Inland lakes and rivers are large reservoirs of microplastics. But currently, not too much research was done on microplastics of mountain rivers. The protection of water sources from microplastics is ...extremely significant for the safety of human drinking water. We quantified the distribution and variation of microplastics in the surface water from tributary (upstream water-source regions) to main stream (human settlements) in the Chin Ling-Wei River Plain Rivers, and assessed the pollution risk. Rivers in the Chin Ling-Wei River Plain contained various levels of microplastics (2.30–21.05 items/L), and the main stream of the river contained higher concentrations most commonly of microplastics than tributaries. The microplastics were fragments and films; they constituted 82.3% of the total abundance of microplastics. Microplastics with a particle size < 500 µm accounted for 64.3% of all the samples. As rivers flow from the mountains to the plains, the land-use types along the rivers become more multifunctional. Thus, the risk of river microplastic pollution increases sharply with distance downstream. Our research explored the microplastics pollution in the Chin Ling mountains based on topography and land-use types and thus provides a reference for further studies exploring the spatial distribution characteristics of microplastics in small-scale rivers and for pollution risk assessments.
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•Microplastics in small-scale rivers of mountain-plain transitional area were quantified.•Microplastics pollution in mountainous areas came from agriculture and tourism.•Urbanization increased the risk of microplastics pollution in rivers.•River embankment protection projects led to an increase in microplastics.
The content of Cd, Cu, Pb, Zn, Cr, Ni and As from 250 soil samples was measured in agricultural soil of Ningxia section of the Yellow River. Positive matrix factorization (PMF) was to identify the ...main sources of these heavy metals; Sequential Gaussian Simulation (SGS) was to identify their spatial distribution and high-risk areas; and Human Health risk (HHR) model was to measure the health risk. Results showed that the average content of Cd and As exceeds the risk screening value of "Soil Environmental Quality-Agricultural Land Soil Pollution Risk Control Standard" (GB 15618-2018), which belongs to slight-level pollution. Although the content of other types of HMs (Cu, Pb, Zn, Cr, Ni) is below the risk screening value, they are still included heavily in the soil (except Cr). PMF indicated that mixed sources of agriculture and industry accounted for 27.06%, natural sources accounted for 14.12%, industrial sources accounted for 23.04%, traffic sources accounted for 21.50%, and Yellow River sedimentary sources accounted for 14.28%. PMF-HHR showed that the mixed sources of agriculture and industry are the most important factor causing non-carcinogenic risk (HI) to children (accounting for 55.75%). Industrial sources and traffic sources were the two main factors that cause HI to adults (industrial sources accounted for 25.16%, and traffic sources accounted for 28.78%). Mixed sources of agriculture and industry and natural sources were the two main factors that cause carcinogenic risk (CR) (mixed sources of agriculture and industry account for 35.34%, and natural sources account for 33.23%). SGS indicated that 0.64% and 9.32% of the total areas were posing as higher HI areas to children and adults respectively; in particular, 0.68% and 1.12% of the areas were identified as higher HI of As and Cr areas at a critical probability of 0.9.
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•PMF model was used to obtain the source of soil HMs.•SGS was used to determine the spatial distribution characteristics of soil HMs.•PMF-HHR model was used to calculate health risk of soil HMs.•SGS with uncertainty analysis was used to determine hazardous areas.
Encouraging insight into novel underlying mechanisms targeting abnormal biological pathways in colorectal cancer (CRC) are currently under investigation, edging closer and closer to clinical use. Of ...note, basic leucine zipper ATF-like transcription factor 3 (BATF3) has been implicated with the tumorigenicity of CRC. The current study aimed to elucidate the oncogenic BATF3-mediated S1PR1/p-STAT3/miR-155-3p/WDR82 axis in CRC. Initially, clinical samples of CRC tissues as well as CRC cell lines were collected to evaluate the expression patterns of BATF3/S1PR1/p-STAT3/miR-155-3p/WDR82. Dual luciferase assay was employed to assess the binding affinity between miR-155-3p and WDR82. Artificial modulation of BATF3 (down- and overexpression) was conducted to measure the malignant phenotypes of CRC cells, while tumor-bearing mice were examined to determine the in vivo effects. BATF3 facilitated the proliferative, migratory, and invasive potential of CRC cells by upregulating S1PR1. Besides, the stimulatory effect of S1PR1 was realized via restored p-STAT3 expression. Furthermore, p-STAT3 was evidenced to heighten the expression of miR-155-3p and subsequently restrict the expression of its target gene WDR82. The in vivo assays provided data further substantiating the in vitro findings that inactivation of the BATF3/S1PR1/p-STAT3/miR-155-3p/WDR82 axis suppresses CRC tumor growth. Collectively, the results of the present study emphasize the oncogenic function of BATF3 illustrated by the reinforcement the biological processes of proliferation, invasion, as well as the metastatic capacity of CRC cells through activating the S1PR1/p-STAT3/miR-155-3p/WDR82 axis.
