The development of adsorbents with outstanding adsorption capacities, wide versatility, and excellent recyclability for the removal of organic dyes remains a challenge. In this study, a quaternised ...chitosan-based aerogel (QCSA) was fabricated via a facile method to effectively treat concomitant anionic dyes. Porous QCSA with high hydrophilicity, nontoxicity, excellent thermal stability, and sustainability exhibits adsorption properties superior to most previously reported adsorbents. The equilibrium adsorption capacities for Congo red, Sunset yellow, and Methyl orange were 1259.6, 550.2, and 607.5 mg/g, respectively. Notably, the spent QCSA exhibits excellent cyclic performance. The multilayer adsorption, external–internal mass transfer resistance, and adsorption on the active site models were employed to enable a more accurate description of the dynamic characteristics, confirming that double-layer chemisorption was the dominant process. A quantitative analysis of the electrostatic potential and the independent gradient model further verified that electrostatic interactions, hydrogen bonding, and van der Waals forces led to the highly efficient adsorption of dye molecules. Therefore, the eco-friendly and recyclable QCSA is a promising adsorbent for trapping anionic dyes from aquatic systems.
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With the development of industry and agriculture, the increasingly serious problems of environmental pollution and water quality deterioration that affect human health need to be solved. Materials ...containing both Fe and Mn, the two most abundant metal elements, have been widely used for wastewater decontamination since they are nontoxic, low-cost, easy to prepare, and highly efficient. This review systematically summarizes the synthesis methods of Fe–Mn-based unloaded materials (such as spinel-type, perovskite-type, layered double hydroxides, metal–organic framework, and its derivatives) and loaded materials (carbon materials, oxides, and other loaded materials). Furthermore, the progress and problems of the application of Fe–Mn-based materials in the fields of Fenton, photo-Fenton, electro-Fenton, persulfate, and sulfite catalysis processes are analyzed. Different activation mechanisms of Fe–Mn-based materials, such as radical pathways and nonradical pathways (like direct electron transfer pathways, singlet oxygen, and high valence metals, etc.) are described. Finally, the application potential of Fe–Mn-based materials in environmental remediation is clarified and the future research directions are pointed out. It is expected that this review can provide new inspiration for subsequent research on the application of Fe–Mn based materials for wastewater treatment.
Aqueous zinc-ion batteries (AZIBs) have attracted widespread attention due to the advantages of high safety and environmental friendliness. Although V
2
O
3
is a promising cathode, the strong ...electrostatic interaction between Zn
2+
and V
2
O
3
crystal, and the sluggish reaction kinetics still limit their application in AZIBs. Herein, the oxygen defects rich V
2
O
3
with conducive poly (3,4-ethylenedioxythiophene) (PEDOT) shell (V
2
O
3
-O
d
@PEDOT) was fabricated for AZIBs by combining the sulfur-assisted thermal reduction and in-situ polymerization method. The introduced oxygen vacancies of V
2
O
3
–O
d
@PEDOT weaken the electrostatic interaction between Zn
2+
and the host material, improving the interfacial electron transport, while the PEDOT coating enhances the structural stability and conductivity of V
2
O
3
, thus accelerating the reaction kinetics. Based on the advantages, V
2
O
3
–O
d
@PEDOT electrode delivers a reversible capacity of 495 mAh·g
−1
at 0.1 A·g
−1
, good rate capability (189 mAh·g
−1
at 8.0 A·g
−1
), and an impressive cycling stability with 90.1% capacity retention over 1000 cycles at 8.0 A·g
−1
. The strategy may provide a path for exploiting the other materials for high performance AZIBs.
Graphic abstract
•The characteristics of rainfall erosivity in the Huaihe River Basin were analyzed.•87% rainfall erosivity concentrated during May – September in the Huaihe River Basin.•Rainfall erosivity in the ...Huaihe River Basin was highest in the upper basin.•Climatic indexes were correlated with rainfall erosivity with different lag times.•Some advice was provide for local human activities based on soil erosion prevention.
