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Introduction: The development of advanced sewage technologies empowers the industry to produce high-quality recycled water, which greatly influences human's life and health. Thus, this study investigates the mechanism of individuals' adoption of recycled water from the technology adoption perspective. Methods: Employing the mixed method of structural equation modeling and artificial neural network analysis, we examined a research model developed from the extended Unified Theory of Acceptance and Use of Technology (UTAUT2) framework. To examine the research model, this study employs a leading web-survey company (Sojump) to collect 308 valid samples from the residents in mainland China. Results: The structural equation modeling results verified the associations between the six predictors (performance expectancy, effort expectancy, social influence, facilitating conditions, environmental motivation, and price value), individuals' cognitive and emotional attitudes, and acceptance intention. The artificial neural network analysis validates and complements the structural equation modeling results by unveiling the importance rank of the significant determinants of the acceptance decisions. Discussion: The study provides theoretical implications for recycled water research and useful insights for practitioners and policymakers to reduce the environmental hazards of water scarcity.
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Nanoscale zerovalent iron synthesized using borohydride (B-NZVI) has been widely applied in environmental remediation in recent decades. However, the contribution of boron in enhancing the inherent reactivity of B-NZVI and its effectiveness in removing hexavalent chromium [Cr(VI)] have not been well recognized and quantified. To the best of our knowledge, herein, a core-shell structure of B-NZVI featuring an Fe-B alloy shell beneath the iron oxide shell is demonstrated for the first time. Alloyed boron can reduce H+, contributing to more than 35.6% of H2 generation during acid digestion of B-NZVIs. In addition, alloyed B provides electrons for Fe3+ reduction during Cr(VI) removal, preventing in situ passivation of the reactive particle surface. Meanwhile, the amorphous oxide shell of B-NZVI exhibits an increased defect density, promoting the release of Fe2+ outside the shell to reduce Cr(VI), forming layer-structured precipitates and intense Fe-O bonds. Consequently, the surface-area-normalized capacity and surface reaction rate of B-NZVI are 6.5 and 6.9 times higher than those of crystalline NZVI, respectively. This study reveals the importance of alloyed B in Cr(VI) removal using B-NZVI and presents a comprehensive approach for investigating electron pathways and mechanisms involved in B-NZVIs for contaminant removal.
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Borohidruros , Boro , Hierro , Hierro/química , Borohidruros/química , Boro/química , Cromo/química , Electrones , Aleaciones/químicaRESUMEN
Solar steam generation technology (SSGT) using unlimited solar energy is regarded as one of the most promising sustainable technologies to produce clean water. However, most of studies on SSGT simply focus on how to improve salt resistance as well as exclude inorganic and organic pollutants in targeted water, and only very limited studies pay attention to the micro-organisms in the collected water. Herein, one porous Cu2 ZnSnS4 -based photothermal hydrogel (CZTS-PH) with antibacterial properties as well as good salt resistance was successfully prepared. The CZTS-PH was measured with the water evaporation rate as high as 3.249â kg m-2 h-1 and photothermal conversion efficiency of 96.3 % under one sun irradiation. Impressively, owing to the amino groups in the skeleton, CZTS-PH can significantly deteriorate the cell membrane and lead to the death of the Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which ensures its long-term stability photothermal conversion and the safety of clean water. Overall, the admired photothermal conversion efficiency, and the excellent salt resistance and antibacterial performance suggest that CZTS-PH could be a promising full-scale device applied in seawater desalination and water purification.
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Hidrogeles , Aguas del Alcantarillado , Destilación , Escherichia coli , Staphylococcus aureus , Cloruro de Sodio , Agua de Mar , Agua , Antibacterianos/farmacologíaRESUMEN
Unraveling the diversification mechanisms of organisms is a fundamental and important macroevolutionary question regarding the diversity, ecological niche, and morphological divergence of life. However, many studies have only explored diversification mechanisms via isolated factors. Here, based on comparative phylogenetic analysis, we performed a macroevolutionary examination of horseshoe bats (Chiroptera: Rhinolophidae: Rhinolophus), to reveal the inter-relationships among diversification, intrinsic/extrinsic factors, and climatic ecological niche characteristics. Results showed a general slowing trajectory during diversification, with two dispersal events from Asia into Southeast Asia and Africa playing key roles in shaping regional heterogeneous diversity. Morphospace expansions of the investigated traits (e.g., body size, echolocation, and climate niche) revealed a decoupled pattern between diversification trajectory and trait divergence, suggesting that other factors (e.g., biotic interactions) potentially played a key role in recent diversification. Based on ancestral traits and pathway analyses, most Rhinolophus lineages belonging to the same region overlapped with each other geographically and were positively associated with the diversification rate, implying a competitive prelude to speciation. Overall, our study showed that multiple approaches need to be integrated to address diversification history. Rather than a single factor, the joint effects of multiple factors (biogeography, environmental drivers, and competition) are responsible for the current diversity patterns in horseshoe bats, and a corresponding multifaceted strategy is recommended to study these patterns in the future.
