Sustainable treatment of aquaculture water employing fungi-microalgae consortium: Nutrients removal enhancement, bacterial communities optimization, emerging contaminants elimination, and mechanism analysis

Fungi-microalgae consortium (FMC) has emerged as a promising system for advanced wastewater treatment due to its high biomass yield and environmental sustainability. This study aimed to investigate the nutrients removal, bacterial community shift, emerging contaminants elimination, and treatment mechanism of a FMC composed of Cordyceps militaris and Navicula seminulum for aquaculture pond water treatment. The fungi and microalgae were cultured and employed either alone or in combination to evaluate the treatment performance. The results demonstrated that the FMC could improve water quality more significantly by reducing nutrient pollutants and optimizing the bacterial community structures. Furthermore, it exhibited stronger positive correlation between the enrichment of functional bacteria for water quality improvement and pollutants removal performance than the single-species treatments. Moreover, the FMC outperformed other groups in eliminating emerging contaminants such as heavy metals, antibiotics, and pathogenic Vibrios. Superiorly, the FMC also showed excellent symbiotic interactions and cooperative mechanisms for pollutants removal. The results collectively corroborated the feasibility and sustainability of using C. militaris and N. seminulum for treating aquaculture water, and the FMC would produce more mutualistic benefits and synergistic effects than single-species treatments.

Sulfur migration mechanism of pig manure in supercritical water: A combined experimental and DFT study

Pig manure (PM) is a high concentration organic waste rich in sulfur, and its biofuel contains various sulfur-containing pollutants, which reduces the safety of the products. Supercritical water (SCW) can dissolve most organic matter, which is a technology worthy of further study. In order to reduce sulfur pollution in the process of PM resource utilization and better control the conversion path of sulfur, it is necessary to explore the migration mechanism of sulfur in the whole PM-SCW gasification process. The experimental results indicated that H2S was the only gaseous product. Only inorganic compounds (S2-, S2O32- and SO42-) were detected in the liquid. Sulfur in the solid mainly included thiol/thioether, thiophene and sulfone. The influence of different reaction conditions (temperature, residence time, PM concentration and catalysts) on sulfur migration was studied in a batch reactor. It was worth noting that the catalysts had a significant effect on H2S absorption. The lowest H2S yield was 3.2 * 10-4 mol/kg and more than 70% of the sulfur was distributed in the liquid under the condition of addition of K2CO3. While, the RTH2110 fixed most of the sulfur of PM (the maximum value reached 50.94%) in the solid. Thus, adding the catalysts flexibly can choose composition of the products. Furthermore, six possible pathways of sulfur migration in the solid were designed and the kinetic parameters were calculated by density functional theory (DFT). The results provided a basis for controlling sulfur in PM. Subsequently, the sulfur migration pathways during PM-SCW gasification process were comprehensively summarized through the combination of experiment and DFT. It provided a method for sulfur treatment in PM, which had guiding significance for the realization of pollution-free treatment of PM.

Selective oxidation decontamination in cobalt molybdate activated Fenton-like oxidation via synergic effect of cobalt and molybdenum

In this study, cobalt molybdate (CoMoO4) activated peracetic acid (PAA) was developed for water purification. CoMoO4/PAA system could remove 95% SMX with pseudo-first-order reaction rate constant of 0.15410 min-1, which was much higher than CoFe2O4/PAA, FeMoO4/PAA, and CoMoO4/persulfate systems. CoMoO4/PAA system follows a non-radical species pathway dominated by the high-valent cobalt (Co(IV)), and CH3C(O)OO• shows a minor contribution to decontamination. Density functional theory (DFT) calculation indicates that the generation of Co(IV) is thermodynamically more favorable than CH3C(O)OO• generation. The abundant Co(IV) generation was attributed to the special structure of CoMoO4 and effect of molybdenum on redox cycle of Co(II)/Co(III). DFT calculation showed that the atoms of SMX with higher ƒ0 and ƒ- values are the main attack sites, which are in accordance with the results of degradation byproducts. CoMoO4/PAA system can effectively reduce biological toxicity after the reaction. Benefiting from the selective of Co(IV) and CH3C(O)OO•, the established CoMoO4/PAA system exhibits excellent anti-interference capacity and satisfactory decontamination performance under actual water conditions. Furthermore, the system was capable of good potential practical application for efficient removal of various organics and favorable reuse. Overall, this study provides a new strategy by CoMoO4 activated PAA for decontamination with high efficiency, high selectivity and favorable anti-interference.

Does natural resource dependence restrict green development? An investigation from the "Belt and road" countries

Addressing natural resource dependence is integral to achieving the Sustainable Development Goals by promoting economic diversification, environmental sustainability, and climate resilience. This study explores the effect of natural resource dependence on green development by adopting the balanced panel dataset from the "Belt and Road" countries from 2005 to 2019. Notably, the novelty of our analysis lies in the empirical analysis using instrument-based techniques that consolidate the "green development curse hypothesis" in the Belt and Road countries. The mechanism analysis reveals that natural resource dependence curbs green development by weakening innovative capability, disturbing institutional quality, reducing population density, and crowding out human capital. Further, the dynamic panel threshold model handling endogeneity verifies the nonlinear relationship between natural resource dependence and green development. Interestingly, digital trade offers greater "resilience" than traditional trade, correcting the resource curse dilemma. Finally, heterogeneity analyses indicate that the green development curse hypothesis only exists in countries with high-level environmental regulations and resource-based countries.

The effect of education expenditure on air pollution: Evidence from China

Education expenditure is essential in mitigating air pollution, but the relationship between education expenditure and air pollution lacks in-depth discussion. Utilizing data at the county level in China during 2007-2021, this study estimates the effect of education expenditure from local governments on air pollution. Our findings demonstrate that education expenditure significantly and negatively affects air pollution, which remains robust after addressing endogeneity. The mechanism analysis presents that education expenditure reduces air pollution through the composition, technique, and income effects. The heterogeneity analysis indicates that the impact of education expenditure exhibits marked regional heterogeneity. Specifically, the role of education expenditure is significant in strong regulation, key, eastern, and central regions. By considering interaction terms, we identify the moderating effects of human capital, economic development, infrastructure construction, and public service for education expenditure. The cost-benefit analysis emphasizes that education expenditure improves social welfare. Our findings can inspire local governments to place more emphasis on air quality and public education expenditure.

Self-cultivating anammox granules for enhancing wastewater nitrogen removal in nitrification-denitrification flocculent sludge system

The feasibility of self-cultivating anammox granules for enhancing wastewater nitrogen removal was investigated in a nitrification-denitrification flocculent sludge system. Desirable nitrogen removal efficiency of 84 ± 4 % was obtained for the influent carbon to nitrogen ratio of 1-1.3 (NH4+-N: 150-200 mg N/L) via alternate anaerobic/oxic/anoxic mode. Meanwhile, some red granular sludge was formed in the system. The abundance and activity of anaerobic ammonia oxidation bacteria (AnAOB) increased from 'not detected' in seed sludge to 0.57 % and 29.4 ± 0.7 mg N/(g mixed liquor volatile suspended solids·h) in granules, respectively, suggesting successful cultivation of anammox granules. Furthermore, some denitrifying bacteria with capability of partial denitrification were enriched, such as Candidatus Competibacter (2.45 %) and Thauera (5.75 %), which could cooperate with AnAOB, facilitating AnAOB enrichment. Anammox was dominant in nitrogen removal with the contribution to nitrogen removed above 68.8 ± 0.3 %. The strategy of self-cultivating anammox granules could promote the application of anammox.

