For a potential and efficient solution in the mitigation of aquatic pollution, this study reported a well-designed and developed protected granulated activated carbon (GAC) material which ensures high strength property and adsorption performance to meet the industrial application. The prepared GAC material was shaped into a spherical core using natural binders basically assumed to constitute waste solids materials. Then after, the granulated carbon core (GAC core) was protected by a porous ceramic shell which confined the material with strong protection and high mechanical strength to resist against degeneration and pressure drop as a limiting factor for most sorbents employed in solution. The CSGAC characterization results proved that the ceramic shell has a smaller thickness (0.1 cm), good mechanical strength (2.0 MPa), and additionally, it presents larger porous channels which promote the fast and higher adsorption performance making it the desired material for the application in the real liquid environment. The test results showed that the prepared material had higher removal of triclosan (TCS) (30–40 mg/L) than BPA counterpart from the aqueous solutions. Moreover, it showed higher adsorption performance compared to the unprotected carbon materials. Furthermore, the mechanisms of BPA and TCS adsorption by core-shell granulated activated carbon (CSGAC) were discussed.

Although it is still a great challenge, developing oil-/water-separating membranes that combine the advantages of high separation efficiency, salty environments tolerance, and fouling resistance are highly demanded for marine oil spill cleanups and oil-/gas-produced water treatment. Here, we report a new type of all-inorganic nanostructured membrane, which is composed of titanate nanofibers and SiO₂ particulate gel for efficient and stable oil/saltwater separation. The nanoporous and interconnected network structure constructed with titanate nanofibers is the key to ensure the high separation efficiency and high water flux of the new membrane. The SiO₂ gel is used as a binder to offer mechanical flexibility and integrity for this type of all-inorganic membrane. The new membrane displays a high oil/water separation efficiency of above 99.5% with oil content in treated effluent lower than US environmental discharge standards (42 ppm) and high water permeation flux of 1600 LMH/bar under low operation pressure. The new membrane also demonstrates outstanding durability in the environment of different salinities, and it has a good resistance for oil fouling due to its excellent underwater superoleophobicity with an oil contact angle above 150 °. Most importantly, the underwater superoleophobic properties can be well maintained after being repeatedly reused. The excellent environmental durability, oil-fouling resistance, high separation efficiency, and facile fabrication process for this new type of membrane render great potential for industrial application in treating produced water.

Mine tailings are a characteristic of landscapes where mineral extraction has occurred and provide a prime opportunity for vegetation succession. In this study, soil heavy metal concentrations, plant composition and biodiversity, heavy metal accumulation, and their relationships were studied in the tailings of the Pingle Mn mine (abandoned for over 15 years) in South China. The total heavy metal concentrations ranged from 440 to 15,590 mg kg⁻¹ for Mn, 5.01 to 20.7 mg kg⁻¹ for Cd, 101 to 319 mg kg⁻¹ for Pb, 546 to 1693 mg kg⁻¹ for Zn, and 116 to 180 mg kg⁻¹ for Cu. According to soil contamination assessment by single contamination indexes and the Nemerow multifactor index, the tailing soil had a heavy pollution level. According to ecological risk assessment by monomial potential ecological risk factors and potential ecological risk indexes, the tailing soil presented a high ecological risk level, to which Cd was the key contributor. A total of 13 plant species from 2 families (Gramineae and Compositae) successfully colonized the tailings. Importance values based on relative height, relative coverage, relative abundance, and relative frequency indicated that Neyraudia reynaudiana K. and Paspalum orbiculare F. were the dominant species. The species were multi-metal-tolerant species, and most of them were shoot accumulators, as their translocation factor values were above 1. Plants exhibited the highest bioconcentration factor for Pb, and the average values for roots, stems, and leaves were 2.56, 1.45, and 1.70, respectively. There were positive relationships (P < 0.01) between soil Mn, Cd, Zn, and Cu and plant Pb; similar results were found for soil heavy metals and leaf/stem Mn. The species composition in the tailings of the Pingle Mn mine was reflective of long-term vegetation succession, and the results obtained in this study provide insight for selecting plant species and reconstruction practices for Mn wasteland restoration.

