Environmental Occurrence Research Articles

Environmental Occurrence and Biotic Concentrations of Ultrashort-Chain Perfluoroalkyl Acids: Overlooked Global Organofluorine Contaminants.

Per- and polyfluoroalkyl substances (PFASs) are a large group of anthropogenic fluorinated chemicals. Ultrashort-chain perfluoroalkyl acids (PFAAs) have recently gained attention due to their prevalence in the environment and increasing environmental concerns. In this review, we established a literature database from 1990 to 2024, encompassing environmental and biological concentrations (>3,500 concentration records) of five historically overlooked ultrashort-chain PFAAs (perfluoroalkyl carboxylic and sulfonic acids with less than 4 carbons): trifluoroacetic acid (TFA), perfluoropropanoic acid (PFPrA), trifluoromethanesulfonic acid (TFMS), perfluoroethanesulfonate (PFEtS), and perfluoropropanesulfonate (PFPrS). Our data mining and analysis reveal that (1) ultrashort-chain PFAAs are globally distributed in various environments including water bodies, solid matrices, and air, with concentrations usually higher than those of longer-chain compounds; (2) TFA, the most extensively studied ultrashort-chain PFAA, shows a consistent upward trend in concentrations in surface water, rainwater, and air over the past three decades; and (3) ultrashort-chain PFAAs are present in various organisms, including plants, wildlife, and human blood, serum, and urine, with concentrations sometimes similar to those of longer-chain compounds. The current state of knowledge regarding the sources and fate of TFA and other ultrashort-chain PFAAs is also reviewed. Amid the global urgency to regulate PFASs, particularly as countries worldwide have intensified such efforts, this critical review will inform scientific research and regulatory policies.

Geochemistry and Mineralogy of Upper Paleozoic Coal in the Renjiazhuang Mining District, Northwest Ordos Basin, China: Evidence for Sediment Sources, Depositional Environment, and Elemental Occurrence

This study aims to investigate the depositional environment, sediment sources, and elemental occurrence of Upper Paleozoic coal in the Renjiazhuang Mining District, Western Ordos Basin. Furthermore, SEM-EDX, optical microscope (OM), ICP-AES, ICP-MS, and AAS were used. Compared with hard coal of the world, M3 coals were enriched in Ga, Li, Zr, Be, Ta, Hf, Nb, Pb, and Th, M5 coals were enriched in Li (CC = 10.21), Ta (CC = 6.96), Nb (CC = 6.95), Be, Sc, Ga, Hf, Th, Pb, Zr, In, and REY, while M9 coals were enriched in Li (CC = 14.79), Ta (CC = 5.41), Ga, W, Hf, Nb, Zr, Pb, and Th. In addition, minerals were mainly composed of kaolinite, dolomite, pyrite, feldspar, calcite, and quartz, locally visible minor amounts of monazite, zircon, clausthalite, chalcopyrite, iron dolomite, albite, fluorite, siderite, galena, barite, boehmite, and rutile. In addition, maceral compositions of M3 coals and M9 coals were dominated by vitrinite (up to 78.50%), while M5 coals were the main inertite (up to 76.26%), and minor amounts of liptinite. REY distribution patterns of all samples exhibited light REY enrichment and negative Eu anomalies. The geochemistry of samples (TiO2 and Al2O3, Nb/Y and Zr × 0.0001/TiO2 ratios, and REY enrichment types) indicates that the sediment sources of samples originated from felsic igneous rocks. Indicator parameters (TPI, GI, VI, GWI, V/I, Sr/Ba, Th/U, and CeN/CeN*) suggest that these coals were formed in different paleopeat swamp environments: M3 coal was formed in a lower delta plain and terrestrial (lacustrine) facies with weak oxidation and reduction, and M5 coal was formed in a terrestrial and dry forest swamp environment with weak oxidation–oxidation, while M9 coal was formed in a seawater environment of humid forest swamps and the transition from the lower delta plain to continental sedimentation with weak oxidation and reduction. Statistical methods were used to study the elemental occurrence. Moreover, Li, Ta, Hf, Nb, Zr, Pb, and Th elements were associated with aluminosilicates, and Ga occurred as silicate.