Rainfall erosivity (RE) is an important factor in the soil erosion process, which cannot be altered by human intervention alone. The Huaihe River Basin (HRB) is a large agricultural watershed, suffering severe water erosion, investigating the spatio-temporal variation of RE is essential for local soil erosion prevention. The linear regression, Yue-Pilon method, and the Hurst exponent were used in analyzing the spatio-temporal variation within the HRB during 1960–2018. The slip correlation analysis and F-test were applied to obtain the correlation between climatic indices the Arctic Oscillation (AO), the Southern Oscillation (SOI), the North Pacific Index (NPI), and the Niño 4SST index (SST) and RE in the HRB. Results revealed that the annual average RE were 4280, 5061, 4068, 4886, and 4089 MJ mm hm−2 h−1 within the HRB, upper-HRB, middle-HRB, lower-HRB, and the Yishusi River Watershed, respectively. The annual average RE will increase within the upper-HRB and lower-HRB and decrease within the middle-HRB and the Yishusi River Watershed in the future. The seasonal average RE was ranked as summer > autumn = spring > winter in the HRB. The spatiotemporal difference was significant in the HRB, and different sub-regions exhibited a different trend in seasonal RE, except for the winter RE that increased significantly in all sub-regions (p < 0.05). The highest monthly RE occurred in July, with RE during May–September accounting for approximately 87% of the annual RE in the HRB. The AO and NPI had significant correlations with RE (p < 0.05) both on the annual and monthly scales with different lag times. The monthly AO, SOI, SST, and NPI were significantly correlated with RE in the long term with different lag times in different months (p < 0.05). These findings could provide potential predictive factors for RE prediction and help prevent soil erosion within the HRB.
The biological behaviors of hepatocellular carcinoma (HCC) are complex mainly due to heterogeneity of progressive genetic and epigenetic mutations as well as tumor environment. Hepatocyte growth ...factor (HGF)/c-Met signaling pathway is regarded to be a prototypical example for stromal-epithelial interactions during developmental morphogenesis, wound healing, organ regeneration and cancer progression. And p53 plays as an important regulator of Met-dependent cell motility and invasion. Present study showed that 2 HCC cell lines, Hep3B and HepG2, displayed different invasive capacity when treated with HGF which was secreted by hepatic stellate cells (HSCs). We found that HGF promoted Hep3B cells invasion and migration as well as epithelial-mesenchymal transition (EMT) occurrence because Hep3B was p53 deficient, which leaded to the c-Met over-expression. Then we found that HGF/c-Met promoted Hep3B cells invasion and migration by upregulating Snail expression. In conclusion, HGF/c-Met signaling is enhanced by loss of p53 expression, resulting in increased ability of invasion and migration by upregulating the expression of Snail.
Ecological stoichiometry focuses on the balance of chemical elements and can enhance our understanding of the adaptive strategies of plants. However, few studies concerning the stoichiometry patterns ...of leaf carbon (C), nitrogen (N) and phosphorous (P) concentrations in aquatic macrophytes across latitudinal gradients have been reported. We collected 681 samples from 213 sites in eastern China, including 122 species from 55 genera and 35 families, to analyse variations in leaf C, N and P and their relationships with latitude, mean annual temperature and mean annual precipitation. The leaf C, N and P concentrations were significantly different among the four investigated life forms, but no significant differences were detected between seed plants and ferns. The N:P ratios were well constrained in different functional groups. The C:P and N:P ratios found in aquatic macrophytes in the present study were lower than previous findings, likely due to higher concentration of P in the surrounding environments. As the temperature increased, the leaf N concentration and leaf N:P ratio increased, whereas the leaf P concentration decreased. Furthermore, temperature was the key factor which can affect the stoichiometry patterns observed in widely distributed species directly and also indirectly at the community level. The slope of the regression line of the log10-transformed N concentrations against the log10-transformed P concentrations found in the seed plants of aquatic macrophytes was conserved and was greater than the slope of 2/3 reported for terrestrial plants, suggesting that the leaf N concentration increases faster relative to leaf P in aquatic than terrestrial plants.
Iron-based PAA activation process is a promising advanced oxidation process for water decontamination which depends on Fe(II) as the main reactive site for PAA activation, resulting in various ...reactive oxidative species (ROSs) generation. For practical application, the impact of water matrix chloride ion (Cl-) on ROSs production and contaminants removal should be carefully considered. In this study, it's found that the introduction of Cl- (0.1-10 mM) could significantly enhance the reaction rate of the rapid stage (kobs1) up to 2.15 times at the initial pH of 4.25 in the Fe(II)/PAA system. Further studies demonstrated that the improved removal capacity of NAP resulted from Cl- induced R-O• generation as indicated by the exposure dose of R-O• increasing from 7.74 × 10-11 M•s to 1.44 × 10-10 M•s, rather than chlorine-containing radicals' generation. DFT calculation results suggested that the formed Fe(II)-Cl- complexes could easily activate PAA to generate more ROSs for NAP removal. Moreover, Fe(II)/PAA treatment can alleviate the biological toxicity of pollutants via both the Escherichia coli test and toxicity assessment. The obtained new knowledge manifested that Cl- can boost ROSs generation and conversion in iron-based PAA systems, providing guidance for the efficient decontamination of chlorine-containing sewage with PAA-based AOPs.
