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To gather enough energy to respond to harmful stimuli, most immune cells quickly shift their metabolic profile. This process of immunometabolism plays a critical role in the regulation of immune cell function. Triclosan, a synthetic antibacterial component present in a wide range of consumer items, has been shown to cause immunotoxicity in a number of organisms. However, it is unclear whether and how triclosan impacts immunometabolism. Here, human macrophages were used as model cells to explore the modulatory effect of triclosan on immunometabolism. Untargeted metabolomics using integrated liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) revealed that triclosan changed the global metabolic profile of macrophages. Furthermore, Seahorse energy analysis and

Thorough investigations of the environmental fate and risks are necessary for the safe application of engineered nanomaterials. Nevertheless, the current understanding of potential transformations of MoS

Benzo[a]pyrene (B[a]P) as a representative polycyclic aromatic hydrocarbons is concerned by global scientists in various fields, but its biological and biochemical actions in soil-wheat systems are still rarely reported. The B[a]P as a ubiquitous soil pollutant possesses varied contents in real environment, and herein was studied in systems of soil and wheat to obtain relative results to reveal their variations in different systems. Its bioavailability (extractability and bioaccumulation) and basic biological toxicity were tested based on three typical soil types (red, black, and brown) in China and spiked amounts (0.1, 1, and 10 mg/kg) with several orders of magnitude. Results showed that B[a]P concentrations in soil-wheat systems extracted by HPCD were insignificantly (p > 0.05) higher than Tenax-TA, and varied with soil types and spiked concentrations. Besides, the root and shoot length were mostly inhibited, in a range of -21.85%-26.35% and -0.48%-54.85%, respectively, by B[a]P in different soil types and increased with its increasing concentration. Comparatively, higher bioconcentration factor and translocation factor values were observed under lower group in red soil-wheat systems, and higher spiked groups in black and brown soil-wheat systems. Moreover, inhibitive effects posed by B[a]P were mainly targeted at wheat shoots in these soils. The simultaneous studies provided a comparable knowledge of B[a]P in ecosystems of different soil types combined with different plant species due to lots of variations, further to serve for contaminated soil remediation and sustainable agricultural management.

Graphene oxide (GO, a popular 2D graphene-based nanomaterial) has developed quickly and has received considerable attention for its applications in environmental protection and pollutant removal. However, significant knowledge gaps still exist about the interaction characteristic and joint toxicity mechanism of GO and cadmium (Cd) on aquatic organisms. In this study, GO showed a high adsorption capacity (120. 6 mg/g) and strong adsorption affinity (K

The union of Plant Growth-Promoting Bacteria (PGPB) and rhizosphere confers a series of functions beneficial to plant. However, the lack of an opearable in situ method limits the further understanding on the mechanism. In this study, a weak electric field was designed to regulate rhizospheric microflora in a constructed root-splitting reactor. Compared with the control, the aboveground and underground biomass of rice seedling increased by 17 % and 18 % (p0.05) respectively under the exist of weak electric field of 0.14 V/cm. The joint action of rhizosphere and PGPB displayed the detoxification ability in the condition of soluble petroleum hydrocarbons, where the height, stem diameter, biomass and root vigor of the plant was increased by 58 %, 32 %, 43 % and 48 % respectively than the control. The selective reproduction of endophytes and ectophytes (denitrifying, auxin-producing, hydrocarbon-degrading and electroactive bacteria) was observed under applied weak electric field, which enhanced the nitrogen utilization, cellular metabolic activity and resistance to toxic organics of plant. This was further confirmed by the up-regulated OTUs related to the hydrocarbon degradation function, tryptophan metabolism and metabolism of nicotinate and nicotinamide. Moreover, the weak electric field also enhanced the transfer ability of partial endophytes grown in the root to improve plant stress resistance. The results in this work inspired an exercisable method for in situ enrichment of PGPB in the rhizosphere to cope with food crisis and provided a new way to deal with sudden environmental events.

As extremely active sites processing terrestrially derived dissolved organic matter (DOM), lakes deserve sufficient attention. Because of high-complexity interactions between DOM and the surrounding environment, the natural and anthropogenic drivers controlling the composition and chemodiversity of DOM molecules in lakes remain unclear. Here, 13,952 DOM molecules were identified and assessed in 45 lakes across China via ultrahigh-resolution mass spectrometry. Furthermore, the effects of both natural and anthropogenic factors on the DOM composition, DOM chemodiversity, and greenhouse gas emissions were investigated. The majority of the variations in DOM chemical composition could be attributed to the differences in the hydrology and nutrient concentrations of the lakes, and human activities also played a role, mainly through atmospheric pollution. Environmental factors mainly influenced DOM chemodiversity in the form of S-containing compounds. N-containing compounds exhibited a positive correlation with CO

Engineered nanomaterials (ENMs), especially transition metal dichalcogenide (TMDC), have received great attention in recent years due to their advantageous properties and applications in various fields and are inevitably released into the environment during their life cycle. However, the effect of natural nanocolloids, widely distributed in the aquatic environment, on the environmental transformation and ecotoxicity of ENMs remains largely unknown. In this study, the effects of natural nanocolloids were compared to humic acid on the environmental transformation and ecotoxicity of single-layer molybdenum disulfide (SLMoS2), a representative TMDC. SLMoS2 with nanocolloids or humic acid (HA) enhanced their dispersion and Mo ion release in deionized water. Nanocolloids induced growth inhibition, reactive oxygen species (ROS) elevation, and cell permeability. Low-toxicity SLMoS2 combined with nanocolloids will enhance the above adverse effects. SLMoS2-nanocolloids induced serious damage (cell distortion and deformation), SLMoS2 internalization, and metabolic perturbation on Chlorella vulgaris (C. vulgaris). In contrast, the addition of HA induced the growth promotion and lower ROS level, inhibited the internalization of SLMoS2, and mitigated metabolic perturbation on C. vulgaris. This work provides insights into the effect of natural nanocolloids on the behaviors and biological risks of ENMs in aquatic environments, deserving substantial future attention.

