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The CdSe nanorod as a one-dimensional nanostructure has an excellent performance in many fields, such as healthcare, new energy, and environmental protection. Thus, it is crucial to investigate its potential adverse health effects prior to their wide exposure. The lung tissue would be the main target organ after CdSe nanorods enter living systems. Here, we showed that pulmonary instillation of CdSe nanorods could decrease the vitality of T-SOD and T-AOC in lung tissues of a rat, increase MDA and hydroxyproline levels and lipid peroxidation products, induce mitochondrial cristae breakage and vacuolization, cause inflammatory responses, and finally induce pulmonary fibrosis. The oral administration of modified procyanidinere could significantly increase the content of antioxidant enzymes, scavenge free radicals, reduce lipid peroxidation, and have protective effects on CdSe nanorods-induced pulmonary fibrosis. The benefit is not only in the early inflammatory stage but also in the later stages of the CdSe nanorods-induced pulmonary fibrosis.

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

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

Microbial electrochemical systems (MESs) can harvest bioelectricity from varieties of organic matter in wastewater through electroactive microorganisms. Oxygen reduction reaction (ORR) in a cathode plays an important role in guaranteeing high power generation, which can be enhanced by cathode catalysts. Herein, the tiny crystalline grain nanocrystal NiCo2O4 is prepared via the economic method and utilized as an effective catalyst in air–cathode MESs. The linear sweep voltammetry results indicate that the current density of 2% nano-NiCo2O4/AC cathode (5.05 A/m2) at 0 V increases by 20% compared to the control (4.21 A/m2). The cyclic voltammetries (CVs) and the electrochemical impedance spectroscopy (EIS) showed that the addition of nano-NiCo2O4 (2%) is efficient in boosting the redox activity. The polarization curves showed that the MESs with 2% nano-NiCo2O4/AC achieved the highest maximum power density (1661 ± 28 mW/m2), which was 1.11 and 1.22 times as much as that of AC and 5% nano-NiCo2O4. Moreover, the adulteration of nano-NiCo2O4 with a content of 2% can not only enable the electrical activity of the electrode to be more stable, but also reduce the cost for the same power generation in MESs. The synthetic nano-NiCo2O4 undoubtedly has great benefits for large-scale MESs in wastewater treatment.

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

As typical pollutants, petroleum hydrocarbons that are widely present in various environmental media such as soil, water, sediments, and air, seriously endanger living organisms and human health. In the meantime, as a green environmental technology that integrates pollutant removal and resource recovery, bioelectrochemical systems (BESs) have been extensively applied to the removal of petroleum hydrocarbons from the environment. This review introduces working principles of BESs, following which it discusses the different reactor structures, application progresses, and key optimization factors when treating water, sewage sludges, sediments, and soil. Furthermore, bibliometrics was first used in this field to analyze the evolution of knowledge structure and forecast future hot topics. The research focus has shifted from the early generation of bioelectric energy to exploring mechanisms of soil remediation and microbial metabolisms, which will be closely integrated in the future. Finally, the future prospects of this field are proposed. This review focuses on the research status of bioelectrochemical degradation of petroleum hydrocarbons and provides a scientific reference for subsequent research.

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.

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.

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.

Combined toxicity is a critical issue in risk assessment of contaminants. However, very little is known about the joint effects of graphene oxide (GO, a crucial 2-dimensional carbon material) and hexavalent chromium (Cr6+, a widespread heavy metal), particularly with respect to the critical period of embryogenesis. In this study, the combined toxicity of GO and Cr6+ was evaluated through embryo-larval toxicity test in Danio rerio (zebrafish). Results indicated that the co-exposure of Cr6+ (1 mg/L) and GO (0.01 mg/L) inhibited hatching and spontaneous movement of embryos, but no significant changes were found in the single Cr6+ or GO group. Compared with the single GO or Cr6+ exposure, their co-exposure (GO+Cr6+) significantly enhanced the teratogenicity in a concentration-dependent pattern, and the spinal curvature was observed as the main deformity. GO+Cr6+ changed the protein secondary structures of embryos result of the generation of ROS and oxidative stress. The degradations of vertical myosepta and cartilages were observed in co-exposure group, suggesting that GO+Cr6+ disrupted the development of musculoskeletal system. The genes col11a1a, col2a1a and postnb were down-regulated but the genes acta1b and mmp9 were up-regulated by GO+Cr6+. The interactions between Cr6+ and GO demonstrated that the morphology, structure, and surface properties of GO were modified by Cr6+. The enhanced defects and O-containing groups of GO could trap more β-sheets, induced oxidative stress, disturbed the development of skeletal muscles and cartilages in zebrafish. These data suggested that GO+Cr6+ enhanced their joint toxicity due to the variation of nanoparticle properties. This finding is important for assessing the ecological risk of graphene family nanomaterials in the natural environment.