A comprehensive Review into Emission Sources, Formation Mechanisms, Ecological Effects, and Biotransformation Routes of Halogenated Polycyclic Aromatic Hydrocarbons (HPAHs)

Halogenated polycyclic aromatic hydrocarbons (HPAHs, H = F, Cl, Br) are a new class of PAHs derivatives that mainly originate from the incomplete combustion of halogen-laden materials and via metallurgical operations. These compounds circulate extensively in various environmental matrices. This survey provides a comprehensive review on governing synthesis routes of HPAHs, their environmental occurrence, and their health and ecological effects. The review comprehensively enlists and presents emission sources of these emerging organic pollutants into the air that serves as their main reservoir. The formation of HPAHs ensues through successive addition reactions of related precursors accompanied by ring cyclization steps; in addition to direct unimolecular fragmentation of parents halogenated. Halogenation of parent PAHs rapidly occurs in saline ecosystems, thus multiplying the availability of these notorious compounds in the environment. Certain HPAHs appear to be more carcinogenic than dioxins. Transmission routes of HPAHs from their emission sources to water bodies, soil, aquatic life, plants, terrestrial animals, and humans are well-documented. Later, the direct and indirect diffusion of HPAHs from air to the biotic (plants, animals, humans) and abiotic components (soil, water, sediments) are described in detail. The study concludes that HPAHs are permeable to the carbon matrices resulting in the alleviation of the source-to-sink interface. As a potential future perspective, understanding the transmission interfaces lays a foundation to intervene in the introduction of these toxicants into the food chain.

Unraveling the pharmaceutical footprint and risks of combining different aquaculture modes and tailwater treatment systems

Aquatic environments serve as repositories for pharmaceuticals, and intensive aquaculture is becoming a significant contributor to the discharge of aquaculture wastewater. The cyclical footprint of pharmaceuticals between the aquatic environment and aquaculture has emerged as a global concern. The environmental occurrence and risk assessment of pharmaceuticals in the aquatic environment via various aquaculture modes, as well as the pharmaceutical removal efficiency in different tailwater treatment systems, have been studied through yearly investigations. Thirty-four pharmaceuticals were detected in the aquaculture environment, and the dominant pharmaceuticals were enrofloxacin, sulfamethoxazole, amantadine, and florfenicol. The highest concentration of pharmaceuticals was found in the fish pond (3826 ± 29.6 ng/L) under the greenhouse aquaculture mode, especially in the early and late aquaculture stages, and the same trend was observed in the pond aquaculture mode. The tailwater removal efficiency was greater in summer months than other months, and the treatment efficiency of the recirculating treatment system was more stable. During the aquaculture period, a low risk was observed for most pharmaceuticals, except for enrofloxacin, sulfamethoxazole, ciprofloxacin and ofloxacin, which had at medium to high risk. High-risk pharmaceuticals show a high potential to contaminate the surrounding aquatic environment and adversely affect associated biota. Reassuringly, the ecological risks of the detected pharmaceuticals can be effectively reduced after tailwater treatment. This study provides valuable data for the growing system to assess risk in aquaculture and serves as a reference to establish quality standards for aquatic products.

