The study area lies in a semi-arid setting of Brazil that comprises some of the largest scheelite mines in the country, but information regarding the mining impacts on the soil quality are relatively scarce. Here, we studied the changes in the soil physical and chemical characteristics caused by the scheelite mining activities in northeast Brazil, including the impacts on heavy metal concentrations in soils. Soil quality was evaluated in three sites: non-mining (reference), mining, and post-mining. The soil samples were physically and chemically characterized and had their content of the heavy metals Cd, Cr, Cu, Ni, Pb, and Zn determined. The results showed that mining activities significantly impacted soil quality. The main environmental degradation caused by scheelite mining was soil compaction, alkalization, and decreasing of soil organic matter, nitrogen, and phosphorus contents. Besides, the soil concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were higher than the soil guideline values (SGVs) for metals proposed by the Environmental Protection Agency of Brazil. The soil characteristics varied widely in the three conditions of the study (non-mining, mining, and post-mining); therefore, our data provide a base for soil quality assessments of areas impacted by scheelite mining. Due to the improvement in soil physical and chemical characteristics promoted by the spontaneous vegetation cover of old tailings piles, the post-mining sites were statistically grouped with the non-mining areas. Such a result highlights the crucial role that vegetation plays in the recovery of mined sites.

Cadmium (Cd) inhibits soybean root growth, but its exact mode of action is still not completely understood. We evaluated the effects of Cd on growth, mitochondrial respiration, lipid peroxidation, total phenols, glutathione, and activities of lipoxygenase (LOX), superoxide dismutase (SOD), and catalase (CAT) in soybean roots. In primary roots, Cd stimulated KCN-insensitive respiration and KCN-SHAM-insensitive respiration, indicating the involvement of the alternative oxidase (AOX) pathway, while it decreased KCN-sensitive respiration, suggesting an inhibition of the cytochrome oxidase pathway (COX). In isolated mitochondria, Cd uncoupled the oxidative phosphorylation since it decreased state III respiration (coupled respiration) and ADP/O and respiratory control ratios, while it increased state IV respiration (depletion of exogenously added ADP). The uncoupling effect increased extramitochondrial LOX activity, lipid peroxidation, and oxidized and reduced glutathione, which induced an antioxidant response with enhanced SOD and CAT activities. In brief, our findings reveal that Cd acts as an uncoupler of the mitochondrial oxidative phosphorylation in soybean roots, disturbing cellular respiration and inducing oxidative cellular stress.

Volatile organic compounds (VOCs) are atmospheric pollutants that can affect human healthy and intensify some environmental problems. Among different techniques to degrade VOCs, heterogeneous photocatalysis has been highlighted. The aim of this research was to obtain high toluene degradation using heterogeneous photocatalysis in the ozone presence (TiO₂/O₃/UV) and analyze VOC degradation over the reactor length comparing with ozone concentration also over the reactor length. Ozone concentration has influence on toluene degradation; 75% of VOC degradation was reached with 69.0 mgL⁻¹ of O₃ meanwhile a degradation of 91% was obtained with 96.2 mgL⁻¹ of O₃. Toluene degradation reached a plateau over reactor length at flowrate of 565 mL min⁻¹, which indicates the reactor was oversized in this case. However, it was not observed at 1425 mL min⁻¹. In addition, it was evaluated that O₃ concentration and toluene reaction rate decreased over the reactor length.

Given the strong impact of air quality on health, environment, and economy, Morocco has implemented an air quality network to assess air pollutants including PM₁₀ (particulate matter with a diameter less than 10 μm). This network which is composed of 29 fixed measurement stations is spatially limited and does not provide sufficient time resolution. The scarcity of measured air quality data led to seek an optimal alternative source to conduct related data-based studies. This represents the primary objective of this paper. PM₁₀ concentrations of global Copernicus Atmosphere Monitoring Service Reanalysis (CAMSRA) data (4D Variational analysis “4v” and analysis “an”), as well as regional CAMSRA data, were examined against the average daily PM₁₀ concentrations collected from six fixed Moroccan air quality measurement stations in 2016 (i.e., observation data). The verification is carried out by studying and analyzing seasonal, extreme, and annual values. The study shows a strong seasonal dependence with a positive bias in winter and a negative bias during summer. For the study of extreme values, global CAMSRA “an” and “4v” data record significant bias of approximately 184 and 161 μg/m³, respectively. However, the annual analysis shows that the CAMSRA global “an” data have the smallest average bias (20.008 μg/m³) and hence has the closest representation of observation data. We conclude that the CAMSRA global analysis data could be used to compute climatology, study trends, evaluate models, benchmark other reanalysis, or serve as boundary conditions for regional models for past periods.

