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As a typical high geological background area in the middle reaches of the Yangtze River tributary basin in China, the Loushao Basin in Hunan is covered with high mineral black shale, with an average element value 4.76-8.97 times higher than the world average rock level. The aim of this study is to analyze the water environment pollution in the middle reaches of the Yangtze River tributary basin under high geological background based on the spatial distribution differences of black shale concentration. PCA source analysis is used to track the source of pollution and highlight the differences in body shape to assess regional health risks. The research results show that Cd in water quality exceeds the background value by 7.5 times. There is a strong homology among Pb, Cd, Cr, As, and Hg elements in water bodies, mainly derived from the natural weathering, migration, and enrichment of rocks. Hg element is a pollution caused by human factors, and water pollution is more severe in areas close to high concentrations, with severe exceedance of Cr element in water quality. The main controlling factor for individual health risk differences is body shape, and men's health is more susceptible to threats., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Bozhi Ren reports financial support was provided by National Natural Science Foundation of China. Bozhi Ren reports financial support was provided by Hunan Provincial Natural Science Foundation. Luyuan Chen reports financial support was provided by Postgraduate Scientific Research Innovation Project., (Copyright © 2024 Elsevier B.V. All rights reserved.)

During the process of black shale weathering, multiple heavy metal elements are concentrated in the soil, causing pollution. This study selected soil and black shale bedrock samples from high geological background areas to investigate the control of heavy metal element pollution by bedrock using spatial analysis. The research results indicate that the heavy metal content in black shale bedrock is extremely high, ranging from 2.3 to 13.1 times the background values of rock heavy metal elements. The heavy metal content in the soil formed through weathering is positively correlated with the bedrock, ranging from 1.1 to 21.3 times the background values. The coefficient of variation of rock samples ranges from 1.09 to 7.18, indicating significant variability.The analysis reveals that the control ability of pure rock over heavy metal elements is mainly moderate and high, accounting for over 70 %, with d being the most affected metal element. Except for As, the other seven elements exhibit strong spatial autocorrelation, showing distinct regional distribution characteristics. The soil elements demonstrate high homogeneity, with heavy metal elements from black shale bedrock primarily released through weathering serving as the main source of these elements., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Bozhi Ren reports financial support was provided by National Natural Science Foundation of China. Bozhi Ren reports financial support was provided by Hunan Provincial Natural Science Foundation. Luyuan Chen reports financial support was provided by Postgraduate Scientific Research Innovation Project., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Harmful algal blooms (HABs) significantly impact on water quality and ecological balance. Ultrasound irradiation has proven to be an effective method for algal control. Nevertheless, the molecular mechanisms underlying the inactivation of M. aeruginosa by ultrasound are still unknown. In this study, the physiological activity and molecular mechanism of algal cells exposed to different frequencies of ultrasound were studied. The results indicated a pronounced inhibition of algal cell growth by high-frequency, high-dose ultrasound. Moreover, with increasing ultrasound dosage, there was a higher percentage of algal cell membrane ruptures. SEM and TEM observed obvious disruptions in membrane structure and internal matrix. Hydroxyl radicals generated by high-frequency ultrasound inflicted substantial cell membrane damage, while increased antioxidant enzyme activities fortified cells against oxidative stress. Following 2 min of ultrasound irradiation at 740 kHz, significant differential gene expression occurred in various aspects, including energy metabolism, carbohydrate metabolism, and environmental information processing pathways. Moreover, ultrasound irradiation influenced DNA repair and cellular apoptosis, suggesting that the algal cells underwent biological stress to counteract the damage caused by ultrasound. These findings reveal that ultrasound irradiation inactivates algae by destroying their cell structures and metabolic pathways, thereby achieving the purpose of algal suppression., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, a new composite with layered double hydroxides (LDHs) anchored grown on expanded graphite (EG) interlayers was prepared by vacuum-assisted intercalation and hydrothermal method. Both sides of EG were completely covered by highly dispersed LDHs