P-Phenylenediamines and p-phenylenediamine quinone derivatives in rubber consumer products and typical urban dust: Sources, transformation profiles, and health risks

N,N′-Substituted p-phenylenediamines (PPDs) are widely used as antioxidants in the rubber industry and are released into the environment in large quantities during the production and use of rubber products. We quantified PPDs and PPD quinone derivatives (PPD-Qs) in rubber consumer products, including car tires, rubber belts, rubber gloves, rubber cables, and rubber hoses, to obtain information on the degree of weathering over time during their use. Additionally, we investigated the occurrences and sources of PPDs and PPD-Qs in dust samples collected from four typical urban environments (roads, parking lots, automotive repair shops, and residences). The detected compounds included the highly toxic N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine quinone, which can cause acute mortality of coho salmon (Oncorhynchus kisutch). Concentrations of PPDs in the automotive repair shops reached 56.0 μg/g, and were much higher than in the other environments, while the residential samples had the lowest contaminant concentrations. In road and residential samples, N,N′-di-2-naphthyl-p-phenylenediamine accounted for 17 %–30 % of the PPDs, and may have originated from different sources. We preliminarily identified 32 transformation products, and 11 of these were N,N′-di-2-naphthyl-p-phenylenediamine transformation products. The average daily intakes of PPDs and PPD-Qs were calculated to assess the health risks of dust exposure in each environment. Workers had high total intakes of PPD [60.3 ng/(kg day)] and PPD-Qs [20.1 ng/(kg day)], and were at some risk of occupational exposure. These results improve our understanding of the environmental occurrences, sources, transformation, and health risks of PPDs and PPD-Qs.

Clubroot disease in soil: An examination of its occurrence in chemical and organic environments

Clubroot is a disease in cruciferous plants caused by the soil-borne pathogen Plasmodiophora brassicae. This pathogen rapidly spreads in soil, and plant growth is inhibited by infection with spores. To reduce clubroot disease, its prevalence in Brassica rapa var. perviridis was investigated in different soil environments (chemical and organic soils). The bacterial biomass, diversity, and community structure of the soils and roots were analyzed by environmental DNA, PCR-DGGE, and 16S rRNA sequencing. Bacterial biomass and diversity in the organic soil were higher than those in the chemical soil. The disease severity of plants cultivated in organic soil was lower than that in chemical soil. The number of endophytic bacteria in the roots decreased when the plants were infected with P. brassicae in both soil types. Higher bacterial biomass in the soils and roots appeared to reduce the infection of P. brassicae.

Synthetic Microplastics in UK tap and bottled water; Implications for human exposure

There is increasing concern for public health over inadvertent human exposure to MPs due to potential adverse health effects linked to MPs polymeric composition, toxic chemical additives, and/or harmful microorganisms adsorbing onto their surfaces. While numerous studies have reported MPs occurrence and risk in the freshwater aquatic environment and drinking water sources (e.g., rivers, lakes, and reservoirs), the current state-of-knowledge on MPs pollution in drinking water (i.e., tap water and bottled water) remains limited at a global level. This paper provides the first comprehensive study of the occurrence, concentrations, size distribution, shape, and polymer type of MPs in 177 tap water samples from 13 cities in the United Kingdom, as well as 85 samples of bottled water from 17 popular brands, with various packaging materials, on the UK market.MPs were detected in all tap water samples (range 6–100 MP/L) and bottled water samples (range 12–62 MP/L). Average MPs concentration in tap water (40 ± 16 MP/L) was statistically indistinguishable from that in bottled water (37 ± 11 MP/L). However, the average MPs particle size in tap water (32.4 μm) exceeded significantly (p < 0.05) that in bottled water (26.5 μm), indicating the various purification processes applied to bottled water may help remove larger MPs, but raises concern over the potential adverse health effects from exposure to smaller MPs. The most frequently detected polymer types were: polypropylene (PP), polyethylene (PE), and polyvinyl chloride (PVC) in tap water, and PE, PP and polyethylene terephthalate (PET) in bottled water. A strong correlation was observed (r = 0.68, P = 0.049) between the plastic cap material (PE) and the predominant polymer type in the bottled water. In terms of morphology, fragments and fibres were the most abundant MPs, together constituting 92 % and 96 % of MPs detected in tap and bottled water samples, respectively.Using EFSA (European Food Safety Authority) recommended daily water intakes, the corresponding exposures to MPs in different UK age groups were estimated. On a body weight (BW) basis, infants and toddlers were exposed (4 MP/kg BW/day) at a higher level than adults (1 MP/kg BW/day). This raises concern, given the former's incompletely developed immune/nervous systems rendering them at higher risk of adverse health effects from such exposure.