Has the opening of high-speed railway in China promoted urban low-carbon transformation along the route: re-estimation based on staggered DID robust estimators

Considering the opening of high-speed railway (HSR) as a quasi-natural experiment, this paper explores the emission reduction effect of HSR opening and its mechanisms and heterogeneity characteristics based on the panel data of 272 cities in China from 2006 to 2019 by staggered DID model and the mediating effect model. It is found that (1) the opening of HSR significantly reduces the carbon emission level of cities, and the conclusion still holds after controlling the endogeneity issue and a series of robustness tests; (2) Bancon decomposition and negative weight diagnostics both show that the estimated average treatment effect bias is small and the robust estimators are more robust; (3) by reducing production costs and promoting inter-regional industrial division of labor, the opening of HSR promotes intra-industrial structural transformation and inter-industrial structural transformation, respectively, thus reducing urban carbon emissions. At the same time, HSR achieves urban carbon emission reduction by promoting free movement of population and human capital agglomeration; and (4) further study finds that there is regional heterogeneity in the emission reduction effect of HSR opening, and the carbon reduction effect is mainly reflected in large and medium-sized cities, near provincial capitals, non-resource-based cities, and cities with rich educational resources, which indicates that the location of future HSR should be combined with the city's own characteristics and be tailored to the city.

Promoting sustainable development: Revisiting digital economy agglomeration and inclusive green growth through two-tier stochastic frontier model

In the global wave of digitization, digital economic agglomeration, as an emerging model, profoundly impacts the economy, environment, and society. Countries worldwide are formulating strategies and policies to promote the development of digital economic agglomeration, yet they also face challenges of widening digital divide and environmental sustainability. Existing research primarily focuses on the positive effects of the digital economy, with limited assessment of the dual effects of digital economic agglomeration on sustainable development. This study utilizes panel data from 282 Chinese cities between 2011 and 2021, employing a two-tier stochastic frontier model. It reexamines the dual impacts and intrinsic mechanisms of digital economic agglomeration, attempting to capture regional and temporal variations in the dual effects to address this research gap. The study shows that: (1) The positive effect of digital economy agglomeration is much more than the negative effect, resulting in a positive net effect that shows an overall increasing trend with significant regional disparities. (2) Digital economic agglomeration has a significant negative spatial spillover effect, promoting local inclusive green growth while inhibiting inclusive green growth in neighboring cities. (3) Regarding the mediating mechanisms, industrial structure, technological innovation and resource allocation efficiency have positive indirect effects on inclusive green growth, while environmental regulation intensity has a negative indirect effect, and it has a nonlinear effect under the threshold constraint of the mediating mechanisms. This study provides policy insights for promoting inclusive green growth, emphasizing the need to consider regional differences in resource distribution, ecological environment, and social demands. It advocates for the organic integration of the digital economy across different regions, reducing polarization effects, and enhancing diffusion effects.

Unlocking sustainable growth: exploring the catalytic role of green finance in firms' green total factor productivity

Promoting the development of green finance (GF) is a critical way to address the environmental and developmental problems in China. While existing studies have examined the macroscopic role of GF, few pay attention to its impact on micro-enterprises. To investigate the effect of GF on micro-enterprises, this study considers green credit as a quasi-natural experiment to investigate the effect on firms' green total factor productivity (GTFP). We use the SBM-Malmquist method to measure firms' GTFP and adopt the double dual machine learning approach to explore its impact and potential mechanisms. The findings indicate that (1) the GF can effectively promote the GTFP at the firm level, which has been reconfirmed by robustness tests. (2) The GF can improve firms' GTFP through three pathways: promoting firms' green innovation, alleviating financing constraints, and strengthening managers' environmental concerns. (3). The heterogeneity analysis verifies that state-owned enterprises and large-size firms are more sensitive to the response of green finance. The results of this study lend support to the establishment of green finance and the formulation of corporate green development strategies.

Diffusion-driven fabrication of calcium and phosphorous-doped zinc oxide heterostructures on titanium to achieve dual functions of osteogenesis and preventing bacterial infections

Conventional Ti-based implants are vulnerable to postsurgical infection and improving the antibacterial efficiency without compromising the osteogenic ability is one of the key issues in bone implant design. Although zinc oxide (ZnO) nanorods grown on Ti substrates hydrothermally can improve the antibacterial properties, but cannot meet the stringent requirements of bone implants, as rapid degradation of ZnO and uncontrolled leaching of Zn2+ are detrimental to peri-implant cells and tissues. To solve these problems, a lattice-damage-free method is adopted to modify the ZnO nanorods with thin calcium phosphate (CaP) shells. The Ca and P ions from the CaP shells diffuse thermally into the ZnO lattice to prevent the ZnO nanorods from rapid degradation and ensure the sustained release of Zn2+ ions as well. Furthermore, the designed heterostructural nanorods not only induce the osteogenic performances of MC3T3-E1 cells but also exhibit excellent antibacterial ability against S. aureus and E. coli bacteria via physical penetration. In vivo studies also reveal that hybrid Ti-ZnO@CaP5 can not only eradicates bacteria in contact, but also provides sufficient biocompatibility without causing excessive inflammation response. Our study provides insights into the design of multifunctional biomaterials for bone implants. STATEMENT OF SIGNIFICANCE: • A lattice-damage-free method is adopted to modify the ZnO nanorods with thin calcium phosphate (CaP) shells. • The dynamic process of Ca and P diffusion into the ZnO lattice is analyzed by experimental verification and theoretical calculation. • The degradation rate of ZnO nanorods is significantly decreased after CaP deposition. • The ZnO nanorods after CaP deposition can not only sterilize bacteria in contact via physical penetration, but also provide sufficient biocompatibility and osteogenic capability without causing excessive inflammation response..

Evaluating the synergistic effect of digitalization and industrialization on total factor carbon emission performance

Combating climate change and reducing carbon dioxide emissions are serious challenges shared by countries around the world. In the current era, digitalization has a significant impact on CO2 emissions. However, prior studies have not assessed the synergy between digitalization and industrialization on carbon emission performance. The principal component analysis and non-radial directional distance function (NDDF) are used to measure the digitalization and total factor carbon emission performance of Chinese 245 prefecture-level cities from 2003 to 2019. This study establishes a fixed effects model to study the panel data. The findings are as follows: (1) Digitalization can significantly promote Chinese cities' CO2 emission reduction. This result still holds after several robustness checks. (2) The heterogeneity results indicate that digitalization mainly improves central cities' carbon emission performance. Meanwhile, the impact of digitalization is more obvious after 2011. (3) Digitalization improves urban carbon emission performance through energy efficiency, industrial transformation, and technological innovation. (4) It is worth noting that digitalization synergizes with industrialization to improve carbon emission performance in Chinese cities. This study provides empirical evidence and some constructive policy recommendations for the government to push the collaborative development of the digitalization and low-carbon economy.

High temperatures and urban entrepreneurship levels: Evidence from China

This paper performed as a frontier try to investigate the effect of high temperatures on entrepreneurship, assessed from an urban perspective. This paper estimated the impact of high temperatures on urban entrepreneurship levels using data from 281 prefecture cities in China, during the period 2000-2017. This paper found that a single day with a temperature of above 30 °C led to a decrease of 0.47 % in urban entrepreneurship levels, compared with a single day recording comfortable temperatures. Following a series of robustness tests, the results were found to be significant. Next, this paper conducted a series of heterogeneity analyses and discovered that cities with advanced industrial structures, larger sizes and more essential hierarchies were less affected by high temperatures. Finally, this paper further analyzed the potential influence mechanisms of high temperatures on entrepreneurship. This paper found that high temperature affects urban entrepreneurship levels by worsening the entrepreneurial environment, especially by reducing human capital, hindering innovation, decreasing the financial support available to enterprises, and hindering economic development. The results of our study have thus enriched the literature on entrepreneurship by exploring the impact of climate change on entrepreneurship.

