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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.

Clubroot caused by Plasmodiophora brassicae is an important disease on cruciferous crops worldwide. Management of clubroot has been challenging, due largely to the millions of resting spores produced within an infected root that can survive dormant in the soil for many years. This study was conducted to investigate some of the environmental conditions that may affect the survival of resting spores in the soil. Soil samples containing clubroot resting spores (1 × 107 spores g-1 soil) were stored at various temperatures for two years. Additionally, other samples were buried in soil, or kept on the soil surface in the field. The content of P. brassicae DNA and the numbers of viable spores in the samples were assessed by quantitative polymerase chain reaction (qPCR) and pathogenicity bioassays, respectively. The results indicated that 4°C, 20°C and being buried in the soil were better conditions for spore survival than were −20°C, 30°C and at the soil surface. Most of the spores kept on the soil surface were killed, suggesting the negative effect of light on spore viability. Additional experiments confirmed that ultraviolet (UV) light contributed a large negative effect on spore viability as lower pathogenicity and less DNA content were observed from the 2-and 3-hour UV light treated spores compared to the untreated control. Finally, this work demonstrated that DNA-based quantification methods such as qPCR can be poor predictors of P. brassicae disease potential due to the presence and persistence of DNA from dead spores.

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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.

Ordered mesoporous Ag/CeO 2 nanocomposites were prepared by combining nanocasting with photo-assisted reduction. The heterogeneous photoreactivity of the prepared samples was tested for inactivating Escherichia coli ( E. coli ). These mesoporous Ag/CeO 2 nanocomposites exhibited superior photocatalytic disinfection efficiency than mesoporous CeO 2 and bulk CeO 2 , respectively. Doping Ag species could extend the absorption range to visible light area and enhance the concentration of Ce 3+ ions and oxygen vacancies, which had significant influence on the surface properties of CeO 2 . Moreover, it is the first time to verify that created midgap states through doping Ag can significantly lower the threshold of incident photon energy and broaden the adsorption spectrum demonstrated by experimental studies and density functional theory (DFT) calculations. The enhanced disinfection mechanism was attributed to the fact that the novel mesoporous structure can promote the mass transfer process and the interfacial interaction between Ag species and CeO 2 and lead to reduced recombination of free charges, rapid separation and transportation of photogenerated electrons-holes. This work provides a new method to develop novel mesoporous plasmonic photocatlysts for disinfection using solar radiation.

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.

Soybean (Glycine max (L.) Merr.) has excellent potential as an alternative crop to canola in southern Alberta farming systems. However, soybean is susceptible to Fusarium root rot, which usually results in the occurrence of dead or dying plants in mid-to-late summer and severe reductions in yield. A total of 102 isolates identified as Fusarium were recovered from diseased soybean root samples collected from central and southern Alberta from 2011 to 2013. Ten species of Fusarium were identified, with F. acuminatum as the predominant species (31 out of 102 isolates, 30.39%), followed by F. equiseti (16.67%), F. culmorum (13.73%), F. avenaceum (10.78%), F. oxysporum (8.82%), F. redolens (7.84%), F. torulosum (4.90%), F. tricinctum (2.94%), F. commune (1.96%) and F. proliferatum (0.98%). This is the first report of F. commune, F. redolens and F. torulosum causing root rot in soybean in Canada. Phylogenetic analyses based on sequence data from the translation elongation factor 1-α (EF-1α) and the internal transcribed spacer (ITS) region were used to evaluate genetic variation and, in conjunction with morphological characters, for species identification. All of the Fusarium isolates were able to infect soybean, although some exhibited varying levels of aggressiveness.

Phytoremediation has attracted increasing attention and is a promising technology for addressing soil contamination problems. Unlike other kinds of remediation plants, ornamental plants grown for decorative purposes in gardens and landscape design projects have been an important source of remediation plants in recent years. In addition to beautifying the environment, some ornamental plants can not only grow well but also accumulate or degrade contaminants when growing in soil contaminated with heavy metals or organic pollutants. Especially in contaminated urban areas, it is comparatively rare and commendable when remediation plants with ornamental value are applied. In this review, we summarized the current research on the phytoremediation of contaminated soils using ornamental plants, evaluated the phytoremediation capacity of ornamental plants in heavy-metal and organic pollutant-contaminated soils, and highlighted specific ornamental plants with a strong accumulation ability and tolerance to pollutants. The findings related to the main mechanisms of the phytoremediation of contaminated soils were explained. Enhancement measures aimed at promoting the bioavailability of contaminants and the tolerance of ornamental plants were also reviewed in this article. It is hoped that this study will draw attention to a new path for phytoremediation technology.

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.

The accumulation of oxytetracycline (OTC) in rice plants has been found, which may directly threaten food safety. Fe(II) ions are among the most common metal ions in the aquatic and soil environment. There have been no published papers discussing the uptake of OTC in plant exposed to treated solution and soil after adding Fe(II). In this work, the effect of Fe(II) on uptake and translocation of OTC in rice plants (Oryza sativa L.) was investigated. Hydroponic and soil culture were conducted under greenhouse conditions to identify changes in rice biomass, OTC uptake, and translocation exposed to three different OTC concentrations, including 0, 10, and 50 mg·L−1/mg·kg−1 for 30 days. For same OTC exposure treatment, rice seedlings were grown in a nutrient solution or paddy soil with adding four different Fe(II) concentrations, including 0, 10, 30, 50, and 70 mg·L−1/mg·kg−1. The concentrations of OTC in iron plaque (IP) on root surface, root, and shoot were analyzed, and biological concentration factor (BCF) and transfer factor (TF) of OTC were calculated. Adding proper Fe(II) (10–50 mg·L−1 in solution and 10–30 mg·kg−1 in soil) alleviated the inhibition function of OTC on rice growth. IP was formed with high amounts after adding Fe(II) although OTC decreased IP amounts. OTC concentration in IP increased with increasing Fe(II) addition. OTC translocation from root surface to root presented a declining trend with increasing Fe(II) concentration. Fe(II) addition inhibited effectively OTC uptake by rice exposed to high OTC of 50 mg·L−1/mg·kg−1 in solution or soil. PCA and correlation analysis showed that the decrease of OTC accumulation in rice was determined more strongly by the increase of OTC accumulation in IP. IP acting as a buffer function reduced effectively OTC uptake by rice seedlings due to promoting OTC accumulation on root surface and reducing OTC translocation from root surface to root. Also, Fe(II) addition promoted OTC degradation and reduced OTC bioavailability due to the complexes of OTC and Fe(II), which then decreased OTC uptake by rice. In soil, OTC uptake was affectted more strongly by the decrease of OTC concentrations in rhizosphere than ones in non-rhizosphere.

Molybdenum disulfide (MoS2) poses great potential in water treatment as a popular transition metal dichalcogenide, arousing considerable concern regarding its fates and risk in aquatic environments. This study revealed that the interplay with extracellular polymeric substances (EPS) of freshwater algae significantly changed the properties and toxicity of MoS2 to aquatic fish. The predominant binding of aromatic compounds, polysaccharides, and carboxyl-rich proteins in EPS on the 1T polymorph of MoS2 via hydrophilic effects and the preferential adsorption of carboxylic groups contributed to morphological alterations, structural disorders (band gap and phase alterations), and the attenuated aggregation of MoS2 in aqueous solutions. Electron charge transfer and n-π* interactions with EPS decreased the catalytic activity of MoS2 by inhibiting its capability of generating reactive intermediates. The dissolution of MoS2 slowed down after interacting with EPS (from 0.089 to 0.045 mg/L per day) owing to rapid initial oxidation (i.e., forming Mo-O bond) and carbon grafting. Notably, the morphological and structural alterations after EPS binding alleviated the toxicity (e.g., malformation and oxidative stress) of MoS2 to infantile zebrafish. Our findings provide insights into the environmental fate and risk of MoS2 by ubiquitous EPS in natural waters, serving as valuable information while developing water treatment processes accordingly.

Electronic regulation via interfacial formation is identified as a versatile strategy to improve the electrocatalytic activity. Herein, we report a feasible electrospinning-pyrolysis approach for the in-situ immobilization of Co/MnO hetero-nanoparticles onto N,S co-doped carbon nanotubes/nanofiber-integrated hierarchical branched superstructures (abbreviated as Co/MnO@N,S-C NT/CNFs hereafter). The simultaneous realization of interfacial engineering and nanocarbon hybridization renders the fabricated Co/MnO@N,S-C NT/CNFs with abundant firmly anchored active sites, modified electronic configuration, improved electric conductivity, efficient mass transport pathways, and significantly reinforced stability. Profiting from the compositional synergy and architectural advantages, the Co/MnO@N,S-C NT/CNFs exhibit outstanding ORR activity, superior tolerance to methanol, and excellent long-term stability in KOH electrolyte. More encouragingly, as a proof-of-concept demonstration, the rechargeable aqueous and flexible all-solid-state Zn-air batteries using Co/MnO@N,S-C NT/NFs + RuO2 as the air-cathode afford higher power densities, larger specific capacities and superb cycling stability, outperforming the state-of-the-art Pt/C + RuO2 counterparts. This work demonstrates the great contribution of heterointerfaces for oxygen electrocatalysis.