nanosheets and formed a sandwich-like structure. The unique structure made expanded graphite/layered double hydroxides (EG/LDHs) composites which had excellent F - adsorption performance. The adsorption performance of F - on EG/LDHs was evaluated, and the results indicated that the adsorption process was consistent with the pseudo-second-order kinetic model and the Langmuir model. Pseudo-second-order kinetic model indicated that the adsorption sites were the main factor in the adsorption process. Moreover, the maximum adsorption capacity (Q m ) reached 63.21 mg·g -1 at 30 min at room temperature, which was better than most of the same type of adsorbents. The highly dispersed of LDHs anchored growth on EG overcame the disadvantage of aggregation, which exposed more adsorption sites and improved the removal efficiency of F - . In addition, the effects of pH, anion interference, different water quality, and regeneration tests on the EG/LDHs composites were also analyzed, showing that the composites have good stability., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The discharge of personal care products (PPCPs) to sewer systems increased due to the rapid expansion of cities, while PPCPs transformation in sewer and the potential threat to receiving water environments have been rarely revealed. In this study, six PPCPs (antibiotics, generic drugs and personal care products) were added continuously over a 90-day experimental period to investigate the effect of transformation in a pilot sewer. The results showed that the biological metabolism of carbon, nitrogen and phosphorus pollutants were restricted under the PPCPs stress condition. The genomic detection also confirmed that the diversity of microflora in sewer sediment were obviously decreased with the PPCPs transformation, and the total relative abundance of dominant phylum species (Firmicutes, Bacteroidetes and Proteobacteria) increased from 67.7% to 94.9%. In addition, principal coordinate analysis and metagenome showed that the two kinds of antibiotics were the most important inducement for the metabolic dysfunction in sewer systems, and led to the increase of functional gene of "Human Disease" (accounted for 0.97%) which could form more harmful metabolites to cause serious exposure hazards. Thus, this investigation provided the insights into the metabolic hazards of PPCPs bioconversions in sewers, which hoped to bring to the forefront of PPCPs emission to sewers by society., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Carbon-bridge-modified malonamide (MLD)/g-C 3 N 4 (CN) was prepared by copolymerization of MLD with urea and melamine and loaded with Fe 3 O 4 for the high-efficiency removal of tetracycline (TC) in water under photo-Fenton. The prepared catalysts were characterized by SEM, TEM, N 2 adsorption-desorption analysis, XPS, XRD, and FTIR, which proved that the modification method successfully introduced the C bridge into the carbon nitride molecular system and increased the structural defects of the catalyst. The Carbon-bridge-modified MLD/CN/Fe 3 O 4 also had good visible-light response and charge-separation and transport abilities in the photoelectrochemical test. Degradation results showed that the photo-Fenton degradation of TC reached 95.8%, and the mineralization rate was 55.7% within 80 min at 80 mM H 2 O 2 dosage, 0.5 g/L catalyst dosage, and near-neutral pH by 0.8MLD/CN/Fe 3 O 4 . Moreover, the oxidation products and mineralization pathways of TC were explored by LC-MS. Toxicity analysis indicated low environmental threat of the intermediates in TC mineralization. EPR analysis and H 2 O 2 decomposition efficiency analyses showed an improvement in the H 2 O 2 decomposition performance of 0.8MLD/CN/Fe 3 O 4 . This work could provide a valuable insight for the application of heterogeneous photo-Fenton technology in wastewater treatment., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In this study, impacts of in-situ ozonation applied directly in the membrane tank of a ceramic MBR (Oz-MBR) were assessed to elucidate its implications on micropollutant removal, microbial taxa and membrane fouling. The basic effluent quality (i.e., bulk organics and nutrients) of the MBR without and with in-situ ozonation was comparable. Importantly, pollutant-specific (10-26%) improvement in micropollutant removal was achieved by the Oz-MBR, which could be attributed to the increase in the abundance of microbial taxa responsible for the removal of structurally complex pollutants and/or ozone-assisted oxidation. In-situ ozonation affected the abundance of denitrifying bacteria and functional genes but total nitrogen removal by the Oz-MBR was comparable to that achieved by the control (C)-MBR. Improved mixed liquor properties, and the reduced accumulation of foulants on the membrane surface resulted in membrane fouling alleviation (53%) in the Oz-MBR. In addition, fouling models evaluated for the first time in the case of Oz-MBR indicated that the cake-complete model was suitable to explain membrane fouling mechanism. This comprehensive study demonstrates the performance of MBR coupled with in-situ ozonation, and the obtained results would serve as a useful reference for its implementation at pilot- and/or full-scale., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The mass production and usage of carbon nanotubes (CNTs) have led to the inevitable release into the environment, and the effects of CNTs on the toxicity of co-existing pollutants have been well documented. However, knowledge of the effects of CNTs on the enantioselective toxicity of chiral compounds is limited. Using zebrafish as an experimental model, the enantioselective expression of the apoptosis, CYP3C and EAAT-related genes were analyzed following exposure to multi-walled carbon nanotubes (MWCNTs) (0.05 and 0.5 mg/L), rac-/R-/S-indoxacarb (0.01 mg/L), or the combination of rac-/R-/S-indoxacarb mixed with MWCNTs for 28d. Sex-specific differences were observed in both the liver and brain of zebrafish. The expression of apoptosis and CYP3C-related genes was 16.55-44.29 times higher in the livers of males treated with R-indoxacarb than in S-indoxacarb treated groups. The EAAT-related genes were expressed at 1.38-2.56 times higher levels in the brain of females treated with R-indoxacarb than in S-indoxacarb-treated groups. In the presence of MWCNTs, the expression of caspase-3, cyp3c3, cyp3c4, eaat1a, eaat1b and eaat2 in the livers of males and brains of females treated with S-indoxacarb were 1.65-15.33 times higher than in fish treated with R-indoxacarb. Based on these results, MWCNTs affected the enantioselective toxicity of indoxacarb toward zebrafish., Competing Interests: Declaration of Competing Interest The authors have no competing financial interests to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Congo red (CR) is a kind of refractory contaminant. Conventional biological treatment processes are ineffective for the CR degradation. However, photocatalysis technology could be an alternative for the decomposition of CR because of its high efficiency. In this study, we prepared three kinds of photocatalysts, all of which have advanced visible light excitation characteristics. The magnetic catalyst C-TiO 2 @Fe 3 O 4 /AC was produced by loading C-TiO 2 and nano-Fe 3 O 4 onto granular activated carbon (AC). C-TiO 2 @Fe 3 O 4 /AC has a band gap of 2.535 eV, stable magnetic characteristics, and stability toward CR removal. C-TiO 2 @Fe 3 O 4 /AC showed the best performance for CR removal under both simulated sunlight (200-800 nm) and visible light (400-800 nm) irradiation compared to the other catalysts. The CR removal rate reached 92.9% after 30 min of simulated sunlight irradiation, and the reaction rate constant was 0.1776 min -1 . Under visible light, the CR removal rate reached 65%. The hydroxyl radical (OH) was detected, and its concentration was determined. Furthermore, the spectral analysis results indicated that the azo bonds and aromatic rings in CR were destroyed. The C-TiO 2 @Fe 3 O 4 /AC has a self-cleaning ability to prevent organic contamination. This study provides a new way of thinking and a simple preparation technique for magnetic visible light catalyst synthesis., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The identification of hyperaccumulators is a key step for the phytoextraction of contaminated soils. However, few cadmium (Cd) hyperaccumulators have been identified in the plant kingdom. In our previous field investigations, Lantana camara L. plants exhibited some traits of hyperaccumulators. To confirm whether this species is a Cd hyperaccumulator, laboratory dose-gradient experiments and field sample analysis experiments were first designed and implemented in an integrated manner. The results showed that lantana plants did not exhibit any visible damage or marked reduction in shoot biomass when grown in Cd-contaminated soil with less than 100 mg kg -1 Cd. Moreover, the lantana plants exhibited high Cd tolerance with effective coordination of photosynthesis and rapid reactive oxygen species scavenging. Most importantly, the bioaccumulation factors (BFs) and translocation factors (TFs) were greater than 1.0 in all the Cd treatments, while the Cd concentrations in the shoots were all greater than those in the roots and were also greater than 100 mg kg -1 , the threshold value for a Cd hyperaccumulator. Our data provide comprehensive evidence that lantana plants have the typical characteristics of a Cd hyperaccumulator and thus can be regarded as potential Cd-hyperaccumulating plants for the restoration of Cd-polluted soils., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Novel Ce-PbO 2 /ZrO 2 composite electrodes were successfully fabricated in lead nitrate solution containing cerium ions and ZrO 2 particles by composite electrodeposition method. SEM images and XRD results indicated that Ce-PbO 2 /ZrO 2 composite electrodes have compact structure and fine grain size. Ce-PbO 2 /ZrO 2 composite electrode has higher oxygen evolution overpotential and stability than Ce-PbO 2 electrode. The service life of Ce-PbO 2 /ZrO 2 composite electrode reaches 318 h, which is 4.2 times as that of Ce-PbO 2 electrodes (74 h). The novel Ce-PbO 2 /ZrO 2 composite electrode was