Effect of different inocula on the granulation process, reactor performance and biodiesel production of algal-bacterial granular sludge (ABGS) under low aeration conditions

The algal-bacterial granular sludge (ABGS) system is a prospective wastewater treatment technology, but few studies focused on the effects of different inoculum types on the establishment of the ABGS system under low aeration conditions (step-decrease superficial gas velocity from 1.4 to 0.5 cm/s). Results from this study indicated that compared with other inocula, the ABGS formed by co-inoculating aerobic granular sludge (AGS) and targeted algae (Chlorella) exhibited a shorter granulation period (shortened by 15 days), higher total nitrogen (89.4%) and PO43--P (95.0%) removal efficiencies, and a greater yield of fatty acid methyl esters (FAMEs) (9.04 mg/g MLSS). This was possibly attributed to that the functional bacteria (e.g. Thauera, Gemmobacter and Rhodobacter) in the inoculated AGS facilitated the ABGS granulation. The inoculated algae promoted their effective enrichment under illumination conditions and enhanced the production of extracellular polymeric substances, thus improving the stability of ABGS. The enriched algae were attached to the outer layer of the granules, which could provide sufficient oxygen for bacterial metabolism, revealing the inherent mechanisms for the good stability of ABGS under low aeration intensity. Overall, the rapid granulation of ABGS can be achieved by inoculating optimal inocula under low aeration conditions, which is convenient and economically feasible, and motivates the application of algal-bacterial consortia.

"Improving with using" effect and mechanism analysis of electrodeposited poly(1,5-diaminoanthraquinone)/carbon cloth electrode for high-performance flexible supercapacitors

As a robust and conductive substrate, carbon cloth (CC) has been modified with various pseudocapacitive materials to boost its electrochemical performance in flexible supercapacitors. Here, poly(1,5-diaminoanthraquinone) (PDAA) electrodeposited CC electrodes were developed and much higher areal specific capacitance was obtained in comparison with the functionalized CC (FCC). Most importantly, an unusual phenomenon of "improving with using" was found for the optimized one, FCC@PDAA-3, which exhibited the increased capacitance retention from 150.4% to 194.8% with increasing the number of cycles from 10,000 to 50,000. Such extraordinary cyclic life was mainly ascribed to the doping and electropolymerization of the encapsulated 1,5-diaminoanthraquinone (DAA) in the immobilized PDAA during the electrochemical cycles. These findings are expected to contribute to a deeper understanding of the pseudocapacitive materials evolution during long charging/discharging cycles, favoring the design of long-life supercapacitors for practical application.

How financial clustering influences China's green development: Mechanism investigation and empirical discussion

Understanding the significance of financial clustering in the context of green development holds immense importance for China as it strives towards achieving high-quality green development. Using a balanced panel dataset encompassing China's 283 cities from 2009 to 2020, we aim to explore the impact of financial clustering on green development from both linear and nonlinear perspectives. Empirical evidence suggests that when the level of financial clustering increases by 1%, the city-level green development increases by 0.1012%. A mediation effect model certifies that there are three essential channels through which financial clustering robustly boosts green development: technical, structural and scale effects. Subsequently, a novel program handling endogeneity is designed and verifies the nonlinear nexus between financial clustering and green development. Moreover, the spatial Durbin model demonstrates that financial clustering significantly sustains local green development, despite its relatively weak spill over effects. Heterogeneity analysis presents that the promoting effect is particularly predominant in Central China, as well as in cities characterized by high levels of financial clustering and large population sizes.

Does green finance reduce environmental pollution?-a study based on China's provincial panel data

As a bridge between economy and ecology, green finance is vital in improving environmental quality and promoting sustainable development. Based on the building of an environmental pollution index system, this paper constructs the [Formula: see text] model to deeply explore the specific impact of green finance on environmental pollution using China's provincial panel data from 2007 to 2020. This paper constructs an intermediary model to test the impact mechanism of green finance on reducing environmental pollution and discusses the regional heterogeneity of green finance in reducing environmental pollution. The results show that (1) green finance can significantly reduce environmental pollution, among which green credit has a pronounced effect on reducing environmental pollution, green investment has a relatively small effect, and green securities have not significant effect. (2) Green finance has the best inhibitory effect on solid pollution, less inhibitory effect on air pollution, and no significant improvement effect on water pollution. (3) Green technology innovation, industrial structure upgrading, and environmental regulation play an intermediary role in the process of green finance reducing environmental pollution and improving environmental quality. (4) The effect of green finance in the eastern and carbon emission pilot areas is significantly better than in the central and western regions and non-carbon emission pilot areas respectively. According to the research results of this paper, suggestions are put forward to promote the development of green finance, which is of great significance to reducing environmental pollution and achieving sustainable development goals.

Impact of China's carbon emissions trading scheme on urban air quality: a time-varying DID model

Using panel data for 277 Chinese cities, this paper applies a time-varying difference-in-differences (DID) model to empirically test the impact of China's carbon emissions trading scheme (ETS) on urban air quality, and further explores its heterogeneity and the mechanisms involved. The results show that ETS can improve urban air quality. This conclusion remains robust through a series of robustness tests, including PSM-DID estimation, varying window periods, exclusion of significant events, lag phase, and placebo tests. The dynamic effect test indicates that ETS has a continuous and effective effect on improving urban air quality. Mechanism analysis reveals that the degree of marketization can enhance the improvement effect that ETS has on urban air quality. Meanwhile, industrial structure upgrading and green technology innovation are important mechanisms by which pilot ETS policy improves urban air quality. Regional heterogeneity analysis finds that ETS only improves urban air quality in eastern and central regions.

How does digital finance affect firm environmental, social and governance (ESG) performance? - Evidence from Chinese listed firms

The use of digital finance to promote firm environmental, social, and governance (ESG) fulfillment is the key to achieving sustainable development. This study uses the data of Chinese listed firms from 2010 to 2019 and China Digital Financial Inclusion Index of Peking University to empirically examine the impact and mechanism of digital finance on firm ESG performance. Results show that digital finance significantly and positively impacts firm ESG performance. Mechanism tests reveal that digital finance influences ESG performance by promoting firm green innovation, improving firm goodwill and reducing agency costs. Moreover, political connections negatively moderate the relationship between digital finance and firm ESG performance, while regional institutional development positively moderates this relationship.. Subdivision of digital finance dimension test shows that the main factors affecting ESG performance are the depth of use and the degree of digitization, while the breadth of coverage is not significant. Digital finance can also promote firm innovation by promoting ESG performance. This study integrates the value effect of digital finance with the concept of sustainable development, which has important theoretical and practical significance.

How does environmental information disclosure affect carbon emissions? Evidence from China

In the context of global carbon peak and carbon neutrality, the issue of how to effectively encourage enterprises to reduce their carbon emissions has drawn the attention of governments and scholars. This paper uses the difference-in-differences method and joint data (2003-2012) from Chinese industrial firm pollution database and Chinese industrial firm database to evaluate the impacts of environmental information disclosure on enterprises' carbon emissions. We find that environmental information disclosure has a significant effect on enterprises' carbon emission reduction. Moderating effect analysis finds that environmental regulations and punishment strengthen the role of environmental information disclosure in reducing carbon emissions, however, the moderating role of environmental punishment is limited. In addition, mechanism analysis show that environmental information disclosure can reduce carbon emissions by improving their energy structures and encouraging polluting enterprises to withdraw from the market.