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).

Manure, soil, and vegetable samples were collected from different-sized livestock farms in Xinxiang, China. The residues of sulfadiazine, sulfamonomethoxine, and sulfamethoxazole were analyzed by high-performance liquid chromatography. The results indicated that the concentration ranges of the three total sulfonamides in manure, soil, and vegetables were 10.13–566.23 µg kg−1, 7.60–176.26 µg kg−1, and 0–32.70 µg kg−1, respectively. The mean concentrations were 219.71 µg kg−1, 70.73 µg kg−1, and 7.08 µg kg−1 for manure, soil, and vegetables, respectively. The mean concentrations in soil were lower than the ecotoxic effect trigger value (100 µg kg−1), indicating a low risk for organisms in soil. The concentrations of the three sulfonamides varied significantly in different types of vegetables and all were lower than the acceptable daily intake value (50 µg (kg day)−1). However, the potential ecotoxicity and danger to human and animal health via accumulation of the antibiotic in the food chain cannot be ignored.

Predicting the biological responses to engineered nanoparticles (ENPs) is critical to their environmental health assessment. The disturbances of metabolic pathways reflect the global profile of biological responses to ENPs but are difficult to predict due to the highly heterogeneous data from complicated biological systems and various ENP properties. Herein, integrating multiple machine learning models and metabolomics enabled accurate prediction of the disturbance of metabolic pathways induced by 33 ENPs. Screening nine typical properties of ENPs identified type and size as the top features determining the effects on metabolic pathways. Similarity network analysis and decision tree models overcame the highly heterogeneous data sources to visualize and judge the occurrence of metabolic pathways depending on the sorting priority features. The model accuracy was verified by animal experiments and reached 75%-100%, even for the prediction of ENPs outside of databases. The models also predicted metabolic pathway-related histopathology. This work provides an approach for the quick assessment of environmental health risks induced by known and unknown ENPs.

The increasing production and applications of graphene oxide (GO, a novel carbon nanomaterial) have raised numerous environmental concerns regarding its ecological risks. Triphenyl phosphate (TPhP) disperses in water and poses an increasing hazard to the ecosystem and human health. It is critical to study the environmental responses and molecular mechanisms of GO and TPhP together to assess both chemicals; however, this information is lacking. The present work revealed that GO promoted the bioaccumulation of TPhP in zebrafish larvae by 5.0%-24.3%. The TPhP-induced growth inhibition of embryos (malformation, mortality, heartbeat, and spontaneous movement) at environmentally relevant concentrations was significantly amplified by GO, and these results were supported by the downregulated levels of genes and proteins associated with cytoskeletal construction and cartilage and eye development. TPhP induced negligible alterations in the genes or proteins involved in oxidative stress and apoptosis, but those related proteins were all upregulated by GO. GO and TPhP coexposure activated the mTOR signaling pathway and subsequently promoted apoptosis in zebrafish by potentiating the oxidative stress induced by TPhP, presenting synergistic toxicity. These findings highlight the potential risks and specific molecular mechanisms of combining emerging carbon nanomaterials with coexisting organic contaminants.

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.

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.

Sudan I-IV as synthetic azo dyes have been concerned worldwide and ever caused a panic on food safety because of illegal addition into foodstuffs. In the past decades, various methods are being developed to identify and determine Sudan dyes in foodstuffs. However, relevant studies about their biogeochemical behaviors and potential environmental effects are rarely reported, although it is of great importance and necessity accounting for their potential environmental contamination from various sources. In this work, the experimental studies on adsorption behavior of Sudan I-IV acting on soil (10, 25, 50, 75, and 100 mg/L) were carried out, and their transport in soil compartments and between soil-water, and air-soil interfaces were discussed. Results showed that the amount of Sudan I-IV adsorbed on soil increased accordingly with the increasing concentration of Sudan dyes in aqueous solution, and Sudan II and IV were more likely adsorbed on the tested soils than Sudan I and III based on their maximum adsorption amount. However, for Sudan I, III, and IV, in some high concentrations (under the treatment of 75 mg/L for Sudan III, 100 mg/L for Sudan I and IV), the adsorption was significantly increased, and then came back to the "normal" level (under the treatment of 100 mg/L for Sudan III). It is expected that relevant researches on their biogeochemical behaviors in soil compartments, and between soil-water and air-soil interfaces would be concerned and addressed.

