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Micro/nanoplastics (M/NPs) in water have raised global concern due to their potential environmental risks. To reestablish a M/NPs free world, enormous attempts have been made toward employing chemical technologies for their removal in water. This review comprehensively summarizes the advances in chemical degradation approaches for M/NPs elimination. It details and discusses promising techniques, including photo-based technologies, Fenton-based reaction, electrochemical oxidation, and novel micro/nanomotors approaches. Subsequently, critical influence factors, such as properties of M/NPs and operating factors, are analyzed in this review specifically. Finally, it concludes by addressing the current challenges and future perspectives in chemical degradation. This review will provide guidance for scientists to further explore novel strategies and develop feasible chemical methods for the improved control and remediation of M/NPs in the future. [Display omitted] • This review summarized the recent chemical degradation methods for M/NPs. • Photo-based approaches pose great potential for M/NPs degradation. • The mechanism, limitations, and influence factors of each technologies are reviewed. • Challenges and perspectives about M/NPs chemical degradation are summarized. [ABSTRACT FROM AUTHOR]

In this study, the preparation of pyrolyzed bone chars for the removal of nitrobenzene (NB) from the water was examined. Adsorption properties of bone chars prepared at diverse pyrolysis temperatures (300–900 ℃) were investigated for removing NB from aqueous solutions. At higher temperatures (700 and 900 ℃), bone chars showed superior adsorption properties for NB removal, and physicochemical characterizations showed that the pyrolyzed bone chars possessed improved properties and amended porous structure after pyrolysis treatment. Pyrolysis temperatures of > 700 ℃ contributed to the dehydroxylation of hydroxyapatite of bone chars, increasing their NB adsorption performance. Maximum NB adsorption capacity of higher temperature pyrolyzed bone chars calculated from the Langmuir isotherm model was 142.41 and 204.34 mg/g for bone char-700 and bone char-900, respectively, indicating that the bone chars had the potential for enhanced NB adsorption. For adsorption isotherm parameters, two-parameter (Langmuir and Freundlich) models showed satisfactory results of NB adsorption on bone char from aqueous solution. Adsorption kinetic parameters of NB adsorption on bone chars showed pleasing results for the pseudo 2nd order model. This study shows that the pyrolyzed bone char is an efficient adsorbent for removing NB from water. • Bone chars were prepared at 300–900 ℃ temperatures for NB removal from water. • Physicochemical properties of bone powder were improved after pyrolysis treatment. • >700 ℃ sponsored hydroxyapatite dehydroxylation of bone char for better NB adsorption. • 700 and 900 ℃ bone chars had superior NB adsorption capacity (142.41 and 204.34 mg/g). • This study shows that pyrolyzed bone chars can be used for environmental remediation. [ABSTRACT FROM AUTHOR]

In this study, taking advantage of the amphiphilic properties of alkali lignin, carbon shell-encapsulated nano-zero-valent iron particles (AL@nZVI) anchored in a porous carbon framework were firstly synthesized by a combination of antisolvent reaction and carbothermal reduction method. AL@nZVI exhibited efficient catalytic performance for the activation of persulfate for the complete removal of 2,4-dichlorophenol at 30 min. The formation of a porous carbon skeleton and carbon shell enhanced the dispersibility and antioxidation of Fe0 nanoparticles and enabled long-term storage of AL@nZVI in air for more than 60 days. Furthermore, oxidation was mainly responsible for the removal of 2,4-dichlorophenol. The adsorption was determined to be 26.9% by analyzing the 2,4-dichlorophenol content in the used material. The generation of O 2 · − , SO 4 · − , 1O 2 and·OH, was confirmed by EPR and scavenging experiments, and O 2 · − and 1O 2 played dominant roles in the AL@nZVI+ persulfate system. The O 2 · − -guided free radical pathway was induced by activation of persulfate by Fe0 nanoparticles, while O 2 · − acted as a precursor to induce the 1O 2 -guided non-radical pathway. It is worth noting that C O may be favourable for the generation of 1O 2. Moreover, the graphitized carbon, micropores, and structural defects contained in AL@nZVI created an electron-rich environment to facilitate the interaction between 2,4-dichlorophenol and reactive oxygen species. Therefore, the free radical and non-radical pathways were coupled to work together to degrade 2,4-dichlorophenol. This work not only develops a new synthesis method for core-shell structured carbon-coated nZVI composites, but also open the way for the high-value utilization of industrial by-products and the advanced oxidation degradation of organic pollutants in environmental remediation. [Display omitted] • AL@nZVI was synthesized by a combination of the antisolvent method and the carbothermal reduction method. • The formation of carbon coated-iron core structure greatly improved the stability of nZVI in the air environment. • The AL@nZVI exhibited excellent degradation performance towards 2,4-DCP through activating PS. • Combination of free radical and non-radical pathways contributed to the degradation of 2,4-DCP. [ABSTRACT FROM AUTHOR]

