The presence of toxic metals in soil enables them to be absorbed by plants. The RDC 42/2013 published by Brazilian Health Regulatory Agency (ANVISA) defines the maximum values of cadmium (0.4 mg kg⁻¹) and lead (0.6 mg kg⁻¹) in yerba mate commercialized in Common Market of the South (Mercosul). This work is a retrospective study that aimed to evaluate cadmium and lead levels in processed yerba mate and in natura leaves in Southern Brazil. The cadmium and lead concentrations in 370 processed yerba mate and 122 in natura leave samples obtained in Southern Brazil were analyzed. In 47.56% of the processed samples, the levels of cadmium and/or lead were found to be above the authorized levels. The cadmium levels found in the processed yerba mate were 0.37 ± 0.19 mg kg⁻¹, and the corresponding values for lead were 0.34 ± 0.21 mg kg⁻¹. Values above the authorized levels were also found in the non-processed leaves. Studies are required to determine whether these levels are natural or represent contamination.

In the northern Great Plains, a potential road dust abatement is the application of oil-well produced water, also known as “brine.” However, little is known about the effectiveness of brine or its potential impacts on dispersion of road materials and the creation of dusts. This study aimed to investigate how sodium adsorption ratios (SAR), electrical conductivity (EC), and Ca/Mg ratios of simulated and non-simulated brine influenced dispersive reactions of three mineralogically different gravel road fine fractions. Ca/Mg ratios had little to no significant influence on the outcome of dispersion. Irrespective of the SAR or clay mineralogy, a threshold EC of 4 dS m⁻¹ was sufficient to control road fine fraction dispersion. Actual oil-well produced water effect on dispersion followed the same order as that treated by simulated solution and the dispersion value can be well-predicted from EC. This information is useful to managers, regulators, scientists, and industry professionals considering the use of brine as a road dust control abatement.

An in situ horizontal well (IHW) fan-shaped test tank was constructed in the laboratory. And nitrate removal rates were analyzed under different hydraulic loads. When the initial concentration of groundwater nitrate-N was 25 mg/L and the hydraulic load increased from 0.78 to 3.90 m³/(m² day), the results show that the nitrate-N concentration was less than 1.25 mg/L after the denitrification process stabilized. Additionally, the nitrate-N removal rate was over 95%. The concentration of nitrite-N was still below 1 mg/L, and the level of ammonia-N was between 0.5 and 1.00 mg/L. No increase in nitrite-N and ammonia-N concentration occurred during the test. The hydraulic conductivity of the medium in the horizontal well showed little variation, ranging from 34.09 to 31.64 m/day, indicating that there was no blockage caused by microbial growth in the IHW during the test. In addition, no ethanol was detected in the test tank except for the horizontal well, revealing that ethanol did not diffuse into the surrounding aquifer. Therefore, when the concentration of groundwater nitrate contamination is 25 mg/L, the hydraulic load under the IHW test tank condition is 3.90 m³/(m² day). The IHW test tank had a stable and good biological denitrification effect, and it can provide certain reference significance for in situ remediation of nitrate-contaminated groundwater.

This study proposed the optimization of a laccase-mediator system to reduce pesticide levels (bentazone, carbofuran, diuron, clomazone, tebuconazole, and pyraclostrobin) on aqueous medium. Firstly, the mediator concentration of 1 mM was established (average removal of 36%). After that, seven redox-mediating compounds, namely, 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, caffeic acid, chlorogenic acid, p-coumaric acid, ferulic acid, gallic acid, protocatechuic acid, and vanillin, were compared regarding their removal efficiency. The highest removal (77%) was achieved with the laccase-vanillin system. After this screening, the optimization was carried out by a 2² full factorial design. Variables under study were the enzyme (laccase) activity and vanillin concentration. Maximum removal (53–85%) was achieved with 0.95 U/mL laccase and 1.8 mM vanillin. Pesticide removal in reaction media was fitted to the first-order kinetics equation with an average half-time life of 2.2 h. This is the first study of the use of this natural compound as a mediator in the degradation of the pesticides under investigation. The results of this study contribute, with alternative methods, to decrease pesticide levels since they are highly persistent in aqueous samples and, as a result, mitigate the environmental impact.