Effects of sewage sludge biochars (SSBCs) on the growth of wheat and the specific toxicological mechanisms were investigated from a metabolic perspective for better ecological risk assessment. We observed that conversion of sludge to biochar remarkably changed the properties, and also caused a significant (p 0.05) reduction of the toxicity towards wheat. Wheat growth under exposure to SSBCs was influenced by the pyrolysis temperature (300 °C, 500 °C and 700 °C), with root length being promoted by SSBCs prepared at higher temperatures (500 °C and 700 °C). In addition to the contaminants, including polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) detected in SSBCs, the morphological characteristics of biochars contributed substantially to the wheat growth. Metabolomics analysis revealed the remarkable differences in the metabolic profiles among the control (CK), SS300- and SS700-treated samples. The toxicological mechanisms involved were found to be associated with the regulation of metabolisms pathways of protein, fatty acids and carbohydrates, among which protein metabolism was most affected by SSBCs. This work presents an innovative concept that SSBCs produced at a proper temperature may minimize the toxic effects on plant growth by regulating the metabolic fluxes in vivo.

Graphene oxide (GO) will enter the soil environment in increasing amounts. The effects of GO on the dissipation of benzo[a]pyrene (B[a]P) from contaminated soil and their phytoremediation system have been explored in this study. B[a]P is a ubiquitous soil pollutant used as a representative indicator of polycyclic aromatic hydrocarbons. A pot experiment was performed to investigate the effects of GO or/and vegetation (Tagetes patula) on B[a]P dissipation and the associated bacterial communities in soil. The bacterial communities in soil were investigated by Illumina sequencing analysis. The presence of vegetation significantly enhanced the dissipation of B[a]P from soil. The addition of GO (100 mg/kg) significantly decreased the B[a]P dissipation. When vegetation and GO coexisted, the inhibition effects of GO on B[a]P dissipation were alleviated by vegetation. Compared with the control treatment, the presence of GO or vegetation had no significant effects on the richness and diversity of bacterial communities in B[a]P-contaminated soil. Compared with the presence of only vegetation, the richness and diversity all significantly decreased when vegetation and GO coexisted. And, vegetation had a greater influence on the bacterial community composition than GO. Vegetation alleviated the inhibition effects of GO on B[a]P dissipation and had a greater influence on the associated bacterial communities than GO. This work helps to understand the interactive effects of GO and vegetation on B[a]P dissipation and the associated bacterial communities in contaminated soil.

Oil spills occur frequently worldwide, resulting in severe damage to water and to human health. Polycyclic aromatic hydrocarbons (PAHs) are the primary toxic components in oil contamination. PAH-degrading microbes have attracted significant attention, but difficulty in their selection and proliferation limits their applications. Graphene oxide quantum dots (GOQDs) improve the proliferation of an indigenous PAH-degrading strain, Bacillus cereus, more effectively than large graphene oxide flakes. Bacillus cereus can metabolize a variety of xenobiotic aromatic compounds as carbon sources and is used in bioremediation. GOQDs contain a variety of aromatic hydrocarbon structures, explaining why the bacteria achieve strong tolerance to PAHs. GOQD-activated cytokinesis increases the secretion of substances important for biofilm formation (extracellular polymeric substances), which further accelerates PAH removal. Proteomic analysis reveals the molecular mechanisms underlying GOQD-induced microbial proliferation. GOQDs induce the overexpression of microbial divisomal proteins associated with division initiation, DNA replication and peptidoglycan hydrolysis/synthesis. Importantly, PAH removal mediated by GOQD-treated Bacillus cereus does not require the addition of GOQDs. The effects of GOQDs on a strain persist for at least 20 generations, suggesting their possible use in low-cost applications. This work proposes a strategy to remove oil contamination using an indigenous bacterial system enhanced by nanomaterials.

With the wide use of graphene-like nanosheets, especially in agriculture, their release into the environment, it is crucial to grasp the fate of nanosheets in soil and minimum ecological risks. The present work discovered that leaching and migration of nanosheets (rGO) in soil is affected by soil porosity and adsorption processes. And the contents of rGO−Pd in soil layers and leachate increased and then decreased with the decreased of soil porosity. Moreover, physicochemical properties of rGO−Pd nanosheets changed by leaching processes, especially the changes of morphology, thickness and oxygen functional groups. Leaching of rGO−Pd also interfered the soil microbial homeostasis accompanied by the increase of microbial species richness and community diversity. In addition, rGO−Pd altered the usage of carbon sources by edaphon. The utilization of carbon sources by soil microbes, such as polymers, sugars, phenolic acids, carboxylic acids, amino acids, and amines, was also reduced by nanosheets. These findings provide new insights into environmental behaviors of nanomaterials and nanogeochemistry.