Soil water content (SWC) is a key factor for successful vegetation restoration in arid and semiarid regions, and vegetation has significant influences on the spatial patterns and temporal dynamics of ...SWC. The aim of this study was to investigate the temporal stability of SWC under different restored grasslands in an arid hilly area of Central China. SWC was measured in the 0‐ to 300‐cm soil profile in the natural grassland (Stipa capillata) and three typical planted grasslands (Medicago sativa, Agropyron cristatum, and Caragana korshinskii) over two growing seasons (from June to October 2015 and 2016) under natural rainfall conditions. The results showed that the mean SWC in the natural grassland was approximately 30% higher than those in the planted grasslands. The SWC consumption of the planted legume grasslands in the deepest soil layers (below 200 cm) was higher than that of the natural grassland, owing to the deep root system of the legumes. Both natural and planted grasslands had low SWC temporal stability in the top soil layers (0–50 cm), whereas more stable conditions were gradually observed with increasing the soil depth. The mean value of the mean relative differences of SWC in natural grassland (ca. 15%) was lower than that in the planted grasslands (A. cristatum grasslands) and much lower than that in the scrubland, highlighting the stronger temporal stability of SWC in the natural grassland. In conclusion, natural grassland could maintain higher and stable SWC and is recommended to be used for achieving sustainable vegetation restoration in arid and semiarid regions.
Hyporheic zone (HZ) influences hydraulic and biogeochemical processes in and alongside streams, therefore, investigating the controlling geographic factors is beneficial for understanding the ...hydrological processes in HZ. Slack water pool (SWP) is an essential micro-topographic structure that has an impact on surface water and groundwater interactions in the HZ during and after high flows. However, only a few studies investigate HZ surface water and groundwater exchange in the SWP. This study used the thermal method to estimate the HZ water exchange in the SWP in a segment of the Weihe River in China during the winter season. The findings show that on the flow-direction parallel to the stream, river recharge dominates the HZ water exchange, while on the opposing flow-direction bank groundwater discharge dominates the water exchange. The water exchange in the opposing flow-direction bank is about 1.6 times of that in the flow-direction bank. The HZ water exchange is not only controlled by flow velocity but also the location and shape of the SWP. Great water exchange amount corresponds to the shape with more deformation. The maximum water exchange within the SWP is close to the river bank where the edge is relatively high. This study provides some guidelines for water resources management during flooding events.
In freshwater ecosystems, microplastics (MPs) are commonly found in reservoirs. However, limited information is available on the distribution of MPs in the reservoirs. In this study, we investigated ...the horizontal and vertical distribution characteristics of MPs in the Guanyingyan reservoir (the upper reaches of the Yangtze River, China) after impoundment and the influence of free-floating plant residues on the distribution of MPs. Results indicated that the MPs abundance in the horizontal distribution of the reservoir decreased significantly while the distance from the dam increased. The abundance of MPs in shoreline waters (average: 8.45 items L−1) was significantly higher than that in central waters (average: 4.80 items L−1). As for the vertical distribution, the percentages of fibers in the three water layers (surface, intermediate, and deep) have less variation when compared to other types of MPs. Besides, MPs who are less than 0.5 mm in size are the majority. With deeper underwater, there would be more MPs with particles smaller than 200 μm in size. At the same time, there would be fewer MPs with particles ranging from 200 to 500 μm in size. PS, PP, and PE are the main polymer types of surface water, while PVC, PE, and PET are the common type in deep water. In shoreline water, the dry weight of floating plant residues showed a positive correlation with microplastic abundance in different layers. As above said, this study confirmed that MPs in reservoirs after impoundment would tend to accumulate in the front section of the reservoir and the shoreline water. Besides, free-floating plant residues would accumulate in reservoirs, resulting in the sinking of MPs.
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•Dam reservoirs are potential enrichment zones for MPs.•Microplastics accumulate in the shoreline waters of a reservoir.•PS, PP, and PE are the most frequent MPs types found on the surface of a reservoir.•Free-floating plant residues in reservoirs lead to an accumulation of MPs.