Layered by layered construction of three novel ZnCo-LDHs/g-C3N4 for the removal of sunset yellow by adsorption-photocatalytic process

The removal of organic dyes has attracted attention by adsorption-photocatalytic synergetic process in water treatment technology. Three novel ZnCo-LDHs/g-C3N4 were successfully prepared for the first time by layered construction technique through the hydrolysis of triethanolamine in this paper. They exhibited high specific surface area which facilitates the adsorption of sunset yellow (SY) from solution to catalyst surface. All the target pollutant dyes are very effectively removed by the three ZnCo-LDHs/g-C3N4 composites through synergetic effect of adsorption and photocatalysis process under UV irradiation (λ = 365 nm). The order of synergistic degradation effect for SY is as follows: ZnCo-LDHs/g-C3N4-3 (99.6%) > ZnCo-LDHs/g-C3N4-2 (99.5%) > ZnCo-LDHs/g-C3N4-1 (99.3%) > pure g-C3N4 (77.4%) > pure ZnCo-LDHs (44.2.6%) at the initial concentration of 75 mg L-1. ZnCo-LDHs/g-C3N4-3 has the largest k value (0.0284 min-1) in SY degradation, which is 2.8 times that of g-C3N4. ZnCo-LDHs/g-C3N4-3 is a very promising adsorption-photocatalyst for the removal of SY from wastewater. The electron spin resonance experiments demonstrate that OH·, 1O2, and O2- are the dominant active species and oxides SY together. This result demonstrates that the three ZnCo-LDHs/g-C3N4 have practical applications as efficient adsorption-photocatalytic materials and also provides a synergetic strategy for the removal of SY wastewater.

Scientization or parametrization? Which system is more advantageous to environmental conservation in the reform of China's state-owned forest farms?

Government leadership and grassroots participation are the most typical institutional arrangements in natural resource management, a topic which has been the subject of vigorous debate for a long time. Individually, these systems are referred to as scientization and parametrization. This paper takes the reform of China's state-owned forest farms (SSFs) as a pointcut, comparing the effects of the 2011 policy (representing scientization) and the 2015 policy (representing parametrization) on environmental conservation. For the period from 2006 to 2018, China's provinces are analyzed via difference-in-differences (DID) and principal components difference-in-differences (PCDID) empirical strategies. The results show that the 2015 policy increased new afforestation by an average of 0.903 units, but the 2011 policy had no significant impact. The influence path of the 2015 policy was to curb corruption, relieve fiscal stress, and stimulate innovation, playing mechanism effects of 20.49%, 14.17%, and 33.55%, respectively. However, the 2015 policy was not ideal in terms of its goal of incentivizing multi-agent participation in investments in conservation. Investors prefer to attempt afforestation projects with shorter payback periods, especially projects related to open forest land. Overall, this study supports the belief that parametric management is a better approach to natural resource management than scientific management, but the latter approach still has limitations. Therefore, we propose to prioritize the promotion of parametric management on the closed forest lands of SSFs, but there is no need to hastily mobilize grassroots participation in open forest land management projects.

Toxicity of ionic liquids against earthworms (Eisenia fetida)

Ionic liquids (ILs) are widely used in frontier fields because of their highly tunable properties. Although ILs may have adverse effects on organisms, few studies have focused on their effect on earthworm gene expression. Herein we investigated the toxicity mechanism of different ILs towards Eisenia fetida using transcriptomics. Earthworms were exposed to soil containing different concentrations and types of ILs, and behavior, weight, enzymatic activity and transcriptome were analyzed. Earthworms exhibited avoidance behavior towards ILs and growth was inhibited. ILs also affected antioxidant and detoxifying enzymatic activity. These effects were concentration and alkyl chain length-dependent. Analysis of intrasample expression levels and differences in transcriptome expression levels showed good parallelism within groups and large differences between groups. Based on functional classification analysis, we speculate that toxicity mainly occurs through translation and modification of proteins and intracellular transport functions, which affect protein-related binding functions and catalytic activity. KEGG pathway analysis revealed that ILs may damage the digestive system of earthworms, among other possible pathological effects. Transcriptome analysis reveals mechanisms that cannot be observed by conventional toxicity endpoints. This is useful to evaluate the potential environmental adverse effects of the industrial use of ILs.

High reusability and adsorption capacity of acid washed calcium alginate/chitosan composite hydrogel spheres in the removal of norfloxacin

Calcium alginate (CA) hydrogel spheres were widely used as adsorbents to remove organics, but their adsorption capacities and reusability to some antibiotics are unsatisfactory. In this study, calcium alginate/chitosan (CA/CTS) hydrogel spheres were prepared as precursors. Acid-washed CA/CTS (CA/CTS-M) hydrogel spheres (310.6 mg/g) behaved much better adsorption capacity of norfloxacin (NOR) than CA (69.5 mg/g) and CA/CTS (87.7 mg/g) hydrogel spheres. Astonishingly, after being reused for 15 cycles, CA/CTS-M has no loss of NOR adsorption capacity. In the original idea, acid wash was expected to remove the chitosan in CA/CTS hydrogel spheres for obtaining a larger specific surface area. Both scanning electron microscopy and Brunauer-Emmett-Teller test showed that acid wash can remove CTS from CA/CTS hydrogel spheres to increase the specific surface area. However, part of the chitosan remained in CA/CTS-M, having a role to enhance the structural stability of the material, because the acid-washed CA (about 2 mm) has a significantly smaller diameter than CA/CTS-M (about 3 mm). According to the influence of pH and density functional theory calculations, electrostatic attraction is the key driving force of NOR adsorption. Importantly, acid wash led to more negative-charged surface characterized by Zeta potential, which is the main reason of the significantly enhanced adsorption capacity of CA/CTS-M in removal of NOR. In short, CA/CTS-M hydrogel spheres are environment friendly and highly stable adsorbents with high adsorption capacity in the removal of NOR.

Effects of smart city construction on employment: mechanism and evidence from China

Based on the first batch of smart city pilots in China, this paper systematically investigates the impact of smart city construction on urban employment and employment structure, and its influence mechanism and urban heterogeneity are explored using the difference-in-differences (DID) model. The main conclusions are as follows: (1) Smart city construction significantly promotes urban employment, especially employment in the secondary and tertiary industries. (2) Digital technology development and public services are important mechanisms for smart city construction to improve urban employment. (3) There was heterogeneity among Chinese cities, with the employment promotion effect of smart city construction is primarily reflected in cities located in the eastern and central regions, medium cities, large cities, as well as cities with higher levels of financial development, human capital, and informatization. (4) Through different impacts on various sectors, smart city construction promotes the transfer of employment to the service sector and optimizes the urban employment structure. Conclusions enrich the academic community's understanding of the development and construction of smart cities and provide enlightenment and reference for the formulation and promulgation of relevant supporting policies.

Research on the policy effect and mechanism of green finance to reduce environmental pollution: micro evidence from 285 cities in China

Based on panel data from 285 Chinese prefecture-level cities from 2003 to 2020, this paper uses the difference-in-difference (DID) method to investigate the policy effect, mechanism, and heterogeneity of green finance (GF) to reduce environmental pollution. (1) Green finance has significant effect on reducing environmental pollution. The parallel trend test demonstrates that DID test results are valid. (2) Following a battery of robustness tests including instrumental variable, propensity score matching (PSM), variable substitution, and changing time-bandwidth, the conclusions are still valid. (3) Mechanism analysis reveals that green finance can reduce environmental pollution by increasing energy efficiency, adjusting industrial structure, and transforming green consumption. (4) Heterogeneity analysis proves that green finance has a substantial impact on reducing the environmental pollution in eastern and western cities, but not in central China. (5) In the "two-control zone" and "low-carbon pilot cities," the results of applying green finance policies are better, and a policy superposition effect exists. To be able to promote environmental pollution control, and green and sustainable development, this paper provides useful enlightenment for environmental pollution control for China and other similar countries.

How does agricultural industrial structure upgrading affect agricultural carbon emissions? Threshold effects analysis for China

China continues to emphasize the importance of reducing agricultural carbon emissions and promoting the upgrading of its agricultural industry structure. However, the relationship between the two is rarely examined. This study aims to investigate the impact of upgrading the agricultural industry structure on agricultural carbon emissions. A two-stage instrumental technique and a threshold regression model are used in this study's analysis. The results indicate that agricultural industrial structure upgrading reduces agricultural carbon emissions by a statistically significant amount above the threshold of 0.378. The examination of the underlying mechanism shows agricultural energy efficiency and off-farm work as mediators of the nonlinear relationship between agricultural industrial structure upgrading and agricultural carbon emissions. Only when the agricultural energy efficiency and off-farm work thresholds are surpassed can improving the structure of the agricultural industry minimize agricultural carbon emissions. Analysis of heterogeneity indicates that the threshold for lowering agricultural carbon emissions is greater in northern China, but the potential for reduction is greater.