In the past two decades, more and more attentions have been paid to soil-derived greenhouse gases (GHGs) including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) because there are signs that they have rising negative impacts on the sustainability of the earth surface system. Farmlands, particularly paddy soils, have been regarded as the most important emitter of GHGs (nearly 17%) due to a large influx of fertilization and the abundance in animals, plants and microorganisms. Geobacter, as an electroactive microorganism widely occurred in soil, has been well studied on electron transport mechanisms and the direct interspecies electron transfer. These studies on Geobacter illustrate that it has the ability to be involved in the pathways of soil GHG emissions through redox reactions under anaerobic conditions. In this review, production mechanisms of soil-derived GHGs and the amount of these GHGs produced had been first summarized. The cycling process of CH4 and N2O was described from the view of microorganisms and discussed the co-culture relationships between Geobacter and other microorganisms. Furthermore, the role of Geobacter in the production of soil-derived GHGs is defined by biogeochemical cycling. The complete view on the effect of Geobacter on the emission of soil-derived GHGs has been shed light on, and appeals further investigation.

Pot experiments were conducted to evaluate the phytoremediation of B[a]P contaminated soil using two ornamental plants (Tagetes patula and Mirabilis jalapa). The results showed that the dry biomass of two plants was increased at low B[a]P contaminated soil and then inhibited with increasing B[a]P concentrations. It exhibited a significantly positive linear relationship between B[a]P absorption in roots, stems, leaves and shoots of the tested plants and the concentration of B[a]P in soils (P

Bioelectrochemical system is an emerging technology for the remediation of soils contaminated by petroleum hydrocarbons. However, performance of such systems can be limited by the inefficient mass transport in soil. Here we report a new method of sand amendment, which significantly increases both oxygen and proton transports, resulting to increased soil porosity (from 44.5% to 51.3%), decreased Ohmic resistance (by 46%), and increased charge output (from 2.5 to 3.5Cg(-1)soil). The degradation rates of petroleum hydrocarbons increased by up to 268% in 135d. The degradation of n-alkanes and polycyclic aromatic hydrocarbons with high molecular weight was accelerated, and denaturing gradient gel electrophoresis showed that the microbial community close to the air-cathode was substantially stimulated by the induced current, especially the hydrocarbon degrading bacteria Alcanivorax. The bioelectrochemical stimulation imposed a selective pressure on the microbial community of anodes, including that far from the cathode. These results suggested that sand amendment can be an effective approach for soil conditioning that will enhances the bioelectrochemical removal of hydrocarbons in contaminated soils.

The environmental release of graphene oxide (GO) will certainly induce the GO exposure to plants. To date, the influence of GO on the intracellular structures and the endophytic bacterial ecology of plants have been rarely reported. In the present study, the rice seedlings were exposed to GO (5 mg/L) under hydroponic condition for fifteen days with periodic stir. The cellular structures damage, GO deposition and oxidative stress were found in rice root after GO exposure. A Illumina analysis based on the bacterial 16 S rRNA gene showed that the richness, evenness and diversity of endophytic bacterial communities of rice root decreased due to GO exposure. The relative abundance of beneficial endophytic bacterial populations decreased after GO exposure. Out of potential phenotypes predicted by BugBase, the relative abundance of Gram negative, stress-tolerant and biofilm-forming phenotypes, presented an increase trend after GO exposure.

The effects of graphene oxide (GO) carbon nanomaterials on ecosystems have been well characterized, but the toxicity of GO at predicted environmental concentrations to living organisms at the protein level remain largely unknown. In the present work, the adverse effects and mechanisms of GO at predicted environmental concentrations were evaluated by integrating proteomics and standard analyses for the first time. The abundances of 243 proteins, including proteins involved in endocytosis (e.g., cltcb, arf6, capzb and dnm1a), oxidative stress (e.g., gpx4b, sod2, and prdx1), cytoskeleton assembly (e.g., krt8, krt94, lmna and vim), mitochondrial function (e.g., ndufa10, ndufa8, cox5aa, and cox6b1), Ca2+ handling (e.g., atp1b2a, atp1b1a, atp6v0a1b and ncx4a) and cardiac function (e.g., tpm4a, tpm2, tnni2a.1 and tnnt3b), were found to be notably altered in response to exposure 100 μg/L GO. The results revealed that GO caused malformation and mortality, likely through the downregulation of proteins related to actin filaments and formation of the cytoskeleton, and induced oxidative stress and mitochondrial disorders by altering the levels of antioxidant enzymes and proteins associated with the mitochondrial membrane respiratory chain. Exposure to GO also increased the heart rate of zebrafish larvae and induced pericardial edema, likely by changing the expression of proteins related to Ca2+ balance and cardiac function. This study provides new proteomic-level insights into GO toxicity against aquatic organisms, which will greatly benefit our understanding of the bio-safety of GO and its toxicity at predicted environmental concentrations.