Considering the stability and economy of immobilized enzymes, this study prepared co-modified biochar immobilized laccase product named Fe

Interactions between microorganisms and clay minerals influence the transport and cycling of metal contaminants in both marine and terrestrial environments. The present study was conducted to quantify the adsorption of dissolved cadmium, Cd(II), under seawater-like conditions to the marine cyanobacterium Synechococcus sp. PCC 7002, three common clay minerals (kaolinite, montmorillonite and illite), as well as cell-clay aggregates. We show here that the Synechococcus-only experiments removed the most Cd above pH 5.5, followed in decreasing order by aggregates of 50% cells:50% individual clays, aggregates of cells and all 3 clays, and individual clays. Electron microscope imaging showed that clays associated in a tangential edge-on orientation to the cells in Synechococcus-clay mineral aggregates. A non-electrostatic surface complexation modeling approach was used to fit Cd adsorption onto Synechococcus cells and individual clay minerals. The resulting Cd binding constants were then used in consort with surface functional group pKa values and site concentrations to accurately predict the extent of Cd adsorption onto the Synechococcus-clay mineral aggregates using the component additivity (CA) approach. We observed that the addition of cyanobacterial cells to clay mineral suspensions led to significantly larger mean aggregate sizes of clay minerals, enhancing the clay sedimentation rate. Although specifically focused on Cd, our study indicates that the ratio of bacterial plankton to clay minerals is an important determinant in terms of understanding the rate with which metals are transferred from the water column to the seafloor.

During land development, some important changes take place in the soil environment. Understanding these responses is of great significance for solving local and global environmental issues caused during land development. Till now, studies within education parks or university/college towns, especially inside and outside of a campus, were rarely reported. Herein, treating a campus as a semi‐open and coupled system, we collected soil samples (109 sites) inside and outside of a campus to reveal the variation in their soil‐geochemical parameters, available microelements, and microbial communities. Results shown that soil samples inside of the campus had lower pH (p

Graphene-based nanomaterials (GBNs) are likely to be entering the soil environment in increasing amounts via consumer products. However, the disturbance of bacterial communities and their associated ecological functions by GBNs remains elusive. We performed a soil incubation experiment with the addition of graphene oxide (GO) and reduced graphene oxide (RGO). The Illumina sequencing technique was used to investigate changes in bacterial communities, and the functional groups of the communities were analyzed using the functional annotation of prokaryotic taxa database. After 90 days of exposure, RGO induced a lower bacterial richness than GO. However, GO induced larger changes in community composition and functions than RGO. After exposure to GBNs, some of the functional groups associated with organic matter degradation and biogeochemical cycling of nitrogen and sulfur decreased. However, the functional group associated with aromatic compound degradation increased, possibly because GBNs contain rich aromatic hydrocarbon structures, which are tolerated by this functional group.

Antibiotic resistance genes (ARGs) are considered to be a type of emerging contaminant; their interaction with biochar (BC) could affect their dissemination and fate in the environment. Although adsorption of ARGs onto bulk-BC has been reported, the interaction with nanosized BC (nano-BC) is largely unknown. In this study, the interactions of a model extracellular DNA (eDNA, calf thymus DNA) and two typical ARGs (ampC and ermB) extracted from a natural river with bulk- and nano-BCs from two pyrolysis temperatures (400 and 700 °C) were investigated. Only adsorption was observed on bulk-BCs, while not only adsorption but also fragmentation of these eDNA molecules was found to occur on nano-BCs. Also, their replication was greatly inhibited by nano-BCs. The electron paramagnetic resonance results indicated that hydroxyl radicals produced from persistent free radicals (PFRs) on nano-BCs played a major role in the damage of eDNA. Moreover, the direct contact with nonradical reacting sites and PFRs on nano-BCs also contributed to the decay of eDNA. Comparatively, PFRs in bulk-BCs were difficult to be reached by eDNA because of steric hindrance and played a negligible role in destroying eDNA. These findings highlight the importance of the size effect in evaluating the reactivity and related environmental risks of PFRs on BC and improve our understanding on the interaction between ARGs and BC.

Nanocolloids (Ncs) are ubiquitous in natural surface waters. However, the effects of Ncs on the fate and ecotoxicity of graphene oxide (GO, a popular engineered nanomaterial (ENM)) remain largely unknown. Ncs exhibit strong adsorption affinity (KL = 1.93 L/mg) and high adsorption capacity (176.2 mg/g) for GO. After Ncs hybridization, GO nanosheets became scrolls, and the aggregation rate of GO decreased. The influence of humic acid and Ncs on GO toxicity was compared. Humic acid mitigated the phytotoxicity of GO. However, GO and GO-Ncs were found to have an envelopment effect on algal cells, and both could enter algal cells. GO-Ncs induced higher reactive oxygen species (ROS) generation, stronger DNA damage and plasmolysis, and more obvious inhibition of photosynthesis compared to GO. Proteomic analysis revealed that photosystem I- and II-related proteins (e.g., E1ZQR2 and E1ZPG5) were regulated more significantly in the GO-Ncs groups than in the GO groups. A combined proteomic and metabolomic analysis showed that inhibition of carbohydrate, fatty acid, and amino acid metabolism contributed to ROS generation. Given the high concentrations and activity of Ncs, the above results highlight the need for reconsideration of the Ncs-mediated environmental behaviors and risks of ENMs and other pollutants.