Microplastics (MPs) are synthetic organic polymers. The particle sizes of MPs range from approximately 0.01 to 5 nm. The photodegradation of MPs is more difficult than that of bulk plastics. Therefore, MPs are regarded as potential persistent organic pollutants. Researches of MPs have become a hot spot, and lots of MPs studies were reported recently. Although there are a lot of studies on the migration, distribution, biological effects and analytical methods of MPs in natural environments, systematic and comprehensive review articles are emergent, especially for the recent literatures. The present work summarized the researches involving the migration, distribution, biological effects and analytical methods of MPs in recent years. MPs are generally divided into two types, primary MPs and secondary MPs. Primary MPs are intentionally designed and produced for certain purposes, while secondary MPs generate from the fragmentations of bulk plastics and the breakage of clothes fibers. Currently, researches of MPs distribution focus on in marine environments, and found that MPs distributed throughout the ocean, even in the north and south poles, driven by the flow of sea water. However, researches of on MPs distribution in fresh water and terrene are limited. Researches also showed that MPs could migrate among terrestrial, freshwater and marine environments, where freshwater environments affected the migration and interaction of MPs between terrene and marine environments. Studies of biological effects of MPs focus on two parts, ingestion effects and combined effects with organic contaminants. Ingestion of MPs damages living beings and then MPs transfer through food chains. The responses of living beings to MPs are mainly related to sublethal effects at environmental-relevant concentrations. The inhibition of individual growth and reproduction, disturbance of proteins and genes, and reduction of nutrition uptake were reported for specific physiological effects of MPs. Some researches proposed that MPs could be accumulated in living organisms. Therefore, humans, as a part of the food chains, will inevitably be affected by MPs. The organic contaminants combine with the MPs released from the plasticizers in the production of MPs and then are adsorbed in the natural environments. MPs have been found in seafood. As a result, MPs become one medium of human exposure to organic pollutants. The analysis and identification of MPs are critical to other researches, such as environmental behaviors and toxicity. In general, the analytical methods of plastic include physical and chemical characterizations. Physical characterizations involve visual, microscopy and spectroscopy methods. Chemical characterization methods, such as differential scanning calorimetry (DSC), gas chromatography mass spectrometry (GC-MS), scanning electron microscope and energy disperse spectroscopy (SEM-EDS), and thermal desorption gas chromatography mass spectrometry (TDS-GC-MS) are frequently used in chemical characterizations. Although lots of analytical methods were proposed by researchers, there are still some shortcomings and limitations, for example, the influence from environmental or biological matrices. It is necessary to develop effective and accurate methods for the analysis of MPs. Through many researches of MPs were reported recently, the information of source, migration, distribution, biological effects and analytical methods of MPs is not enough to scientifically evaluate their environmental and health risks. Consequently, the present review also proposes some perspectives for MPs researches. It is worth to study the distribution of MPs in terrestrial and freshwater environments, the biological effects at individual level, the prevention and control of MPs pollution and the environmental behavior of nanoplastics. Integrating the data of MPs source, distribution, behavior and toxicity is necessary to the scientific evaluations of MPs risks. This review provides insights in the control techniques and theoretical researches of MPs.

Root rot is a major constraint on field pea ( Pisum sativum L.) production. Species of Phytophthora can cause seed rot, pre- and post-emergence damping-off, and stem and root rot in many legume crops, but have not been reported in association with pea root rot in Canada. Following a survey of pea fields in Alberta, Canada, in 2015, root tissue with typical symptoms of root rot was plated onto a growth medium, and one isolate was identified as a putative Phytophthora spp. based on its colony characteristics. The isolate was homothallic, producing smooth, thick-walled oospores and both paragynous and amphigynous antheridia on lima bean agar. The sporangia were ovoid or elliptical, non-papillate, and had internal proliferations. Based on these criteria, the isolate was tentatively identified as Phytophthora sansomeana . Sequencing of the internal transcribed spacer (ITS) and Cox II regions revealed 100% identity with the ITS and Cox II sequences of P. sansomeana available in GenBank, confirming this identification. A pathogenicity test indicated that the isolate was pathogenic and caused pre-emergence damping-off, root discoloration, and root rot with brown to dark brown lesions on pea cultivars. This is the first report of P. sansomeana causing root rot in pea in North America.

The combined effects of the porous structure, acidity, and ion-exchange properties of zeolites and the structures of the degradation products of nitrosamines in aqueous solution on adsorption were evaluated. The degradation products of nitrosamines including the aliphatic low-molecular-weight amines methylamine, dimethylamine, ethylamine, and diethylamine and the aromatic amine aniline all exhibited significant adsorption affinities to HZSM-5 zeolites, and aliphatic low-molecular-weight amines exhibited much greater adsorption affinities to HY zeolite than to NaY and HZSM-5 zeolites, but aromatic amines exhibited little adsorption affinity to HY and NaY zeolites. The results of the pH-dependency experiments further indicated that the acidity and polarity of the adsorbates and the acidity of the adsorbents play a combinational role in determining the significance of the adsorption interactions between low-molecular-weight amines in aqueous solution and zeolites. We propose that the acid–base and electrosta...