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Quirópteros , Ecolocación , Animales , Quirópteros/genética , Filogenia , Ecosistema , AsiaRESUMEN
Nanoscale zero-valent iron (NZVI) can effectively remove and recover Cd(II) from aqueous solutions. However, the oxygen effects on Cd(II) removal by NZVI have been overlooked and not well studied. In this research, the Cd MNN auger lines obtained by X-ray photoelectron spectroscopy (XPS) revealed that Cd(II) adsorbed on the NZVI surface could be reduced to Cd(0) by the Fe(0) core under anaerobic conditions. With coexisting oxygen, the Cd(II) removal efficiency declined significantly, and Cd(II) reduction was inhibited by the thickened surface γ-FeOOH layer. Furthermore, the post-oxygen intrusion corroded the generated Cd(0) and led to the dramatic leaching of Cd(II) ions. According to the density functional theory (DFT) simulation, the adsorbed Cd(II) was preferably coordinated via a monodentate model on the surface of Fe3O4 and γ-FeOOH, which are the dominant surface species of NZVI under anaerobic and aerobic conditions, respectively. Thus, γ-FeOOH with doubly coordinated hydroxyl groups provided fewer adsorption sites than Fe3O4 for Cd(II) ions. Overall, the atmospheric conditions of subsurface remediation and wastewater treatment should be considered when applying NZVI for Cd(II) removal. Favorable atmospheric conditions would improve the efficiency and cost-effectiveness of NZVI-based technologies for the practical remediation of Cd(II) pollution.
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Interfacial photo-vapor conversion has been suggested as a cost-effective and sustainable technology for seawater desalination. However, the conversion performance was still limited by some drawbacks, like salt accumulation and poor mechanical stability. Herein, a scalable MoS2 -based porous hydrogel (SMoS2 -PH) with good mechanical stability and salt resistance was successfully constructed through a crosslinking foaming polymerization method. With the high porosity (92.63 %), the SMoS2 -PH performed an impressive evaporation rate of 3.297â kg m-2 h-1 and photothermal conversion efficiency of 93.4 % under 1-sun illumination. Most importantly, the SMoS2 -PH could maintain high and stable photothermal properties for 15â days on the surface of seawater. We believe that the excellent salt resistance, the high photothermal conversion efficiency, the ease of scale preparation method and the available commercial MoS2 make the SMoS2 -PH a promising device for full-scale seawater desalination.
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A novel composite of multiwall carbon nanotube (MWCNT) supported V2O5 quantum dots decorated Bi2O3 hybrid was prepared by the simple wet-impregnation method, and the photocatalytic performance of the prepared samples was investigated against the photodegradation of ciprofloxacin (CIP). Herein, different samples of pristine, V2O5/Bi2O3 and MWCNT@V2O5/Bi2O3 hybrid photocatalyst were prepared and systematically characterized by various physicochemical techniques. The characterization results demonstrated that the introduction of MWCNT can change the energy band gap of V2O5/Bi2O3, and the band energies vary with a constituent of MWCNT@V2O5/Bi2O3 catalyst, in which MWCNT@V2O5/Bi2O3-5 (0.05 g@0.50 g:0.50 g) has the optimal band gap energy of 2.46 eV. The photocatalytic test demonstrates that the MWCNT@V2O5/Bi2O3-5 hybrid composites exhibited enhanced photocatalytic activity in CIP degradation compared to that pure and other photocatalyst and its degradation efficiency did not decrease significantly even after five cyclic experiments. The enhanced photocatalytic activity was due to the formation of heterojunction among MWCNT, V2O5 and Bi2O3, which distinctly improved the separation efficiency of the photogenerated charge carrier, thus increasing the degradation performance. This work gives a new approach to designing an efficient photocatalyst for contaminants degradation.