Emerging transition-metal dichalcogenide (TMDC) nanosheets, such as WS2 nanosheets, have shown tremendous potential for use in many fields such as intelligent manufacturing and environmental protection. However, considerable knowledge gaps still exist regarding the impact of TMDCs on environmental risks, especially risks involving organic pollutants. Here, a synergistic toxicity between WS2 nanosheets and organic pollutants (triclosan or tris(1,3-dichloro-2-propyl) phosphate) was found using the median-effect and combination index equations. In particular, the effect of synergy had a higher magnitude at low cytotoxicity levels and a noncytotoxic concentration of WS2 nanosheets clearly enhanced the cytotoxicity and intracellular accumulation of organic pollutants. On the one hand, WS2 nanosheets damaged the plasma membrane and cytoskeleton, resulting in increased membrane permeability and organic pollutant uptake. On the other hand, as shown by fluorescence substrate accumulation experiments and molecular dynamics simulations, WS2 nanosheets affected the secondary structure of the efflux pumps and competitively bound with efflux pumps, blocking xenobiotic removal. This work emphasized that TMDCs, especially at the noncytotoxic level, in combination with organic pollutants caused damage that cannot be ignored, providing insight into comprehensive safety assessment and the specific toxicological mechanisms of TMDCs that accompany organic pollutant exposure.

Many countries have developed university/college towns with specific characteristics (temporal, spatial, structural, and functional aspects). During the land development, there were obvious changes in soil metal levels and distribution patterns attributed to anthropogenic activities, thus having induced comparable results in university/college towns due to similar anthropogenic activities. Until now, specific studies on the metal status in university/college towns, especially the variation inside and outside of a campus were rarely involved. Herin we report on 109 soil samples around a new campus within a developing education park, in which the levels, spatial distributions, and possible sources of (alkali, alkaline‐earth, transition, and main group) metals and metalloids (Cd, Cr, As, Pb, Zn, Cu, Mn, Ba, Ni, Ti, Be, Bi, Sb, Sn, Co, V, and Zr) were systematically investigated. The Nemerow pollution indexes, spatial analysis, principal components analysis, and cluster analysis were calculated and analyzed. The results showed that the level of most metals within the campus with different functional areas (college, activity, and greening areas) was 1–1.3‐times as much as that outside in four directions and had greater variations. Moreover, the level of most metals was 1–1.5‐times as much as their background value and they distributed in the areas under specific developments and might mainly be attributed to anthropogenic sources. These findings provide the knowledge about effects of land development and anthropogenic activities on soil metal status that could be used by university/college towns in the similar context around the world.

Silver nanoparticles (AgNPs) are promising bactericidal agents and plasmonic NPs for environmental applications, owing to their various favorable properties. For example, AgNPs enables reactive oxygen species (ROS) generation, surface plasmon resonance (SPR), and specific reaction selectivities. In fact, AgNPs-based materials and their antimicrobial, optical, and electrical effects are at the forefront of nanotechnology, having applications in environmental disinfection, elimination of environmental pollutants, environmental detection, and energy conversions. This review aims to comprehensively summarize the advanced applications and fundamental mechanisms to provide the guidelines for future work in the field of AgNPs implanted functional materials. The state-of-art terms including (photo)(electro)catalytic reactions, heterojunction formation, the generation and attacking of ROS, genetic damage, hot electron generation and transfer, localized surface plasmon resonance (LSPR), plasmon resonance energy transfer (PERT), near field electromagnetic enhancement, structure-function relationship, and reaction selectivities have been covered in this review. It is expected that this review may provide insights into the rational development in the next generation of AgNPs-based nanomaterials with excellent performances.

Anhui province is a big agricultural province in China with regional heterogeneity, but there is still a lack of its regional soil-environmental quality standard for food safety and agricultural land protection. Herein, we collected 42 typical soil samples and 125 crop samples (roots, shoots and grains of wheat and rape) in the typical regions of northern, middle and southern Anhui province, and derived the regional criteria based on the current levels of eight metals (Cd, Cr, As, Pb, Hg, Cu, Zn, and Ni) as the basic items. Results showed that the metal concentrations in soil and crop samples varied with different Anhui regions and soil-crop systems. It was observed that there exists slight or moderate soil pollution (0.77-2.67), significantly higher concentrations (P0.05) in rape soils, generally higher concentrations (P0.05) in wheats, highest bioconcentration factor (BCF) in roots (0-9.570), and higher (P0.05) metal concentrations in the crops of southern and middle areas. The calculated regional soil-environmental quality criteria for Anhui province provided a new insight on developing regional soil-environmental quality criteria, which varied with different Anhui regions, and were ≥0.13-times lower than the screening values, except for Cd in the southern rape soil (0.351 mg/kg), but were generally higher for rape soils, except for Zn and As.