A review of the literature published in 2016 on topics relating to water reclamation and reuse is summarized. The review is divided into the following sections: 1) General: monitoring and assessment, social awareness and acceptance, and energy and resources recovery; 2) Treatment technology: integrated technologies, membrane treatment, reactors, WSPs, disinfection, and others; 3) Planning and Management: modeling, LCA, GHG emission, and case studies. Much of the water treatment research focused on the integrated technologies and membrane treatment.

The thorny issue of membrane biofouling in membrane bioreactors (MBR) calls for new effective control measures. Herein, D-amino acid (DAA) was employed to mediate MBR membrane biofouling by inhibiting biofilm information and disintegrating formed biofilm. Different DAA control ways involving membrane property, DAA-adding timing, and DAA-control mode were explored through experiments and the multiple linear regression model and the response surface methodology. The optimized DAA control ways were acquired, involving DAA used as an active agent, and the DAA-adding timing of 4 h cultured before running, as well as both hydrophilic and hydrophobic membrane, resulting in an approximately 40.24% decrease in the membrane biofouling rate in comparison with the conventional MBR. DAA is an efficient membrane biofouling mediating approach for MBR under optimized control ways combination and a facile solution for solving membrane biofouling in actual membrane systems.

The Development of transformative technology capable of producing inexpensive superior lithium electroactive anode material with low volume changes and stable performance on cycling is an important step on the path to advanced application of lithium ion batteries (LIBs). In this work, a new synthesis strategy for hybrid SnO2-Co3O4 nanotubes, based on electrospun polyvinylpyrrolidone (PVP) fibers with co-embedded metal precursors is explored. This low cost, template-free, Kirkendall effect-derived process first yields phase-separated core-sheath PVP/SnO2-Co3O4 composites, creating highly uniform and well-dispersed nanotubes via self-assembly accompanying gradual PVP combustion. Control experiments show that the heat-treatment atmosphere is the key for the in situ growing in a large yield. On account of the great buffering capability in hierarchical porous architecture, synergistic effect of active multi-components and the present interfacial Co nanophase, the proposed tubular hybrids possess enhanced cyclic stability and lithium storage capacity as anodes with retained capacity as high as 873 mAh g−1 even after 200 cycles at 100 mA g−1. The protocol paves the way for rational design of hollow hybrid nanotubes with wide applications.

Elaborate design of cost-effective and highly-efficiency bifunctional electrocatalysts towards the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critically essential for the advancement of rechargeable metal-air batteries. Herein, we develop a straightforward and scalable hydrogel-bridged pyrolysis strategy for the exquisite construction of a “ship-in-a-bottle”-structured bifunctional catalyst consisting of fine CoFe nanoparticles encapsulated inside the carbon nanowall-assembled frameworks (abbreviated as CoFe@N-CNWF hereafter). The deliberate design of such intriguing hierarchical honeycomb-like architecture with tightly confined CoFe nanoparticles and open configuration endows the as-fabricated CoFe@N-CNWF with sufficient well-dispersed active sites, rapid charge transfer efficiency, accelerated mass diffusion and robust mechanical strength. Consequently, the resultant CoFe@N-CNWF catalyst shows outstanding catalytic performance toward the ORR and OER with high activity and long-term stability. More encouragingly, a rechargeable Zn–air battery using CoFe@N-CNWF as the air cathode displays superb energy density, high energy efficiency and robust reversibility, surpassing the state-of-the-art precious Pt/C + RuO2–assembled counterpart. The developed methodology for the fabrication of “ship-in-a-bottle” architectures may open new opportunities to low-cost, mass production of high-efficiency bifunctional oxygen electrocatalysts for a variety of renewable energy technologies and beyond.

The development of stable, adequate, and cost-effective catalysts to meet current fuel cell requirements is urgent in the face of ever-intensifying energy demands. Heteroatom-doped carbons are promising non-noble metal-based catalysts expected to replace or reduce platinum consumption required for the electrocatalytic oxygen reduction reaction (ORR). Metal–organic frameworks (MOFs) are rapidly evolving as porous functional materials owing to their high surface area, permanent porosity, and diverse structure, thus rendering their derivatives suitable potential catalysts for electrocatalysis. Herein, we systematically reviewed the latest advances in the design and synthesis of MOF-derived heteroatom-doped carbons, which were further divided into metal-free and metal-containing materials to identify the effects of component manipulation, morphological control, and structural engineering on their ORR performance. Additionally, future challenges and research directions for MOF-derived heteroatom-doped carbon electrocatalysts are proposed.