Lake Karla Watershed is an agricultural basin characterized by intense agricultural activities, which lead to quantitative and qualitative aquifer degradation. The exploitation of non-renewable groundwater resources and nitrate contamination are the major threats to aquifer sustainability. Groundwater resources cover mainly irrigation and domestic water needs. Hence, the simulation of groundwater resources is necessary to (a) determine the quantity available for water supply and (b) estimate probable nitrate contamination to propose subsequent remediation techniques to protect public health. Furthermore, the aquifer’s heterogeneity as well as the lack of hydraulic conductivity data, in a large-scale study area, creates uncertainty regarding groundwater flow and nitrate transport simulation. Deterministic modelling approaches for spatially distributed nitrate concentration simulation could not estimate the contamination risk, since it can address only one realization of the aquifer. This study estimates the effect of hydraulic conductivity uncertainty on the simulation of groundwater nitrate concentration. The proposed framework uses Geostatistical Sequential Gaussian Simulation (SGSIM) for the generation of equally probable realizations of the spatial distribution of hydraulic conductivity. It includes the application of a modelling system based on the following inter-linked models: a rainfall-runoff model, a reservoir operation model, a lake-aquifer interaction model, a groundwater flow model, and a nitrate transport and dispersion model. The last two models simulate the multiple realizations of aquifer’s groundwater flow and nitrate concentration. Furthermore, two analyses (a statistical and a threshold analysis) are employed to estimate the exceedance probability of the nitrate concentrations and their spatial extent. The results indicate that hydraulic conductivity uncertainty does affect the simulation of nitrate concentration and that nitrate concentrations will most probably exceed the thresholds in areas where groundwater is extracted for domestic use.

We constructed binary and ternary systems between U (VI) and Shewanella putrefaciens, kaolin, and nano-α-Fe₂O₃, and studied the interactions of mixtures in the systems to determine and describe the role of microorganisms in regulating the environmental mobility of U. Shewanella putrefaciens, kaolin, or nano-α-Fe₂O₃ was placed in U (VI) solution to form a binary system. In this system, the adsorption of U (VI) by Shewanella putrefaciens increased with the increase of time, while the adsorption of U (VI) by kaolin and nano-α-Fe₂O₃ was not obvious at low concentration. The mixture of bacteria, kaolin, or nano-α-Fe₂O₃ was placed in U (VI) solution to form a ternary system, in which the adsorption capacity of Shewanella putrefaciens to (VI) was significantly reduced after the addition of minerals. The results indicate that the combination of minerals and bacteria may affect the respiration of bacteria, thereby reducing the adsorption and reduction of (VI) by Shewanella putrefaciens. Fourier transform infrared spectroscopy (FTIR) was used to analyze the possible functional groups in the interaction between cells, minerals, and U. The results showed that the distribution of U on the cell surface was related to the carboxyl, amide, and hydroxyl groups of Shewanella putrefaciens.

In this study, we focused on investigating the plastic microfibers and how their aging due to UV irradiation could be further aggravating their negative effects on the environment. Hence, we examined the microfibers of polypropylene (PP) and polystyrene (PS) as model microplastics to observe the induced surface changes caused by aging through UV irradiation when the plastic is discarded in the environment. We also observed the enzymatic activity and microbial community changes in the soil when microplastics are added. Increases in the stretching vibrations of the –OH and C=O groups in the aged microplastic samples were observed using the attenuated total reflection Fourier-transform infrared spectroscopy analysis, confirming photo-oxidation on the microplastic surface. The soil enzyme activity was significantly reduced with the addition of virgin PP and PS, with a further reduction when adding aged PP and PS. Furthermore, the comparison of the microbial community analysis results before and after aging indicated that a slight decrease in Alphaproteobacteria and an increase in Betaproteobacteria were at the class level. Overall, the findings of this study can be used to understand the functional changes in the soil environment as a result of microplastic accumulation.