Many notorious invasive plants are clonal, however, little is known about the different roles of clonal integration effects between invasive and native plants. Here, we hypothesize that clonal ...integration affect growth, photosynthetic performance, biomass allocation and thus competitive ability of invasive and native clonal plants, and invasive clonal plants benefit from clonal integration more than co-occurring native plants in heterogeneous habitats. To test these hypotheses, two stoloniferous clonal plants, Alternanthera philoxeroides (invasive), Jussiaea repens (native) were studied in China. The apical parts of both species were grown either with or without neighboring vegetation and the basal parts without competitors were in nutrient- rich or -poor habitats, with stolon connections were either severed or kept intact. Competition significantly reduced growth and photosynthetic performance of the apical ramets in both species, but not the biomass of neighboring vegetation. Without competition, clonal integration greatly improved the growth and photosynthetic performance of both species, especially when the basal parts were in nutrient-rich habitats. When grown with neighboring vegetation, growth of J. repens and photosynthetic performance of both species were significantly enhanced by clonal integration with the basal parts in both nutrient-rich and -poor habitats, while growth and relative neighbor effect (RNE) of A. philoxeroides were greatly improved by clonal integration only when the basal parts were in nutrient-rich habitats. Moreover, clonal integration increased A. philoxeroides's biomass allocation to roots without competition, but decreased it with competition, especially when the basal ramets were in nutrient-rich sections. Effects of clonal integration on biomass allocation of J. repens was similar to that of A. philoxeroides but with less significance. These results supported our hypothesis that invasive clonal plants A. philoxeroides benefits from clonal integration more than co-occurring native J. repens, suggesting that the invasiveness of A. philoxeroides may be closely related to clonal integration in heterogeneous environments.
Cerambycidae is one of the most diversified groups within Coleoptera and includes nearly 35,000 known species. The relationships at the subfamily level within Cerambycidae have not been convincingly ...demonstrated and the gene rearrangement of mitochondrial genomes in Cerambycidae remains unclear due to the low numbers of sequenced mitogenomes. In the present study, we determined five complete mitogenomes of Cerambycidae and investigated the phylogenetic relationship among the subfamilies of Cerambycidae based on mitogenomes. The mitogenomic arrangement of all five species was identical to the ancestral Cerambycidae type without gene rearrangement. Remarkably, however, two large intergenic spacers were detected in the mitogenome of Pterolophia sp. ZJY-2019. The origins of these intergenic spacers could be explained by the slipped-strand mispairing and duplication/random loss models. A conserved motif was found between trnS2 and nad1 gene, which was proposed to be a binding site of a transcription termination peptide. Also, tandem repeat units were identified in the A + T-rich region of all five mitogenomes. The monophyly of Lamiinae and Prioninae was strongly supported by both MrBayes and RAxML analyses based on nucleotide datasets, whereas the Cerambycinae and Lepturinae were recovered as non-monophyletic.
Flooding represents one of the most severe natural disasters threatening the
development of human society. A model that is capable of predicting the
hydrological responses in watershed with ...management practices during flood
period would be a crucial tool for pre-assessment of flood reduction
measures. The Soil and Water Assessment Tool (SWAT) is a semi-distributed
hydrological model that is well capable of runoff and water quality modeling
under changed scenarios. The original SWAT model is a long-term yield model.
However, a daily simulation time step and a continuous time marching limit
the application of the SWAT model for detailed, event-based flood simulation.
In addition, SWAT uses a basin level parameter that is fixed for the whole
catchment to parameterize the unit hydrograph (UH), thereby ignoring the
spatial heterogeneity among the sub-basins when adjusting the shape of the
UHs. This paper developed a method to perform event-based flood simulation on
a sub-daily timescale based on SWAT2005 and simultaneously improved the UH
method used in the original SWAT model. First, model programs for surface
runoff and water routing were modified to a sub-daily timescale.
Subsequently, the entire loop structure was broken into discrete flood events
in order to obtain a SWAT-EVENT model in which antecedent soil moisture and
antecedent reach storage could be obtained from daily simulations of the
original SWAT model. Finally, the original lumped UH parameter was refined
into a set of distributed ones to reflect the spatial variability of the
studied area. The modified SWAT-EVENT model was used in the Wangjiaba
catchment located in the upper reaches of the Huaihe River in China. Daily
calibration and validation procedures were first performed for the SWAT model
with long-term flow data from 1990 to 2010, after which sub-daily
(Δt=2 h) calibration and validation in the SWAT-EVENT model
were conducted with 24 flood events originating primarily during the flood
seasons within the same time span. Daily simulation results demonstrated that
the SWAT model could yield very good performances in reproducing streamflow
for both whole year and flood period. Event-based flood simulation results
simulated by the sub-daily SWAT-EVENT model indicated reliable performances,
with ENS values varying from 0.67 to 0.95. The SWAT-EVENT
model, compared to the SWAT model, particularly improved the simulation
accuracies of the flood peaks. Furthermore, the SWAT-EVENT model results of
the two UH parameterization methods indicated that the use of the distributed
parameters resulted in a more reasonable UH characterization and better model
fit compared to the lumped UH parameter.
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