Toxic effects of widely used CuO nanoparticles (NPs) on the genus Streptomyces has been seldom studied. This work investigated toxicities of several sizes of CuO nanoparticles (NPs) to Streptomyces coelicolor M145 ( S. coelicolor M145). Compared with NPs, toxicity of micrometer-sized CuO on M145 was trivial. In 0.9% NaCl, when the concentration of CuO NPs was 100 mg/L, survival of bacteria increased from 18.3% in 20 nm particles to 31.1% in 100 nm particles. With increasing concentrations of CuO, the level of ROS gradually increased and there were significant differences ( p  ＜ 0.05) in ROS exposed to 20, 40 and 100 nm (80 nm) CuO NPs. In TSBY medium, toxicity of CuO NPs was less and mainly attributed to release of Cu 2+ , analysis by confocal laser scanning microscope (CLSM) showed that size of the mycelium did not change although some individual bacteria died. This was likely due to Cu 2+ released from NPs entering cells through the membrane, while in 0.9% NaCl, lesions on membranes was caused by NPs outside the bacteria. This research indicated that toxicity of CuO NPs to S. coelicolor, is related to both size of NPs and is dependent on characteristics of the medium. Capsule This is the first time to measure the toxicity of nano materials to Streptomyces , and toxic CuO NPs to Streptomyces have been shown to differ depending on medium. [ABSTRACT FROM AUTHOR]

With the goal of combining the advantages of ball-milling and biochar technologies, a variety of ball-milled biochars (BM-biochars) were synthesized, characterized, and tested for nickel (Ni(II)) removal from aqueous solution. Ball milling increased only the external surface area of low temperature biochars, but still dramatically enhanced their ability to sorb aqueous Ni(II). For higher temperature biochars with relatively low surface area, ball milling increased both external and internal surface area. Measurements of pH, zeta potential, stability, and Boehm titration demonstrated that ball milling also added oxygen-containing functional groups (e.g., carboxyl, lactonic, and hydroxyl) to biochar's surface. With these changed, all the BM-biochars showed much better Ni(II) removal efficiency than unmilled biochars. Ball-milled 600 °C bagasse biochar (BMBG600) showed the greatest Ni(II) adsorption capacity (230–650 compared to 26–110 mmol/kg for unmilled biochar) and the adsorption was dosage and pH dependent. Compared with the unmilled biochar, BMBG600 also displayed faster adsorption kinetics, likely due to an increase in rates of intra-particle diffusion in the latter. Experimental and modeling results suggest that the increase in BM-biochar's external and internal surface areas exposed its graphitic structure, thus enhancing Ni(II) adsorption via strong cation-π interaction. In addition, the increase in acidic surface functional groups enhanced Ni(II) adsorption by BM-biochar via electrostatic interaction and surface complexation. Ball milling thus has great potential to increase the efficiency of environmentally friendly biochar for various environmental applications. [ABSTRACT FROM AUTHOR]

