The unique hydrogeological conditions of karst area make the groundwater react rapidly to rainfall events, which makes the groundwater more susceptible to anthropogenic pollutions. The current study based on a combined excitation-emission matrix fluorescence spectroscopy and parallel factor analysis (EEM-PARAFAC) and geochemical–statistical investigation of water samples from the karst water system in Xintian County, Hunan Province, China, gives crucial information about the principal factors influencing karst water hydrochemistry and dissolved organic matter (DOM). The analyzed data revealed that both surface water and descending spring samples were within the Ca-Mg–HCO₃ water type and dominated by humic-like fluorophore, and well water samples were within both the Ca–Mg–HCO₃ and Na–HCO₃ water types and controlled by protein-like fluorophore. The chemical compositions of surface water and descending springs were mainly influenced by the weathering of silicate, carbonate, and evaporate rocks and precipitation. In addition to be affected by the weathering of silicate, carbonate, and evaporate rocks and precipitation, the well water was also impacted by ion exchange and other activities like anthropogenic. The DOM in the karst water system was affected by allochthonous and autochthonous inputs as well as the chemical compositions of the water.

Microplastics are a global environmental pollution. Due to this fact, new solutions are needed to reduce the amount in various aquatic environments. A new concept introduced by Herbort and Schuhen from the year 2016 describes the agglomeration of microplastics in water using silicon-based precursors. In the study presented here, alkyltrichlorosilanes with different linear and branched alkyl groups and a chain length between 1 and 18 carbon (C-) atoms are investigated for their suitability to fix microplastics (mixtures of polyethylene (PE) and polypropylene (PP)) and to form larger agglomerates. As the alkyl group has a major influence on the reaction rate and agglomeration behavior, we present here the extensive data collection of the evaluation of the best case. The removal efficiency is determined gravimetrically. The reaction behavior and the fixation process are characterized by hydrolysis kinetics. ²⁹Si-MAS-NMR spectroscopy, IR spectroscopy, and thermogravimetry (TGA) are used to characterize the chemical composition of the agglomerates. Finally, the use of optical coherence tomography (OCT) allows the visualization of the formed agglomerates. The results show that the different alkyl groups have a strong impact on the suitability of the alkyltrichlorosilanes for the agglomeration, as they influence the hydrolysis and condensation kinetics in water and the affinity to the microplastics. Best suited for microplastic removal were intermediate chain length between 3 and 5 C-atoms.

Nanostructures of titanium dioxide, polyaniline, halloysite, and carbon nanotubes have an excellent effect to improve environmental protection and surface properties of coatings like anticorrosion and self-cleaning attributes. In this research, we studied the individual effect of adding each nanostructure within the polyurethane matrix and also all nanostructure combinations with each other on the mentioned properties. To reach this aim, the polyurethane nanocomposites were prepared; then, anticorrosion and self-cleaning tests were carried out on the samples. FTIR spectroscopy and FESEM images were used to characterize the nanocomposite additives and coating influence. According to the obtained results, the polyurethane coating modified with titanium dioxide/polyaniline/halloysite nanotube/carbon nanotube nanocomposite showed very higher corrosion potential and resistance and lower corrosion current in the comparison with other coatings. Also, the mentioned polyurethane nanocomposite coating showed good hydrophilicity and it decolorized a dye contaminant with high efficiency which makes them appropriate candidate for the protection of the substrate against environmental destructive factors.

Transportation has significantly contributed to carbon emissions, and concerns regarding emissions mitigation have become central research issues. To avoid a reversal of the reduction convergence in the environmental field, mitigation strategies should aim to reduce the environmental risks posed by carbon inequality. This article uses the Gini index and Theil index to examine carbon inequality in the transport sector in China and decomposes the per capita carbon inequality using Kaya factors. Then, the variations within and between regions are analyzed by decomposing the Theil index of the carbon intensity by region. Our major findings are as follows. First, carbon inequality is relatively insignificant in the regional transport sector in China. Second, the main drivers of the per capita carbon inequality include the carbon intensity and per capita added value in the transport sector. Third, intra-regional components are major contributors to the heterogeneous spatial distribution of the carbon intensity, and the degree of carbon inequality in the eastern region is much greater than that in other regions. Moreover, the four economic regional components of the Theil index of the carbon intensity have had an obvious convergence effect since 2009. In addition, this study provides some suggestions for developing differentiated mitigation policies in different regions.

Pyrrolizidine alkaloids (PAs) and related N-oxides (PANOs) are secondary plant metabolites thought to be found in approximately 3% of the flowering plants worldwide and exhibiting hepatotoxic properties to humans. As a consequence, beehive products are prone to be contaminated with those compounds by bees foraging PA-producing plants. Downstream contamination can also occur through food items containing honey. Analytical methods based on UHPLC separation and MS/MS detection were developed with a focus on very low LOQs and validated for the analysis of 16 PAs and 14 PANOs in honey, honey-based candies and snacks, as well as beehive product–based food supplements. A maximum level of 182 ng/g of PAs was detected in a Mediterranean honey, and high levels of heliotrine-type compounds were reported for the first time. An extensive sampling of honeys harvested in Belgium was performed (N = 374), the concentration levels were more limited with a maximum of 60 ng/g, and the contamination pattern was dominated by senecionine-type PAs. The PA levels in honey-based candies and snacks were very low, with respective maxima of 7.61 ng/g and 0.36 ng/g. Seventy-five percent among the pre-dosed food supplements based on beehive products were contaminated, with a maximum of 43 ng/g. The highest level was detected in a bee-collected pollen sample (1672 ng/g). The analytical results were consistent with the previously reported data for beehive products and confirmed that PA/PANO contamination in these food commodities is recurrent.