The dissolution of metal carbonate precipitation under the external electric and magnetic fields: reactive force field molecular dynamics simulation

Abstract The dissolution of metal carbonates holds a pivotal role in diverse industrial processes, environmental occurrences, and geological formations. Grasping the fundamental mechanisms underlying these processes is imperative for enhancing industrial applications and mitigating environmental impacts. Herein, we undertake a thorough investigation employing reactive forcefieldmolecular dynamics simulations to delve into the dissolution process of metal carbonates. These simulations afford profound insights into the mechanisms and kinetics governing the process across various conditions, encompassing temperature, acidity, and external electric and magnetic fields. Although temperature itself exerts a limited influence, the study reveals a synergistic enhancement of metal carbonate dissolution kinetics when temperature is combined with static electric and magnetic fields. Our revelations offer enlightening perspectives on the intricate interplay of factors shaping dissolution processes, laying the foundation for future inquiries in this domain.

Simulating multi-scale optimization and variable selection in species distribution modeling

Species distribution modeling (SDM) is a fundamental tool in theoretical and applied ecology. However, relatively little is known about the performance of different approaches for scale optimization, model selection, and algorithmic prediction in the context of nonlinear, multiscale and interactive relationships between environmental variables and species occurrence. Modelers often struggle to optimize a tradeoff between ecological relevance, model robustness, complexity, and overfitting. In this paper, we investigated several methods designed to optimize spatial scale and variable selection in SDMs, in each case evaluating model fitness, parsimony and predictive performance. We used a simulation approach to produce a large pool of alternative underlying habitat relationships that reflect a broad range of realistic habitat associations. We also compared several different modeling algorithms, including logistic regression with a generalized linear model (GLM), Lasso and Elastic-Net Regularized GLMs (GLMNet), and random forest (RF), as well as alternative variable and scale selection methods. We found that GLM methods employing all-subsets dredge routines for variable selection were consistently the best predictors based on all criteria of our model performance assessment and across all attributes of the simulated underlying relationship, including nonlinearity and interaction. We had expected machine learning approaches, such as random forest, to perform better in these more complex forms of species-environment relationships. GLM using dredge variable selection was also the method that included the fewest spurious covariates and included the most correct predictors as a proportion of all predictors. We found that univariate scaling was the most robust method of variable and scale selection, along with Minimal Redundancy Maximal Relevancy (MRMR) which performed equivalently. The simulation experiment presented here provides a robust assessment of simulated multi-species distribution model performance, complexity and fidelity. By simulating a large range of potential habitat relationships with varying spatial scale, effect sizes, linearity, and interactions, we comprehensively evaluated model performance across gradients of complexity of the underlying relationships and violations of classical statistical assumptions. This study provides a valuable assessment and a broader example of the power and utility of controlled simulation experiments in habitat relationships and other ecological spatial predictive modeling.

Fate and transport of ten plant protection products of emerging concern in a coastal lagoon: Application and evaluation of a multimedia level III fugacity model

