Tire wear particles (TWPs), common mixed particulate emerging contaminants in the environment, have global per capita emissions accounting for 0.23–1.9 kg/year, attracting global attention recently due to their wide detection, small size, mobility, and high toxicity. This review focuses on the occurrence characteristics of TWPs in multiple environmental media, adverse effects on organisms, potential toxicity mechanisms, and environmental risk prevention and control strategies of TWPs. The environmental fate of TWPs throughout the entire process is systematically investigated by the bibliometric analysis function of CiteSpace. This review supplements the gap in the joint toxicity and related toxicity mechanisms of TWPs with other environmental pollutants. Based on the risks review of TWPs and their additives, adverse impacts have been found in organisms from aquatic environments, soil, and humans, such as the growth inhibition effect on Chironomus dilutes. A multi-faceted and rationalized prevention and control treatment of "source-process-end" for the whole process can be achieved by regulating the use of studded tires, improving the tire additive formula, growing plants roadside, encouraging micro-degradation, and other methods, which are first reviewed. By addressing the current knowledge gaps and exploring prospects, this study contributes to developing strategies for reducing risks and assessing the fate of TWPs in multiple environmental media.

The primary goal of this investigation was to formulate an ecologically sustainable alternative to amide herbicides (AHs) characterized by robust herbicidal effectiveness, minimal corn phytotoxicity, and commendable pharmaceutical safety. We employed comparative molecular similarity index analysis (CoMSIA), a threedimensional quantitative structure-activity relationship (3D-QSAR) model, which systematically outlined parameters such as herbicidal effectiveness, corn phytotoxicity, and AHs biodegradability. Subsequently, after thorough evaluation, we carefully selected a group of fourteen stable AH-substitute compounds known for their safety and environmental compatibility, considering aspects like pharmacokinetics, toxicokinetics, functional properties, and environmental friendliness. This resulted in a significant increase in herbicidal effectiveness, ranging from 21.64% to 34.07%, alongside a decrease in corn phytotoxicity within the range of 12.19-20.87%. Furthermore, we achieved an improvement in biodegradability, measured within the spectrum of 4.92-9.40%. Importantly, these changes also correlated with the reduction of hepatotoxicity, mutagenicity, and cutaneous health risks. Finally, we delved into the mechanisms underlying the improved herbicidal effectiveness, reduced corn phytotoxicity, and enhanced biodegradability of AHs substitutes through molecular docking and analysis of amino acid interactions. The investigation concluded that non-covalent forces governing the interaction between AHs substitutes and receptor proteins are crucial in determinin g herbicidal effectiveness, corn phytotoxicity, and biodegradability. Specifically, Van der Waals and electrostatic forces emerged as key factors governing the binding affinities of AH molecules with receptor proteins, both before and after modification. In summary, this study introduces innovative approaches in the field of agricultural chemical weeding technology and provides a theoretical framework for the environmentally responsible management of AHs herbicides.

The variability and intrinsic mechanisms of oxidative stress induced by microplastics at different trophic levels in freshwater food chains are not well understood. To comprehensively assess the oxidative stress induced by polystyrene microplastics (PS-MPs) in freshwater food chains, the present study first quantified the oxidative stress induced by PS-MPs in organisms at different trophic levels using factorial experimental design and molecular dynamics methods. Then focuses on analyzing the variability of these responses across different trophic levels using mathematical statistical analysis. Notably, higher trophic level organisms exhibit diminished responses under PS-MPs exposure. Furthermore, the coexistence of multiple additives was found to mask these responses, with antioxidant plastic additives significantly influencing oxidative stress responses. Mechanism analysis using computational chemistry simulation determines that protein structure and amino acid characteristics are key factors driving PS-MPs induced oxidative stress variation in freshwater organisms at different nutrient levels. Increased hydrophobic additives induce protein helicalization and amino acid residue aggregation. This study systematically reveals the variability of biological oxidative stress response under different nutrient levels, emphasizing the pivotal role of chemical additives. Overall, this study offers crucial insights into PS-MPs' impact on oxidative stress responses in freshwater ecosystems, informing future environmental risk assessment.

