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Currently, microplastic pollution is more serious and complicates the toxic effects of other co-existing pollutants in the environment. However, the effect and mechanism of biodegradable plastics on the growth and metabolism of probiotic remain unclear. This work selected Bacillus amyloliquefaciens as model bacterium for a three-day exposure experiment to probe the issues. The results showed that 100 mg/L polylactic acid microplastics (PLA MPs) (3–4 mm, flake shape) caused oxidative damage to cell membranes, disrupted cell wall composition and inhibited cell growth by 21.2–27.5 %. The toxicity was not simply additive or synergistic effects when PLA MPs (100 mg/L) and copper ions (10 mg/L) coexisted. PLA MPs did not significantly increase the toxicity of copper to bacteria, instead triggered some mechanisms to resist the toxicity of copper. The bacteria formed spores to resist PLA MPs, while the copper ions toxicity was weaken by chelation and efflux. It is worth noting that copper ions instead increased the expression of genes related fengycin and iturin then improving the bacteriostatic activity of the probiotic. This paper deeply analyzes the toxicity mechanism of combined pollution on Bacillus amyloliquefacien, and also provides new perspective for helping to inhibit pathogenic bacteria under biodegradable microplastics and metal stress. [Display omitted] • Paper discussed the toxicity of biodegradable microplastics and copper on probiotic. • Polylactic acid microplastics still had a certain toxicity to bacteria. • The toxicity of combined pollutants was not simple synergistic or additive effects. • Pollutants might instead improve the bacteriostatic effect of inoculants. [ABSTRACT FROM AUTHOR]

Industrial progress has brought us an important polymer material, i.e. plastic. Because of mass production and use, and improper management and disposal, plastic pollution has become one of the most pivotal environmental issues in the world today. However, the current researches on microplastics/nanoplastics are mainly focused on individual aquatic, terrestrial and atmospheric environments, ignoring the fact that the natural environment is a whole. In this regard, the transport of microplastics/nanoplastics among the three environment compartments, including reciprocal contributions and inherent connections, and the impact of microplastics/nanoplastics on organisms living in multiple environments are research problems that we pay special attention to. Furthermore, this paper comprehensively reviews the transport and distribution of microplastics/nanoplastics in individual compartments and the toxicity of organisms, either alone or in combination with other pollutants. The properties of microplastics/nanoplastics, environment condition and the growth habit of organisms are critical to the transport, distribution and toxicity of microplastics/nanoplastics. These knowledge gaps need to be addressed urgently to improve cognition of the degree of plastic pollution and enhance our ability to deal with pollution. Meanwhile, it is hoped that the paper can provide a relatively complete theoretical knowledge system and multiple "leads" for future innovative ideas in this field. ga1 • Discuss the interface transport of microplastics/nanoplastics (MPs/NPs) among three major environment compartments. • Analyze the effects of MPs/NPs to creatures that need to span aquatic, terrestrial and atmospheric environment. • Completely review the transport pathway and toxicity of MPs/NPs in individual environments. [ABSTRACT FROM AUTHOR]