Multimedia fugacity models are effective tools for studying the environmental behaviour and occurrence of contaminants of emerging concern (CECs) and assessing associated risks, especially when experimental data is limited. These models describe processes controlling chemical partitioning, transport, and reactions in environmental media using mathematical statements based on the concept of fugacity.To aid in identifying and prioritizing CECs for future local monitoring, we present here the application of a level III multimedia fugacity model assuming non-equilibrium between compartments and steady-state conditions. This model estimated predicted environmental concentrations (PECs), persistence, distribution, and transport of ten plant protection products (PPPs) in the Venice Lagoon, a complex coastal environment under high anthropogenic pressure.The model was evaluated through uncertainty and sensitivity analysis using the Monte Carlo approach and by comparing PECs with PPP concentrations measured during four sampling campaigns. Results showed good agreement with field data, with the highest concentrations in water and sediments estimated for glyphosate, followed by imidacloprid, metaflumizone, and triallate. The model indicated accumulation of all investigated PPPs in sediments. For most chemicals, advection outflow and degradation in the water column were the main removal mechanisms, while volatilization was significant only for oxadiazon and triallate.Sensitivity and uncertainty analysis revealed that degradation rates, organic carbon/water partitioning coefficients (KOC), and parameters describing air-water interactions had the strongest influence on the model's results, followed by inputs accounting for sediment sinking and resuspension. The lack of data on PPP degradation in brackish waters accounted for most of the uncertainty in model results.This work shows how a relatively simple multimedia model can offer new insights into the environmental behaviour of PPPs in a complex transitional waterbody such as the Venice lagoon, providing useful data for the identification of the CECs to be prioritised in future local monitoring efforts.

A High-Throughput Screening Approach for Evaluating the Binding Affinity of Environmental Pollutants to Nuclear Receptors.

Increasing levels of compounds have been detected in the environment, causing widespread pollution and posing risks to human health. However, despite their high environmental occurrence, there is very limited information regarding their toxicological effects. It is urgent to develop high-throughput screening (HTS) methods to guide toxicological studies. In this study, a receptor-ligand binding assay using an HTS system was developed to determine the binding potency of environmental pollutants on nuclear receptors. The test is conducted using a microplate reader (i.e., a 96-well plate containing various chemicals) by measuring the fluorescence polarization (FP) of a specific fluorescent probe. This assay consists of four parts: the construction and transformation of recombinant vectors, the expression and purification of the receptor protein (ligand-binding domain), receptor-probe binding, and competitive binding of chemicals with the receptor. The binding potency of two environmental pollutants, perfluorooctanesulfonic acid (PFOS) and triphenyl phosphate (TPHP), with peroxisome proliferator-activated receptor gamma (PPARγ) was determined to illustrate the assay procedure. Finally, the advantages and disadvantages of this method and its potential applications were also discussed.

Early prediction of grape disease attack using a hybrid classifier in association with IoT sensors

Machine learning with IoT practices in the agriculture sector has the potential to address numerous challenges encountered by farmers, including disease prediction and estimation of soil profile. This paper extensively explores the classification of diseases in grape plants and provides detailed information about the conducted experiments. It is important to keep track of each crop's current environmental conditions because different environmental conditions, such as humidity, temperature, moisture, leaf wetness, light intensity, wind speed, and wind direction, can affect or sustain the quality of a crop. IoT will increasingly be used in precision agriculture and smart environments to detect, gather, and share data about environmental occurrences. The environmental factor that is active at all times and has an effect on a crop from its cultivation to harvest. With the aid of an IoT, we will monitor the following factors: temperature, humidity, and leaf wetness, all of which have an impact on the overall quality and lifespan of grapes. A Self-created database of weather parameter using sensors is introduced in this article. It consists of 5 categories with a total of 10,000 records. Here, experiment has been carried out using our dataset to predict grape diseases on various machines learning algorithm. The system receives overall accuracy of 98.25 % for Powdery Mildew, 98.85 % for Downy Mildew and 93.95 % for Bacterial Leaf Spot.

Ecological risk of synthetic phenolic antioxidants: A study based on their spatial distribution in water, sediment, and soil from the Yangtze River Delta, China