Antibiotic wastewater presents serious challenges in water treatment. Metal-organic frameworks (MOFs) have received significant attention as promising precursors and sacrificial templates in the preparation of porous carbon-supported catalysts. Herein, we investigated the sulfamethoxazole (SMX) degradation and electrochemical performance of microbial fuel cells (MFCs) that applied as-prepared Ni-MOF-74 and Ni–N–C (Ni-MOF-74 underwent pyrolysis treatment at different temperatures) as air-cathode catalyst. Firstly, the electrocatalytic activity towards oxygen reduction reaction (ORR) of the catalyst was investigated by rotating disk electrode. The results showed that electron transfer number for Ni-MOF-74 was 2.12, while that of 800Ni–N–C was 3.44, which was close to four-electron reduction. Applying Ni-MOF-74 in MFCs, a maximum power density of 446 mW/m2 was obtained, which was close to that of 800Ni–N–C. Besides, using Ni-MOF-74 as cathode catalyst, a chemical oxygen demand removal rate of about 84% was obtained, and the degradation rate of 10 mg/L SMX was 61%. The degradation rate decreased with increasing antibiotic concentration, but the average degradation efficiency increased stepwise. Additionally, the relative abundance of resistant gene sul1 in the reactors of the new catalytic material was about 62% lower than that of sul1 in the control (Pt/C) reactors, and the relative abundance of sul2 was about 73% lower. Moreover, cost assessments related to the catalyst performance are presented. The findings of this study demonstrated that Ni-MOF-74 could be considered as a two-electron transfer ORR catalyst, and offers a promising technique for preparation of Ni–N–C for use as four-electron transfer ORR catalysts. In comparison, Ni-MOF-74 could be a promising ORR catalyst of MFCs for antibiotic degradation.

In Canada, Verticillium wilt of canola (Brassica napus L.), caused by Verticillium longisporum, was first confirmed in Manitoba in 2014. Verticillium dahliae, however, has not been reported to cause this disease. In 2016, a field survey in Alberta revealed canola plants with vascular wilt symptoms. Symptomatic plants were collected and infected stem tissue was cultured on agar medium, with one isolate designated A1-SS05 identified as a putative Verticillium spp. based on its colony characteristics. The colony was off-white in colour with a felt-like surface. On potato dextrose agar, the underside of the colony was dark only in the central area with radiating ridges. On Howell’s medium, only the test isolate exhibited polyphenol oxidase activity. The isolate formed conidiophores with 4–5 verticillate phialides. Mean conidial length was 5.96 µm (range of 4.65–6.64 µm) and mean width was 2.37 µm (range of 1.71–2.79 µm). The isolate also produced irregularly elongated chain-like microsclerotia of vari...

Soil salinity is a destructive environmental stressor that greatly reduces plant growth and productivity. In recent years, large tracts of farmland in arid and semiarid regions have been simultaneously affected by salinity and heavy metal pollution, arousing widespread environmental concern. Phytoremediation, defined as the use of plants to remove pollutants from the environment and (or) to render them harmless, is a low cost, environmentally friendly, and effective method for the decontamination of soils polluted by heavy metals. Halophytes, which can survive and reproduce in high-salt environments, are potentially ideal candidates for phytoremediation of heavy metal contaminated saline soils. In this review, we discuss the current progress on the use of halophytes, their tolerance mechanisms to salt and heavy metal toxicity, and their potential for phytoremediation in heavy metal contaminated saline soils. The relative mechanisms are discussed and the future perspectives are proposed.

Single-layer molybdenum disulfide (SLMoS2) is a novel kind of 2D nanosheet that has attracted great attention regarding its use in biosensors, drug delivery, tissue engineering, and therapy. However, our results demonstrated that SLMoS2 accelerated proliferation and promoted myogenic differentiation and epithelial-mesenchymal transition (EMT) in human embryonic lung fibroblasts (HELFs). The abnormal proliferation and differentiation of HELFs contribute to idiopathic pulmonary fibrosis. Specifically, SLMoS2 significantly stimulated the expression of myofibroblast- and mesenchymal-associated genes and proteins. The Akt-mTOR-p70S6K signaling pathway plays a critical role in the acceleration of proliferation and promotion of myogenic differentiation and EMT in HELFs induced by SLMoS2. After cell uptake, SLMoS2 was primarily located in the cytoplasm and the perinuclear region and activated Akt-dependent signaling due to the generation of reactive oxygen species (ROS). Moreover, bovine serum albumin (BSA) binding markedly inhibited the cellular uptake of SLMoS2 and the production of intracellular ROS due to an increased thickness and reduced adhesion of HELFs. BSA binding also mitigated the SLMoS2-activated phosphorylation of Akt-dependent signaling pathways. This study is the first to illustrate the induction of cellular proliferation and differentiation by SLMoS2 and the related mediation by proteins through Akt-mTOR-p70S6K signaling pathway.