Biochars have increasingly been used as adsorbents for organic and inorganic contaminants in soils. However, during the carbonization process of pyrolysis, contaminants, including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated dioxins and furans (PCDD/DF) can be generated. In this study, biochars made from sawdust, were prepared at various temperatures ranging from 250 to 700 °C. The Microtox ® and rat hepatoma cell line H4IIE- luc assays were used to characterize the general toxic and effects, mediated through the aryl hydrocarbon receptor (AhR), or dioxin-like potencies of organic extracts of biochars. The greatest total concentrations of PAHs (8.6 × 10 2 μg kg −1 ) and PCDD/DF (6.1 × 10 2 pg g −1 ) were found in biochar generated at 400 °C and 300 °C, respectively. Results of the H4IIE- luc assay, which gives total concentrations of 2,3,7,8-TCDD equivalents (TEQ H4IIE- luc ), indicated that total potencies of aryl hydrocarbon receptor (AhR) agonists were in decreasing order: 300 °C > 250 °C > 400 °C > 500 °C > 700 °C. The 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ chem ) calculated as the sum of products of 16 PAHs and 17 PCDD/DF congers multiplied by their respective relative potencies (RePs) was less than that of TEQ H4IIE- luc determined by use of the bioanalytical method, with the H4IIE- luc assay, which measures the total dioxin-like potency of a mixtures. The ratio of TEQ chem /TEQ H4IIE- luc was in the range of 0.7%–3.8%. Thus, a rather small proportion of the AhR-mediated potencies extracted from biochars were identified by instrumental analyses. Results of the Microtox test showed similar tendencies as those of the H4IIE- luc test, and a linear correlation between EC50 of Microtox test and EC20 of H4IIE- luc test was found. The results demonstrated that biochars produced at higher pyrolysis temperatures (>400 °C) were less toxic and had lower potencies of AhR-mediated effects, which may be more suitable for soil application. [ABSTRACT FROM AUTHOR]

In this study, simple and environmentally friendly magnetic biochars were successfully prepared by ball-milling biochar with Fe 3 O 4 nanoparticles to remove NPs from water. The magnetic biochars synthesized at various pyrolysis temperatures of 300 °C (MBC300), 500 °C (MBC500), and 700 °C (MBC700) were used to eliminate the unmodified (PS), aged under UV radiation (UVPS), amine-modified (PS–NH 2) and carboxylate-modified (PS–COOH) polystyrene NPs of 100 nm in size. Results showed that the removal efficiency of MBC300, MBC500, and MBC700 for PS were 43.67, 82.73 and 57.02%, which were 3.01, 5.76, and 3.10 times greater than that of corresponding pristine biochars at the same temperatures, respectively, and the strongest removal efficiency of MBC500 was 95.2% since it has the largest specific surface area and abundant oxygen-containing functional groups. The surface properties of the NPs affected their removal, and the PS-NH 2 had the highest removal rate using magnetic biochars. Compared to pristine biochars, the magnetic biochars displayed faster adsorption kinetics. The Langmuir maximum adsorption capacity of magnetic biochars for NPs were 107.7181–229.5772 mg/g, much greater than those of the pristine biochars (55.4602–80.3096 mg/g). Mechanism analysis revealed that the hydrophobicity, electrostatic attraction, H-bonding formation and π-π conjunction between the NPs and MBCs contributed to the adsorption process. This work highlights the promising potential of ball milling to be used as a simple technique for the preparation of magnetic biochar to remove NPs, especially NPs with various surface groups. [Display omitted] • Magnetic biochars presented stronger potential than pristine biochars for NPs adsorption. • The functionality of nanoplastics significantly influenced their adsorption performance. • Hydrophobicity, electrostatics, H-bonding and π-π conjunction all involved in NPs adsorption. [ABSTRACT FROM AUTHOR]