Over the past few decades, data-driven machine learning (ML) has distinguished itself from hypothesis-driven studies and has recently received much attention in environmental toxicology. However, the use of ML in environmental toxicology remains in the early stages, with knowledge gaps, technical bottlenecks in data quality, high-dimensional/heterogeneous/small-sample data analysis and model interpretability, and a lack of an in-depth understanding of environmental toxicology. Given the above problems, we review the recent progress in the literature and highlight state-of-the-art toxicological studies using ML (such as learning and predicting toxicity in complicated biosystems and multiple-factor environmental scenarios of long-term and large-scale pollution). Beyond predicting simple biological endpoints by integrating untargeted omics and adverse outcome pathways, ML development should focus on revealing toxicological mechanisms. The integration of data-driven ML with other methods (e.g., omics analysis and adverse outcome pathway frameworks) endows ML with widely promising application in revealing toxicological mechanisms. High-quality databases and interpretable algorithms are urgently needed for toxicology and environmental science. Addressing the core issues and future challenges for ML in this review may narrow the knowledge gap between environmental toxicity and computational science and facilitate the control of environmental risk in the future.

The transformation of silver ions (Ag

Azo dye pollution has become a worldwide issue, and the current treatment methods can hardly meet the expected emission standards. Microbial electrochemical systems (MESs) show promising applications for decolorization, but their performance critically depends on the microorganisms. Electrode modification is an interesting method of improving decolorization performance. However, the mechanisms of how the modification can affect microbial communities and the decolorization process remain unclear. Here, a modified anode with polyaniline (PANI) and graphene was fabricated via electro-deposition. Consequently, the highest decolorization efficiency was obtained. The Congo red (CR) decolorization rate of the MESs with the PANI/graphene-modified electrode (PG) reached 90% at 54 h. By contrast, the CR decolorization rates of the MESs with the PANI-modified electrode (P) and those of the MESs with the unmodified electrode (C) only reached 68% and 79%, respectively. Results of the microbial community analysis showed abundant Methanobrevibacter arboriphilus in PG (11%), which was 5.5 times that in C (2%) at 18 h. This phenomenon may be related to the rapid decolorization. The upregulated metabolism pathways, including arginine and proline metabolism, purine metabolism, arginine biosynthesis, and riboflavin metabolism, provided more electron shuttles and redox mediators that facilitated the extracellular electron transfer. Therefore, the PG-modified electrode facilitated the decolorization by altering certain metabolic pathways. This study can help to improve the guideline on the potential application of MESs for wastewater treatment.

PbSe nanoparticles (PbSe-NPs) attract ever-growing interest owing to their great promise in various fields. However, potential toxic effects of PbSe-NPs on male reproductive systems have not been reported. This study aimed to determine whether early-life exposure to PbSe-NPs could affect male reproductive systems and other related health effects in rats. The male rats were intraperitoneally injected with 10 mg/kg/week PbSe-NPs for 60 days followed by a series of reproductive-related analyses. We found that the nanoparticles could accumulate in testes in a size-dependent manner. Furthermore, accumulation of PbSe-NPs resulted in oxidative stress and disorder of normal serum sex hormones. Endoplasmic reticulum and mitochondria-mediated cell apoptosis were triggered via oxidative stress, as shown by upregulation of cytoplasmic Cyt-c, Bax, cleaved Caspase-3, GRP78, and Caspase-12. Notably, PbSe-NP administration led to reduction in the quantity and quality of sperm, which caused a great fertility decrease. In contrast, released Pb2+ from PbSe-NPs did not result in any testis toxicity and fertility declines. These results demonstrate that PbSe-NPs could cause severe reproductive toxicity in a size-dependent manner and these toxic effects should be responsible for PbSe-NPs themselves rather than released Pb2+. The application of PbSe-NPs might be a double-edged sword, and corresponding measures should be taken before use.

Understanding environmental fate is a prerequisite for the safe application of nanoparticles. However, the fundamental persistence and environmental transformation of single-layer molybdenum disulfide (SLMoS2, a 2D nanosheet attracting substantial attention in various fields) remain largely unknown. The present work found that the dissolution of SLMoS2 was pH and dissolved oxygen dependent and that alterations in phase composition significantly occur under visible light irradiation. The 1T phase was preferentially oxidized to yield soluble species (MoO42- and SO42-), and the 2H phase remained as a residual. The transformed SLMoS2 exhibited a ribbon-like and multilayered structure and low colloidal stability due to the loss of surface charge. Dissolved oxygen competitively captured the electrons of SLMoS2 to generate superoxide radicals and accelerated the dissolution of nanosheets. Compared to pristine 1T-phase SLMoS2, the transformed 2H-phase SLMoS2 could not easily enter algal cells and induced a low developmental inhibition, oxidative stress, plasmolysis, photosynthetic toxicity and metabolic perturbation. The downregulation of amino acids and upregulation of unsaturated fatty acids contributed to the higher toxicity of 1T-phase SLMoS2. The dissolved ions did not induce apparent phytotoxicity. The connections between environmental transformation (phase change and ion release) and phytotoxicity provide insights into the safe design and evaluation of 2D nanomaterials.

Lakes are critical for biogeochemical and ecological processes and are sensitive and vulnerable to anthropogenic disturbances, but how and to what extent human activities disturb the biodiversity in lakes remain unknown. Here, we showed the microbial diversity in 46 lakes and assessed the influence of 27 anthropogenic factors. We found that the economic level (e.g., per capita gross domestic product) was strongly negatively correlated (r = -0.97) with bacterial diversity but positively correlated (r = 0.17) with fungal diversity in lakes. The composition of the microbial community significantly changed with increasing economic level. Bacteria are more sensitive than fungi to anthropogenic impacts. Expanding the population size and increasing the economic level may promote the development of fungal diversity but inhibit bacterial diversity. Air quality, urbanization and ozone were negatively correlated with bacterial diversity, and fisheries had a negative correlation with fungal diversity. The anti-interference ability of lake microorganisms in the middle economic level zones (45,000-90,000 yuan/person) was stronger than that in high-level (90,000 yuan/person) and low-level (45,000 yuan/person) economic zones. Overall, our investigation provides national-scale evidence that changes in the microbial diversity in lakes were related to economic levels.