Clubroot, caused by Plasmodiophora brassicae, has become a serious threat to canola (Brassica napus) production in western Canada. Experiments were conducted to evaluate the effect of rate of metam sodium fumigant (dithiocarbamate; sodium N-methyldithiocarbamate; trade name Vapam) and application methods including watering, soil surface covering, and soil incorporation on clubroot of canola. At higher rates (0.4–1.6 mL−1 L soil) metam sodium increased canola seedling emergence and plant health, and reduced root hair infection, gall weight and clubroot severity under greenhouse conditions. Metam sodium application improved subsequent plant growth and reduced clubroot severity, but land preparation and volume of water applied did not affect efficacy. The incorporation of metam sodium into the soil and plastic covering after application improved fumigant efficacy. The study showed that soil fumigation with metam sodium can reduce clubroot severity and improve plant health in the subsequent canola crop.

Recently, developing high-efficiency photocatalytic hydrogen generation photocatalysts and clarifying the inherent mechanism behind the enhancement of hydrogen generation activity have been the research focus. Here, we present a step-wise strategy to prepare Pt/TiO 2 /reduced graphene oxide photocatalysts and the inherent mechanism of the enhanced photocatalytic activities were systematically investigated. Experimentally, the 2 wt% rGO doped rGO/Pt-TiO 2 nanocomposites showed the superior solar-driven hydrogen generation rate (1075.68 μmol h −1 g −1 ), which was 81 times and 5 times higher than bare TiO 2 and Pt/TiO 2 samples, respectively. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectra (FT-IR) demonstrated the formation of Ti O C bonds in the hybrid, which drove the shifting upwards of the valence band edge from +2.2 eV to +1.83 eV. Furthermore, photoelectrochemical tests indicated the electron density of PTG-2 was about one order of magnitude higher than TiO 2 . Moreover, DFT calculations displayed that the bandgap had been successfully narrowed from 2.88 eV to 2.76 eV and the original blank energy region located at TiO 2 bandgap was filled with C2p orbitals, which resulted in excited electrons in TiO 2 efficiently transferring to graphene. Consequently, the DFT calculations are in good agreement with the experimental results and physical characterizations. This study affords us a rational design of a high efficiency photocatalytic system for solar energy conversion.

Efficient noninvasive techniques are desired for repairing organic-contaminated soils. Bioelectrochemical technology, especially microbial fuel cells (MFCs), has been widely used to promote a polluted environmental remediation approach, and applications include wastewater, sludge, sediment, and soil remediation. Soil MFC remediation has been of significant concern in recent years, and thus, several aspects, including reactor configuration, electrode materials, soil conductivity, mass transfer, and microbial activity, are reviewed. Recent studies and key issues of soil MFCs and perspectives of organic-contamination remedial application are summarized, with the aim of assisting environmental scholars and engineers to gain a comprehensive understanding of MFC remediation. Insights are also offered on how to extend applications to help soil MFC remediation technology to advance and be applied in the future on a large scale.

Metal selenides have been proposed as counter electrodes (CEs) to substitute for Pt in dye-sensitized solar cells (DSSCs) due to their good catalytic activity for the reduction of triiodide. In this paper, NiSe 2 nanoparticles were synthesized by a facile, room-temperature process and used as the CEs. In order to further enhance the photovoltaic property, graphene was introduced by facile physical mixing. Eventually, with the assistance of graphene, NiSe 2 + 6 wt% graphene CE exhibited better power conversion efficiency ( PCE ) compared with Pt CE.

In this study, removal efficiency and mechanism of four typical ARGs with two different molecular structures (i.e., cyclic (c)- and double-stranded (ds)-ARGs) by graphene oxide (GO) nanosheet were systematically investigated. The average removal of four ARGs was as high as 3.11 logs toward c-ARGs and 2.88 logs toward ds-ARGs at 300 μg/mL GO solution. The data of adsorption were fitted well with Freundlich isotherm and pseudo-second-order kinetic model. The apparent adsorption equilibrium can be obtained within 15 mins for both c-ARGs and ds-ARGs, indicating the effective removal by GO. The free-energy parameters demonstrated that the removal processes were exothermic and spontaneous. The structural differences of genetic molecular structures can be responsible for the removal discrepancy. Moreover, several removal factors containing initial ARGs concentration, pH and ion species were also investigated. The results of Raman spectra, Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTs) and electrochemical analysis indicated that the adsorption of ARGs by GO was mainly attributed to the oxygen containing groups and π-bonding system of GO nanosheet, which resulted in chemical binding with aromatic nucleic acid and strongly π-stacking interactions. Furthermore, a detailed verification test of real water samples was conducted and 80% of the ARGs can be removed from a natural water sample. As a result, it would be great potential to apply GO nanosheet as a novel adsorbent for effective treatment of ARG-contaminated waters.