Phthalate esters (PAEs) as plasticizers posed significant environmental and human health risks during the production and application processes. This study aims to investigate the synthesizability of previously designed environmentally friendly PAEs alternatives by in silico approaches and explore the key factors influencing their synthesizability. Firstly, a novel approach combining positive and unlabeled (PU) machine learning (ML) and k Nearest Neighbor (kNN) models was utilized to screen three environmentally friendly PAEs alternatives with high synthesizability. Subsequently, the synthesizability and environmental friendliness of the selected PAEs alternatives were evaluated and confirmed using ADMETlab 2.0. Results demonstrated that all three PAEs alternatives exhibited high synthesizability and environmental friendliness. Finally, the SHapley Additive exPlanation (SHAP) method was employed to analyze the synthesis mechanisms of PAEs alternatives, revealing that the VE2_DzZ (molecular substitutability) and maxHCsats (molecular structure) could influence their synthesizability. Based on these findings, the synthesizability of the three PAEs alternatives was validated using density functional theory (DFT) and three-dimensional quantitative structure-activity relationship (3D-QSAR) methods. This cost-effective study provided the first evaluation of the synthesizability of PAEs alternatives and reduced the number of unlabeled samples by 95.83%. Moreover, these findings offered a theoretical foundation for developing environmentally friendly PAEs alternatives and provided new insights for substituting emerging pollutants and developing new materials.

Marine benthic dinoflagellate toxins, potent bioactive compounds with wide-ranging presence in marine ecosystems, have surged in response to global climate change and human activities, prompting an urgent and imperative inquiry. This study conducts an in-depth review of contemporary research concerning these toxins, employing meticulous bibliometric analysis. Leveraging a dataset of 736 relevant literatures sourced from the Web of Science (spanning from 2000 to May 2023), our analysis delves comprehensively into the scientific discourse surrounding these toxic compounds. Employing tools such as VOSviewer, co-citation analysis, co-occurrence analysis, and cluster analysis, our study yields nuanced insights into the intricate characteristics and trajectories of the field. The co-citation analysis underscores the pivotal role played by benthic and epiphytic dinoflagellates like Ostreopsis and Gambierdiscus in shaping prevailing research trends. Our study identifies four distinct research directions, encompassing the domains of ecology, toxicology, toxin production, and taxonomy. Moreover, it traces the evolutionary journey of research stages, marking the transition from a focus on taxonomy to an emphasis on unraveling molecular mechanisms. The culmination of our comprehensive analysis yields three pertinent research recommendations: a call for widescale global studies, the advancement of rapid toxin monitoring techniques, and a deeper exploration of the factors influencing toxin synthesis and toxicity. These findings provide invaluable insights to researchers grappling with the complex realm of harmful algal blooms and substantially enrich the understanding of this pivotal and pressing field.

Tire wear particles are a notable source of tire microplastics (TMPs) in the environment. However, only a few reports have focused on the aquatic toxicity effects of composite TMPs and their additives and the mechanistic analysis at the microscopic level. Therefore, this paper study the toxic effects of tire microplastics and their additives on zebrafish based on theoretical chemical calculation method (Taguchi orthogonal experiment method, full factorial experimental design, molecular docking, and molecular dynamics computational technique). We designed five kinds of proportioning schemes of tire rubber polymers and additive components (64 groups in each). The compound toxicity effects of the tire rubber polymers and their additives on zebrafish were simulated and calculated. The simulation results indicated styrene butadiene rubber had the most significant toxic effect on zebrafish. Subsequently, taking the composition ratio scheme of styrene butadiene rubber with the lowest biotoxicity effect as an example, we analyzed the main effects, second-order interactions, and third-order interactions of styrene butadiene rubber polymer and its additive combination in terms of biotoxicity using the fixed effects model. The toxic effects (developmental toxicity, neurotoxicity, and reproductive toxicity) of styrene butadiene rubber on marine and freshwater organisms could be drastically alleviated by adjusting the ratio of rubber additives. The analysis of the interaction between amino acid residues and non-bonds during the docking process of styrene butadiene rubber and toxic receptors revealed the interaction mechanisms between the styrene butadiene rubber polymer and its additives and between the additive molecules. Hydrophobic interaction was found to be the key factor for the binding of styrene butadiene rubber additives to nonpolar amino acids in the receptor proteins. Our findings are expected to provide theoretical support for identifying and regulating the toxicity characteristics of rubber TMPs and to aid in proposing a strategy to alleviate the toxic effects on aquatic organisms.

