International Journal of Environmental Research最新文献

Perfluorooctane Sulfonate (PFOS) is widely used in various commercial applications, including food packaging, fabrics, and fire-fighting foams. This toxic and carcinogenic compound could be present in water and food products, which could be fatal to living beings. Zeolite-based materials are promising PFOS sorbents due to their high anion exchange capacity and specific surface area. In this study, a natural Clinoptilolite-type zeolite was modified with Hexadecyl Trimetilammonium Bromide (HDTMA) for PFOS remediation in aqueous solutions. The modification introduced an inversion of Clinoptilolite's natural surface net charge, i.e., from negative to positive, making it effective in capturing PFOS. At pH 7, the modified material (Clinop_HDTMA) showed ~ 96–98% removal of PFOS at a low concentration range of 0.5–1 mg L⁻¹. The adsorption isotherm and kinetic data followed the Freundlich and pseudo second-order model, respectively, which suggested the involvement of physicochemical forces in the adsorption process. Thus, this study demonstrates a viable and cost-effective solution to remove PFOS ions from wastewater.

Graphical Abstract

With the increased activity from humans in agriculture and industry, a growing amount of waste containing heavy metals is discharged into the environment, which brings great risk to human health. Biochar, as a great absorbent for heavy metals remediation, has been extensively studied. The adsorption capability of biochar is affected by many factors, such as the species and properties of raw materials, the preparation methods (temperature, heating rate, and residence time), and functional sites introduced by the modification agent. However, how these factors determine the adsorption of heavy metals on biochar is not clear. The present work thoroughly reviewed the traditionally used methods for biochar preparation such as pyrolysis, hydrothermal carbonization and gasification, meanwhile, the emerging biochar preparation techniques (retort carbonization and torrefaction) are also explored. Accordingly, the commonly used modification methods (alkali modification, acid modification, ferromagnetic modification, microbial modification, etc.) are comprehensively investigated. The adsorption kinetics and isotherms are also discussed to demonstrate the adsorption mechanism from a theoretical basis. Notably, to facilitate the large-scale biochar application in practice, a discussion focusing on the factors associated with practical utilization is provided. Consequently, the review of environmental risk and the challenge regarding biochar disposal safety, a thorough economic analysis, detailed exploration of industrial-scale implementation challenges, enhanced life cycle assessment and sustainability analysis are included, aiming to contribute a better understanding of the practical implications of engineering biochar for application in heavy metals remediation.

This study explores the utilization of electrospun polysulfone (PSF) as a thin-film support in the pressure-retarded osmosis (PRO) system, leveraging its notable thermal, chemical, and oxidative stability. To enhance the efficiency of the PRO system, the inherently hydrophobic PSF surface is modified through functionalization with benzenesulfonamide groups (BSA-PSF). The modification process involves chloromethylation of PSF, followed by substitution with BSA, and subsequent electrospinning to produce BSA-PSF fibers. A thin-film composite forward osmosis membrane, composed of an electrospun BSA-PSF support layer and a polyamide thin layer synthesized through interfacial polymerization (BSA-PSF/PA), is developed. The incorporation of BSA improves the hydrophilicity of the membrane surface, while also imparting antibacterial features to the electrospun BSA-PSF. Comparative analyses with pristine PSF membranes reveal that the pure water flux of the BSA-PSF membrane achieves a notable 65 LMH, surpassing the pristine PSF membrane’s flux of 45 LMH. Moreover, protein absorption is significantly reduced in the BSA-PSF membrane (40.6 μg cm⁻²) compared to the unmodified PSF membrane (64.2 μg cm⁻²). The establishment of a hydration layer near the surface, facilitated by hydrogen interactions between water units and the hydrophilic sulfonamide chains in the polymer, contributes to lower protein adsorption than observed in the pristine PSF membrane. Notably, the prepared BSA-PSF/PA membrane exhibits advanced surface hydrophilicity, commendable antibacterial properties, exceptional fouling resistance, and high water permeability. These attributes position it as a promising candidate for widespread applications in power generation and large-scale water treatment.