Electrocatalytic persulfate (PS) generation of sulfate radicals has been extensively studied for the removal of organic pollutants, while continuous electricity output causes high energy consumption. Microbial fuel cell (MFC) is an environmentally friendly approach that can catalyze PS for degradation of pollutants through bioelectricity and achieve electricity recovery and utilization at the same time. In this study, a MFC based on electrocatalytic PS activation in cathode (PS-MFC) was constructed to remove 2,4-dichlorophenol (2,4-DCP) with simultaneous electricity recovery. Results showed that 2,4-DCP was successfully removed by PS-MFC with a maximum removal rate of 68.7% after 220 mins of reaction, and the removal process followed pseudo-second-order kinetic. In addition to the wide pH reaction range (pH 3–11), PS-MFC exhibited excellent electrical performance with a higher maximum power density (300.28 mW/m2) than reported studies of the similar type of MFC. Active species for the degradation of 2,4-DCP by PS-MFC system are O 2 • − , • O H , S O 4 • − and O 2 1 , with O 2 • − and • O H accounting for major part. The degradation pathway of 2,4-DCP in PS-MFC was proposed by free radical quenching experiments and intermediate product analysis. This work provided a green and sustainable solution for the removal of refractory organic pollutants and promoted research for the further practical application of MFCs. • PS-based MFC achieved effective degradation of 2,4-DCP. • Valuable electricity was recovered in PS-based MFC during 2,4-DCP degradation. • Two active species (O 2 • and •OH) dominated degradation of 2,4-DCP in neutrality. [ABSTRACT FROM AUTHOR]

Low molecular weight organic acids with low cost and environmentally friendly characteristics can enhance the electron transfer between materials and contaminants. In this study, oxalic acid (OA), citric acid (CA), and ethylenediaminetetraacetic acid (EDTA) were selected to strengthen ball milled natural FeS 2 /biochar composite (FeS 2 /biochar) for aqueous Cr(VI) removal. 100% of Cr(VI) was removed when 5 mM of OA and 0.25 g·L−1 FeS 2 /biochar were used together. In contrast, the removal rate of Cr(VI) by the individual FeS 2 /biochar and OA was 57.9% and 6.3%, respectively. The experimental and characterization results suggested that OA was adsorbed on the surface of FeS 2 /biochar through the conjugated structure of pine biochar, thereby enhancing the dissolution rate of Fe(II) and S(-II) in the FeS 2 /biochar composite, and facilitating the conversion of Fe(II), S(-II), and Cr(VI) to Fe(III), SO 4 2-, and Cr(III), respectively. In addition, the complexation of OA with Fe(III) and Cr(III) reduced the formation of Fe(OH) 3 and Cr(OH) 3 , exposing more surface active site of FeS 2 /biochar for the reduction of Cr(VI). As an electron donor, the addition of OA enhanced the electron transfer process of FeS 2 /biochar to Cr(VI) on the one hand, and on the other hand promoted the redox cycle of Fe(II) through the electron transfer between OA and Fe ions. FeS 2 /biochar showed better stability even after 5 cycles (in 5 mM OA system). The present study demonstrated the promise of low molecular weight organic acids in strengthening materials for environmental remediation. [Display omitted] • Oxalic acid enhanced the dissolution rate of Fe(II) and S(-II) in the FeS 2 /biochar. • Oxalic acid promoted the transfer of electrons from FeS 2 /biochar to Cr(VI). • Oxalic acid reduced the formation of Fe(OH) 3 and Cr(OH) 3. • Oxalic acid promoted the redox cycle of iron and sulfur, enhancing Cr(VI) removal by the FeS 2 /biochar. • The graphite structure and conjugate structure in biochar transferred electrons to Cr(VI). [ABSTRACT FROM AUTHOR]