The impact of digital transformation on innovation performance - The mediating role of innovation factors

Existing digital transformation research has focused on economic and environmental performance, which few studies directly explored the relationship between digital transformation and innovation. Based on the innovation factor perspective, we explored the relationship between digital transformation and innovation by using firm data between 2009 and 2019. The findings are as follows: (1) The corporate digital transformation was measured through based on textual analysis methods and it was found that digital transformation can promote corporate innovation. (2) Knowledge flow, technical personnel, R&D investment, and innovation awareness are important mediating paths. (3) In the innovation quantity dimension, the mediating role of innovation awareness is greater. And in the innovation quality dimension, the mediating role of technicians is greater. (4) Digital transformation has a greater impact on innovation of non-SOEs, non-high-tech enterprises and non-heavily polluting enterprises, alleviating the gap between different types of firms. The results of this paper alleviate the concerns of digital transformation in developing countries such as China and provide experiences and evidence for them to promote Industry 4.0 and sustainable innovation.

How to achieve sustainable development: From the perspective of science and technology financial policy in China

To solve coordination between economic development and pollutant emissions, it is necessary to face the innovation problem of energy saving and emission reduction. Promoting the effective integration of tech and the financial system is an effective way to solve this problem. According to panel data for prefecture-level cities in China, this paper is based on the pilot policy of combining science and technology with finance implemented in 2011 as a quasi-natural experiment and uses the difference-in-differences (DID) method to evaluate the impact of Science and Technology Financial Policies (STFP) on the air pollutant emission, meanwhile, considering the spatial overflow effect of policy implementation. The research results show that: (1) The STFP has certain inhibitions on pollutant emissions, and this finding holds after a series of robustness tests. (2) The policy has different effects on cities that have different scale, different regions, and different government efficiency. (3) From the results of mechanism analysis, the policy mainly enhances regional pollutant emission reduction capacity through ways such as increasing regional green total factor productivity, enhancing regional science and technology levels, and promoting regional industrial structure optimization. (4) The policy shows a negative spatial spillover effect in reducing pollutant emissions.

Rational construction and understanding the effect of metal cation substitution of three novel ternary Zn-Co-Ni-LDHs from 2D to 3D and its enhanced adsorption properties for MO

The layered double hydroxides (LDHs) have attracted attention in the water treatment field. In this paper, three novel ternary Zn-Co-Ni-LDH adsorbents were prepared successfully through rational construction from 2D to 3D using triethanolamine (TEA) as an alkali source and a structural controlling reagent by hydrothermal technique. Samples were characterized by the SEM, XRD, XPS, FTIR, BET, solid-state UV/vis spectra, and TG. Three Zn-Co-Ni-LDHs exhibited higher crystallinity and surface area which were beneficial to the adsorption for methyl orange (MO). The maximum adsorption capacity of three Zn-Co-Ni-LDH adsorbents can even reach as high as 1871.65 mg·g^-1, 1799.56 mg·g^-1, and 1646.44 mg·g^-1 for MO, respectively, which surpass those of most previously reported LDH-based adsorbents. The pseudo-second-order kinetic equation fitted the kinetic data of adsorption, while the equilibrium adsorption isotherm data followed the Langmuir model. The adsorption mechanism, electrochemical, and the antibacterial properties of three Zn-Co-Ni-LDHs were also discussed. This results not only demonstrates that three Zn-Co-Ni-LDHs are practical interest as an efficient adsorbent for the removal of MO from dye waste water, but also provides a strategy for the rational design through three ternary Zn-Co-Ni-LDHs from 2D to 3D.

Dynamic monitoring of bacteriostatic process by SERS analysis based on a simple but effective detection strategy

Investigating antibacterial process at a molecular level is helpful to fully understand the mechanism of bacteriostasis and develop new antimicrobial agents. Herein, a simple but effective sensor strategy of antibacterial nanocomposite combined with surface-enhanced Raman scattering (SERS) substrate was applied for the robust detection of bacteriostatic process. The synergistic SERS effect of nanocomposite and Ag nanoparticles (NPs) substrate was confirmed by finite difference time domain (FDTD) solutions. A curcumin liposome@Au NPs nanocomposite was designed and prepared as a kind of bacteriostatic agent and SERS material as well. By means of electrostatic attraction between the nanocomposite and bacteria (methicillin resistant staphylococcus aureus, MRSA), specific detection of MRSA and monitoring of the molecular structure changes after bacteriostaticeffect were realized by SERS. Important intermediates produced in the bacteriostatic process were also measured at the same time. The relationship between the relative peak intensities and the structure of MRSA were thus established. The results were verified by high performance liquid chromatography-mass spectrometry (HPLC-MS), reactive oxygen species (ROS) kit, and flow cytometry. The detection strategy we proposed could not only be used for real-time detection of bacteriostatic processes with a high efficiency, but also a powerful tool for analyzing the mechanism in biochemical processes.

How can urban administrative boundary expansion affect air pollution? Mechanism analysis and empirical test

As a momentous policy tool for spatial management, urban administrative boundary expansion (UABE) significantly impacts resource reorganization and development modes. However, the environmental effects of UABE are easily ignored. Whether UABE can also impove the environmental quality in addition to its economic effects remains to be answered. To fill this gap, we took the city-county merger policy (CCMP) in China as quasi-experimental evidence and empirically investigated the impacts of CCMP on air pollution based on the difference-in-difference method. The impact mechanisms were also analyzed from a whole-process perspective. The results demonstrate that, apart from expanding the urban scale, UABE can improve urban air quality as well. Further analysis shows that the positive effect is mainly realized by source control and process management, rather than end-of-pipe treatment. Besides, the impacts of UABE on air pollution exhibit obvious spatial heterogeneous characteristics. We also reported that the environmental effects of UABE are largely dependent on governmental control, rather than market factors. According to the results above, flexible administrative boundary adjustment, strict government regulations, and effective market systems are required to realize the dual goals of environmental improvement and space optimization.

Comprehensive evaluation of cobalt incorporated cryptomelane-type manganese oxide molecular sieve as an efficient adsorbent for enhanced removal of europium from wastewater systems

Extraction of radionuclide contaminants from wastewater systems has recently drawn widespread attention, and then developing a novel and green extracting technology has also become an enormous challenge. Herein, a facile hydrothermal method was employed to fabricate cobalt-incorporated cryptomelane-type manganese oxide molecular sieve (Co-OMS-2) for extraction Eu(III) from wastewater under diverse experimental conditions. All kinds of characterized techniques, such as SEM, TEM, XRD, FTIR, BET, EDS and XPS had verified the qualified synthesis process and splendid structural features of the Co-OMS-2. The maximum adsorption capacity of Co-OMS-2 was 7.62 × 10^-4 mol/g for Eu(III) at 298 K, which was superior than primarily traditional materials reported previous literatures. The high adsorption capacity of Eu(III) onto Co-OMS-2 was primarily attributed to high specific surface area and abundant surface functional groups, and the interactions were mainly contributed to strong surface complexation and electrostatic attraction. Under the condition of low pH, the outer-sphere surface complexation and cation exchange were primary mechanisms to Eu(III) adsorption onto Co-OMS-2 composites, while inner-sphere surface complexation was mainly assigned to Eu(III) adsorption onto Co-OMS-2 under the high pH sections. The Co-OMS-2 composite achieved equilibrium in a relatively short time, and this excellent performance was conducive to the treatment of Eu(III) under the extreme emergency conditions. In view of the extraordinary adsorption capacity and recycled reusability, the Co-OMS-2 composites can be as prospective adsorbents adopted for the extraction of Eu(III) in real wastewater management.