• The catalyst activated PDS efficiently with high stability and generalizability. • The complexation of AL with RM favored the exposure of Fe active sites and adsorption of PDS. • The electron transfer pathway was the main pathway for PDS activation and SMZ degradation. • DFT demonstrated that Fe-active species are the primary site where electron transfer occurs. • T.E.S.T and biological experiments predicted lower toxicity of degradation intermediates. Advanced oxidation processes based on peroxydisulfate (PDS-AOPs) have been used for the remediation of organic wastewater. However, the mechanism for the generation of electron transfer sub-stable complexes in the metal–carbon/PDS system has not been fully elucidated. Herein, two environmental solid wastes were selected to synthesize a novel Fe-carbon catalyst (RM@KC 1:2 –800) using alkali lignin as the carrier and red mud (RM) as the iron source, and applied for peroxydisulfate (PDS) activation in sulfamethazine (SMZ) removal. The complexation of alkali lignin with RM favored the exposure of Fe active sites and adsorption of PDS. 97% of SMZ could be removed efficiently in the RM@KC 1:2 –800/PDS system, and the degradation efficiency remained at 80.81% after 5 cycles without metal leaching, which was suitable for a variety of natural water bodies. Combined with density functional theory (DFT) and other analyses confirmed that the electron transfer pathway is the main pathway for PDS activation and SMZ degradation. And the reactive Fe species were the active sites that contributed to the adsorption of PDS on the RM@KC 1:2 –800 surface to form sub-stable complexes (RM@KC-PDS*), whereby the electron transfer occurred. Surprisingly, the prediction of environmental toxicity of the degradation intermediates based on T.E.S.T software and biological experiments proved their environmental friendliness. Overall, this study follows the concept of "waste-to-waste" and proposes a strategy for a suitable and cost-effective Fe-carbon catalyst for large-scale production, while demonstrating its potential application in the treatment of organic wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microbial community and HGT are the key factors of ARGs changes. • Carbon-based materials and clay minerals can decontaminate ARGs and heavy metals. • Functional materials act as adsorbents and alleviate heavy metals to inhibit HGT. • Functional materials change microbial community to slow the VGT of ARGs. Antimicrobial resistance (AMR), especially antibiotic resistance, has posed a huge threat to public health. Moreover, heavy metal, another significant contaminant, can accelerate the generation and dissemination of AMR. Thus, the method and mechanism of AMR removal under heavy metal stress need to be elucidated urgently. Adsorption has been proved to be an important means to deal with AMR pollution. However, there is still a lack of systematic reviews on decontaminating the combined pollution of AMR and heavy metal by adsorption. With this in mind, this review introduces two types of adsorbents, carbon-based materials (biochar and graphene oxide) and clay minerals, which can remove antibiotic resistance genes (ARGs) efficiently even under heavy metal stress. Besides, we summarize the crucial factors affecting the variations of ARGs, and the mechanisms of ARGs removal by two materials under the influences of these factors are proposed. Then, the pathways of two materials to decrease ARGs by reducing heavy metal co-selection and altering microbial communities under heavy metal stress are emphasized. Finally, the bottlenecks of the research on reducing ARGs by these adsorbents and the prior study directions in the future are described in detail. To sum up, the review offers new insight into the mitigation of AMR and heavy metal pollution and facilitates the progress of feasible methods for the removal of ARGs and heavy metal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Surface-modified bismuth vanadate is prepared for PMS activation under visible light. • CIP oxidation in BVO-2/PMS/Vis system is dominated by 1O 2 and photogenerated holes. • Surface C O acts as Lewis base site to induce PMS hydrolysis in acidic condition. • The efficiently separated electrons can reduce PMS for SO 4 − and OH generation. Lewis basic sites have been shown to induce singlet oxygen (1O 2) generation in metal-free catalysts while have yet to be elucidated in metal-containing bismuth vanadate (BiVO 4). Herein, surface-modified BiVO 4 photocatalysts are developed and applied in peroxymonosulfate (PMS) activation for ciprofloxacin (CIP) abatement employing 1O 2 and photogenerated holes as the primary reactive species. The surface carbonyl moiety acts as Lewis basic sites to induce PMS hydrolysis under acidic conditions for 1O 2 generation. The occurrence of electron transfer from PMS to catalyst accounts for 1O 2 generation via PMS oxidation. Moreover, PMS as an electron acceptor kinetically accelerates charge separation, not only inducing SO 4 − and OH generation but also allowing direct oxidation of CIP by efficiently separated holes. Accordingly, the optimal BVO-2/PMS/Vis system can completely degrade CIP in 9 min under visible light with a reaction rate of 0.4264 min−1, far exceeding the BVO-2/PMS (0.0063 min−1) and BVO-2/Vis (0.0411 min−1) systems. [ABSTRACT FROM AUTHOR]

Plastics enter the environment and break up into microplastics (MPs) and even nanoplastics (NPs) by biotic and abiotic weathering. These small particles are widely distributed in the environmental media and extremely mobile and reactive, easily suspending in the air, infiltrating into the soil, and interacting with biota. Current research on MPs/NPs is either in the abiotic or biotic compartments, with little attention paid to the fact that the biosphere as a whole. To better understand the complex and continuous movement of plastics from biological to planetary scales, this review firstly discusses the transport processes and drivers of microplastics in the macroscopic compartment. We then summarize insightfully the uptake pathways of MPs/NPs by different species in the ecological compartment and analyze the internalization mechanisms of NPs in the organism. Finally, we highlight the bioaccumulation potential, biomagnification effects and trophic transfer of MPs/NPs in the food chain. This work is expected to provide a meaningful theoretical body of knowledge for understanding the biogeochemical cycles of plastics. [Display omitted] • The transport of MPs in macroscopic compartments are discussed. • Uptake pathways of MPs/NPs in different biota are summarized. • Different mechanisms of cellular internalization of NPs in organisms are analyzed. • Bioaccumulation potential and biomagnification effects of MPs/NPs are assessed. • Evidence for trophic transfer of MPs/NPs along the food chain is highlighted. [ABSTRACT FROM AUTHOR]