Cropland contamination by toxic trace metal (loid)s (TTMs) has attracted increasing attention due to the serious consequential threat to crop quality and human health. Mitigation of plant TTM stress by silica amendment has been proposed recently. However, the relationship between the siliceous structure of phytoliths and TTMs in plants, and the environmental implications of phytolith-occluded trace metal (loid)s (PhytTMs) remain unclear. This study assessed the accumulation of five metal (loid)s, including lead (Pb), zinc (Zn), cadmium (Cd), copper (Cu) and arsenic (As), in the organic tissues and phytoliths of wheat grown in a mixed-TTM contaminated soil under both lightly and heavily contaminated conditions. The results show that the concentrations of plant TTMs and PhytTMs were significantly (p < 0.05) positively correlated, and higher in heavily contaminated wheats than those in lightly contaminated ones. The bio-enrichment factors between phytoliths and organic tissues were higher for As (1.83), Pb (0.27) and Zn (0.30) than for Cd (0.03) and Cu (0.14), implying that As, Pb and Zn were more readily co-precipitated with silicon (Si) in phytolith structures than Cd and Cu. Network analysis of the relationship between soil and plant elements with PhytTMs showed that severe contamination could impact the homeostasis of elements in plants by altering the translocation of TTMs between soils, plants, and phytoliths. The accumulation of TTMs in phytoliths was affected by the capacity of Si deposition in tissues and chelation of TTMs with silica, which could impact the role of PhytTMs in global biogeochemical TTM cycles. [Display omitted] • The concentrated silica develops into various phytolith morphologies in wheat plants. • Phytolith encapsulates metal (loid)s through their co-precipitation process in plants. • Heavily metal-contaminated soil leads to increased TTM accumulation in phytoliths. • PhytTMs affect long-term TTM cycles of the cropland with multi-metal contamination. [ABSTRACT FROM AUTHOR]

Multiple sources of microplastics (MPs) in farmland could result in the changing of microbial community and the plant growth. Most studies of MPs in agricultural system have focused on the effects of single types of MPs on growth of plants, while neglect interactions between multiple types of MPs. In this study a pot-experiment was conducted to investigate the effects of multiple types of MPs, including polystyrene beads: M1, 5 μm, M2, 70 nm and degradable mulching film (DMF) fragments on growth of wheat seedlings and associated rhizosphere microbial community. CKD (adding DMF) significantly reduced plant height and base diameter of wheat seedlings. DMF in combination with M2, significantly increased plant height and aboveground biomass, but decreased the base diameter. Actinobacteria was the dominant taxa in the rhizosphere bacterial community in various treatments. PCoA analysis showed that the bacterial composition in M2HD (100 mg kg−1 M2 with DMF) was significantly different from that of CKD and M2LD (10 mg kg−1 M2 with DMF). At the level of genera, the dominant fungi in CKD and M2LD were in the genus Fusarium , which is the cause of wheat fusarium blight and Alternaria, which results in decreased base diameter. In CK (control group) and M2HD, Blastobotrys exhibited the greatest abundance, which assisted wheat seedlings in resisting Verticillium disease. Cluster and PCoA analysis showed the fungal composition in CKD was significantly different from CK, M2LD and M2HD. These findings suggest MPs potentially have selective effects on pathogens that affect growth of plants and potentially safety of the food. [Display omitted] • DMF increased the abundance of Fusarium which could cause Wheat Fusarium Blight. • M2LD increased the abundance of Alternaria potentially decreased the base diameter. • Blastobotrys had the highest abundance in M2HD could resist Verticillium disease. • Bacterial community composition in M2HD significantly differred from CKD and M2LD. • Fungal composition in CKD significantly differred from that in CK, M2LD and M2HD. DMF and M2LD increased Fusarium and Alternaria related to the weaken growth of wheat while M2HD promoted the Blastobotrys helping resist Verticillium disease. [ABSTRACT FROM AUTHOR]

Abstract: Urban environmental pressure is increasing with acceleration of urbanization and urban ecological situation is not optimistic any more. It''s very necessary to conduct ecological security assessment on cities. This paper employed the PSR (pressure-state-response) model and determined the weight of index based on improved analytic hierarchy process (IAHP) and entropy method. Index system of ecological security assessment of Tianjin with time scale from the year 2001 to 2007 was also established. From the evaluation result, the urban ecological security state in Tianjin from 2001 to 2007 was getting better, which can measure situation of ecological security in Tianjin in the past seven years and in order to assist early-warning, management and decision-making of city ecological safety. [Copyright &y& Elsevier]