Novel brominated flame retardants (NBFRs), one of the most widely used synthetic flame-retardant materials, have been considered as a new group of pollutants that potentially affect human health. To overcome the adverse effects of NBFRs, a systematic approach for molecular design, screening, and performance evaluation was developed to generate environmentally friendly NBFR derivatives with unaltered functionality. In the present study, the features of NBFRs (long-distance migration, biotoxicity, bioenrichment, and environmental persistence) were determined and characterized by the multifactor comprehensive characterization method with equal weight addition, and the similarity index analysis (CoMSIA) model was constructed. Based on the threedimensional equipotential diagram of the target molecule 2-ethylhexyl tetrabromobenzoic acid (TBB), 23 TBB derivatives were designed. Of these, 22 derivatives with decreased environmental impact and unaltered functional properties (i.e., flame retardancy and stability) were selected using 3D-QSAR models and density functional theory methods. The health risks of these derivatives to humans were assessed by toxicokinetic analysis; the results narrowed down the number of candidates to three (Derivative-7, Derivative-10, and Derivative-15). The environmental impact of these candidates was further evaluated and regulated in the real-world environment by using molecular dynamics simulation assisted by the Taguchi experimental design method. The relationship between the binding effects and the nonbonding interaction resultant force (TBB derivatives-receptor proteins) was also studied, and it was found that the larger the modulus of the binding force, the stronger the binding ability of the two. This finding indicated that the environmental impact of the designed NBFR derivatives was decreased. The present study aimed to provide a new idea and method for designing NBFR substitutes and to provide theoretical support for restraining the potential environmental risks of NBFRs.

The presence of dissolved organic matter (DOM) is known to inhibit the degradation of trace organic contaminants (TrOCs) in SO4•--based advanced oxidation processes (AOPs) due to filtering of the photochemically active light and radical scavenging effects. This study revealed an unexpected contribution for DOM in the degradation of nitroimidazoles (NZs) in the UV/persulfate AOP. The apparent second-order rate constants of NZs with SO4•- increased by 2.05 to 4.77 times in the presence of different DOMs. The increments were linearly related to the total electron capacity of DOM. Quinone and polyphenol moieties were found to play a dominant role. The reactive species generated from SO4•-'s oxidation of DOM, including semiquinone radical (SQ•-) and superoxide (O2•-), were found to react with NZs via Michael addition and O2•- addition. The second-order rate constants of tinidazole with SQ•- is determined to be (5.69 ± 0.59) × 106 M-1 s-1 by laser flash photolysis. Reactive species potentially generated from DOM may be considered in designing processes for the abatement of different types of TrOCs.

Conventional coagulation process is not effective to eliminate trace organic compounds (TrOCs). This study proposed a novel peroxomonosulfate (PMS) amended iron coagulation process and found its effectiveness in eliminating TrOCs in synthetic and natural waters. In synthetic waters containing hydroquinone (HQ) or benzoquinone (BQ), Fe(III)/PMS effectively degraded carbamazepine (CBZ), a representative of resistant TrOCs. The step of reduction of Fe(III) to form Fe(II) governed the degradation rate of CBZ as PMS activation by Fe(II) was the dominant reaction to generate SO4•-, which was the major reactive oxidant in the system. Meanwhile, HQ was quickly transformed to BQ in the Fe(III)/PMS system and BQ acted as an electron shuttle to induce Fe(III)/Fe(II) redox cycle and accelerate PMS activation. Natural organic matter (NOM) bearing phenolic and quinone moieties played similar roles as HQ and BQ and fast CBZ degradation was also observed. Finally, two surface waters spiked CBZ were subjected to bench-scale experimentation to simulate coagulation/flocculation/sedimentation processes in water treatment plants. Compared to the conventional iron coagulation process, the PMS-amended iron coagulation process increased the removal percentage of CBZ by 50%–80%. Overall, this study demonstrates that PMS enhanced iron coagulation is a promising process for the abatement of TrOCs in water treatment.