Environmental occurrence and risks of novel synthetic phenolic antioxidants (SPAs) remain largely unclear. By using a typical algae (Chlorella pyrenoidosa) as model organism, we evaluated the ecological risks of both traditional and novel SPAs, based on their concentrations in water, sediment, and soil collected from the Yangtze River Delta, China. Detection frequencies (DFs) of 10 novel SPAs were 25–100% in water, 3–100% in sediment, and 0–100% in soil, with geometric means (GMs) of 2700 ng/L, 1270 ng/g, and 2440 ng/g, respectively. For 8 traditional SPAs, DFs were 50–100% (GM: 680 ng/L), 3–100% (534 ng/g), and 47–100% (2240 ng/g) in water, sediment, and soil, respectively. AO3114 was the main pollutant in water, while AO1010 dominated in sediment and soil. Notably, low-molecular-weight SPAs showed migration behavior from sediment to water. Four SPAs (AO626, AO1035, AO1098, and AO1076) showed dose- and time-dependent toxicity on Chlorella pyrenoidosa. As time progressed, sediment-released SPAs became more toxic than those in water. Two SPAs (AO1135 and BHT-Q) posed high risks (RQW > 1) to green algae, daphnia, and fish. The SPA mixture exhibited high risks (RQmix > 1) to these organisms, increasing with the trophic level. This research holds valuable guidance for further SPA risk assessments.

Occurrence of Novel and Legacy Per/Polyfluoroalkyl Substances (PFASs) in Scopoli’s Shearwater (Calonectris diomedea) Feathers

Per- and polyfluoroalkyl substances (PFASs) are contaminants of great concern due to their ubiquitous environmental occurrence in the environment and their potential adverse effects on organisms. There is currently limited information regarding the occurrence of PFASs in Scopoli’s Shearwater (Calonectris diomedea). In this study, two feather samples per bird were obtained from 26 adults on Strofades colony (Ionian Sea/Greece) during the early phase of the chick-rearing period (late July 2019). The samples consisted of barbs and barbules of the primary feathers, P1 and P10, reflecting pollution pressures at the time and the place of feather growth, i.e., at the species’ breeding and wintering grounds for P1 and P10, respectively. There were 25 PFAS detected in the feathers, with detection rates ranging from 2% (perfluorododecanoic acid—PFDoDA; perfluorohexane sulfonate—PFHxS; 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate—9Cl-PF3ONS; 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)propanoate—Gen-X) to 98% (sodium 1H,1H,2H,2H-perfluorooctane sulfonate; 6:2 FTSA). ∑PFAS ranged from 25.93 ng/g to 426.86 ng/g of feather sample. The highest mean concentration (109.10 ng/g feather) was reported for perfluorononanoic acid (PFNA). No significant differences in PFAS concentrations with high detection rate (&gt;20%) were found according to the sex of the birds. PFAS concentrations with a detection rate &gt; 20% in the P1 vs. P10 feathers of Scopoli’s Shearwater adults were not significantly different, reflecting the fact that breeding grounds in the Mediterranean and wintering grounds in the Atlantic seem to be contaminated with similar PFASs levels, even though some compounds showed regional trends.

Development and application of diffusive gradients in thin-films for in-situ monitoring of 6PPD-Quinone in urban waters

The occurrence and risk of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-Q), derived from the oxidation of the tire antidegradant 6PPD, has raised significant concern since it was found to cause acute mortality in coho salmon when exposed to urban runoff. Given the short half-life period and low solubility of 6PPD-Q, reliable in situ measurement techniques are required to accurately understand its occurrence and behaviour in aquatic environments. Here, using the diffusive gradients in thin-films (DGT) method with HLB as a binding agent, we developed a new methodology to measure 6PPD-Q in urban waters. 6PPD-Q was rapidly and strongly adsorbed on the HLB-binding gel and was efficiently extracted using organic solvents. The HLB-DGT accumulated 6PPD-Q linearly for >7 d and its performance was not significantly affected by pH (6.5–8.5), ionic strength (0.0001–0.5 M) or dissolved organic matter (0–20 mg L−1). Field evaluation of the DGT method demonstrated its effectiveness in urban runoff, detecting 6PPD-Q levels of 15.8–39.5 ng L−1 in rivers. In snowmelt, DGT detected 6PPD-Q levels of 210 ng L−1 which is two times higher than the value obtained by grab sampling. 6PPD-Q levels were much higher in snowmelt than those in rivers. This indicates that snowfall constitutes an important transport pathway for 6PPD-Q and that DGT effectively captured the fraction continuously released from dust particles in the snow samples. 6PPD-Q posed a substantial risk to migratory fish in urban waters, and its release from tire wear particles requires further investigation. This study is the first to develop a DGT-based in situ measurement method for 6PPD-Q in urban waters, and the method can ensure an accurate measurement of the release of 6PPD-Q to the environment, particularly in rainfall or snowmelt, important pathways for its entry into the aquatic environment.