Graphical Abstract

BSA functionalized the electrospun PSF used as the PRO membrane’s thin-film support. The introduction of BSA to PSF improved the hydrophilicity, water flux, antibacterial properties, and fouling resistance of thin-film composite PRO membrane

This study investigates the effect of microwave treatment on the disintegration of municipal activated sludge. Sludge samples underwent heating at a targeted temperature of 90 °C for 35 min, with a 5-min retention time. Soluble chemical oxygen demand, sugars, proteins, nitrogen, and phosphorus exhibited notable increases compared to untreated samples. Results indicate a substantial (42–45%) rise in CH₄ production during the anaerobic digestion process of the disintegrated sludge compared to the untreated counterpart CH₄ production was estimated using a transference model, which showed the best fit compared to other models. Further experimentation involved testing digested sludge with excess soluble NH₄–N and PO₄–P for the recovery of struvite at a 1.50/1/1 (Mg/N/P) ratio. The findings reveal that up to 90.1% and 90.4% of PO₄–P and NH₄–N, respectively, can be efficiently removed from the solution. Despite the increased CH₄ output, the energy recovered was insufficient to offset the electrical energy used by the microwave. There was a significant deterioration in sludge filter resistance due to the increase in fine particles and bound water after anaerobic digestion of the pretreated sludge.

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The depletion of phosphorus resources and the problem of environmental pollution are driving the advancement of traditional methods for wastewater treatment. Researchers have taken an interest in microalgae-based processes, which offer a sustainable approach by effectively converting phosphorus into biomass. To improve the environment and make better use of waste phosphorus resources, the efficiency of phosphorus removal by microalgae must be increased. Therefore, studying the mechanisms of phosphorus uptake by microalgae cells is valuable. This review outlines the typical microalgae systems used for phosphorus removal from wastewater. It summarizes the procedures of phosphorus surface adsorption, membrane transport, and intercellular utilization by microalgae. Additionally, this work analyzed the phenomena of excess phosphorus uptake and emerging organic phosphorus uptake by microalgae. Furthermore, the article examines the primary external factors that affect phosphorous removal. Lastly, this review proposes utilizing microalgal biomass phosphorus in fertilizer and transition metal phosphide catalysts. This review provides innovative approaches for removing phosphorus from wastewater and applying microalgal biomass phosphorus.

Anthropogenic greenhouse gas emissions are reshaping oceanic CO₂ uptake patterns. This study focuses on the crucial regions of the Arabian Sea, Red Sea, and Mediterranean Sea which are highly affected by human-caused climate change, aiming to unravel the complexities of air–sea CO₂ exchange dynamics. Understanding these processes is essential for predicting climate changes and assessing the health of marine ecosystems. In this context, a combination of observation-based data (Oc_v2020), and a multi-model ensemble of climate model simulations, were employed to explore the spatial and temporal variations in air–sea CO₂ flux (FCO₂) over these areas from 1982 to 2019. We implemented the Bayesian Model Averaging approach on the model outputs, resulting in a better representation of simulated CO₂ flux. Overall, climate models seem to underestimate the FCO₂ over the western Arabian Sea. We speculate that this model failure is attributed to the negative biased in vertical water velocity and the unrealistically representation of carbon release during coastal upwelling processes in the model. Our findings suggest that CO₂ source across the Red Sea, the Arabian Sea, and the central region of the Mediterranean Sea has been reduced with a trend of − 0.494 ± 0.009, − 1.350 ± 0.001, and − 0.329 ± 0.074 gCm⁻² year⁻¹ decade⁻¹, respectively. In contrast, the CO₂ sink across the Western Mediterranean has been enhanced with a trend of − 0.793 ± 0.086 gCm⁻² year⁻¹ decade⁻¹. In general, change in the water temperature was recognized as the major contributor to the sea surface partial pressure of CO₂ (pCO₂). The exception was found in the Arabian Sea, where non-thermal effects play the major role. Our results show that the CO₂ flux variation is accompanied by regional changes in the sea surface pCO₂. Across the North Arabian Sea, FCO₂ is also correlated with the surface wind variability, which is likely due to the changes in wind-driven upwelling. In conclusion, our study advances the understanding of regional air–sea CO₂ exchange dynamics, emphasizing the need for improved model representation in areas with intense seasonal upwelling. The prominent changes in the Arabian Sea, underscore the immediate necessity for science-based management in this region to mitigate the impacts of human-induced global warming.