To mitigate the impact and dissemination of clubroot in western Canada, canola (Brassica napus) producers have relied on clubroot resistance traits. However, in 2013 and 2014, new strains of the clubroot pathogen, Plasmodiophora brassicae, emerged that are virulent on most clubroot-resistant (CR) canola genotypes. Novel strains of the pathogen were inoculated onto two susceptible canola cultivars, one resistant line and six CR cultivars. Although all cultivars/lines showed a susceptible response to inoculation with the new strains of P. brassicae, the severity of disease reaction, root hair infection rates and the amount of P. brassicae DNA present in each canola genotype varied depending on the strain. In addition, the effect of inoculum density on disease severity and gall formation was recorded for one of these new strains on a universally susceptible Chinese cabbage cultivar and one susceptible and 10 resistant canola genotypes. Although root galls were observed at an inoculum density of 103 spores per mL of soil, clear differentiation of susceptible and resistant reactions among canola cultivars/lines was not observed until the inoculum density reached 105 spores mL−1. At a spore density of 106 spores mL−1 and above, all cultivars/lines developed susceptible reactions, although there was some differentiation in the degree of reaction. This study shows the potential to develop a unique disease profile for emergent clubroot pathotypes and shows a useful range of spore densities at which to study new P. brassicae strains.

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.

Oxygen reduction reaction (ORR) plays an important role in green energy conversion, although catalysts are necessary for overcoming its sluggish kinetic. Herein, a nanocrystal NiCo2O4/N-doped graphene composite material showing high ORR electrocatalytic activity is prepared. The resulting NiCo2O4/N-doped graphene composite (NiCo2O4-NG/C) combines the advantages of both component materials and shows enhanced ORR electrocatalytic activity (i.e., more positive peak potential and half-wave potential compared with NiCo2O4) while having higher diffusion-limited current density values (−5.7 mA cm−2, 1600 rpm), better tolerance to methanol, and improved stability than 20 wt% Pt/C. NiCo2O4 anchored on N-doped graphene are demonstrated to be nanocrystal with tiny crystalline grain (diameter

Arsenic (As) originating from natural and anthropogenic sources is an ubiquitous metalloid in soils, and can pose potential risks on human health and ecosystems. It is of great practical significance to carry out this study to prompt development or revision of soil-environmental quality standards, further to efficiently control its risks and hazards. Firstly, we briefly introduced the researching background of As soil-environmental quality criteria and standards. Secondly, we summarized the methods of deriving As soil-environmental quality criteria, respectively, based on its soil-environmental background values, ecotoxicological effects, accumulation, exposure models and soil-water partition equations. Thirdly, we reckoned and assessed the quantitative or qualitative relationships of As soil-environmental quality standards in various countries and regions according to land uses, tiers and extractants. In addition, the variation on soil-environmental quality standards was generally analyzed. Finally, we prospected the future researches on soil-environmental quality criteria and standards of As.

Soybean [Glycine max (L.) Merr.] has great potential as an alternative crop in western Canada. Root rot is a common constraint in soybean production, and the occurrence of root rot was documented in all 29 fields surveyed in southern Alberta in 2014. Phytophthora spp. cause seed rot, pre- and post-emergence damping-off, and stem and root rot wherever soybean is produced, but it has not been previously reported in association with soybean in Alberta. Following a survey of soybean fields in 2014, root tissue with typical symptoms of root rot was plated onto a selective growth medium, and two isolates were designated as putative Phytophthora spp. based on their colony characteristics. These two isolates were homothallic on lima bean agar, producing smooth, thick-walled oospores and mostly paragynous with some amphigynous antheridia. Based on these criteria, the two isolates were identified as Phytophthora sojae Kaufmann & Gerdemann. Sequencing of the internal transcribed spacer (ITS) region revealed 100% identity with ITS sequences of P. sojae available in GenBank. A pathogenicity test revealed that both isolates of P. sojae were able to cause root rot on soybean and produce typical chocolate brown stem lesions just above the base of the plants. The two isolates were classified as races 4 and 28 of P. sojae based on their virulence on a set of soybean differential cultivars. Race 28 was more virulent than race 4 on the soybean cultivars ‘XBP27005’ and ‘XBP29002’. Regression analysis showed the positive linear relationships of the log of inoculum density with disease severity, and negative linear relationships with seedling emergence, plant height, and plant biomass. This is the first report of Phytophthora spp. causing root rot in soybean in Alberta.

Flocculants have been used to clarify water for thousands of years. However, the in situ evaluation of flocculant toxicity is difficult because flocculants usually exist as growing complex flocs which is hard to monitor. With alum (KAl(SO4)2·12H2O) as the typical flocculant, a bioelectrochemical sensor is designed to in situ detect its bacterial toxicity. The attenuation ratio of current densities linearly increased with alum concentration (R2 > 0.98) with a slope of 0.0054 A m–2 drop per mg L–1 of alum, indicating a typical toxic response of alum. Turnover and nonturnover cyclic voltammetries (CVs) revealed that the alum inhibited the electrochemical activity of bacteria rather than changing the electron transfer pathways. Alum also hindered the diffusion by flocculation at a concentration larger than 100 mg L–1, which was further confirmed by the linear decrease in viability when biofilm thickness increased. It was revealed that both inactivation of biofilm and influences on diffusion by alum can be det...