The impact of smart city pilots on corporate total factor productivity

The existing literature on smart city pilots mainly focuses on the city level and rarely addresses the firm level. This paper assesses the impact of smart city pilot policy (SCP) on firms' total factor productivity (TFP) and explores the impact of SCP under different heterogeneities as well as the mechanisms of action of the SCP. The LP approach is used in this paper to measure firms' TFP, and the impact of SCP is analyzed by the DID model with firms' panel data from 2009 to 2019 as research objects. First, it was found that the SCP can significantly increase the TFP of firms (0.041). Second, through heterogeneity analysis, we found that SCP can strengthen the monopoly position of monopolistic firms and state-owned enterprises. Moreover, the SCP can also alleviate the development imbalance of TFP between firms in coastal and non-coastal areas. In addition, SCP can significantly improve TFP of heavy polluting enterprises. Finally, we find that the important ways for SCP to improve firms' TFP is increasing investment in technological innovation, talent agglomeration, attracting financing, improving resource allocation efficiency, and digital transformation. The study provides unique insights for policy makers and business managers in China and other emerging countries to enhance TFP and achieve corporate sustainable development.

Highly sensitive detection of H2S gas at low temperature based on ZnCo2O4 microtube sensors

It is extremely necessary to detect Hydrogen sulfide (H₂S) due to the hazardous nature. Thus, it is required to design a material which can detect H₂S gas at low temperature. In this work, ZnCo₂O₄ microtubes are prepared by using absorbent cotton as template, combining immersion method in metal salt solution (Zn:Co=1:2) with calcination treatment in air. The influence of calcination temperature on the particle size and sensing property was also discussed. The diameter of particles on the ZnCo₂O₄ microtubes increases with increasing calcination temperature. The hollow microtubes of ZnCo₂O₄ materials calcined at 600 °C (ZCO-600) exhibit superb sensing performance to H₂S at 90 °C with the lowest detection limit of 50 ppb. The optimum operating temperature (90 °C) was lower than the other reported ZnCo₂O₄ sensors. ZCO-600 sensor also shows excellent selectivity, repeatability, stability, humidity resistance and the good linear relationship in ppb and ppm level H₂S. In addition, the feasible sensing mechanism of ZCO-600 to H₂S is explored on the basis of XPS analysis. Thus, ZnCo₂O₄ as a sensing material possesses widespread application prospects for the detection of trace H₂S gas.

Two-dimensional activated carbon nanosheets for rapid removal of tetracycline via strong π-π electron donor receptor interactions

Two-dimensional carbonaceous materials have sparked extensive attention in organic pollutants adsorption due to their unique structure to facilitate the formation of the physical or chemical bonding. Herein, natural two-dimensional porous activated carbon nanosheets with ultra-high specific surface area (2276.44 m² g^-1) are prepared by alkaline immersion-assisted circulating calcination techniques from corn straw piths. The prepared nanosheets exhibit rapid tetracycline adsorption capacity (633 mg g^-1 within 5 min) and high equilibrium adsorption capacity of 804.5 mg g^-1. Significantly, the nanosheets can adapt to a wide range of pH (at least between pH = 3-10) and are almost unaffected by coexisting ions. Mechanism studies and theoretical calculations demonstrate that the rapid and high-efficient adsorption of tetracycline mainly depends on the π-π electron donor receptor interactions. In addition, hydrogen bonding and pore filling was also responsible for tetracycline adsorption. This work provides important guidance for the development of the biobased high-performance adsorbents from agricultural waste.

Environmental regulation, market demand, and green innovation: spatial perspective evidence from China

This paper used a dynamic spatial panel model to empirically analyze the effects of environmental regulation, market demand, and the associated spatial spillovers on regional green innovation in China, from which the following was found. (1) The environmental regulations had a positive "U-shaped" effect on local green innovation and a positive neighborhood spillover effect, and market demand had a significant positive effect on local green innovation and a "ripple effect." (2) The mechanism analysis found that the environmental regulations tended to inhibit regional green innovation input through a "cost compliance" effect, and market demand had a stronger incentive effect on innovation input than the environmental regulations, thus promoting the improvement of green innovation level. (3) The environmental regulation and market demand effects on green innovation had obvious spatial and temporal heterogeneity. The results of this study could help to promote regional green innovation by formulating reasonable environmental policies and stimulating the vitality of green technology market.

Investigation on the application of by-product steam in iron ore sintering: performance and function mechanism

The combustion-supporting effect of steam to coke breeze in sintering has the potential to improve sinter quality and reduce pollutants emissions. The results show that increasing the by-product steam injection concentration (0.32-0.47vol%) and prolonging the injection time (5 min) within a proper range (10-15 min) can improve sinter quality. 2.13kgce/t_-sinter of the fuel consumption was decreased by reducing coke breeze usage from 5.60 to 5.45% under the recommended parameters, with 15.16% decrease of CO in sintering waste gas. By comparing experimental data with thermodynamic calculations, although the reaction between CO and steam can reduce CO emission and generate H₂, steam tends to react with coke breeze to generate H₂ and CO (react at 674℃), and OH radical produced by H₂ which can reduce the activation energy of CO oxidation reaction is the key to reducing pollutant emissions. The potential economic benefit of steam injection technology was calculated based on a 360m² sintering machine (the annual sinter output is 3.2million tons), excluding the equipment modification and steam injection cost of $300,000; a profit of $737491.2 per year or 0.23 dollars per ton sinter can be achieved. Therefore, low-carbon and cleaner iron ore sintering production can be realized through applying by-product steam.

Activation of persulfate by a water falling film DBD process for the enhancement of enrofloxacin degradation

A synergetic system of water falling film dielectric barrier discharge (DBD) plasma and persulfate (PS) was established and applied to enhance the enrofloxacin (EFA) degradation in this study. The simultaneous existence of electrons, reactive species, heat and UV-visible light in the DBD plasma system were utilized together to activate the PS to form SO₄^-· and other reactive oxygen species (ROS), and then worked in synergy with the DBD plasma to oxidize the EFA. The obtained results verified that there was a significant increase in the degradation percentages of EFA (20 mg L^-1) in the DBD/PS system, and the trend was more obvious under the condition of larger discharge power input. When 0.8 mM PS was added into the DBD system with 0.8 kW discharge power, the degradation percentage of EFA could reach 99.35% after 60 min treatment, the corresponding synergetic factor (SF) was 7.94. Analysis of the O₃ and the H₂O₂ concentrations in the DBD plasma system before and after the PS addition explained the activation of the PS by the HO·. The quenching experiments on reactive species suggested that SO4^-·, HO·, and ¹O₂ were all important reactive species for EFA degradation. The intermediates formed by the EFA degradation were detected and the degradation pathways were speculated. Results of toxicity analysis illustrated that the toxicity of the initial EFA solution decreased after degradation in the synergetic system of DBD/PS.