Under different technological innovation modes, regional energy consumption may have spatial heterogeneity. Spatial heterogeneity complicates the nexus between environmental regulation and energy consumption. Traditional spatial homogeneity analysis is hard to describe the nonlinear nexus between them. Based on the data of 30 provinces in China from 2007 to 2017, this paper employs the spatial econometric method and the nonlinear econometric method to investigate the spatial effects and nonlinearity of energy consumption, respectively. The results display that under the current level of economic development, per capita energy consumption has a significant spatial spillover effect. Environmental regulation promotes regional per capita energy consumption in the short term. On the contrary, the technological effect of environmental regulation has significantly reduced Chinese per capita energy consumption. Therefore, energy policy should be tailored to local conditions, and policymakers can strengthen the environmental regulatory system and encourage enterprises to implement green technology innovation.

Membrane fouling is still the main obstacle that hinders the development and implementation of anaerobic membrane bioreactor (AnMBR). In conventional upflow anaerobic reactors, sludge at different height usually presents certain differences in characteristics in terms of particle size, etc. The immersion depth of membrane modules in anaerobic reactors can also influence the fouling of membrane. Thus, it is of great interest to investigate the fouling mechanism with the membrane installed at different heights in reactors. The filtration performance and sludge properties were investigated at different heights of AnMBR. The fouling of membrane in the middle position was severer than that in the top and bottom positions. The total resistance of membrane in the top, middle, and bottom positions was 27.31 × 10¹¹ m⁻¹, 34.67 × 10¹¹ m⁻¹, and 25.29 × 10¹¹ m⁻¹, respectively. By comparing the characteristics and structure of bulk sludge and cake layer at three heights, the bulk sludge in the middle position presented higher content of soluble microbial products (SMP) and finer flocs, and the cake layer was also denser. The results obtained in this study indicated that small size of sludge flocs as well as adhesion of SMP might be the major factors governing membrane fouling at different height in the AnMBR.

The environmental pollution indicators and multivariate statistical analysis were used to evaluate the potential ecological risk and the contamination of Fe, Mn, Zn, Ni, Pb, Cu, Cd, and Co in surface sediments of the Egyptian Red Sea coast. The results revealed that the studied area suffers from high contamination of certain metals such as the Hurghada area (Pb, Cd, Zn, Ni, and Cu), Quseir City area (Cd, Co, Pb, and Ni), and Safaga and Marsa Alam areas (Cd and Pb). Enrichment factor and principal components analysis reported that the pollution sources of Fe, Mn, and Co are related to natural weathering process while Cu, Zn, Ni, and Pb are related to anthropogenic sources as landfill, plastic rubbish, fishing boats, phosphate operations, and tourist activities. Moreover, Co and Cd metals can come from both of natural and anthropogenic sources. The average concentrations of Cd, Cu, Zn, Pb, Ni, and Co in sediments of the Egyptian Red Sea coast are higher than those in the coasts of the Red Sea (Saudi Arabia), Mediterranean Sea (Egypt and Libya), Bengal bay (India), and the Caspian Sea (Russia). However, the studied metal content is lower than the sediment quality guideline values except for Cd.

This study examined the nexus between carbon emissions, renewable energy consumption, and the economic growth of West African countries for the period 1990 to 2018. To be able to uncover reliable and valid findings, more robust panel estimation methods were employed for the study. From the heterogeneity and cross-sectional dependence tests, the study’s panels were heterogeneous and cross-sectionally dependent. Also, all the series were non-stationary at levels, but gained stationarity after first difference. Further, the Fisher test and the Westerlund and Edgerton bootstrap test found the variables to be cointegrated in the long run. The CCEMG and the DCCEMG estimators were used to explore the long-run equilibrium relationship amid the series, and from the results of the whole sample, CO₂ emissions and renewable energy consumption (REC) had no vital influence on economic growth (GDP) in both estimators. However, the results were a bit different in the sub-panels. Also from the whole sample, control variables urbanization (URB) and population growth (POP) had no material effect on GDP in both estimators. The results were, however, dissimilar in the sub-panels. Finally, the Dumitrescu-Hurlin test was employed to examine the causalities amid the series, and the results were diverse in the various panels. Policy recommendations are further discussed.

