Water, Air, & Soil Pollution最新文献

The article presents a basic scheme of graphene oxide modifications and applications of these products in wastewater treatment and biomedical applications. The main part concerns one particular modification, namely etching (hole formation) in the carbon layer. 30% hydrogen peroxide was used as an etching agent to gain holey GO (HGO). The paper describes the change in morphology, thermal stability and reactivity after etching and reduction of GO. Prepared materials (GO, reduced GO and HGO) were tested for the adsorption of micropollutants from model solutions. The concentration of analytes was measured by the HPLC–MS/MS method. The adsorption efficiency for paracetamol, atenolol and metformin differed for the type of GO modification (HGO ≥ GO > rGO). The adsorption of pharmaceuticals from real wastewater samples depended on the contact time and the amount of adsorbent, with the best results being obtained for unmodified GO.

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Jordan currently lacks a comprehensive national methane inventory with uncertainty analysis that integrates multi-sectoral sources, future projections, and mitigation pathways. This study develops Jordan’s national methane inventory and assesses emission trajectories and mitigation potential through 2050. Methane emissions from the energy, transport, agriculture, solid waste and wastewater sectors were quantified using the Low Emissions Analysis Platform–Integrated Benefits Calculator (LEAP-IBC), based on national activity data and IPCC emission factors. Stakeholder-validated intervention scenarios were evaluated against a business-as-usual trajectory. Baseline methane emissions in 2022 were estimated at 217.1 Gg CH₄ (109.2–358.7), dominated by the waste sectors (71%)—driven by municipal waste (66.5%) and domestic wastewater (4%)—followed by agriculture (22%), energy (7%), and transport (0.5%). Using GWP₁₀₀ = 28, 2022 emissions equal 6,082.9 Gg CO₂-eq (3,058.1–10,043.7) and are projected to increase to ~ 11,100 Gg CO₂-eq (5,500–18,300) by 2050 under business-as-usual scenario, corresponding to a rise from ~ 217 to ~ 397 Gg CH₄ yr⁻¹. Implementing the full mitigation package reduces emissions by up to 44.6% by 2030 and 59.8% by 2050 (to ~ 159 Gg CH₄ yr⁻¹), with solid-waste interventions providing the largest and most robust reductions.

The aim of this study was to develop a low-cost and highly efficient electrocatalyst with high H₂O₂ yield and rapid Fe²⁺ regeneration for the treatment of refractory organic pollutants. In this work, activated g-C₃N₄-modified carbon nanotubes (n-g-C₃N₄/CNT, n = 0.5, 1, 2, mass ratio) were prepared by CNT surface oxidation followed by calcination to enhance electro-Fenton degradation efficiency. The results showed that among the three cathode compositions, the 0.5-g-C₃N₄/CNT cathode achieved the highest electro-Fenton degradation performance, with complete phenol removal within 10 min and a total organic carbon (TOC) removal of 55% after 60 min. The optimized 0.5-g-C₃N₄/CNT cathode achieved nearly complete phenol degradation within 10 min, with a high apparent rate constant of 0.39 min⁻¹, while simultaneously delivering a considerable H₂O₂ generation rate of 85.68 mg L⁻¹ h⁻¹.The enhanced electro-Fenton performance of the g-C₃N₄-modified carbon nanotubes is attributed to promoted electro-generation of H₂O₂ and, at low g-C₃N₄ loading (0.5-g-C₃N₄/CNT), accelerated regeneration of Fe²⁺ from Fe³⁺, thereby facilitating the reaction between Fe²⁺ and in situ generated H₂O₂ to produce highly reactive hydroxyl radicals (·OH). In addition, the electrode exhibited broad applicability to different pollutants and good stability, as demonstrated by degradation experiments and five successive cyclic tests. The superior electro-Fenton performance is attributed to the synergistic coupling of the conductive CNT framework and nitrogen-rich g-C₃N₄, which not only promotes the two-electron oxygen reduction pathway for efficient H₂O₂ production but also accelerates Fe³⁺/Fe²⁺ regeneration, enabling a low-cost and highly efficient electrocatalytic system.