Facile synthesis of CoOOH@MXene to activate peroxymonosulfate for efficient degradation of sulfamethoxazole: performance and mechanism investigation

Using MXene as substrate, CoOOH@MXene with different mass content of CoOOH were prepared and used to active peroxymonosulfate (PMS) for the sulfamethoxazole (SMX) degradation. The sample characterizations demonstrated the successful preparation of CoOOH@MXene. CoOOH@MXene possessed much higher BET surface area (183.82 m²/g) than CoOOH (85.36 m²/g) and MXene (6.89 m²/g) due to the good dispersibility of CoOOH particles on MXene. Due to its large surface area, 1.3CoOOH@MXene displayed the best catalytic performance for the degradation of SMX. With 0.2 g/L of 1.3CoOOH@MXene and 0.5 mM of PMS, 20 μM of SMX was completely eliminated in 10 min. The degradation followed pseudo-first-order kinetic model well, with rate constants of 0.33 min^-1 for 1.3CoOOH@MXene and 0.054 min^-1 for CoOOH. Influencing factors of initial pH, catalyst dosage, PMS concentration, SMX concentration, and co-existing anions on SMX degradation were assessed systematically. Recycling tests verified the excellent reusability and stability of the catalyst. Quenching experiments and electron paramagnetic resonance analysis substantiated that ¹O₂ played a leading role. Moreover, the intermediates were identified, and degradation pathways and activation mechanism of CoOOH@MXene for PMS were proposed. This work may highlight the application of MXene with transition metals in PMS activation.

Does air pollution collaborative governance promote green technology innovation? Evidence from China

With the data of Chinese A-share-listed companies from 2004 to 2017, this paper builds a difference-in-differences model to investigate the impact of air pollution collaborative governance on green technology innovation. The main results show that air pollution collaborative governance promotes green technology innovation, and a series of robustness tests also verify this conclusion. Patent heterogeneity analysis suggests that air pollution collaborative governance increases the number of green utility model patents, but has no obvious impact on green invention patents. In terms of enterprise heterogeneity, air pollution collaborative governance can effectively stimulate the non-heavy-polluting enterprises to innovate green technology, but the incentive effect on heavy-polluting enterprises is not evident. Moreover, by constructing a mediating effect model and a moderating effect model, mechanism analysis reveals that R&D investment plays a positive mediating role in the impact of air pollution collaborative governance on green technology innovation, and the increase of government subsidy also enhances the promotion effect of air pollution collaborative governance on green technology innovation.

Oxidoreduction potential controlling for increasing the fermentability of enzymatically hydrolyzed steam-exploded corn stover for butanol production

Background

Lignocellulosic biomass is recognized as an effective potential substrate for biobutanol production. Though many pretreatment and detoxification methods have been set up, the fermentability of detoxicated lignocellulosic substrate is still far lower than that of starchy feedstocks. On the other hand, the number of recent efforts on rational metabolic engineering approaches to increase butanol production in Clostridium strains is also quite limited, demonstrating the physiological complexity of solventogenic clostridia. In fact, the strain performance is greatly impacted by process control. developing efficient process control strategies could be a feasible solution to this problem.

Results

In this study, oxidoreduction potential (ORP) controlling was applied to increase the fermentability of enzymatically hydrolyzed steam-exploded corn stover (SECS) for butanol production. When ORP of detoxicated SECS was controlled at − 350 mV, the period of fermentation was shortened by 6 h with an increase of 27.5% in the total solvent (to 18.1 g/L) and 34.2% in butanol (to 10.2 g/L) respectively. Silico modeling revealed that the fluxes of NADPH, NADH and ATP strongly differed between the different scenarios. Quantitative analysis showed that intracellular concentrations of ATP, NADPH/NADP⁺, and NADH/NAD⁺ were increased by 25.1%, 81.8%, and 62.5%. ORP controlling also resulted in a 2.1-fold increase in butyraldehyde dehydrogenase, a 1.2-fold increase in butanol dehydrogenase and 29% increase in the cell integrity.

Conclusion

ORP control strategy effectively changed the intracellular metabolic spectrum and significantly improved Clostridium cell growth and butanol production. The working mechanism can be summarized into three aspects: First, Glycolysis and TCA circulation pathways were strengthened through key nodes such as pyruvate carboxylase [EC: 6.4.1.1], which provided sufficient NADH and NADPH for the cell. Second, sufficient ATP was provided to avoid “acid crash”. Third, the key enzymes activities regulating butanol biosynthesis and cell membrane integrity were improved.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01824-2.

Rare pattern of Maisonneuve fracture: A case report

BACKGROUND

Maisonneuve fracture is a special type of ankle fracture that consists of proximal fibular fracture, a lesion of the inferior tibiofibular syndesmotic complex (interosseous ligament, anterior inferior tibiofibular ligament and posterior inferior tibiofibular ligament), and injury of the medial structure of the ankle (deltoid ligament tear or medial malleolar fracture). The accepted mechanism of Maisonneuve fracture is pronation external rotation according to the Lauge-Hansen classification. In this paper, we report a rare pattern of Maisonneuve fracture, which has the characteristics of both pronation external rotation ankle fracture and supination adduction ankle fracture.

CASE SUMMARY

A 31-year-old female patient accidentally sprained her right ankle while walking 5 d before hospitalization in our hospital. The patient was initially missed in other hospitals and later rediagnosed in our outpatient department. Full-length radiographs of the lower leg revealed proximal fibula fracture, inferior tibiofibular joint separation, and medial malleolar fracture involving the posterior malleolus, which was also revealed on computed tomography scans. Magnetic resonance imaging revealed rupture of the anterior inferior tibiofibular ligament and anterior talofibular ligament. We diagnosed a rare pattern of Maisonneuve fracture with proximal fibular fracture, inferior tibiofibular joint separation, medial malleolar fracture and ruptures of the anterior inferior tibiofibular ligament and anterior talofibular ligament. The patient underwent open reduction and internal fixation in our hospital. A 6-mo postoperative follow-up confirmed a good clinical outcome.

CONCLUSION

To our knowledge, this rare pattern of Maisonneuve fracture has not been previously described. The possible mechanism of injury is supination adduction combined with pronation external rotation. Careful analysis of the injury mechanism of Maisonneuve fracture is of great clinical significance and can better guide clinical treatment.

Pilot-scale microsand-ballasted flocculation of wastewater: turbidity removal, parameters optimization, and mechanism analysis

The flocs formed during microsand-ballasted flocculation (MBF) have attracted much attention. However, few studies have reported on comprehensive process parameters of MBF and its mechanism is still not well understood. Jar test and pilot-scale continuous experiments were here conducted on two kinds of simulated wastewater, labeled S1 (21.6-25.9 NTU) and S2 (96-105 NTU). Results revealed the hydraulic retention time ratio in the coagulation cell, injection and maturation cell, lamella settler of pilot-scale MBF equipment was 1:3:7.3. The optimum poly aluminum chloride doses for samples S1 and S2 were 0.875 g/L and 1.0 g/L. Besides, the optimum size of microsand was 49-106 μm and the optimum dose was 1.0 g/L. Under aforementioned conditions, the effluent turbidity of S1 was below 0.47 NTU, even lower than the Chinese drinking water standard; that of S2 was below 1.7 NTU, meeting the Chinese recycled water standard. Turbidity removal ranged from 98.0 to 98.8% for S1 and 98.5 to 99.5% for S2 when microsand was added. Therefore, microsand addition enhances MBF performance, where microsand serves as an initial core particle. Some microsand core particles bond together to form a dense core structure of micro-flocs by the adsorption bridging of inorganic polymeric flocculant. Moreover, the size of the largest micro-flocs may be controllable as long as the effective energy dissipation coefficient is adjusted appropriately through specific stirring speeds. This work provides comprehensive pilot-scale process parameters for using MBF to effectively treat wastewater and offers a clearer explanation of the formation mechanism of microsand-ballasted flocs.