Investigation of distribution system modification using operation voltage unification in order to decrease interruptions in dust climate

Many events in power networks which caused failure and outage of subsystems have root in design and initial selection of equipment and their specification. This concern will be important while the any kind of expanding and acclimation plan need to be executed to strengthen the existing infrastructures in order to provide better condition with regard to satisfied criteria. In Iran one of the most adverse environmental occurrences known Fine Dust, may force several distribution utilities to be changed due to new technical requirements. Medium voltage level regrading in way to decrease or unification of distribution system have been proposed in this paper to reach reduced faults and fast replacement of equipment in damaged situations. Voltage level changing and selection have been investigated in order to increase the network strengthen and reselection of equipment and redesigning critical sections of system against natural events that called fine dust with aim to attain an upgraded distribution utility. Operating of existing 33 kV and 11 kV network in 20 kV level and investigation of changing process have been done for Ahvaz medium voltage distribution system as a case study in these paper's sections. Calculations and results will be contained maximum current capacities in different line conductors, insulation and air clearances assessment, poles acceptable mechanical values, short circuit current and protection coordination for changing voltage level in distribution system.

Construction a flow through catalytic ozonation system with activated sludge based ceramsite for enhanced ibuprofen removal

Emerging contaminants had drawn much attention due to their ubiquitous occurrence in aquatic environment, and their potential negative effects. In this study, a flow catalytic ozonation system with activated sludge based ceramsite was established, and its catalytic performance was evaluated for degradation of ibuprofen (IBU). Firstly, the proportion of activated sludge and fly ash was 1:1 based on Reliy model for successfully preparation of ceramsite which could catalyze ozone to completely remove IBU within 10 min, while degradation ratio was just 19.9 % in ozonation system. The effects of operational conditions including initial concentration of IBU, ozone dosage, hydraulic retention time, and pH were considered to further verify the applicability of the system. The prepared ceramsite could not only enhance ozone dissolution, but also promote the decomposition of ozone to produce more •OH, which was contributed by metal ions active sites and surface hydroxyl groups. And the contribution of •OH for IBU degradation was about 95.3 % indicating that the •OH played an important role in degradation. The inorganic ions except CO32−/HCO3− and phosphates had less effect on catalytic performances. Furthermore, the degradation products and possible pathways were proposed. The catalytic ozonation system could effectively control the toxicity of the treatment solution. This study not only provided new ideas for resource utilization, but also provided advisable practice application of heterogeneous catalysts for dealing with wastewater.

A Novel Dataset Replenishment Strategy Integrating Time-Series InSAR for Refined Landslide Susceptibility Mapping in Karst Regions