The spread of antibiotic resistance genes (ARGs) is a global environmental issue. Dissolved biochar is more likely to contact bacteria in water, producing ecological risks. This study explored the effects of dissolved biochar on ARGs transfer in bacteria. Conjugative transfer efficiency was significantly different following treatment with different types of dissolved biochar. Typically, humic acid-like substance in dissolved biochar can significantly improve the transfer efficiency of ARGs between bacteria. When the concentration of dissolved biochar was ≤ 10 mg biochar/mL, humic acid-like substance substantially promoted ARGs transfer. An increase in dissolved biochar concentration weakened the ARGs transfer from humic acid-like substance. The inhibitory effects of small-molecule matters dominated, decreasing conjugative transfer frequency. At a concentration of 100 mg biochar/mL, the conjugative transfer efficiency of all treatments was lower than that of control. Compared with corn straw dissolved biochar, there were more transconjugants in pine sawdust dissolved biochar. Following treatment with 10 mg biochar/mL pine sawdust dissolved biochar, the number of transconjugants was at its maximum; approximately 7.3 folds higher than the control. We also explored mechanisms by which dissolved biochar impacts conjugative transfer. Due to the complex composition of dissolved biochar, its effects on the expression of conjugative transfer-related genes were also dynamic. This study investigates the ecological risk of biochar and guides its scientific application. [Display omitted] • 1.It was the first time to found dissolved biochar could affect the spread of ARGs. • 2.The transfer efficiency was pyrolytic conditions and concentration dependent. • 3.Humic acid can significantly improve the transfer efficiency of ARGs between bacteria. This is the first study to confirm that dissolved biochar can significantly improve the transfer efficiency of ARGs between bacteria. [ABSTRACT FROM AUTHOR]

Awareness of risks posed by widespread presence of nanoplastics (NPs) and bioavailability and potential to interact with organic pollutants has been increasing. Inhalation is one of the more important pathways of exposure of humans to NPs. In this study, combined toxicity of concentrations of polystyrene NPs and various phthalate esters (PAEs), some of the most common plasticizers, including dibutyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) on human lung epithelial A549 cells were investigated. When co-exposed, 20 μg NPs/mL increased viabilities of cells exposed to either DBP or DEHP and the modulation of toxic potency of DEHP was greater than that of DBP, while the 200 μg NPs/mL resulted in lesser viability of cells. PAEs sorbed to NPs decreased free phase concentrations (C free) of PAEs, which resulted in a corresponding lesser bioavailability and joint toxicity at the lesser concentration of NPs. The opposite effect was observed at the greater concentration of NPs, which may result from the dominated role of NPs in the combined toxicity. Furthermore, our data showed that oxidative stress and inflammatory reactions were mechanisms for combined cytotoxicities of PAEs and NPs on A549 cells. Results of this study emphasized the combined toxic effects and mechanisms on human lung cells, which are helpful for assessing the risk of the co-exposure of NPs and organic contaminants in humans. [Display omitted] • Assessment of human cells co-exposed to nanoplastics (NPs) and phthalate esters (PAEs) were conducted. • A lesser concentration of NPs reduced toxicity of PAEs by decreasing free concentrations of PAEs. • The PAEs with greater adsorption capacity to NPs showed greater reduction in combined cytotoxicity. • NPs dominated the cytotoxicity at the co-exposure of a greater concentration of NPs and PAEs. [ABSTRACT FROM AUTHOR]