The combined bioremediation of microorganisms and plant roots is an environmentally friendly soil remediation technology with the application prospect. The inefficiency of electron transfer hinders the decomposition of reluctant petroleum hydrocarbons and the further absorption by plant roots in plant-rhizosphere microbial electrochemical system. A conductive network of extracellular electron transfer was constructed in this study by the combination of magnetite and external electrode, committed to strengthening the process of Direct interspecific electron transfer (DIET), Dissimilation iron reduction (DIR), and long-distance electron transport. The microbial conversions of C, N, and Fe related to the hydrocarbon removal were investigated in the compound remediation system (Fe + MEC). Compared with the control group (PCK), an increased 174–232% of Total petroleum hydrocarbons (TPHs) was removed from Fe + MEC, accompanied by the generation of bio-current. Synchronously, the reduction of iron oxide (mainly DIR) and nitrogen (mainly denitrification) was promoted due to the rapid transfer of extracellular electrons. A reinforced synergistic network of the potential degradation, denitrification, and iron-reducing/exoelectrogenic bacteria was constructed in the compound system, which may be connected through the magnetite-mediated electron transport chain. The results in this study provide an insight into the impasse overcoming of inefficient electron transfer during the remediation of organic contaminated soil.

As an important type of typical synthetic azo dyes, the use of sudan I-IV dyes has been of concern worldwide because of their wide applications and illegal addition into various foodstuffs, potentially resulting in water and soil pollution and having adverse effects on human health and ecosystems. However, to date, little has been reported regarding the environmental levels of these dyes and the risks that they pose to human health and ecosystems. Understanding the responses of soil enzymes, functional groups of bacteria and microbial communities to sudan dyes is of great importance to reveal their effect on the soil environment. In this study, we performed a toxicological study on the specific and overall effects of sudan I-IV dyes on the activity of soil enzymes including catalase, urease, and alkaline phosphatase after a 2- and 7-day exposure, functional groups of soil bacteria including nitrogen-fixing, ammonia-oxidizing, and denitrifying bacteria on day 14, and the structure and diversity of soil microbial community compositions on day 30. The results showed that sudan I-IV affected the activity of the soil enzymes, the abundance of the bacterium functional groups, and the structure and diversity of microbial community compositions, and the effects varied by sudan dyes I-IV, the exposure concentration, and the exposure time.

Application of transition metal dichalcogenide (TMDC) nanosheets with different phases have attracted much attention in various fields. However, the effects of TMDC phases on environmental biology remain largely unknown. In this study, chemically exfoliated WS2 nanosheets (Ce-WS2, mainly the 1T phase) and annealed exfoliated WS2 nanosheets (Ae-WS2, 2H phase) were fabricated to serve as representative TMDC nanomaterials. Ce-WS2 showed higher levels of cellular uptake, oxidative stress, lipid peroxidation, membrane damage, and inhibition of photosynthesis than Ae-WS2 in Chlorella vulgaris. These differences were attributed to the higher electron conductivity and higher separation efficiency of electrons and holes in the 1T phase, a typical feature of Ce-WS2. Correspondingly, 2H-phase Ae-WS2 exhibited lower photooxidation/reduction activity and a lower ability to generate reactive oxygen species (mainly •OH) under visible-light irradiation. 1T-phase Ce-WS2 dissolved more readily than Ae-WS2 and released more...

An experimental study on adsorption and desorption behaviors of rhodamine B (RhB) with/without cadmium ion (Cd2+) on a coastal soil was carried out in the face of the scarce studies on its environmental behaviors, especially its combined pollution with metal ions. The implications on mariculture and seafood safety, rarely concerned either, were also analyzed for providing a new insight between azo dyes and them. It showed that the adsorption of RhB on the tested soil was affected by Cd2+ and could be better fitted by the Freundlich model and dominantly identified as chemical adsorption according to the threshold of ΔG0 (40 kJ/mol). There is a positive hysteresis on the desorption of RhB, which was generally strengthened with the increasing concentration of RhB but generally weakened in the presence of Cd2+. The azo dyes including RhB and heavy metals such as Cd, as the major class of typical pollutants in coastal environment, are closely related to the mariculture and seafood safety. In the consideration of three aspects including potential pollutants for the mariculture, potential risks for seafood safety, and potential relationships between dyes and mariculture and seafood safety, their implications were further clarified.

Soils are a repository for polychlorinated biphenyls (PCBs). A pot incubation experiment was performed with four soils (black soil, paddy soil, oasis soil, and fluvo-aquic soil) treated with Aroclor 1242 to achieve PCB concentrations of 5 mg kg−1. The soil enzyme activities of protease, phosphatase, catalase, dehydrogenase, and laccase were determined by spectrophotometry. The soil bacterial communities were investigated using Illumina sequencing analysis. The results showed that the characteristics of the test soils varied among the soil types. The fluvo-aquic soil had the greatest PCB dissipation rate (86.41%), followed by the oasis (79.31%), paddy (56.09%), and black (50.65%) soils. The soil pH, cation exchange capacity, soil organic matter content, and particle diameter played significant roles in PCB dissipation from soils. The soil type had a greater influence than PCB contamination on the soil enzyme activities and bacterial communities (alpha diversity, community structure, and composition). Among the four soils, the bacterial communities of the fluvo-aquic soil were the most susceptible to PCB contamination. However, the bacterial communities of the black soil were not changed by PCB contamination.