A novel strategy for rapid development of a self-sustaining symbiotic algal-bacterial granular sludge: Applying algal-mycelial pellets as nuclei

Algal-bacterial granular sludge (ABGS) is a promising technology for wastewater treatment, benefiting from the synergetic interactions between algae and bacteria. However, the rapid start-up of the ABGS system is not trivial. Herein, a novel strategy was proposed by applying the algal-mycelial pellets (AMPs) as the primary nuclei for accelerating the development of a self-sustaining symbiotic ABGS system. The results indicated that by using this strategy complete granulation was shortened to 12 days, much shorter than the control system without AMPs dosage (28 days). The ABGS had a large particle diameter (3.3 mm), compact granular structure (1.0253 g/mL), and excellent settleability (SVI30 of 53.2 mL/g). Moreover, 98.6% of COD, 80.8% of TN and 80.0% of PO43--P were removed by the ABGS. The nuclei of targeted algae (Chlorella) and filamentous fungi (Aspergillus niger), the enhanced production of extracellular polymeric substances (especially proteins) and the enrichment of functional bacteria (such as Neomegalonema and Flavobacterium) facilitated the granules development. The low surface free energy (-69.56 mJ/m2) and energy barrier (89.93 KT) were the inherent mechanisms for the strong surface hydrophobicity, the easy bacterial adhesion, and the short granulation period. This study provides an economically feasible approach to accelerate ABGS granulation and sustain system stability.

Can "new infrastructure" reverse the "growth with pollution" profit growth pattern? An empirical analysis based on listed companies in China

With the increasing severity of environmental regulations, Chinese enterprises are gradually transforming from the profit growth pattern of "growth with pollution" to green development. However, this paper finds that this transformation is not complete. While catering to the national environmental protection governance requirements, some enterprises still persist the profit growth pattern of "growth with pollution." How to solve this problem? By attracting government subsidies, reducing tax burdens, and increasing the proportion of technical personnel employed, we theoretically and empirically demonstrate that the positive effect of "new infrastructure" in accelerating enterprises' transformation away from the profit growth pattern of "growth with pollution" to sustainable development. In the heterogeneity analysis section, we found that in enterprises with higher political correlation, more technical personnel, and lower labor cost, the "new infrastructure" has a stronger restraining effect on the "growth with pollution" pattern.

Mechanistic insight into selective adsorption and easy regeneration of carboxyl-functionalized MOFs towards heavy metals

The development of heavy metal adsorbents with high selectivity has become a research hotspot due to the interference of coexisting ions (e.g., Na⁺, Ca²⁺) in the actual wastewater, but the more difficult regeneration caused by high adsorption selectivity severely limits its practical applications. Herein, a carboxyl adsorbent, MIL-121, demonstrated high adsorption selectivity for heavy metals at 10,000 mg/L of Na⁺ (removal > 99% for Cu²⁺) as well as unexpected easy regeneration (desorption > 99%) at low H⁺ concentration (10^-3.5-10^-3.0 M), which is hundreds of times lower than that of ever reported selective adsorbents (> 10^-1 M H⁺). X-ray photoelectron spectrometry (XPS), extended X-ray absorption fine structure (EXAFS) coupled with Density functional theory (DFT) simulation unveil that the -COOH groups in MIL-121 for heavy metals adsorption is specific inner-sphere coordination with higher binding energy (1.31 eV for Cu), and less energy required for regeneration (0.26 eV for H). Similar high selectivity and easy regeneration were also satisfied with other heavy metals (e.g., Pb²⁺, Ni²⁺), and removal of heavy metals remained > 99% in 10 consecutive adsorption-desorption cycles. For actual copper electroplating wastewater treatment, MIL-121 could produce ~ 3600 mL clean water/g sample, outperforming 300 mL that of the benchmark commercial adsorbent D-113. This study shows the potential of MIL-121 for heavy metal wastewater treatment and provides mechanistic insight for developing adsorbents with high selective adsorption and easy regeneration.

Considering photocatalytic activity of Cu2+/biochar-doped TiO2 using corn straw as sacrificial agent in water decomposition to hydrogen

In this paper, a simple one-pot thermal synthesis method was used to successfully prepare Cu²⁺/biochar-doped TiO₂ composite catalytic materials. The photocatalytic hydrogen production performance of the composites under different environmental conditions (dark, solar, and visible light irradiation) was analyzed in a biomass photocatalytic system using a corn straw suspension as a sacrificial agent. The Cu²⁺/biochar-doped TiO₂ materials were characterized by SEM, TEM, XRD, FT-IR, XPS, and UV analysis. The photoelectric properties of the Cu²⁺/biochar-doped TiO₂ composites were also analyzed, and the charge separation mechanism of photogenerated carriers under different environmental conditions was investigated. Compared with pure TiO₂, the hydrogen production rate of Cu²⁺/biochar-doped TiO₂ is 23.6 times higher under visible light irradiation and 16.8 times higher under simulated solar irradiation. Using density functional theory, a crystal structure model of Cu²⁺/biochar-doped TiO₂ was established to analyze its energy band structure and density of states. An analysis of the mechanism shows that under simulated sunlight irradiation, the synergistic effect of the TiO₂ doped with Cu²⁺ and biochar causes the formation of a potential Schottky heterojunction on the surface and induces interfacial charge transfer. Furthermore, under visible light irradiation, the photocatalytic production of hydrogen by the Cu²⁺/biochar-doped TiO₂ composite is mainly due to the surface plasmon resonance mechanism of Cu ion-doped TiO₂.

Can campaign-style enforcement facilitate water pollution control? Learning from China's Environmental Protection Interview

The effectiveness of campaign-style enforcement (CSE) on water pollution, especially the long-term effectiveness, is controversial, and little knowledge is known about the channels through which the effectiveness happens. We take advantage of China's Environmental Protection Interview (EPI)- a distinguished form of CSE launched in 2014, as a natural experiment to estimate the short-term and long-term effects of CSE on water pollution. Using a time-varying difference-in-differences model based on city panel data from 2006 to 2018, we find that EPI can lead to an average 14.5% reduction in water pollution, and this effect is still persistent in the long term. Mechanism analysis shows that EPI reduces water pollution mainly through the pressure effect on the government, the penalty effect on the firms, and the mobilization effect on the public. Heterogeneity analysis shows that the effect of EPI on water pollution is more significant in cities with high initial pollution, low public complaints, and low economic levels. Further cost-benefit analysis based on the estimated value of water pollution reduction shows that the upper health benefit of EPI is $520.97 billion, which is 4.87 times higher than its estimated cost of $107.05 billion.

Does Social Capital Promote Health?

The determinants of health are influenced by genetics, lifestyle, social environment, medical conditions, etc. As an informal system, social capital plays an increasingly recognized role in individual health. The purpose of this paper is to discuss the direct and indirect effects of social capital on individual health in China. Using cross-sectional data from the China Family Panel Studies 2016, this paper explores the effects of cognitive and structural social capital on individual health from a micro perspective. The results show that both types of social capital have significant positive effects on individual health, and this effect remains after endogeneity is considered. The two types of social capital show obvious heterogeneity in age samples, urban and rural samples and north-south samples. In addition, the mechanism analysis shows that the health promotion effects of the two types of social capital are mainly derived from the effects of informal finance and access to medical resources. Based on the above findings, this paper puts forward policy recommendations.

Highly-efficient visible-light-driven photocatalytic H2 evolution integrated with microplastic degradation over MXene/ZnxCd1-xS photocatalyst

The development of highly-efficient photocatalyst for H₂ production integrated with microplastic degradation is significant to meet the demand for clean energy and resolve "white pollution". Herein, a series of MXene/Zn_xCd_1-xS photocatalysts were successfully fabricated for H₂ evolution integrated with degradation of polyethylene terephthalate (PET). The resultant photocatalysts exhibited excellent photocatalytic performance, and the best photocatalytic H₂ evolution rate can reach 14.17 mmol·g^-1·h^-1 in alkaline PET alkaline solution. What's more, the PET was also converted to the useful organic micromolecule, including glycolate, acetate, ethanol, etc. The highly-efficient photocatalytic performance of MXene/Zn_xCd_1-xS photocatalysts can be attributed to the enhanced separation ability of photocarriers and optimum band structure with enhanced oxidation capacity of valence band. Finally, the photocatalytic mechanism was investigated in detail. Overall, this work supplied a new useful guidance for solving the energy problem and microplastic pollution issues, simultaneously.