The effect of modified biochar on the greenhouse gas emission in soil is not clear until now. In this study, biochar (BC) was modified by phosphoric acid (P) and further combined with nano-zero-valent iron (nZVI) to form nZVI-P-BC composite. The P modified biochar could significantly increase the available phosphorus in soil. The release of CO 2 and N 2 O in soil was inhibited during the initial stage of the experiment, with inhibition becoming more obvious over time. On the contrary, CH 4 and N 2 O emission in soil was enhanced by nZVI-P-BC composite. The proportion of Sphingomonas and Gemmatimonas were the most abundant bacterial species, which were related to the metabolism and transformation of nitrogen. The community structure of the fungus was also affected by nZVI-P-BC composite with Fusarium as the main species. PCoA analysis result suggested that bacterial community was more affected by the incubation time while fungal community was more related to the addition of different biochar and modified biochars. Image 1 • P modified biochar and nZVI biochar composite was developed. • P modified biochar can increase the available P in soil. • The CO 2 and N 2 O emission were mitigated by P modified biochar. • The CH 4 emission was enhanced by nZVI-BC composite in soil. • Microbial community was affected by both incubation time and biochar addition. Capsule: P modification of biochar enhanced the stability and further developed nZVI-P-BC composite inhibited greenhouse gas emission in soil. [ABSTRACT FROM AUTHOR]

An increasing amount of Fluoranthene (Fla) and Benz(a)anthracene (BaA) is being produced and used, eventually entering the soil sediments. The accumulation of Fla and BaA will cause poisoning to typical enzymes (α-Amylase) and organisms (Eisenia fetida) in soil. However, the studies about exploring and comparing the different effects of Fla, BaA and their joint effect at different levels are rarely reported. In this paper, the different effects of Fla, BaA and their mixed pollutant on α-Amylase were evaluated and compared at the molecular level, and the effect of Fla-BaA to the antioxidant system of earthworm (Eisenia fetida) was investigated from the aspects of concentration and exposure time at the animal level. The results showed that Fla-BaA had the greatest influence on the skeleton structure and the microenvironment of amino acid residue of α-Amylase compared to Fla and BaA, and in the mixed pollutant system, the joint effect mode was additive mode. The inhibitory effect of Fla-BaA on the activity of α-Amylase was also stronger than that of the system alone. The assays at the animal level showed that low concentrations (below 5 mg/kg) of Fla-BaA increased the activity of GSH-Px and SOD while high concentrations inhibited their activity. The POD that was activated throughout the experiment period suggested its key role in the earthworm antioxidant system. Changes in T-AOC and MDA showed that long-term and high-dose of Fla-BaA exposure inhibited the antioxidant capacity of Eisenia fetida , causing lipid peroxidation and damage to cells. Image 1 • Fla-BaA had a deeper influence on structure and function of α-Amylase. • Interaction mechanism of α-Amylase with Fla, BaA and Fla-BaA was compared. • Long-term and high-dose of Fla-BaA exposure will inhibit the antioxidant capacity, causing lipid peroxidation. • Fla-BaA had two-phase effects on GSH-Px and SOD. [ABSTRACT FROM AUTHOR]