Although carbon nanomaterials have been widely used as effective nanofillers for fabrication of mixed matrix membranes (MMMs) with outstanding performances, the reproducibility of the fabricated MMMs is still hindered by the non-homogenous dispersion of these carbon nanofillers in membrane substrate. Herein, we report an effective way to improve the compatibility of carbon-based nanomaterials with membrane matrixes. By chemically conjugating the oxidized CNTs (o-CNTs) and GO using hexanediamine as cross-linker, a novel carbon nanohybrid material (G-CNTs) was synthesized, which inherited both the advanced properties of multi-walled carbon nanotubes (CNTs) and graphene oxide (GO). The G-CNTs incorporated polyvinylidene fluoride (PVDF) MMMs (GCNTs/PVDF) were fabricated via a non-solvent induced phase separation (NIPS) method. The filtration and antifouling performances of G-CNTs/PVDF were evaluated using distillate water and a 1 g/L bovine serum albumin (BSA) aqueous solution under 0.10 MPa. Compared to the MMMs prepared with o-CNTs, GO, the physical mixture of o-CNTs and GO and pure PVDF membrane, the G-CNTs/PVDF membrane exhibited the highest water flux up to 220 L/m2/h and a flux recovery ratio as high as 90%, as well as the best BSA rejection rate. The excellent performances should be attributed to the increased membrane pore size, porosity and hydrophilicity of the resulted membrane. The successful synthesis of the novel nanohybrid G-CNTs provides a new type of nanofillers for MMMs fabrication.

Alzheimer's disease (AD) is one of the most common age-associated brain diseases and is induced by the accumulation of amyloid beta (Aβ) and oxidative stress. Many studies have focused on eliminating Aβ by nanoparticle affinity; however, nanoparticles are taken up mainly by microglia rather than neurons, leading poor control of AD. Herein, mitochondria-targeted nanozymes known as (3-carboxypropyl)triphenyl-phosphonium bromide-conjugated 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000]-functionalized molybdenum disulfide quantum dots (TPP-MoS

A feasible and green sol-gel method is proposed to fabricate well-distributed nano-particulate Fe-Ni2P incorporated in N, P-codoped porous carbon nanosheets (Fe-Ni2P@N,P-CNSs) using biomass agarose as a carbon source, and ethylenediamine tetra (methylenephosphonic acid) (EDTMPA) as both the N and P source. The doped Fe in Ni2P is essential for a substantial increase in intrinsic catalytic activity, while the combined N,P-containing porous carbon matrix with a better degree of graphitization endows the prepared Fe-Ni2P@N,P-CNSs catalyst with a high specific surface area and improved electrical conductivity. Benefiting from the specific chemical composition and designed active site structure, the as-synthesized Fe-Ni2P@N,P-CNSs manifests a satisfying catalytic performance toward both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in an alkaline solution, with low overpotential, small Tafel slope and long-term durability, relative to the counterparts (Fe-free Ni12P5/Ni2P2O7@N,P-CNSs and CNSs) with single components and even comparable to Pt/C and RuO2 catalysts. The present work broadens the exploration of efficient bifunctional oxygen electrocatalysts using earth abundant biomass as carbon sources based on non-noble metals for low cost renewable energy conversion/storage.

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.

Solar-driven evaporation has been proposed as an efficient way to harvest solar energy for water treatment and desalination. However, the complex preparation process and the degradation of photothermal absorbers restrict their practical applications in solar thermal technology. Herein, a solar-assisted fabrication of three-dimensional dimpled MoS

The environmental behaviors and risks associated with graphene oxide (GO, a popular 2D nanomaterial) have attracted considerable attention. GO released to aquatic systems will most likely interact with ubiquitous nanocolloids (Nc) in surface water. However, the effects of Nc on the fate and risk of GO remain largely unknown in water. Herein, the binding of Nc onto GO was investigated via electron microscopy, electron paramagnetic resonance, 2D correlation spectroscopy and biolayer interferometry. The results revealed that electron charge transfers, hydrophilic effects and π-π stacking contributed to a strong affinity (KD = 5.6 nM) and high adsorption capacity (159.8 mg/g) of Nc onto the GO surface. Moreover, GO nanosheets transformed to a scroll morphology or multiple GO particles bridging by Nc, which remarkably reduced the aggregation and sedimentation rates after binding with Nc. Interestingly, co-exposure with Nc greatly alleviated the toxicity (e.g., tail malformation, yolk sac edema and oxidative stress) of GO to zebrafish embryos. Morphological and structural alterations of GO after binding to Nc contributed to the mechanisms for the antagonistic effects on the zebrafish embryos toxicity. The present work provides insights into the environmental fate and risk of GO by ubiquitous Nc in natural water.