employed as anode to decontaminate acridine orange (AO) by electrochemical oxidization methods. The effect of initial concentration of AO, current density, and initial pH values on the removal ratio of AO were analyzed. The results showed that AO could be completely removed after 90 min electrolysis under the optimal condition: initial AO concentration was 30 mg L -1 , current density was 50 mA cm -2 , and the initial pH value was 5.0. Moreover, the possible degradation pathway of AO was elucidated based on the identification of stable byproducts generated during the electrochemical degradation process by HPLC-MS, which revealed that AO and its byproducts could be effectively eliminated and mineralized into CO 2 , H 2 O, ammonium and nitrate ions., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Dual-porosity materials containing both macropores and mesopores are highly desired in many fields. In this work, we prepared dual-porosity Mn 2 O 3 cube materials with large-pore mesopores, in which, macropores are made by using carbon spheres as the hard templates, while the mesopores are produced via a template-free route. The attained dual-porosity Mn 2 O 3 materials have 24nm of large-pore mesopores and 700nm of macropores. Besides, the achieved materials own cubic morphologies with particle sizes as large as 6.0μm, making them separable in the solution by a facile natural sedimentation. Dye adsorption measurements reveal that the dual-porosity materials possess a very high maximum adsorption capacity of 125.6mg/g, much larger than many reported materials. Particularly, the adsorbents can be recycled and the dye removal efficiency can be well maintained at 98% after four cycles. Adsorption isotherm and kinetics show that the Langmuir model and the pseudo-second-order kinetics model can well describe the adsorption process of Congo Red on the dual-porosity Mn 2 O 3 cube materials. In brief, the reported dual-porosity Mn 2 O 3 demonstrates a good example for controlled preparation of dual-porosity materials with large-pore mesopores, and the macropore-mesopore dual-porosity distribution is good for mass transfer in dye adsorption application., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Despite numerous reports implicating nitric oxide (NO) in the environmental-stress responses of plants, the specific metabolic and ionic mechanisms of NO-mediated adaptation to metal stress remain unclear. Here, the impacts of copper (Cu) and NO donor (SNP, 50μM) alone or in combination on the well-known medicinal plant Catharanthus roseus L. were investigated. Our results showed that Cu markedly increased Cu(2+) accumulation, decreased NO production, and disrupted mineral equilibrium and proton pumps, thereby stimulating a burst of ROS; in addition, SNP ameliorates the negative toxicity of Cu, and cPTIO reverses this action. Furthermore, the accumulations of ROS and NO resulted in reciprocal changes. Interestingly, nearly all of the investigated amino acids and the total phenolic content in the roots were promoted by the SNP treatment but were depleted by the Cu+SNP treatment, which is consistent with the self-evident increases in phenylalanine ammonia-lyase activity and total soluble phenol content induced by SNP. Unexpectedly, leaf vincristine and vinblastine as well as the total alkaloid content (ca. 1.5-fold) were decreased by Cu but markedly increased by SNP (+38% and +49% of the control levels). This study provides the first evidence of the beneficial behavior of NO, rather than other compounds, in depleting Cu toxicity by regulating mineral absorption, reestablishing ATPase activities, and stimulating secondary metabolites., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The explicit-solvent molecular dynamic (MD) simulation and adaptive biased forces (ABF) methods were employed to systemically study the structural and thermodynamic nature of the β-cyclodextrin (βCD) monomer, phenanthrene (Phe) monomer, and their inclusion complexes in both the aqueous and membrane environments, aiming at clarifying the atomic-level mechanisms underlying in the CD-enhanced degradation of polycyclic aromatic hydrocarbons (PAHs) by bacteria. Simulations showed that βCD and Phe monomers could associate together to construct two distinctive assemblies, i.e, βCD1-Phe1 and βCD2-Phe1, respectively. The membrane-involved equilibrium simulations and the data of potential of mean forces (PMFs) further confirmed that Phe monomer was capable of penetrating through the membranes without confronting any large energy barrier, whereas, the single βCD and βCD-involved assemblies were unable to pass across the membranes. These observations clearly suggested that βCD only served as the carrier to enhance the bioavailability of Phe rather than the co-substrate in the Phe biodegradation process. The Phe-separation PMF profiles indicated that the maximum of the Phe uptake by bacteria would be achieved by the "optimal" βCD:Phe molar ratio, which facilitated the maximal formation of βCD1-Phe1 inclusion and the minimal construction of βCD2-Phe1 complex., (Copyright © 2014 Elsevier B.V. All rights reserved.)