Chromium (Cr) is one of the most severe heavy metal contaminants in soil, and it seriously threatens ecosystems and human health through the food chain. It is fundamental to collect toxicity data of Cr before developing soil quality criteria/standards in order to efficiently prevent health risks. In this work, the short-term toxic effects of Cr(VI) and Cr(III) on the root growth of eleven terrestrial plants were investigated. The corresponding fifth percentile hazardous concentrations (HC5) by the best fitting species sensitivity distribution (SSD) curves based on the tenth percentile effect concentrations (EC10) were determined to be 0.60 and 4.51 mg/kg for Cr (VI) and Cr (III), respectively. Compared to the screening level values worldwide, the HC5 values in this study were higher for Cr(VI) and lower for Cr(III) to some extent. The results provide useful toxicity data for deriving national or local soil quality criteria for trivalent and hexavalent Cr.

At present, the uptake and accumulation of nanoplastics by plants have raised particular concerns. However, molecular mechanisms underlying nanoplastic phytotoxicity are still vague and insufficient. To address this scientific gap, we analyzed the transcriptome response of hydroponically grown wheat (Triticum aestivum L.) to polystyrene nanoplastics (PSNPs) (100 nm) by integrating the differentially expressed gene analysis (DEGA) and the weighted gene correlation network analysis (WGCNA). PSNPs could significantly shape the gene expression patterns of wheat in a tissue-specific manner. Four candidate modules and corresponding hub genes associated with plant traits were identified using WGCNA. PSNPs significantly altered carbon metabolism, amino acid biosynthesis, mitogen-activated protein kinase (MAPK) signaling pathway-plant, plant hormone signal transduction, and plant-pathogen interaction Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. In addition, some Gene Ontology (GO) terms associated with the metal ion transport were further screened. These findings shed new light on the phytotoxic mechanism and environmental implication behind the interaction of nanoplastics and crop plants, and advance our understanding of the potential adverse effect induced by the presence of nanoplastics in agricultural systems.

Zeolitic imidazole frameworks (ZIFs) have attracted a considerable amount of attention for use in environmental applications (e.g., pollutant adsorption and photocatalysis in water treatments). The environmental stability and toxicity of ZIFs are key prerequisites for their practical applications, but information about these factors is largely lacking. The present work finds that pristine ZIFs (ZIF-8 and ZIF-67) photodegrade from frame structures into two-dimensional nanosheets and are oxidized to zinc carbonate (ZIF-8) and Co3O4 (ZIF-67) under visible-light irradiation. The photoinduced electrons, holes and free radicals promote dissolution of the metal cores and organic ligands, leading to collapse of the frame structure. The photodegradation of ZIF-8 alleviates developmental inhibition, oxidative stress, plasmolysis, and photosynthetic toxicity, while the photodegradation of ZIF-67 aggravates nanotoxicity. The integration of metabolomics and transcriptomics analysis reveals that unsaturated fatty acid biosynthesis and metal ion-binding transcription contribute to the altered toxicity of ZIF photodegradation. These findings highlight the roles of photodegradation in structural transformation and alteration of the toxicity of ZIFs, alarming the study of pristine metal-organic frameworks (MOFs).

The increasing applications of single-layer molybdenum disulfide (SLMoS2) pose great potential risks associated with environmental exposure. This study found that metallic-phase SLMoS2 with nanoscale (N-1T-SLMoS2, ∼400 nm) and microscale (M-1T-SLMoS2, ∼3.6 μm) diameters at 10-25 mg/L induced significant algal growth inhibition (maximum 72.7 and 74.6%, respectively), plasmolysis, and oxidative damage, but these alterations were recoverable. Nevertheless, membrane permeability, chloroplast damage, and chlorophyll biosynthesis reduction were persistent. By contrast, the growth inhibition (maximum 55.3%) and adverse effects of nano-sized semiconductive-phase SLMoS2 (N-2H-SLMoS2, ∼400 nm) were weak and easily alleviated after 96 h of recovery. N-1T-SLMoS2 (0.011 μg/h) and N-2H-SLMoS2 (0.008 μg/h) were quickly biodegraded to soluble Mo compared with M-1T-SLMoS2 (0.004 μg/h) and excreted by algae. Incomplete biodegradation of SLMoS2 (26.8-43.9%) did not significantly mitigate its toxicity. Proteomics and metabolomics indicated that the downregulation of proteins (50.7-99.2%) related to antioxidants and photosynthesis and inhibition of carbon fixation and carbohydrate metabolism contributed to the persistent phytotoxicity. These findings highlight the roles and mechanisms of the size and phase in the persistent phytotoxicity of SLMoS2, which has potential implications for risk assessment and environmental applications of nanomaterials.

Electroactive biofilm (EAB) sensor had shown great potential in the field of early warning of toxicants in water because of the low-cost and broad-spectrum. However, the traditional calculation of sensitivity strongly relied on the time and concentration gradient which weakened time-efficiency of the sensor. Moreover, the sensitivity could be further improved to respond trace concentrations. Here EAB sensors with different substrate concentrations were formed to respond different concentrations formaldehyde ranging from 1 ppm to 50 ppm and immediate current attenuation (ICA) was induced to evaluate the sensitivity. The ICA (~70 s) exhibited a shorter time than that calculated by calculable sensitivity (CS) and current attenuation (CA), which not only achieved the response of trace concentration but also improved the time-efficiency of the sensor. The EAB formed with 0.1 g/L acetate (EAB-0.1) had a 380% higher sensitivity than that formed with 1.0 g/L acetate (EAB-1.0), leading to a significant electrochemical toxicity response to 1 ppm of formaldehyde. The results of electrochemical response coefficient confirmed that EAB-0.1 was 1.5–6.3 times of that formed with acetate from 0.2 to 1.0 g/L, which was related with microbial community and component of EAB as described in our previous study. Our findings demonstrated that calculation of sensitivity could be optimized to reflect time-efficiency and EAB with limit acetate could be applied in trace toxicant detection.