Photocatalytic degradation is a promising approach for mitigating water pollution, with catalyst reusability being essential for achieving sustainable treatment processes. In this study, Gelatin-(Polyethylene glycol, PEG) composite films were prepared and modified by incorporating tungsten trioxide (WO₃) at different concentrations- to enhance photocatalytic performance. The photocatalytic activity and reusability of the WO₃-loaded Gelatin-PEG (WO₃@Gelatin-PEG) films were systematically evaluated using Rhodamine-B (Rh-B) and methyl orange (MO) as model organic dyes under visible-light irradiation. The effects of catalyst loadings and initial dye concentration on the degradation efficiency and reaction kinetics were investigated. The results revealed that WO₃ incorporation significantly improved photocatalytic activity, and dye degradation followed pseudo-first-order kinetics under the investigated conditions. Reusability tests demonstrated that the composite films retained a substantial portion of their photocatalytic activity over multiple cycles. Overall, this study demonstrates the potential application of WO₃-loaded gelatin–PEG (WO₃@Gelatin-PEG) composite films as reusable, visible-light-responsive photocatalysts and contributes to the development of sustainable photocatalytic systems for wastewater treatment.

Microplastics are widely present in the natural environment and can act as carriers for heavy metal pollutants in aquatic systems. In this study, an in situ aging approach was employed, in which polyethylene (PE) microplastic powder was confined in mesh bags and exposed to river conditions. This method was used to investigate the aging characteristics of the microplastics and their subsequent adsorption performance and mechanisms for the heavy metal cadmium (Cd²⁺). The study found that natural aging caused fragmentation of the microplastic surfaces, producing cracks, increasing roughness, and altering surface functional groups. Compared to pristine microplastics, aged PE microplastics exhibited varying degrees of increased adsorption capacity for Cd²⁺. The adsorption capacity of PE microplastics for Cd²⁺was influenced by multiple factors, including microplastic dosage, pH, salinity, background electrolytes, and different aqueous media. The adsorption process of Cd²⁺ onto pristine PE microplastics was better described by the pseudo-first-order kinetic model, whereas aged PE microplastics followed the pseudo-second-order kinetic model more closely. The Freundlich isotherm model provided a better fit for the adsorption behavior of Cd²⁺ onto PE microplastics aged for 2 and 4 months, while the adsorption isotherm data for pristine microplastics and those aged for other durations were more consistent with the Langmuir model. The adsorption of Cd²⁺ onto aged microplastics was determined to be a multi-mechanism process.

Salinity poses a major threat to agriculture and food security globally. The salinization of soil and water is further deteriorating the pressure that climate change puts on the agrifood sector. Regions that are prone to salinity are reporting significant yield reductions and are coping with suboptimal agricultural production. One such region is the Middle East and North Africa (MENA). MENA constitutes one of the most climate sensitive regions of the world and agriculture is severely hindered by salinity. Despite the extensive research on salinity management in MENA, literature lacks region-wide assessments that could be used for the development of implementable and governance-informed management frameworks. The aim of the present study is to assess the impact of salinity in the countries of MENA, present measures for the mitigation and adaptation to salinity, and facilitate the development of a holistic framework for the management of soil and water salinization. Mitigation and adaptation measures for salinity in MENA include soil, water, and fertilization management, crop and agricultural diversification, breeding and genetic tools, and novel technologies and nature-based solutions. Despite the availability of measures and strategies that could significantly benefit the region in managing salinity, effective and efficient governance is necessary for the successful implementation of any holistic salinity-related policy.

In this paper, a biochar was prepared through hydrothermal carbonization, followed by activation with KOH and pyrolysis, using waste bamboo powder as the feedstock. The efficiency of the KOH-activated bamboo biochar (KBB) as an adsorbent for the antibiotic levofloxacin (LEV) was studied. Results indicated that the maximum specific surface area, mesoporous specific surface area, and total pore volume of KBB sample, designated as HK-80-BC-800–1.5, was obtained under the conditions of 80 g/L KOH, 800 °C pyrolysis temperature, and 1.5 h residence time, holding a LEV adsorption capacity of 178.0 mg/g. Following optimization of the adsorption process, a corresponding Langmuir adsorption maximum of 277.0 mg/g for LEV was simulated under the conditions of 20 mg/L initial LEV, 10 mg adsorbent, and pH 7.0. Besides, the adsorption mechanisms were determined by analyzing the adsorption kinetics and adsorption isotherms and characterizing the samples before and after adsorption. The findings suggest that pore filling, hydrophobic interaction, and hydrogen bonding force are crucial in the adsorption of LEV by KBB.