Data-driven statistical air quality prediction methods usually build models fast with moderate accuracy and have been studied a lot in recent years. However, due to the complexity of air quality prediction which usually involves multiple factors, such as meteorological, spatial, and temporal properties, it is still a challenge to propose a model with required accuracy. In this paper, we propose a hybrid ensemble model CERL to exploit the merits of both forward neural networks and recurrent neural networks that are designed for handling time serial data to predict air quality hourly. Measured air pollutant factors including Air Quality Index (AQI), PM₂.₅, PM₁₀, CO, SO₂, NO₂, and O₃ are used as input to predict air quality from 1 to 8 h ahead. Based on the air quality prediction evaluation in Lanzhou and Xi’an, which are two important provincial capitals in Northwest China, CERL provides better performance over other baseline models. Moreover, as the step length increases, CERL has more obvious improvement. For example, the improvements of CERL in the 1-step, 3-step, 5-step, and 8-step prediction for PM₂.₅ in Lanzhou are 1.82%, 8.01%, 9.98%, and 20.03%, respectively. The superiority of CERL is also proved by a hypothesis Diebold Mariano test with level of significance 5%.

The reason that some molecules, but not others, are easily adsorbed was not fully understood. In order to spotlight the effect of morphological structure and surface functional composition of adsorbate rather than focusing only on the nature of adsorbent as in most of literature reports, this work reports the biosorption of two dyes (anionic Orange G and cationic malachite green) and two pharmaceuticals (Ibuprofen and ampicillin) as target representative contaminants onto plasma-modified cocoa shell (CPHP) used as alternative low-cost adsorbent. As results, when molecules were mixed in solution and then exposed to a substrate, the factors that affect adsorption include the relative solvation of the adsorbates, the ability of each molecule to adhere to the surface, and the degree of interaction between the molecules once they were adsorbed. The maximum adsorbed amounts at 298 K of OG, MG, IBP, and AMP were 23.96, 14.65, 13.99, and 06.66 mg/g, respectively. The most solvated molecules may not adsorb rapidly to the surface, while comparatively, the less soluble molecules will aggregate, so as to maximize self-interactions via Van der Waals, hydrogen bonds or other interactions. This work demonstrated that the adsorbate intrinsic properties could play a significant role in the adsorption process. Hence, properties such as functional active groups, dimensions, and hydrophobicity were the determining parameters in the adsorption process mechanism. Accordingly, the pharmaceuticals biosorption mechanism involved π-π bonding, hydrophobic effect, electrostatic interaction, and van der Waals forces whereas the dye biosorption mechanism was dominated as well known by electrostatic attraction and hydrogen bonding phenomenon. Experimental parameters such as initial pH of solution and contact time were optimized. The optimum pH values were 2.0 for ibuprofen (IBP) and 7.0 for ampicillin (AMP). The kinetics of adsorption and the experimental isotherms data were analyzed using non-linear models. Results indicated that Avrami fractional order was the most successfully fitted model for pharmaceutical biosorption and based on the statistical values of SD and R²ₐdⱼ parameters, Liu isotherm was the most successfully fitted model.

TCEs stands for technology-critical elements, a group of chemical elements for which imbalances between supply and demand exist or are deemed probable. This article challenges the scientific usefulness of such a classification when dealing with environmental and toxicological issues. Criticality is an economic conceptualization that is not well suited to guiding environmental chemistry research efforts. The classification is even counterproductive because it does not foster collaborative research with the countries directly touched by the environmental problems which are directly linked to the production of the elements.