Copper ion (Cu(II)) in water or wastewater has been reported to trigger peroxymonosulfate (PMS) oxidation of organic contaminants (OCs). However, this process can only work in alkaline condition, which limits its potential application. In this study, we found that the introduction of natural polyphenols in the Cu(II)/PMS process can significantly promote the degradation of tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame retardants, in the pH range of 4.3 -9.0. With gallic acid (GA) as a representative natural polyphenol, the degradation of TBBPA by GA/Cu(II)/PMS process reached 84.6% in 10 min at initial pH of 4.3 (without pH adjustment), which was 2.2 times higher than that by Cu(II)/PMS process. Multiple reactive oxidants, including Cu(III), hydroxyl radical (HO center dot) and singlet oxygen, were generated in this process among which Cu(III) and HO center dot contributed to TBBPA degradation with Cu(III) playing the dominant role. GA accelerated the reduction of Cu(II) to Cu(I) due to the strong chelation and electron-donating capacity of ortho-hydroxyl groups in GA, and then Cu(I) was quickly oxidized by PMS to Cu(III) which can be further acid-catalyzed to produce HO center dot. TBBPA transformation mainly proceeded through electron abstraction, oxidative debromination and ring-opening reaction pathways. The feasibility of in-situ utilizing natural organic matter (NOM, enriched with polyphenol moieties) to accelerate the degradation of TBBPA by Cu(II)/PMS process in surface water and wastewater was confirmed. The findings of this study indicate that the coupling of NOM and Cu(II), which are present in contaminated water or wastewater, can potentially improve PMS oxidation of OCs in a wide range of pH. (c) 2020 Elsevier Ltd. All rights reserved.

The degradation of tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame retardant, was evaluated during peroxymonosulfate (PMS) oxidation. TBBPA degradation was pH-dependent, with peak degradation rate constants occurring at pH 8.0-9.0, which was distinct from some other phenolic compounds. Singlet oxygen and radicals were found to play negligible roles in TBBPA degradation. TBBPA oxidation by PMS mainly proceeded via a direct oxidation pathway and the in-situ formed HOBr was found to greatly accelerate its degradation rates. The values of species-specific second-order rate constants for the reactions of PMS with the TBBPA kHSO5-+TBBPA, kHSO5-+TBBPA- and kHSO5-+TBBPA2- were determined to be (1.11 ± 0.84) × 10-2, (8.05 ± 2.31) × 10-2, and (1.34 ± 0.25) × 10-1 M-1 s-1, respectively, while the reaction rate constants for HOBr/OBr- with TBBPA kHOBr+TBBPA, kHOBr+TBBPA-, kHOBr+TBBPA2-and kOBr-+TBBPA2- were determined to be (9.38 ± 2.10) × 103, (1.59 ± 0.56) × 105, (8.22 ± 0.41) × 106, and (1.81 ± 0.12) × 106 M-1 s-1, respectively. The bromine mass balance analysis showed that bromide ion and HOBr/OBr- occupied 19.5% of total Br and brominated organic compounds accounted for the remaining percentages at pH 7.0. No formation of bromate was observed. Based on the identified products, a reaction pathway was proposed, which included oxidation, β-scission, hydroxylation, and dimerization reaction pathways. The results indicate that unactivated PMS is useful for the remediation of TBBPA contaminated water.