Veterinary antibiotics introduced into soil environment may change the composition and functioning of soil microbial communities and promote the spreading of antibiotic resistance. Actual risks depend on the antibiotic’s bioaccessibility and sequestration in soils, which may vary with contact time and soil properties. We elucidated changes in the horsebean plant’s bioaccessible oxytetracycline with increasing contact time in three different soils (cinnamon, red, and brown soil) and observed discrepancy in oxytetracycline dissipation using sequential extractions with H2O-, 0.01 M CaCl2-, and Mcllvaine- in the same three soils. The results showed lower quantities of oxytetracycline with increasing contact time over 20 days than the level in freshly contaminated soils but hugely discrepant quantities among the three tested soils. In addition, aging largely reduced dissipation of H2O-, 0.01 M CaCl2-, and Mcllvaine- extracted oxytetracycline in soils before planting. However, bioturbation helped increase the H2O-, CaCl2-, and Mcllvaine- extracted oxytetracyline from cinnamon and brown soils with aging. Lastly, correlation analysis indicated that bioaccessibility of oxytetracycline significantly correlates with the total of H2O-, CaCl2-, and Mcllvaine- extracted oxytetracycline (0.676**, p

The concentrations of total petroleum hydrocarbons (TPH), n-alkanes (n-C8 through n-C40), and 16 polycyclic aromatic hydrocarbons (PAHs) in soils were determined to assess the level of organic contamination in soils from the Da-gang Petrochemical Industry Park with several big state-run enterprises, a recent rapid flourishing park in China. The results showed that the concentration of TPH in soil was high, up to 20 ng/g-12.8478%; in particular, the content in most sites ranged from 1 to 2%. Thus, it is clear that soil environment in the Da-gang Petrochemical Industry Park has been seriously polluted by TPH according to the Nemerow pollution index method. Furthermore, the average concentration of Σ(n-C>16 through n-C34) in 30 sampling sites was above the maximum limit set for F3 under all the conditions in the Canada-wide standards for petroleum hydrocarbons (PHC CWS) with 43.33-93.33% soil samples exceeding F3 standards, and n-alkanes possessing higher concentrations were proved much abundant alkanes in this study. Besides, the predominance of even n-alkanes and lower carbon preference index (CPI) demonstrated that n-alkanes in surface soils were mainly caused by anthropogenic inputs, while the concentration of Σ16-PAHs was in the range of 1652.5-8217.3 ng/g and the BaA/(BaA + Chr) and Flu/(Flu + Pyr) ratios indicated that pyrogenic PAHs may be the dominant PAHs in most soils with the contribution of petrogenic hydrocarbons in some sites.

Sawdust and wheat straw biochars prepared at 300°C and 500°C were applied to petroleum-polluted soil for an 84-day incubation to estimate their effectiveness on polycyclic aromatic hydrocarbons (PAHs) removal. Biochars alone were most effective at reducing PAHs contents. However, adding biochar to soils in company with NaN3 solution resulted in a decreasing trend in terms of PAHs removal, which was even lower than treatment CK without biochar. Moreover, it was discovered by PCR-DGGE files and sequencing analysis that the predominant bacterial diversity slightly decreased but the abundance of some specific taxa, including PAHs degraders, was promoted with biochar input. These results highlighted the potential of biochar application on accelerating PAHs biodegradation, which could be attributed to the properties of biochars that benefit for making the amended soil a better habitat for microbes. The impacts of biochar preparation and pollutants nature on PAHs removal were also determined. Significant reduction in the PAHs contents was detected when adding biochar prepared at a high temperature (500°C), while the feedstocks of biochar showed little effect on PAHs removal. Due to the high hydrophobicity of aromatic rings, high-molecular weight PAHs were found much more resistant to microbial degradation in comparison with low-molecular weight PAHs.

With the aim of in situ bioremediation of soil contaminated by hydrocarbons, anodes arranged with two different ways (horizontal or vertical) were compared in microbial fuel cells (MFCs). Charge outputs as high as 833 and 762C were achieved in reactors with anodes horizontally arranged (HA) and vertically arranged (VA). Up to 12.5 % of the total petroleum hydrocarbon (TPH) was removed in HA after 135 days, which was 50.6 % higher than that in VA (8.3 %) and 95.3 % higher than that in the disconnected control (6.4 %). Hydrocarbon fingerprint analysis showed that the degradation rates of both alkanes and polycyclic aromatic hydrocarbons (PAHs) in HA were higher than those in VA. Lower mass transport resistance in the HA than that of the VA seems to result in more power and more TPH degradation. Soil pH was increased from 8.26 to 9.12 in HA and from 8.26 to 8.64 in VA, whereas the conductivity was decreased from 1.99 to 1.54 mS/cm in HA and from 1.99 to 1.46 mS/cm in VA accompanied with the removal of TPH. Considering both enhanced biodegradation of hydrocarbon and generation of charge in HA, the MFC with anodes horizontally arranged is a promising configuration for future applications.