Massive Cladophora growth was reported half a century ago around Birds Island in Qinghai Lake, and in 2015, Cladophora populations have rebloomed and have formed green “meadows,” with areas up to thousands of hectares. The present study investigated the distribution and biomass of Cladophora in Qinghai Lake and found that two key factors contribute to Cladophora blooming. First, recent climate change, especially increased precipitation, has induced the expansion of the lake’s area, and the submerged grassland around Birds Island has provided a plethora of grass stems on which Cladophora can attach and twine. In addition, the submerged grasslands are covered with less than 1 m of water, which allows enough sunlight to support the growth of Cladophora on available substrates. Second, the submerged grassland may function as a key source of nutrients, especially phosphate. A large number of migratory birds live in these area for very long times, which lead to higher phosphorus content due to the accumulated birds dropping. Thus, the high phosphate level further exacerbates the massive growth. Future studies should investigate the functions of Cladophora in the nutrient cycling of submerged areas, and the improvement of methods for removing Cladophora biomass.

Wind energy continues to make inroads in Africa due to falling costs and technological advancements. Most African countries are planning, exsiccating and connecting their renewable energy projects with national grid system with giving high propriety to energy security, sustainable energy consumption and low carbon emission. Many policies have been enacted by countries to promote the scaling up of wind energy and renewable energy in particular, across the globe. However, these policies have mixed effects on the deployment of wind energy. For this purpose, current study used panel data and fixed effects model for 17 African countries with wind installed generation capacity to determine the driver of wind energy development on the African continent between 2008 and 2017. The variables were grouped into three thematic areas: policy, socioeconomic, and country-specific factors. After conducting the analysis, socioeconomic variables (GDP, CO₂, energy use) and energy security variables (energy import, electricity consumption) have significant effects in determining the scaling up of wind energy in Africa. However, the policy variables of FITs, licensing during, and Tax did not have significant effects on wind energy capacity addition for the case of Africa. This study adds to the drivers of nascent wind energy deployment literature in Africa. This study suggests that set of effecitive policies are deem necessary to scale up wind energy in Africa.

This study seeks to assess the reaction of the eggplant (Solanum melongena L.) to soil samples contaminated. Following, cultivation, growth, and harvest, the plant samples were prepared and maximum absorption rates of heavy metals were measured in both leaf and fruit. The estimated daily intake (EDI), the target hazard quotient (THQ), and the bio-concentration factor (BCF) were measured at various intervals during the growth period of the plant. Spectral analysis was also performed to assess the reaction of target crops to heavy metals. The results showed that in the second and third stages of plant growth, the THQ values were more than 1 for infected plants with Cd, Pb, and Zn. According to results from the BCF analysis, the absorption rate in Pb, during the growth stages was relatively high, in crops contaminated by Ni was around 1 in the second and third stages, and in plants contaminated by Cd was extremely high. All crops contaminated by heavy metals showed higher reflection rates in the 400–500 and 600–700 nm range. So, using electromagnetic waves during different stages of growth, the reaction of eggplant cultivated in soil samples contaminated by heavy metals is predictable.

This paper analyzes the extent to which CEO (chief executive officer) tenure affects the corporate social and environmental performance of all nonfinancial Chinese firms listed in Shanghai and Shenzhen stock exchanges during 2009–2015. The study uses a fixed-effect panel regression model by considering the overtime data across the firms. 2SLS regression model then is used to control the problem of endogeneity. The study confirms the negative effect (8.8%) of the increase in CEO tenure on the corporate social and environmental performance. The findings also explain that the corporate social and environmental performance of CEOs increases significantly in the initial years of service than in their later years. The study concludes that an inverse relationship between CEO tenure and corporate social and environmental performance is more pronounced with a higher percentage of independent directors, where CEOs have longer anticipated employment tenure and firms under state control, consistent with the signalling explanation of career concern and career horizon effect. Finally, the impact of CEO tenure on corporate social and environmental performance has become stronger in recent years.

Recently, several seminal works have been drawing attention to the revolution of shale gas production technology of the USA, the impact of shale gas on energy sectors, as well as the influences of shale gas on macroeconomic variables of employment, economic growth, etc. Nevertheless, one may claim that two gaps appear in literature. The first gap is the absence of an econometric study estimating the effect of shale oil/gas on national economies. The more considerable second gap is the absence of econometric analyses revealing the impulses of shale gas on local economies. Therefore, this paper observes the possible causalities between the shale gas and local gross domestic product (GDP) employing quarterly data covering the period 2007–2016 for 12 states in the US. After performing the tests of cross-sectional dependence, heterogeneity, stationarity, and cointegration, the paper conducts the panel Granger causality analyses. The empirical findings depict that (i) there is available unidirectional relationship from local shale gas production to local GDP in Colorado, Ohio, and West Virginia; (ii) there occurs an impulse from GDP to local shale gas production for Louisiana, North Dakota, and Oklahoma; (iii) a bidirectional causality coexists between local shale gas production and GDP in Arkansas, California, and Texas; and (iv) there exists no association between local GDP and local shale gas extraction in Montana, New Mexico, and Wyoming.