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Paleolimnological studies provide valuable long-term records of environmental changes, crucial for assessing ecosystem services (ES) and understanding how aquatic ecosystems respond to various pressures. This study employs an integrated approach, combining paleolimnological, monitoring, and socioeconomic data to investigate changes in two interconnected reservoirs. Geochemical measurements related to eutrophication and metal contamination, along with monitoring data and official statistics, were used to identify the main drivers influencing the ES in these reservoirs. A stratigraphically constrained cluster analysis defined the primary paleoenvironmental zones. Standardized aggregated values for each ES were calculated. Redundancy Analysis was applied to investigate potential external drivers of these temporal changes, using demographic and economic data. The sediment profile revealed that significant changes were linked to eutrophication, characterized by increased nutrient levels, higher phytoplankton biomass (Chlorophyll-a and Pheophytin), and dominance of carotenoid pigments from Chlorophyceae and Cyanobacteria. Eutrophication intensified between the mid-1990s and early 2000s, leading to notable changes in ES by 2022, especially in support and regulation services. Although metal distribution did not adversely affect biological communities, it indicated increased anthropogenic activity. Provisioning services also faced challenges due to reduced reservoir flows, exacerbated by low precipitation and population growth. The impacts were more severe in the Jaguari than in the Jacareí reservoir, attributed to different land-use patterns. To mitigate these ES trade-offs, where enhancing one service diminishes another, investments in infrastructure and strategies to control diffuse pollution. Recommendations include land-use planning, wetland restoration, reforestation, and recovery of riparian vegetation to improve water security and address extreme drought effects.

Microbially induced carbonate precipitation (MICP), a new soil solidification technology, can effectively repair Pb²⁺ contaminated soil. However, heavy metal ions have toxic effects on microorganisms, inhibit urease activity, and reduce solidification efficiency. The natural environment of dry–wet alternation will also destroy soil structure. To further enhance the remediation effect of MICP solidified Pb²⁺ contaminated soil, this paper proposes introducing MgO to cooperate with MICP, thereby strengthening the remediation efficiency of Pb²⁺ contaminated soil. The unconfined compressive strength test, direct shear test, fracture quantitative analysis, toxicity leaching test, and XRD test were investigated under a dry–wet cycle. The effects of the MICP-MgO composite system on the strength evolution of Pb²⁺-contaminated soil, the inhibition mechanism of fracture development, and the stabilization effect of Pb²⁺ were revealed. It fills the gap in current research on the remediation of heavy metal-contaminated soil using MICP combined with MgO under a dry–wet cycle. The results show that when the MgO content is 5%, the strength of Pb²⁺ contaminated soil can be significantly improved, and the compressive strength, shear strength, cohesion, and internal friction angle of the sample are significantly enhanced at the initial stage of the dry–wet cycle. At the same time, the dosage can effectively inhibit the crack propagation induced by the dry–wet cycle, making the Pb²⁺ leaching concentration of the soil stable below the standard limit after the repair. It provides new insights for the long-term, stable remediation of sites contaminated with heavy metals.

This study presents the development and field-scale evaluation of a solar-activated TiO₂/Zinc-Activated Charcoal/Soil (TiO₂/ZAC/Soil) composite for the degradation of microcystin-LR (MC-LR) in water systems impacted by harmful algal blooms (HABs). The composite, synthesized from Miscanthus-derived zinc activated charcoal (ZAC), exhibited combined adsorption and photocatalytic functionality under both artificial (~ 500 W/m²) and natural sunlight (400–600 W/m²). Laboratory experiments achieved 96 ± 2% MC-LR removal, while a 144-L outdoor prototype system reached 92 ± 2.6% MC-LR reduction within 96 h of late-summer solar exposure. Kinetic modeling, corrected for water volume loss, followed pseudo-first-order behavior with an apparent rate constant of 0.058 ± 0.004 h⁻¹ and a half-life of 11.92 ± 0.82 h. LC–MS analysis confirmed progressive degradation of the parent MC-LR molecule and oxidative modification of the toxic Adda moiety, indicating substantial detoxification during early exposure stages. The Area Under the Curve (AUC) analysis was applied to quantify cumulative toxin burden over time. While field replication and environmental variability impose practical limitations, these results demonstrate the potential of TiO₂/ZAC/Soil composite as a low-cost, solar-driven approach for MC-LR attenuation in surface waters and provide a framework for future optimization and large-scale validation.