Triclosan (TCS) is released into the terrestrial environment via the application of sewage sludge and reclaimed water to agricultural land. More attention has been paid to its effect on non-target soil organisms. In the present study, chronic toxic effects of TCS on earthworms at a wide range of concentrations were investigated. The reproduction, DNA damage, and expression levels of heat shock protein (Hsp70) gene of earthworms were studied as toxicity endpoints. The results showed that the reproduction of earthworms were significantly reduced (p < 0.05) after exposure to the concentrations ranges from 50 to 300 mg kg(-1), with a half-maximal effective concentration (EC50) of 142.11 mg kg(-1). DNA damage, detected by the comet assay, was observed and there was a clear significant (R(2) = 0.941) relationship between TCS concentrations and DNA damage, with the EC50 value of 8.85 mg kg(-1). The expression levels of Hsp70 gene of earthworms were found to be up-regulated under the experimental conditions. The expression level of hsp70 gene increased, up to about 2.28 folds that in the control at 50 mg kg(-1). The EC50 value based on the Hsp70 biomarker was 1.79 mg kg(-1). Thus, among the three toxicity endpoints, the Hsp70 gene was more sensitive to TCS in soil.

The selection and breeding of lead pollution-safe cultivars (Pb-PSCs) has been used to minimize the influx of Pb into the human food chain. We examined the growth response of 23 selected soybean cultivars to various lead concentrations and also assessed their tolerance to lead. Variations in uptake, enrichment, and translocation of lead among these cultivars were studied to screen out soybean Pb-PSCs. The results indicated that the seed Pb concentrations under three Pb treatments (500, 1,000, and 2,000 mg kg(-1)) varied significantly (P0.05), with average values of 0.20, 0.25, and 0.33 mg kg(-1), respectively. Cultivars Shennong 6, Shennong 8, Tiefeng 29, Tiefeng 37, Ji 1005, Liaodou 15, and Suke 1 were found to fit the criteria for Pb-PSCs. The seeds of these seven cultivars were further assessed for interactions between Pb and other mineral nutrient elements such as Ca, Cu, Fe, Mg, Mn, and Zn. High lead concentration in soil was found to inhibit the uptake of Ca, Cu, Fe, Mg, and Zn. Furthermore, Mn accumulation was found to be enhanced in the seeds of all of the seven Pb-PSCs in response to high Pb concentration.

To better assess and understand potential health risk of urban residents exposed to urban street dust, the total concentration, sources, and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in 87 urban street dust samples from Tianjin as a Chinese megacity that has undergone rapid urbanization were investigated. In the meantime, potential sources of PAHs were identified using the principal component analysis (PCA), and the risk of residents' exposure to PAHs via urban street dust was calculated using the Incremental Lifetime Cancer Risk (ILCR) model. The results showed that the total PAHs (∑PAHs) in urban street dust from Tianjin ranged from 538 μg kg(-1) to 34.3 mg kg(-1), averaging 7.99 mg kg(-1). According to PCA, the two to three- and four to six-ring PAHs contributed 10.3 and 89.7 % of ∑PAHs, respectively. The ratio of the sum of major combustion specific compounds (ΣCOMB) / ∑PAHs varied from 0.57 to 0.79, averaging 0.64. The ratio of Ant/(Ant + Phe) varied from 0.05 to 0.41, averaging 0.10; Fla/(Fla + Pyr) from 0.40 to 0.68, averaging 0.60; BaA/(BaA + Chry) from 0.29 to 0.51, averaging 0.38; and IcdP/(IcdP + BghiP) from 0.07 to 0.37, averaging 0.22. The biomass combustion, coal combustion, and traffic emission were the main sources of PAHs in urban street dust with the similar proportion. According to the ILCR model, the total cancer risk for children and adults was up to 2.55 × 10(-5) and 9.33 × 10(-5), respectively.

Ethylbenzene is classified as a priority pollutant; however, toxicity data, especially those regarding sublethal toxicity, are rarely reported on gastropods. The present work was performed to elucidate the sublethal effects of ethylbenzene using a freshwater snail, Bellamya aeruginosa (Reeve), exposed to ethylbenzene for 21 days followed by a 17-day recovery period. Superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), reduced glutathione (GSH), and malonyldialdehyde (MDA) were used as biomarkers to evaluate oxidative stress in hepatopancreas of snails. In addition, alkaline comet assay was applied to determine the genotoxicity of ethylbenzene in hepatopancreas of snails. These biomarkers and DNA damage exhibited various responses to ethylbenzene in the tested snails. SOD and CAT activities were almost significantly stimulated during the exposure period. As exposure time was prolonged beyond 7 days, CAT activity gradually became significantly increased at higher doses of ethylbenzene. GSH concentration was positively and linearly related with exposure dose. MDA concentration was significantly greater than that in the control only under the lowest treatment after a 7-day exposure. Alkaline comet assay showed that ethylbenzene could significantly induce DNA damage in hepatopancreas of snails, and there was a good dose- and time-response in DNA damage, indicating potential genotoxicity of ethylbenzene on snails. At the end of the recovery period, the repair of DNA damage was not yet completed, showing that DNA repair requires more time. The findings from this study could indicate that SOD, GST, and GSH seem to be effective oxidative biomarkers for snails exposed to ethylbenzene in the short term. CAT proved to be a valuable discriminating biomarker in subchronic exposure to ethylbenzene, but MDA was not a suitable oxidative biomarker for exposure to ethylbenzene in either the short or long term. Alkaline comet assay was efficient tool with which to evaluate the potential genotoxicity of ethylbenzene.