Industrial transformation and upgrading is an important step for China to carry out cleaner production and achieve the goal of carbon neutrality. With the help of green finance, we can optimize the allocation of financial resources and promote the optimization and upgrading of industrial structure. In order to explore the impact efficiency and policy effect of green finance on industrial transformation and upgrading in China, through the establishment of VAR model and super-efficiency DEA model, the relationship between green finance and industrial transformation and upgrading and its impact on efficiency are studied. In addition, the Tobit regression model is used to empirically test the impact of public environmental demands, government regulations, and their interaction terms on the efficiency of green finance in promoting industrial transformation and upgrading. The results show that the overall efficiency of green finance in promoting industrial transformation and upgrading is high, but it shows a downward trend, which may be due to the unbalanced development of the green financial system, information asymmetry, and the absence of enterprises from regulation. The impact coefficient of input-oriented government regulation is significantly negative, which indicates that increasing the investment in pollution control may encourage polluting enterprises’ emission behavior to obtain benefits. The impact of performance-oriented government regulation and public environmental demands on efficiency is not significant, which indicates that the supervision and binding force of enterprises are insufficient. Public environmental demands and input government regulations have significant synergistic governance advantages, indicating that the government should enhance the regulatory intensity of differentiated policies. The study provides a reference for the government to enhance the intensity of policy regulation and establish a diversified environmental governance system.

To enhance the reliability of active biomonitoring of air pollution using lichens, we tested how a water-washing procedure influences element concentrations in lichens growing on bark and rock substrates. Thalli of the lichen Parmotrema tinctorum were collected from tree bark and sandstones from a relatively clean air site in Khao Yai National Park, Thailand. After dry cleaning, each thallus was divided equally: the first part was directly used for element analysis, and the second part was washed with deionized water before it was sent for element analysis. The concentrations of 13 elements, including Al, As, Ca, Cu, Fe, K, Mg, Mn, Se, Sr, Ti, V, and Zn, were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the washing procedure substantially decreased the amounts of most elements in the lichens; after washing, concentrations of the elements in the epiphytic thalli showed decreases ranging from 17 to 81% (54% on average), and those in the epilithic thalli showed decreases ranging from 10 to 27% (18% on average). The coefficient of variation (CV) was also reduced for most elements, especially for those in the epiphytic thalli, indicating that washing could produce more homogeneous samples. All elements from the unwashed samples had higher contents in the epiphytic thalli than in the epilithic thalli, but the element contents were higher in the epilithic thalli after washing. Most elements in the washed epiphytic and epilithic thalli were not comparable, indicating that the washing procedure did not produce the same order of magnitude of element contents in the epiphytic and epilithic thalli. Based on the results of this study, we recommend washing pre-exposed lichen samples for more reliable results in active biomonitoring studies of air pollution.

The current agricultural system in China highly depends on chemical fertilizers and pesticides. Consequently, agricultural production activities cause various environmental issues. Carrying out safe production provides vital support for sustainable development of agriculture, which may improve this situation. The past decades have witnessed the fast development of rural cooperatives organization in China. Given the fact that rural cooperative organization plays a crucial role in agricultural production, however, there is little empirical evidence on the relationship between cooperative membership and safe production of smallholders in China. This study aims to investigate whether the participation in farmer cooperatives contributes to safe production in agriculture in China. Using survey data covering 623 rice-producing farm households in Sichuan province in China, this study employs the endogenous switching regression model to examine the effects of the participation in farmer cooperatives on safe production in rice agriculture. The results show that cooperative membership has significantly positive effects on safe production in rice agriculture. In particular, the average treatment effects demonstrate that without the participation in cooperatives, the members’ adoption of the green control techniques would reduce by 74.491%, the application of artificial weeding would reduce by 38.768%, and organic fertilizer input would reduce by 23.448%. Furthermore, the marginal treatment effect is employed to evaluate the heterogeneous effects of the participation in farmer cooperatives on safe production in rice agriculture. Heterogeneous effect analyses suggest that farmers who are more likely to participate in farmer cooperatives are easier to adopt green control technology, while farmers who are less likely to participate in farmer cooperatives are easier to adopt artificial weeding and increase organic fertilizer input. To improve safe production in rice agriculture, the Chinese government is expected to encourage rice farmers to participate in rural cooperative organizations, and to stimulate rice farmers to take collective action to address environment issues arising from agricultural production.