A novel Au-graphene oxide (GO)-Co3O4 hollow sphere (Au/GO-Co3O4) was synthesized and its potential in binding with antibiotic resistance genes (ARGs) and inhibiting their replication was examined in this study. Tetracycline-resistant genes (tetA) with two amplicon lengths were selected as the model ARGs due to its highly detected in the environment. The Au/GO-Co3O4 composite was synthesized using tetra-n-butylammonium bromide (TBAB) as a mediating proxy. We found that it could bind with tetA and consequently inhibit its replication to a greater extent compared with pure Co3O4 and GO-Co3O4 hybrid. Furthermore, the Au-GO-Co3O4 composite was more efficient in binding with short fragments of tetA-ARGs (S-tetA) than long fragments (L-tetA). The interaction mechanism between the composite and tetA was systematically analyzed using spectra methods (FTIR, Raman, UV–Vis, and fluorimetric spectra), isolated filtrate assays, and gel electrophoresis. It is found that the adsorption of both GO and gold nanoparticles for tetA as well as cleavage effect of cobalt oxide/cobalt ions played a critical role in the capture and damage of tetA. Furthermore, we found that the interaction of both Co3O4 and GO-Co3O4 with tetA was mainly through intercalation mechanism, however, that of Au/GO-Co3O4 with tetA was mainly through groove binding mechanism. These findings in this study throw light on the new approaches for purification of ARGs contaminated water and elimination of antibiotic resistance of ARGs by novel inhibitor.

Single-layer molybdenum disulfide (SLMoS2) are applied as a hot 2D nanosheet in various fields involving water treatments. Both intentional design and environmental or biological processes induce many nanoholes in SLMoS2. However, the effects of nanoholes on the environmental stability and ecotoxicity of SLMoS2 remain largely unknown. The present work discovered that visible-light irradiation induced nanoholes (diameters, approximately 20 nm) in the plane of SLMoS2, with irregular edges and increased interplanar crystal spacing. The ratios of Mo to S in pristine and transformed SLMoS2 were 0.53 and 0.33, respectively. After 96 h exposure at concentrations from 0.1 to 1 mg/L, the above nanoholes promoted algal division, induced a stress-response hormesis, decreased the generation of •OH, and mitigated the cell shrinkage and wall rupture of Chlorella vulgaris induced by SLMoS2. In terms of stress response, the nanohole-bearing SLMoS2 induced fewer vacuoles and polyphosphate bodies of Chlorella vulgaris than the pristine form. Metabolomic analysis revealed that nanoholes perturbed the metabolisms of energy, carbohydrates, and fatty acids. This work proposes that nanoholes cause obvious effects on the environmental fate and ecotoxicity of SLMoS2 and that the environmental risks of engineered nanomaterials should be reevaluated using nanohole-bearing rather than pristine forms for testing.

Due to the numerous factors (e.g., nanoparticle [NP] properties and experimental conditions) influencing nanotoxicity, it is difficult to identify the priority factors dominating nanotoxicity. Herein, by integrating data from the literature and a random forest model, the priority factors determining reproductive toxicity were successfully screened from highly heterogeneous data. Among 10 factors from more than 18 different NPs, the NP type and the exposure pathway were found to dominantly determine NP accumulation. The reproductive toxicity of various NPs primarily depended on the NP type and the toxicity indicators. Nanoparticles containing major elements (e.g., Zn and Fe) tended to accumulate in rats but induced lower toxicity than NPs containing noble elements. Compared with other exposure pathways, i.p. injection posed significantly higher risks for NP accumulation. By combining similarity network analysis and hierarchical clustering, the sources of highly heterogeneous data were identified, the factor-toxicity dependencies were extracted and visualized, and the prediction of nanotoxicity was then achieved based on the screened priority factors. The present work provides insights for the design of animal experiments and the illustration and prediction of nanotoxicity.

Acid rain poses significant threats to crops and causes a decline in food production, but current monitoring and response to acid rain damage is either slow or expensive. The direct damage observation on plants can take several hours to days when the damage is irreversible. This study presents a real time bioelectrochemical monitoring approach that can detect acid rain damage within minutes. The rhizospheric bioelectrochemical sensor (RBS) takes advantage of the fast chain responses from leaves to roots, and then to the microbial electrochemical reactions in the rhizosphere. Immediate and repeatable current fluctuations were observed within 2 min after acid rain, and such changes were found to correspond well to the changes in rhizospheric organic concentration and electrochemical responses. Such correlation not only can be observed during acid rain events that can be remedied via rinsing, but it was also validated when such damage is irreversible, resulted in zero current, photosynthetic efficiency, and electrochemical signals. The alanine, aspartate, and glutamate metabolism and galactose metabolism in leaves and roots were inhibited by the acid rain, which resulted in the decrease of rhizodeposits such as fumaric acid, d-galactose, and d-glucose. These changes resulted in reduced electroactivity of anodic microorganisms, which was confirmed by a reduced redox current, a narrower spectrum in differential pulse voltammetry, and the loss of peak in the Bode plot. These findings indicate that the RBS process can be a simple, swift, and low-cost monitoring tool for acid rain that allows swift remediation measures, and its potential may be broadened to other environmental monitoring applications.