The accuracy of landslide susceptibility mapping is influenced by the quality of sample data, factor systems, and assessment methods. This study aims to enhance the representativeness and overall quality of the sample dataset through an effective sample expansion strategy, achieving greater precision and reliability in the landslide susceptibility model. An integrated interpretative framework for landslide susceptibility assessment is developed using the XGBoost-SHAP-PDP algorithm to deeply investigate the key contributing factors of landslides in karst areas. Firstly, 17 conditioning factors (e.g., surface deformation rate, land surface temperature, slope, lithology, and NDVI) were introduced based on field surveys, satellite imagery, and literature reviews, to construct a landslide susceptibility conditioning factor system in line with karst geomorphology characteristics. Secondly, a sample expansion strategy combining the frequency ratio (FR) with SBAS-InSAR interpretation results was proposed to optimize the landslide susceptibility assessment dataset. The XGBoost algorithm was then utilized to build the assessment model. Finally, the SHAP and PDP algorithms were applied to interpret the model, examining the primary contributing factors and their influence on landslides in karst areas from both global and single-factor perspectives. Results showed a significant improvement in model accuracy after sample expansion, with AUC values of 0.9579 and 0.9790 for the training and testing sets, respectively. The top three important factors were distance from mining sites, lithology, and NDVI, while land surface temperature, soil erosion modulus, and surface deformation rate also significantly contributed to landslide susceptibility. In summary, this paper provides an in-depth discussion of the effectiveness of LSM in predicting landslide occurrence in complex terrain environments. The reliability and accuracy of the landslide susceptibility assessment model were significantly improved by optimizing the sample dataset within the karst landscape region. In addition, the research results not only provide an essential reference for landslide prevention and control in the karst region of Southwest China and regional central engineering construction planning but also provide a scientific basis for the prevention and control of geologic hazards globally, showing a wide range of application prospects and practical significance.

Nontarget analysis and characterization of p-phenylenediamine-quinones and -phenols in tire rubbers by LC-HRMS and chemical species-specific algorithm

BackgroundN,N′-disubstituted p-phenylenediamine-quinones (PPDQs) are oxidization derivatives of p-phenylenediamines (PPDs) and have raised extensive concerns recently, due to their toxicities and prevalence in the environment, particularly in water environment. PPDQs are derived from tire rubbers, in which other PPD oxidization products besides reported PPDQs may also exist, e.g., unknown PPDQs and PPD-phenols (PPDPs). ResultsThis study implemented nontarget analysis and profiling for PPDQ/Ps in aged tire rubbers using liquid chromatography-high-resolution mass spectrometry and a species-specific algorithm. The algorithm took into account the ionization behaviors of PPDQ/Ps in both positive and negative electrospray ionization, and their specific carbon isotopologue distributions. A total of 47 formulas of PPDQ/Ps were found and elucidated with tentative or accurate structures, including 25 PPDQs, 18 PPDPs and 4 PPD-hydroxy-quinones (PPDHQs). The semiquantified total concentrations of PPDQ/Ps were 14.08–30.62 μg/g, and the concentrations followed the order as: PPDPs (6.48–17.39) > PPDQs (5.86–12.14) > PPDHQs (0.16–1.35 μg/g). SignificanceThe high concentrations and potential toxicities indicate that these PPDQ/Ps could seriously threaten the eco-environment, as they may finally enter the environment, accordingly requiring further investigation. The analysis strategy and data-processing algorithm can be extended to nontarget analysis for other zwitterionic pollutants, and the analysis results provide new understandings on the environmental occurrence of PPDQ/Ps from source and overall perspectives.

Impact of COVID-19 pandemic on microplastic occurrence in aquatic environments: A three-year study in Taihu Lake Basin, China

The impact of the Coronavirus Disease 2019 (COVID-19) pandemic on microplastic (MP) occurrence in aquatic environments deserves an in-depth study. In this study, the occurrence of MPs and environmental flux of plastics before (2019) and during (2020 and 2021) the pandemic were comparatively investigated in various aquatic compartments in the Taihu Lake Basin in China. The field-based investigations from 2019 to 2021 for Taihu Lake have shown that, at the onset of the outbreak, the MP abundance declined at a rate of 62.3 %, but gradually recovered to the pre-pandemic level. However, the amount of plastics being released into aquatic environments showed a declining trend in 2020 and 2021 compared to those in 2019, with decrease rates of 13.7 % and 15.8 %, respectively. Characterization analysis of MP particles and source apportionment framework implied that while the contributions of tire abrasion and domestic waste to MP occurrence were depleted owing to the reduction in human activity during the pandemic, weathering and fragmentation of retained plastics contributed to the recovery of stored MPs. This study provides insights into the anthropogenic influences on MP occurrence, and supports policymakers in managing and controlling plastic contamination in large freshwater systems in the “new normal” phase.