There has been an increase on the research of microplastics (<5 mm in diameter) as carriers for toxic chemicals to evaluate their risks for human health and environment, but only few works focused on nanoplastics (1 nm–1000 nm in diameter) interacting with pre-existing contaminants such as heavy metals. It is still unclear whether polystyrene nanoplastics (PSNPs) could affect the toxicity of cadmium to wheat (Triticum aestivum L.). Here, we assessed the impact of polystyrene nanoplastics (0, 10 mg/L) on the Cd (0, 20 μM) toxicity to wheat grown in 25% Hoagland solution for three weeks. We found that the presence of PSNPs could partially reduce Cd contents in leaves and alleviate Cd toxicity to wheat, which might be due to weakened adsorption capacity of PSNPs affected by ionic strength. In addition, PSNPs have little effect on catalase (CAT), peroxidase (POD) activities, except for decreasing superoxide dismutase (SOD) activity, which suggested that antioxidant defense systems might not be the main mechanism to reduce the oxidative damage induced by Cd in wheat. Electron paramagnetic resonance (EPR) analysis showed that PSNPs could accelerate the formation of long-lived radicals in leaves after exposure to Cd. Notably, our metabolomics profiling further indicated that the simultaneously elevated carbohydrate and amino acid metabolisms induced by PSNPs could partly alleviate Cd toxicity to wheat. Nevertheless, the present study provides important implications for the toxicological interaction and future risk assessment of co-contamination of nanoplastics and heavy metals in the environment. Image 1 • PSNPs reversibly adsorbed Cd but adsorption is significantly weakened by ionic strength. • Cd-induced toxicity in wheat could be partly alleviated by PSNPs. • PSNPs did not markedly improve antioxidant enzyme activities under Cd treatment. • Carbohydrates and amino acid metabolisms were elevated by PSNPs to resist Cd toxicity. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are characterized by small particle sizes (<5 mm) and are widely distributed in the soil environment. To date, little research has been conducted on investigating the effects of MPs on the soil microbial community, which plays a vital role in biogeochemical cycling. In the present study, we investigate the influence of two particle sizes of MPs on dissolved organic carbon (DOC) and its relative functional groups, fluxes of greenhouse gases (GHGs), and the bacterial and fungal communities in fertilized soil. The results showed that a 5% concentration of MPs had no significant effect on soil DOC, whereas the formation of aromatic functional groups was accelerated. In fertilized soil, the existence of MPs decreased the global warming potential (GWP) as a result of a reduction in N 2 O emissions during the first three days. A potential mechanism for this reduction in N 2 O emissions might be that MPs inhibited the phylum Chloroflexi , Rhodoplanes genera, and increased the abundance of Thermoleophilia on day 3. An increase in N 2 O emissions was observed on day 30, mainly due to the acceleration of the NO 3 − reduction and a decrease in the abundance of Gemmatimonadacea. The CH 4 uptake was significantly correlated with Hyphomicrobiaceae on day 3 and Rhodomicrobium on day 30. In soil with MPs, Actinobacteria replaced Proteobacteria as the dominant phylum. Larger MPs increased the richness (Chao1) and abundance-based coverage estimators (ACE) and diversity (Shannon) of the bacterial community on day 3, whereas these decreased on day 30. The richness and diversity of the fungal community were also reduced on days 3 and 30. Smaller MPs increased the community richness and diversity of both bacterial and fungal communities in fertilized soil. Our findings suggest that MPs have selective effects on microbes and can potentially have a serious impact on terrestrial biogeochemical cycles. Image 1 • Smaller particle size microplastics could accelerate the aromatic matters' formation. • Microplastics in fertilized soil could reduce N 2 O emission. • Actinobacteria replaced Proteobacteria as the Dominant phylum in microplastics soil. • Microplastic size effect was shown on alpha diversity. • Microplastics influenced the co-occurrence network among different microorganisms. Main findings : Microplastics decreased the global warming potential of soil. Particle size affected alpha diversity, and Actinobacteria replaced Proteobacteria as the dominant phylum in soil with microplastics. [ABSTRACT FROM AUTHOR]

Perfluorodecanoic acid (PFDA) has been widely used in production of many daily necessities because of its special nature. Althoughtoxic effects of PFDA to organisms have been reported, there is little research on the genotoxicity induced by oxidative stress of PFDA on the cellular and molecular levels simultaneously. Thus, we investigated the DNA oxidative damage caused by PFDA in mouse hepatocytes. On the cellular level, an increase in ROS content indicated that PFDA caused oxidative stress in mouse hepatocytes. In addition, after PFDA exposure, the comet assay confirmed DNA strand breaks and an increased 8-OHdG content demonstrated DNA oxidative damage. On the molecular level, the microenvironment of aromatic amino acids, skeleton and secondary structure of catalase (CAT) were varied after PFDA exposure and the enzyme activity was reduced because PFDA bound near the heme groups of CAT. Moreover, PFDA was shown to interact with DNA molecule by groove binding. This study suggests that PFDA can cause genotoxicity by inducing oxidative stress both on the cellular and molecular levels. PFDA causes oxidative stress and DNA damage both in cellular and molecular levels. Image 1 • The work establishes a combined molecular and cellular toxicity evaluation method. • PFDA causes DNA damage by inducing oxidative stress. • Binding interactions of PFDA with CAT are systematically investigated. • PFDA binds to the DNA molecule in a minor groove. [ABSTRACT FROM AUTHOR]