This study aims to evaluate toxic effects of exposure to chlortetracycline (CTC) in soil on reproductive endpoints (juvenile counts and cocoon counts), biochemical responses, and genotoxic potentials of the earthworm Eisenia fetida. Results showed that juvenile counts and cocoon counts of the tested earthworms were reduced after exposure to CTC. The effective concentrations (EC(50) values) for juvenile and cocoon counts were 96.1 and 120.3 mg/kg, respectively. Treatment of earthworms with CTC significantly changed the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione S-transferase (GST). An increase in malondialdehyde (MDA) indicated that CTC could cause cellular lipid peroxidation in the tested earthworms. The percentage of DNA in the tail of single-cell gel electrophoresis of coelomocytes as an indication of DNA damage increased after treatment with different doses of CTC, and a dose-dependent DNA damage of coelomocytes was found. In conclusion, CTC induces physiological responses and genotoxicity on earthworms.

Although organophosphate flame retardants (OPFRs) have been shown to accumulate in abiotic and biotic environmental compartments, data about OPFRs concentrations in various foods are limited and are none in humans through diets. In this work, the concentrations of 6 typical OPFRs were investigated in 50 rice samples, 75 commonly consumed foods and 45 human hair samples from China. The dietary intakes of OPFRs for adult people via food ingestion were estimated. The concentrations of ΣOPFRs in foods ranged from 0.004ng/g to 287ng/g. OPFRs were detected in 53.3% of the human hair samples. The highest OPFRs concentrations were found in rice and vegetables. Tri(2-chloroethyl)phosphate(TCEP), tris(2-chloroisopropyl)phosphate(TCIPP), and tri(2-ethyltexyl)phosphate(TEHP) were predominant in all food samples. OPFRs concentrations in foods were not significantly affected by the packaging materials. The mean dietary intakes of ΣOPFRs for adult males and females were 539 and 601ng/kg body weight/day, respectively. The greatest contribution to these values is from rice, accounting for approximately 60% of the total intake, particularly from rice protein. Rice ingestion was considered a potential major pathway for human exposure to OPFRs, and regional differences in the levels of OPFRs in foods and dietary differences should be given more attention in the future.

Polycyclic aromatic hydrocarbons (PAHs) in the surface urban soils of Shenyang in Northeastern China were investigated. The total concentration of the PAHs ranged from 0.09 to 8.35 mg kg−1, with an average value of 1.51 ± 1.64 mg kg−1. 3–5-ring PAHs accounted for 90% of total PAHs. The functional areas, such as the industrial regions (4.95 mg kg−1) and main roads (1.56 mg kg−1), as well as the administrative divisions, including the districts of Shenhe (1.49 mg kg−1), Heping (2.08 mg kg−1), and Tiexi (2.14 mg kg−1), were heavily polluted by PAHs. The diagnostic ratios and principal component analysis (PCA) for PAHs indicate that the pollutants probably originated primarily from coal combustion and petroleum sources. The Nemerow composite index, used to assess environmental quality, shows that the soil samples were heavily polluted with PAHs, and although 52.8% of the soil sampling sites were safe, 47.2% of the soil sampling sites registered different grades of PAH pollution. The PAH contamination in Sheny...

The growth, photosynthesis rate, and ultrastructure of Mirabilis jalapa L. as a newly-found remediation species under stress of nitrobenzene (NB) and its uptake and removal of NB by the plants were investigated. The results showed that M. jalapa plants could endure contaminated soils by lower than 10.0mgNBkg -1 because there was no decrease in the total length of the plant roots, the maximum length of the hypocotyle, the length of the first seminal root, the height of the shoots and the dry biomass of the seedlings as well as the photosynthesis rate of the plants compared with those in the control. In particular, the growth of the plants could be significantly (P

The objective of this study was to assess potential toxic effects of simulated urban runoff on Carassius auratus using oxidative stress biomarkers. The activity of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the content of malondialdehyde (MDA) in the liver of C. auratus were analyzed after a 7-, 14- and 21-day exposure to simulated urban runoff containing galaxolide (HHCB) and cadmium (Cd). The results showed that the activity of antioxidant enzymes and the content of MDA increased significantly exposed to the simulated urban runoff containing HHCB alone or mixture of HHCB and Cd. The activity of the investigated enzymes and the content of MDA then returned to the blank level over a longer period of exposure. The oxidative stress could be obviously caused in the liver of C. auratus under the experimental conditions. This could provide useful information for toxic risk assessment of urban runoff.