Microplastics, as emerging contaminants, have attracted widespread attention for their increasing detection frequency in aquatic environment. It has been reported that microplastics may co-presence with heavy metals in water, which might have impact on heavy metals removal in water. Furthermore, the effects of microplastics on the co-remediation efficiency of plants with engineered nanomaterials are ambiguous. To this end, this study was dedicated to unveil the intrinsic effects of polystyrene microplastics (PSMPs) on the cadmium (Cd) removal efficiency by co-remediation of ryegrass (Lolium perenne L.) and three engineered nanomaterials, respectively were nano-zerovalent iron (nZVI), carboxymethylcellulose-modified-nZVI (C-nZVI) and sulfidated nZVI (S-nZVI). Significant changes were observed in Cd content, plant biomass, chlorophyll b and antioxidant enzymes. It was surprising to find that with the treatment of nZVI or C-nZVI, polystyrene microplastics would enter plants roots, and these plants were found to contain more Cd among all series. Accordingly, four possible mechanisms were proposed to explain why plants that observed the internalization of PSMPs contained more Cd. This work reveals the impact of coexisting microplastics in water on Cd remediation efficiency and provides new insights into the entry of polystyrene microplastics into plant roots. [Display omitted] • Presence of PSMPs in water promoted ryegrass take in more Cd. • nZVI or C-nZVI promoted the internalization of PSMPs in ryegrass. • Ryegrass that observed the internalization of PSMPs contained more Cd. • PSMPs inhibited ryegrass growth and photosynthesis, disrupted antioxidant system. • Part of PSMPs could be removed by ryegrass combined nZVI or C-nZVI. [ABSTRACT FROM AUTHOR]

Lignin exhibits some antioxidant and UV protection due to its large number of phenolic hydroxyl and methoxy groups, which can be used in the field of sun protection. However, its complex macromolecular structure, high polydispersity, low solubility and deep coloration limit their development in the sunscreen field. In this work, we purified and separated lignin by solvent fractionation so that its phenolic hydroxyl content could be retained or even increased without modification. Consequently, by controlling environmental factors, lignin rapidly self-assembles into nanospheres without changing its structure, which not only achieves the standard of light-colored lignin but also meets the requirement of high sunscreen performance. It was measured that the lignin nanospheres formed by this method could meet more than 90% of UV blocking, especially for ultraviolet (UVA) fragments, when mixed with commercially available creams. It not only promotes the application of lignin in the field of sun protection, realizes the sustainable development of lignin, but also alleviates the problem of solid waste treatment and disposal. [Display omitted] • Lignin fractions with different molecular weight, functional groups and solubility were obtained by solvent fractionation. • The union of solvent fractionation and self-assembly avoids the modification of lignin and promotes the synthesis of NPs. • Lignin sunscreens block UV rays up to 90% or more, especially for the UVA portion. • Compared with other methods for reducing lignin color rendering, it is simpler and environmentally friendly. • 30g of bamboo chips can meet the synthesis demand of sunscreen and realize the resource utilization of solid waste. [ABSTRACT FROM AUTHOR]

Stabilization is the most important remediation mechanisms for sediment polluted heavy metals. However, little research has been done on the identification of microenvironmental response and internal correlation, as well as synergistic mechanisms during heavy metal remediation. This study aims to investigate the inner response mechanisms of microenvironment after the lead (Pb) are gradually stabilized in sediment. An eco-friendly amendment strategy which firstly used 100% biodegradable sophorolipids (SOP) to modify chlorapatite (ClAP) for the fabrication of SOP@nClAP was applied in this study. The stabilization efficiency of Pb was significantly improved by SOP@nClAP compared with ClAP. Most importantly, the high-throughput sequencing showed that the dominant species in the sediment changed with the stabilization of Pb. The decrease of Proteobacteria and increase of Firmicutes , especially the Sedimentibacter within the phylum Firmicute directly suggested that large amounts of Pb were stabilized. This research is not only devoted to stabilize Pb in sediment by eco-friendly amendment strategy, but also keep a watchful eye on microenvironment response mechanisms during the Pb stabilization in sediment. Therefore, this study lays a foundation for the future application of more heavy metal amendment strategies in the sediment environment and improves the possibility of large-scale site amendment. [Display omitted] • An eco-friendly sophorolipids modified chlorapatite (SOP@nClAP) was fabricated. • Pb was significantly stabilized in sediment by SOP@nClAP. • Response of microenvironment was also beneficial to remediation of sediment. • SOP can greatly improve the effective utilization of phosphorus in ClAP. [ABSTRACT FROM AUTHOR]