Hydrolysis is generally considered as the main pathway for the degradation of ester-type pollutants in aquatic environments. In this study, we found that when methanol or ethanol presented as the external carbon in the activated sludge, transesterification is very important for the degradation of para-hydroxybenzoic acid esters (parabens). In the activated sludge solutions with 1% methanol added, contribution of transesterification to the degradation of the propyl substituted paraben (PrP) and ethyl substituted paraben (EtP) accounted for 46% and 83%, respectively, in the early stage of the reaction. This indicates that in aquatic environments with alcohols presence, parabens prefer to form small molecule homologues than hydrolysis to acid. The predominant transesterification in the activated sludge is related to enzyme preference. Amano lipase from Pseudomonas fluorescens was verified to catalyze hydrolysis and transesterification of parabens, while the latter was dominant in water solution with 1% methanol or ethanol. Considering the common application of small molecular alcohols as the external carbon sources in wastewater treatment plants, transesterification might be an important pathway for the degradation of parabens pollutants in these engineering aquatic environments.

Much attention has been paid to extracting and isolating specific and well-known nanoparticles (especially for engineered nanomaterials) from complex environmental matrices. However, such research may not provide global information on actual contamination because nanoscale fragments exist as mixtures of various elements and matrices in the real environment. The present work first isolated and characterized nanoscale fragments in effluents from municipal wastewater treatment plants (WWTPs). The nanoscale fragments were found to be composed of 70–85% carbon and low amounts of oxygen, heavy metals and other elements and exhibited nanosheet topographies (approximately 0.87–1.31 nm thickness and 68–187 nm lateral length). Because the isolated nanoscale fragments were mixtures rather than one specific type of nanoparticle, they were present at high concentrations ranging from 0.07 to 0.55 mg/L. It was also found that the accumulation of nanoscale fragments in rice reached 0.59 mg/g under exposure to environmentally relevant concentrations, leading to marked phytotoxicity (e.g., ultrastructural damage to chloroplasts and mitochondria). Metabolic analysis revealed the toxicological mechanisms to be related to disorders of carbohydrate, amino acid and fatty acid metabolism. This study is the first to characterize the properties and analyze the toxicity of nanoscale fragments in the effluents of WWTPs. Given that WWTP effluents containing nanoscale fragments are continuously discharged to the soil, surface water and seas, nanoscale fragment materials deserve considerable attention in future work compared with the few widely studied engineered nanoparticles.

Nanocolloids are widespread in natural water systems, but their characterization and ecological risks are largely unknown. Herein, tangential flow ultrafiltration (TFU) was used to separate and concentrate nanocolloids from surface waters. Unexpectedly, nanocolloids were present in high concentrations ranging from 3.7 to 7.2 mg/L in the surface waters of the Harihe River in Tianjin City, China. Most of the nanocolloids were 10-40 nm in size, contained various trace metals and polycyclic aromatic hydrocarbons, and exhibited fluorescence properties. Envelopment effects and aggregation of Chlorella vulgaris in the presence of nanocolloids were observed. Nanocolloids entered cells and nanocolloid-exposed cells exhibited stronger plasmolysis, chloroplast damage and more starch grains than the control cells. Moreover, nanocolloids inhibited the cell growth, promoted reactive oxygen species (ROS), reduce the chlorophyll a content and increased the cell permeability. The genotoxicity of nanocolloids was also observed. The metabolomics analysis revealed a significant ( p0.05) downregulation of amino acids and upregulation of fatty acids contributing to ROS increase, chlorophyll a decrease and plasmolysis. The present work reveals that nanocolloids, which are different from specific, engineered nanoparticles (e.g., Ag nanoparticles), are present at high concentrations, exhibit an obvious toxicity in environments, and deserve more attention in the future.

Soil contaminated by aged petroleum hydrocarbons is faced with scarcity of electron acceptors, low activity of functional microbes and inefficient electron transfer, which hinder the bioremediation application. The soil microbial fuel cell (MFC) simultaneously solves these problems with bioelectricity production. In this study, five types of surfactants were introduced to enhance the bioavailability of aged petroleum hydrocarbon in soils. The ampholytic surfactant (lecithos) was optimal due to the highest bioelectricity generation (0.321C d −1 g −1 ) and promoted hydrocarbon degradation (328%), while the nonionic (glyceryl monostearate) and cationic (cetyltrimethylammonium bromide) surfactants were inefficient. The surfactants induced a special microbial enrichment affiliated with Proteobacteria , Firmicutes , Bacteroidetes , Actinobacteria , Chloroflexi , Planctomycetes and Acidobacteria (93%–99% of total) in soil MFCs. The anionic surfactant (sodium dodecyl sulfate) exhibited the strongest selectivity, and α- proteobacteria and γ - proteobacteria abundances decreased while Clostridia increased, much like the result obtained with the biosurfactant β -cyclodextrin. Furthermore, Bacillus abundance was increased in connected soil MFCs, except addition of lecithos in which Clostridium increased to 14.88% from 3.61% in the control. The high correlations among Bacillus , Phenylobacterium , Solibacillus (0.9162–0.9577) and among Alcaligenes , Dysgonomonas , Sedimentibacter (0.9538–0.9966) indicated a metabolic network of microorganisms in the soil bioelectrochemical remediation system.