The toxic effect of the oxidation hair dyes on Phanerochaete chrysosporium was investigated by exposure of this fungus in a nitrogen-limited culture medium to various concentrations of the oxidation hair dyes.The results showed that both the size and the dry weight of the mycelial pellets of P. chrysosporium could be reduced when the concentration of the oxidation hair dyes was higher than 300 mg/L. By using the AFLP analysis and the UPGMA dendrogram, the DNA damage of P. chrysosporium by the oxidation hair dyes was also detected. Comparing with that in the control, the percent polymorphism under different concentrations of the oxidation hair dyes increased. In the meantime, the DNA similarity was decreased, which meant that the DNA damage was aggravated with an increase in the concentrations of the oxidation hair dyes.Thus, as an environmental pollutant, the oxidation hair dyes have a toxic effect on P. chrysosporium at both cellular and molecular levels.

Screening out cadmium (Cd) excluding cultivars of a crop in agricultural production is an effective way to prohibit Cd entering into food chain.A judging criterion for Cd-excluding cultivars based on food safety was suggested and used in the identification of Cd-excluding welsh onion (Allium fistulosum L.) cultivars. A pot culture experiment was carried out to screen out Cd-excluding cultivars, of which the results were confirmed by plot experiments. The relevant factors of Cd accumulation in the pseudostem were analyzed and used in the correlation analysis aiming to study the low Cd accumulation mechanisms.The concentration of Cd in the pseudostem of welsh onions was 0.08-0.20, 0.18-0.41, and 0.26-0.61 mg/kg fresh weight (FW) under three treatments (1.0, 2.5, and 5.0 mg/kg), respectively. The significant (p0.05) difference in the concentration of Cd in the pseudostem was observed among 25 welsh onion cultivars, but Cd contamination in soil had little influence on biomass and the contents of soluble sugar, NO(3)(-)-N, and eight other elements in the tested welsh onion cultivars. Two cultivars were identified as Cd-excluding cultivars, mainly because the accumulation of Cd in their pseudostem was only 0.041 ± 0.003 and 0.046 ± 0.002 mg/kg FW, and 0.054 ± 0.001 and 0.066 ± 0.011 mg/kg FW, when growing in plots with Cd concentration of 0.49 and 0.99 mg/kg, respectively.Ribentiegancongwang and Wuyeqi could be identified as Cd-excluding cultivars. Low bioaccumulation factor of the roots was the main mechanism of Cd-excluding welsh onion cultivars.

Little information is available about the toxicity of toluene, ethylbenzene and xylene acting on macrophytes, and their toxicity data are rarely used in regulation and criteria decisions. The results extended the knowledge on toxic effects of toluene, ethylbenzene and xylene on aquatic plants. The responses of Hydrilla verticillata to these pollutants were investigated. Chlorophyll levels, lipid peroxidation, and antioxidant enzymes (superoxide dismutase and guaiacol peroxidase) showed diverse responses at different concentrations of toluene, ethylbenzene and xylene. The linear regression analyses were performed respectively, suggesting the concentrations of toluene, ethylbenzene and xylene expected to protect aquatic macrophytes were 7.30 mg L⁻¹, 1.15 mg L⁻¹ and 2.36 mg L⁻¹, respectively. This study emphasized that aquatic plants are also sensitive to organic pollutants as fishes and zooplanktons, indicating that macrophytes could be helpful in predicting the toxicity of these pollutants and should be considered in regulation and criteria decisions for aquatic environment protection.

The heavy use of organophosphorus pesticides in northeastern China strongly affects the ecological functions and the quality of the soil environment. In this work, a 30-day soil incubation experiment was conducted to evaluate the potential of using soil available P and the activities of soil dehydrogenase and acid phosphatase as indicators of the application of methamidophos and glyphosate. Two kinds of unpolluted soils, phaiozem and burozem, were selected as the test soils. The higher application rate of organophosphorus pesticide to the two soils caused more release of PO4 3− which finally entered the soil available P pool, suggesting that soil available P is one of the effective chemical markers for biodegradation of organophosphorus pesticides. Methamidophos exhibited a significant inhibitory effect on the activity of soil dehydrogenase. The extent of enzyme inhibition was almost positively correlated with the insecticide concentration, and the enzyme activity was gradually restored after day 15. Howe...