This research aims to study the effect on industrial carbon intensity by decomposing electricity consumption into electricity consumption volume and electric power intensity by using panel data of 27 China’s manufacturing sectors. An improved STIRPAT model is also developed by this article to identify the unexplored potential influencing factors. The research findings suggest that there exists a long-run equilibrium relationship between electricity consumption and carbon intensity and unidirectional causality from electricity consumption volume to carbon intensity. Regression results indicate that electricity consumption volume has a significantly negative effect on industrial carbon intensity for the full sample. However, due to the significantly positive influence that electric power intensity has on carbon intensity, we conclude that energy consumption and industrial economy failed to achieve the decoupling effect. The impacts of electricity consumption volume and electric power intensity have industrial heterogeneity. Electric power intensity impacts carbon intensity the most for resource intensive sectors. The effects of subgroups are further examined for sectors with high/low carbon emission volume and carbon intensity. Foreign direct investment (FDI) is conducive to reducing carbon intensity for sectors with high volume and sectors with high intensity. Industrialization level demonstrates a significantly positive effect on improving carbon intensity for sectors with low volume and sectors with low intensity. Finally, we put forward specific suggestions on the basis of these empirical findings.

The present study describes the impregnation of coffee extract (CE) into bacterial cellulose synthesized from kombucha tea fungus (KBC) of different cellulose content, incubated for different incubation periods (2, 4, and 10 days), to prepare biocomposites having the potential for wound healing applications. Total polyphenols in hydroalcoholic extracts from ground roasted coffee and its release from the prepared biocomposites were determined as gallic acid equivalent. The polyphenols content was found to be 13.66 mg/g and the minimum inhibitory concentration (MIC) of the CE was determined using colony-forming unit (CFU) method against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus where the growth inhibition was 86 and 97% respectively. Biocomposites (KBC/CE) with the lowest cellulose and CE content showed the highest wet tensile stress (3.35 MPa), absorption of pseudo extracellular fluid (154.32% ± 4.84), and water vapor transmission rate (3184.94 ± 198.07 g/m²/day), whereas it showed the lowest polyphenols’ release (51.85% ± 2.94)when immersed in PBS buffer of pH 7.4. The impregnation of CE into KBC provided biocomposites that can enlarge the range of BC in the biomedical application.

Vehicular evaporative emissions have been recognized as an important source of volatile organic compounds to the environment and are of high environmental concern since these compounds have been associated to the formation of surface ozone and secondary organic aerosols. Evaporative emissions occur during any vehicle operation. In Europe, a revised legislative test procedure has been recently introduced to better control evaporative emissions during parking. However, emissions related to normal driving conditions—the so-called running losses—have received less attention compared with the other categories. The current study aims at giving some insights to the prevailing temperature conditions in fuel tanks of typical European vehicles during normal driving operation. The effects of ambient air temperature, trip duration, vehicle speed, and fuel tank level on the temperature reached by the fuel inside the tank under different real-world operating conditions were studied. Tank temperature can exceed 40 °C depending on ambient and driving conditions. Ambient temperature was found to be the most important parameter affecting the tank temperature. Trip duration and driving pattern may also have an influence on the tank temperature particularly when long trips combined with high vehicle speed are examined. Additionally, the difference between tank and ambient temperature was examined during the individual trips and was found to vary between 1 and 10 °C depending on the testing conditions. The most important parameters affecting the delta temperature were found to be the trip duration and the maximum vehicle speed. Finally, the purging strategy of two of the test vehicles was monitored, and the parameters affecting the purging flow rate were investigated. No strong correlation between the canister flow rate with ambient temperature, vehicle speed, or fuel level was observed in either of the tested vehicles. Substantially different canister flow rate levels between the two vehicles point to different purging strategies.