Metal-organic frameworks (MOFs) are gradually used since of their huge specific surface area and superior pore structure. However, there are problems such as easy aggregation and difficult separation ...in water treatment. In this study, we prepared composite microspheres (FMCS-1) by modifying MIL-125-NH2 with Fe3O4 and chitosan. The structural characterization and performance analysis of the materials showed that the introduction of chitosan effectively prevents the stacking of MOFs. The magnetic test manifested that Fe3O4 solved the problem of the difficult separation of MOFs from water. The removal potential of toxic Cr(VI) was tested by adsorption experiments. The isotherm model indicated that FMCS-1 is a single molecular layer adsorbent with a maximum adsorption capacity of 109.46 mg/g at pH = 2. The adsorption kinetics showed that the adsorption of Cr(VI) by FMCS-1 was chemical adsorption. The acid resistance test demonstrated that FMCS-1 can exist stably in acid solutions. The recycling experiments proved that the adsorbent can be reused and the removal percentage still reaches 50 % after 5 cycles. This work expands the application of MOFs in water treatment and also provides an effective adsorbent for Cr(VI) removal.
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•A magnetic MIL-125-NH2@chitosan composite was prepared.•Physicochemical properties of FMCS-1 microspheres were evaluated.•FMCS-1 microspheres displayed high efficiency for Cr(VI) removal.•The adsorption mechanism of Cr(VI) by FMCS-1 was investigated.•FMCS-1 can efficiently separate from aqueous solutions.
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•Chitosan-rGO dual network structure enhanced bead stability and show high reusability.•TC and NOR adsorption by rGO@ZIF-67@CS was studied in single and binary systems.•TC and NOR had ...maximum adsorption of 1685.26 and 1890.3 mg·g−1, respectively.•Pore filling, bonding, complexation, and π-π stacking aided TC and NOR adsorption by rGO@ZIF-67@CS.•Fixed-bed treated 410 mL of TC solution and 340 mL of NOR solution in real water samples.
In this study, a novel hydrogel bead (rGO@ZIF-67@CS) was synthesized by integrating ZIF-67 into a chitosan and reduced graphene oxide (rGO) dual-network system. This hydrogel was designed for efficient removal of tetracycline (TC) and norfloxacin (NOR) in single- and binary-solute systems. The adsorption experiments revealed that TC and NOR can be effectively removed over a wide range of pH (4–8), achieving maximum adsorption capacities of 1685.26 mg·g−1 at pH = 4 for TC and 1890.32 mg·g−1 at pH = 5 for NOR. The pseudo-second-order kinetic and Langmuir models better fitted the kinetic and isotherm data of both antibiotics, indicating a homogeneous adsorption process dominated by monolayer chemisorption. Even after five adsorption–desorption cycles, the adsorption efficiency of the two antibiotics remained above 80 %. In the binary systems, rGO@ZIF-67@CS simultaneously removed 92.68 % of TC and 82.46 % of NOR. Additionally, in practical applications, the fixed-bed system treated 320 mL of the TC solution and 290 mL of the NOR solution. Microscopic characterization suggested that the adsorption mechanisms were likely attributed to pore filling, π-π stacking, hydrogen bond interactions, and complexation.
Agricultural activities are among the most significant sources of microplastics (MPs) in water. However, few studies have explored the effect of irrigation on the fate of MPs in agricultural systems. ...This study investigated the distribution of MPs in agricultural soil, surface water, and sediment of adjacent rivers, as well as the “MP communities” in various environments before and after irrigation in a typical agricultural irrigation area of the Yellow River. MPs were detected in all of the examined sites. The number of MPs in surface water and sediment increased after irrigation, whereas those in the surface soil of croplands decreased. In the vertical direction, irrigation accelerated the migration of MPs (< 100 µm) deep into the soil. The vertical mobility of fibers in soil was faster than that of other types of MPs. Moreover, irrigation decreased the correlation between soil properties and MPs in soils. MP community analysis indicated that irrigation enhanced the differences between MP communities among adjacent environments. Collectively, our findings confirmed that river water irrigation caused secondary MP pollution in the soil environment and accelerated MP pollution in deep soil. Therefore, this study provides a theoretical basis for the development of strategies for MP pollution control in agricultural soil.
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•River water irrigation led to the secondary pollution of MPs in soil.•Fibers in soils had a higher vertical mobility than those in water.•Irrigation lowered the correlation between soil properties and MPs in soils.•MPs communities in various environments were significantly different.•Irrigation decreased the similarity of MP communities between environments.
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