Environmental regulations can effectively mitigate environmental degradation, yet their impact on energy efficiency remains unclear. This study contributes to the existing literature by examining how the Environmental Protection Tax Law (EPTL) drives energy efficiency and demonstrating its environmental and economic dividends. Empirical evidence from a dataset of 271 Chinese prefecture-level cities from 2011 to 2020 reveals that EPTL significantly enhances energy efficiency by 3.8%, and it has a positive spatial spillover effect. The underlying mechanisms are improvements in environmental governance and economic development. Heterogeneity analysis highlights a particularly prominent positive impact in the eastern and western regions. Our study confirms the effectiveness of EPTL in promoting energy efficiency and supports the double dividend hypothesis, providing policymakers with insights for formulating differentiated policies.

Micro and nano plastics (MNPs) have emerged as significant environmental pollutants globally, with numerous research findings extensively addressing the environmental and biohazards resulting from the bioavailability of contaminants. Rice, serving as the staple carbohydrate source for more than half of the global population, demands a concrete understanding of MNPs' toxicity in rice plants. However, the literature pertaining to the impact of MNPs on rice plant growth and development is limited and the future research scope related to MNPs exposure in rice plants is poorly defined. Thus, this review aims to synthesize current research findings regarding MNPs exposure in rice plants and identify existing research gaps. Furthermore, this review article comprehensively discusses up-to-date findings on various impacts on rice plant growth and development, covering key areas such as morphological, biochemical, physiological, metabolic, molecular, and microbial alterations. In addition, it explores MNP sources, uptake and translocation mechanisms, potential health risks, and available remedial approaches to alleviate MNPs bioavailability in rice plants. The review concludes that addressing the current research gaps related to MNPs in paddy fields requires further studies in the future. This would contribute to a more comprehensive understanding of the impact of MNPs on rice plants and aid in developing effective mitigation strategies.

Arsenic in drinking water threatens public health worldwide. Phytoremediation has brought new vitality to solve this problem. The aim of this work was to study the role of emergent macrophyte sweet flag (Acorus calamus L.) in phytoremediation of arsenate [As(V)] and arsenite [As(III)] from polluted water. For that, the methods of analytic chemistry and physiology were used. The results showed that As(III) could be removed by A. calamus more efficiently than As(V). The removal efficiencies of As(V) and As(III) both reached more than 95%. In As(V)- and As(III)-exposed A. calamus, the arsenic contents were much higher in root than in stem and leaf. The translocation factors of As(V) and As(III) were no more than 0.152. Both As(V) and As(III) were found in the whole plant, whereas dimethylarsinic acid (DMA, 0.06‒0.13 mg kg^‒1) was only present in the aboveground part. As(V) was the main species in the As(V)-exposed plants (45.86–70.21%). As(III) was the main species in stem and leaf of As(III)-exposed plants (55.76–85.52%), while As(V) was still dominant in root. A. calamus could keep its green leaves during the 31 days of inorganic arsenic (iAs) exposure. However, iAs had a little inhibitory effect on biomass accumulation, and high-concentration iAs was beneficial to promote root growth. The concentrations of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), as well as the activity of catalase (CAT) were significantly higher in root than those in stem and leaf. The oxidative stress response of A. calamus to As(III) was more than that to As(V). The findings of this study indicated that A. calamus was regarded as a promising material for the phytoremediation of arsenic from water.

Due to imperfect environmental regulation system, developing countries may be treated as “Pollution Havens” by firms from developed countries, imposing impacts on the local and even global environment. Thus, this paper examines the following questions at the country and city levels, respectively: First, whether China’s environmental regulation system (i.e., government and civil environmental regulations) has an impact on the M&A location choices of developed-country acquirers and what the moderating role will the acquirers’ carbon risks play. Second, whether the carbon risks of acquirers from developed countries entering China have an impact on carbon emissions in target regions and what moderating role will the environmental regulation system in the target regions play. By collecting 810 M&A deals from 2002 to 2021 in BvD_Zephyr database and conducting empirical analysis based on logistic, time series, and panel fixed effect regressions, we find that: first, environmental regulations at the country level often have a greater deterrent effect than those at the city level. Second, environmental regulations in China suffer from the problem of a “top down” system, i.e., although government environmental regulations have many measures and thus a high deterrent effect, the effects of civil environmental regulations are poor. Third, attracting foreign investment may help reduce carbon emissions.