The objective of this study is to identify the feasibility of using rhamnolipid biosurfactant to remediate heavy metals contained in manganese nodules collected from the Clarion-Clipperton Fracture Zone, Pacific Ocean. Deep-sea manganese nodules may represent one of the most important future natural resources for heavy metals due to the depletion of resources on land. Since international marine environment guidelines for deep-sea mining will be set up by international organisations in the 2020s, remediation technologies are urgently required for deep-sea mining tailings. We show that rhamnolipid biosurfactant is an environmentally friendly substance and can be successfully used for the remediation of heavy metals in deep-sea mining tailings under various reaction conditions. Rhamnolipids therefore represent a useful extracting agent for heavy metals in deep-sea mining tailings. The removal of nickel (Ni), copper (Cu), and cadmium (Cd) would be enhanced in the presence of rhamnolipids with specific reaction times and concentrations. Future actual remediation technologies should be developed using rhamnolipid biosurfactant on the basis of these results.

Alkali-leaching residual wire sludge (AWRS) is an abundant by-product in the harmless disposal process of wire rope sludge. In this study, we modified AWRS through thermal treatment to produce a low-cost and highly efficient adsorbent for the removal of Cu²⁺ and Ni²⁺ from wastewater. The results indicated that AWRS calcinated at 700 °C exhibited maximum Cu²⁺ and Ni²⁺ removal capacities (36.48 mg/g and 46.58 mg/g, respectively). The adsorption process was observed to follow the Elovich kinetic model and the Langmuir–Freundlich isotherm model. The sorption of Cu²⁺ and Ni²⁺ on AWRS700 was highly pH dependent and behaved optimally at the solution pH values of 6 and 5, respectively. Column studies and physicochemical analyses (XRD, SEM-EDS, and XPS) indicated that the sorption of Cu²⁺ and Ni²⁺ on AWRS700 was mainly governed by the chemisorption mechanism, and this was attributed to active metal oxides (Fe₂O₃, CaO, and Al₂O₃) in AWRS700. Specifically, Cu²⁺ is mainly adsorbed on AWRS700 in the form of Cu(OH)₂, CuO₂, and CuFeO₂, and Ni²⁺ is mainly adsorbed in the form of NiAlO₄, Ni₂O₃, and Ni(OH)₂. Given the low-cost and high adsorption efficiency of AWRS700, the developed AWRS700 is a promising adsorbent for Cu²⁺ and Ni²⁺ removal from wastewater.

The aim of the present study was to isolate several bacterial consortia from a soil sample and to establish if they could colonize zirconium-tin alloy, such as Zircaloy-4. Two bacterial consortia containing aerobic heterotrophic bacteria and anaerobic sulfate-reducing bacteria were isolated from a soil sample. The aerobic heterotrophic bacteria exhibited a higher capability to utilize different sole carbon sources, as compared with anaerobic sulfate-reducing bacteria. Based on a morphological, biochemical, and molecular analysis, bacterial isolates were identified as Pseudomonas putida IBBHA₁, Pseudomonas aeruginosa IBBHA₂, Achromobacter spanius IBBHA₃, Citrobacter freundii IBBSR₁, Citrobacter youngae IBBSR₂, and Citrobacter braakii IBBSR₃. Isolated bacterial consortia which possess distinct DNA fingerprints were able to form biofilms and colonize the surface of zirconium-tin alloy coupons, although the colonization of coupons by the aerobic heterotrophic bacteria or anaerobic sulfate-reducing bacteria alone was lower compared with that observed when the coupon was immersed in a mixture of both bacterial consortia. Coupons immersed in these bacterial consortia revealed changes in the surface characteristics, which can facilitate or accelerate zirconium-tin alloy corrosion. The accumulation of corrosion products on coupons surface was less significant when the coupons were immersed solely in aerobic heterotrophic bacteria or anaerobic sulfate-reducing bacteria, compared with that observed when the coupon was immersed in a mixture of both bacterial consortia.