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Nanotubos de Carbono , Puntos Cuánticos , Bismuto/química , Ciprofloxacina , LuzRESUMEN
Catalytic ozonation based on heterogeneous metal oxides is a promising approach to removing ammonia as gaseous nitrogen from water. Herein, MgO/Co3O4/CeO2 was prepared for catalytic ozonation of ammonia in an aqueous solution. The influence of various reaction conditions was systematically investigated and optimized, in which the reaction kinetics was also analyzed. After doping Ce, the catalyst with Mg-Co-Ce molar ratio of 4:1:1 and calcined at 700 °C for 3 h, has abundant surface oxygen vacancies and exhibited excellent performance for the selective catalytic oxidation of ammonia to gaseous nitrogen by ozone. It was found that the catalytic activity of catalysts was positively related to oxygen vacancies concentration on the composites surface, which might play a vital role in selective catalytic ozonation. Under the optimal conditions, the ammonia removal rate in MgO/Co3O4/CeO2 catalytic system was 0.03328 min-1 (R2 = 0.99942), about 2.1 times greater than that of MgO/Co3O4 (0.01597 min-1, R2 = 0.99813), and the selectivity was further enhanced from 73.57% to 86.94%. Moreover, the evolution of nitrogen and chlorine species was determined to discuss the mechanism of selective oxidation of ammonia in the low chlorine-containing solution. This study might promote the understanding of catalytic ozonation of ammonia to gaseous nitrogen selectively.
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The effect of polyethylene microplastics (PE-MPs) on the disinfection of Escherichia coli (E. coli) by sodium hypochlorite was investigated in different pH value, ionic strength, and NOM concentration to illustrate the impact of MPs on the pathogenic bacteria disinfection efficiency in nature water environment. The results showed that PE-MPs tended to agglomerate rather than disperse due to their strong hydrophobicity in water. Within 30 s, about 1.5 log10 of E. coli was adsorbed on the surface of PE-MPs, forming subsequent protection for E. coli. Thus, the presence of PE-MPs reduced the inactivation rate of E. coli. As for the particle-free solutions, the higher solution pH, the presence of natural organic matter (NOM), and the higher concentrations of cations (monovalent Na+ and divalent Ca2+) were confirmed as the major influencing factors decreasing the E. coli disinfection efficiency. However, due to the adsorption and protection of PE-MPs on E. coli, the influences of complex chemistry factors on the inactivation of E. coli were reduced. The inactivation of E. coli in PE-MPs (20 NTU) solution was 1 log10 lower than that in particle-free solution under the same water quality conditions. Therefore, considering the complex water chemistry, the existence of MPs could be a potential challenge for disinfection efficiency in the water treatment plants.
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Microplásticos , Contaminantes Químicos del Agua , Adsorción , Desinfección , Escherichia coli , Plásticos , Polietileno , Hipoclorito de Sodio , Contaminantes Químicos del Agua/análisisRESUMEN
Hyperpigmented skin diseases such as melasma, freckles, and melanosis usually mar the appearance of patients. Traditional herbal medicines are highly accepted in inhibiting skin pigmentation, with advantages of high efficiency, low cost, and low side effects. Selaginellin (SEL), one of the active compounds of selaginella, has been proved to be exhibit antineoplastic, antioxidant, antisenescence, and antiapoptosis activities. In this study, we found that SEL can inhibit melanogenesis in vitro and in vivo. A mechanism study found that SEL inhibits melanogenesis through inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway, then down-regulating the expression of microphthalmia-associated transcription factor (MITF) and downstream genes tyrosinase (TYR) and tyrosinase-related protein 2 (TYRP2). UVB-activated paracrine function of fibroblasts and keratinocytes promotes melanogenesis of melanocytes. Interestingly, SEL antagonizes UVB-activated paracrine function of fibroblasts and keratinocytes. These findings indicate that SEL can be a potential whitening compound to inhibit melanogenesis.
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Melaninas , Proteínas Quinasas Activadas por Mitógenos , Humanos , Melanocitos , Factor de Transcripción Asociado a Microftalmía/genética , Factor de Transcripción Asociado a Microftalmía/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Monofenol Monooxigenasa/metabolismo , Transducción de SeñalRESUMEN
Aggregation and surface passivation of nanoscale zero-valent iron (NZVI) particles have limited their reactivity and application for environmental remediation. In this study, an aluminum hydroxide/polyacrylic acid (Al(OH)3/PAA) hybrid shell was homogeneously coated on the NZVI surface to overcome the limitations. PAA molecules were confined onto the NZVI surface by hydration of Al(III) cations. The Al(OH)3/PAA coating shell provided more electrostatic repulsion forces between NZVI particles to hinder the particle aggregation and preserve the NZVI reactivity. On the other hand, the surface-anchored PAA provided a thickened reactive layer for Cr(VI) reduction. Besides, XPS and TEM results showed that the surface carboxylic groups bound produced Cr(III) and Fe(III) cations and inhibited the precipitation of hydroxides on the NZVI surface. The reduced passivation layer increased the longevity of NZVI for surface reactions. As a result, the 24-h Cr(VI) reduction capacity of NZVI particles was improved from 49.4 to 92.6 mg/g with a 2 wt% (Al/Fe) Al(OH)3/PAA coating shell. Overall, this study presented a promising strategy to effectively tune the surface properties of nanoparticles and improve the feasibility of NZVI for environmental remediation.
