catalyst Mn(II) performs inadequately in activating PI. Herein, we exploited a novel AOP technology by employing the complex of Mn(II) with the biodegradable picolinic acid (PICA) to activate PI for the degradation of electron-rich pollutants. The performance of the Mn(II)-PICA complex surpassed that of ligand-free Mn(II) and other Mn(II) complexes with common aminopolycarboxylate ligands. Through scavenger, sulfoxide-probe transformation, and 18O isotope-labeling experiments, we confirmed that the dominant reactive oxidant generated in the Mn(II)-PICA/PI system was high-valent manganese-oxo species (Mn(V)=O). Due to its reliance on Mn(V)=O, the Mn(II)-PICA/PI process exhibited remarkable selectivity and strong anti-interference during EC oxidation in complex water matrices. Nine structurally diverse pollutants were selected for evaluation, and their lnkobs values in the Mn(II)-PICA/PI system correlated well with their electrophilic/nucleophilic indexes, EHOMO, and vertical IP (R2 = 0.79–0.94). Additionally, IO4- was converted into non-toxic iodate (IO3-) without producing undesired iodine species such as HOI, I2, and I3-. This study provides a novel protocol for metal-based AOPs using PI in combination with chelating agents and high-valent metal-oxo species formation during water purification.

Valorizing waste activated sludge incineration ash to S-doped Fe2+@Zeolite 4A catalyst for the treatment of emerging contaminants exemplified by sulfamethoxazole

The global attention towards waste management and valorization has led to significant interest in recovering valuable components from sludge incineration ash (SIA) for the synthesis of functional environmental materials. In this study, the SIA was converted to an S-doped Fe2+-zeolite type catalyst (FZA) for the treatment of emerging contaminants (ECs), exemplified by sulfamethoxazole (SMX). Results demonstrate that FZA effectively catalyzed the activation of peracetic acid (PAA), achieving a remarkable degradation of 99.8% under optimized conditions. Mechanistic investigations reveal that the FZA/PAA system can generate ·OH, 1O2, O2·－, and Fe(Ⅳ), with ·OH playing a dominant role in ECs degradation. Additionally, the doped S facilitated electrochemical performance, Fe2+ regeneration and fixation in FZA. Practical application elucidated that the FZA/PAA system can work in complex environments to degrade various ECs without generating high-toxicity ingredients. Overall, valorizing SIA to FZA provides dual achievement in waste management and ECs removal.

Food Contamination with Micro-plastics: Occurrences, Bioavailability, Human Vulnerability, and Prevention

Abstract: Microplastics (MPs) are emergent environmental contaminants that are designated as either primary or secondary dependent on their origins. Formulation, morphology, dimensions, and colour scheme, along with other features, are connected with their propensity to reach the food webs and their dangers. Whilst ecological adversities of MPs have drawn considerable interest, the hazards to individuals from dietary exposure have yet to be determined. The aim of this review is to gauge existing understanding concerning MPs in foodstuffs and to explore the problems and inadequacies for threat assessment. The prevalence of MPs in foodstuffs and sugary drinks has been detected all over the world, but most researchers judged the existing information to be not only inadequate but also of dubious value, owing to the notable lack of agreement on a regulated quantification methods and a consistent appellation. Most published papers have highlighted potable water and condiments such as sugars, salts, and nectar as significant food components of MPs for humans. The threat assessment reveals significant discrepancies in our understanding of MP toxicity for human consumption, which hinders the estimate of risk-based regulations regarding food safety. The lack of comparators for evaluating MPs food consumption prohibits dietary MPs risk description and risk mitigation. Researchers and Food Safety Administrators confer various obstacles along with possibilities linked to the appearance of MPs in foodstuffs. Further investigation on the MPs categorization and exposures is essential considering that any subsequent threat evaluation record can contain a comprehensive dietary viewpoint.