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2,4-dichlorophenol (2,4-DCP) is a typical chlorophenol that has been widely used in industrial production and caused serious pollution to the environment. In this study, the performance of Fe/Ni bimetallic nanoparticles supported on polystyrene cation exchange resin (Fe/Ni-D072) to remove 2,4-DCP was evaluated. The effects including the doping amount of Ni, the dosage of Fe/Ni-DCP, the initial concentration of 2,4-DCP, and pH value of the solution on the removal efficiency were also investigated. The results showed that when the initial concentration of 2,4-DCP was 20 mg/L and pH = 7.3, 90% of 2,4-DCP could be dechlorinated by Fe/Ni-D072 (Ni% = 30 wt%, dosage: 6.7 g/L) after 12 h reaction. The dechlorination process followed a pseudo-first-order model, and the reaction constant was 0.252 h-1. In addition, the effects of humic acid and common coexisting ions on dechlorination were studied. The results showed that humic acid with a low concentration (5 mg/L) and CO32- restrained the degradation of 2,4-DCP. The dechlorination products of 2,4-DCP were identified by HPLC and the result showed phenol was the main product with a slight amount of 2-CP as the dechlorination intermediate, and 4-CP was barely detected. These results suggest that Fe/Ni-D072 was a promising catalytic material for the removal of chlorophenol and has great application prospects in groundwater remediation.
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Clorofenoles , Nanopartículas , Contaminantes Químicos del Agua , Hierro , Níquel , PoliestirenosRESUMEN
Nanoscale zero-valent iron (NZVI) has been engineered as an attractive tool for in-situ groundwater remediation. However, the poor mobility and aqueous corrosion of NZVI in the porous subsurface have hindered its practical applications. In this research, the NZVI surface was coated with a novel Mg(OH)2 shell (NZVI@Mg(OH)2) to improve the feasibility of NZVI for remediation. In the column tests for continuous removal of Cr(VI) from the flowing water, the Mg(OH)2 shell greatly improved the delivery of NZVI into the sand columns. Coating NZVI with Mg(OH)2 shell also showed considerably greater chemical stability than bare NZVI and thus greater resistance to aqueous corrosion. In addition, the dissolution of Mg(OH)2 allowed the reactivity to be gradually recovered along the sand column for Cr(VI) reduction. As a result, compared to bare NZVI in the columns, NZVI@Mg(OH)2 significantly prolonged the breakthrough period of Cr(VI) and hence increased the columns' Cr(VI) removal capacity. Moreover, the Cr(III) produced was effectively immobilized by NZVI@Mg(OH)2, even under an acidic condition (pH 4.0). The results show that Mg(OH)2 coating is a promising technique to improve the longevity and capacity of NZVI for full-scale in-situ soil and groundwater remediation.
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Cromo/química , Hierro/química , Hidróxido de Magnesio/química , Arena/química , Contaminantes Químicos del Agua/química , Restauración y Remediación Ambiental , Agua Subterránea , HumanosRESUMEN
An autocatalytic system, permanganate-ultrasonic (PM-US) system, was applied to degrade perfluorooctanoic acid (PFOA) in aqueous solutions. After a 120-min ultrasonication, a PM dosage of 6 mM increased the pseudo first-order rate constant (k1) for PFOA decomposition from 3.5 × 10-3 to 13.0 × 10-3 min-1 and increased the pseudo zeroth-order rate constant (k2) for PFOA defluorination from 1.5 × 10-3 to 7.9 × 10-3 mM·min-1, respectively. The PFOA degradation rates increased proportionally with the enhanced production rates of MnO2 particles. An initial pH 4 condition was optimal for the PFOA degradation compared to highly acidic and neutral conditions. PFOA degradation could be significantly facilitated by increasing power density of ultrasonication from 60 to 180 W·L-1. While increasing solution temperature to 50 °C only slightly promoted the PFOA decomposition and defluorination to 1.15 and 1.07 times of that at 30 °C, respectively. The solution saturated with argon was more favorable for the PFOA degradation in the PM-US system than that saturated with air and oxygen. Co-dissolved Cu(II), Fe(II) and Fe(III) ions inhibited the PFOA degradation by forming metal-PFOA complexes. Based on the experimental results and intermediates analysis, mechanisms and pathways of PFOA decomposition and defluorination in the PM-US system were proposed.