Advancements and obstacles in the production of biodiesel: its environmental impact, feedstocks, technology, and sustainabilityYenare, Pankaj Popatrao; Patare, Rohini Dattatraya; Sonawane, Bhausaheb Parashram; Sanap, Kailas Khandu
doi: 10.1007/s11356-025-37348-6pmid: 41627684
This review provides a comprehensive summary of recent advancements in biodiesel development, integrating bibliometric, techno-economic, and environmental perspectives. Biodiesel has emerged as a sustainable alternative to fossil fuels, and the growing international energy demand has made its production increasingly attractive. Feedstock selection remains a critical factor, encompassing first-generation edible oils, second-generation non-edible oils, third-generation algal biomass, and waste-derived sources. The analysis highlights issues related to land-use change, food-versus-fuel competition, and carbon debt. Technological progress has been achieved through transesterification, supercritical methods, and ultrasound- and microwave-assisted processes, all of which have improved conversion efficiency. Innovations have also introduced furnace-type, homogeneous, heterogeneous, and enzyme-based catalysts. However, these systems present challenges concerning catalyst reusability, soap formation, glycerol recovery, and NOx emissions. Life cycle assessments and greenhouse gas (GHG) modeling reveal key ecological trade-offs, while economic evaluations emphasize the need for more realistic estimates of commercial scalability. Operational limitations such as oxidative instability, low-temperature performance, and reduced flow yields continue to hinder standardization and large-scale deployment. Future directions focus on hybrid catalysts, integrated biorefineries, microalgae-based closed-loop systems, and decentralized processing. As supported by recent studies, implementing carbon–neutral cultivation and circular bioeconomy principles offers the most promising pathway toward sustainable biodiesel production.Graphical Abstract[graphic not available: see fulltext]
Evaluating human health risk assessment tools for contaminated soil: a comparative reviewLupu, Rusalina; Cocarta, Diana-Mariana; Verginelli, Iason
doi: 10.1007/s11356-026-37411-wpmid: 41636942
At the European Union level, approximately 60–70% of soil is in unhealthy or degraded conditions. One of the soil threats is the legacy of industrial pollution, as historic industrial pollutants discharged into the ground continue to pose risks to both the environment and human health. As part of the legislative measures adopted in the late 90 s, Human Health Risk Assessment (HHRA) was introduced as a standardized method for evaluating risks associated with contaminated sites. To support the quantification of these risks, various software tool models were developed. This study reviews 12 HHRA tools for contaminated sites developed across different countries. First, an overview of national legislative frameworks concerning contaminated sites, with a particular focus on the use of HHRA as a decision-making tool, is provided. Subsequently, the study compares and discusses the methodologies adopted by each tool, the exposure pathways and receptors considered, the integrated contaminant databases, and additional features provided by the models. The comparison highlights the diversity of functionalities offered by the different tools, reflecting a lack of harmonization among national regulations regarding contaminated site management. Beyond the need for a harmonized approach at the EU level, potential future developments include the design of more user-friendly interfaces capable of expanding exposure scenarios, updating contaminant lists (including emerging pollutants such as PFAS), integrating uncertainty analysis, incorporating Geographic Information System (GIS)-based visualizations, and integrating artificial intelligence (AI)/machine learning (ML).
Impact of anthropogenic pollution on lake ecosystem: a review of Koka and Ziway lakes in the Central Rift Valley, EthiopiaMito, Misgana Dabessa; Benti, Natei Ermias; Green, Lesley; Geleto, Sileshi Degefa; Asfaw, Seyoum Leta
doi: 10.1007/s11356-025-37244-zpmid: 41642451
Lakes Koka and Ziway in the Central Rift Valley (CRV) of Ethiopia are essential socio-ecological systems that provide water for domestic use, irrigation, hydropower, and fisheries, while also sustaining diverse biological communities. However, these lakes are under severe ecological stress due to intensifying anthropogenic pollution from industrial, agricultural, and urban sources. This review synthesizes multidisciplinary evidence on pollution sources, types, and ecological consequences, focusing on impacts to water quality and ecosystem services. Physicochemical data reveal that concentrations of heavy metals, nutrients, and organic pollutants regularly exceed World Health Organization (WHO) guidelines, with alarming levels of nitrate, phosphate, lead, chromium, and cadmium observed in both lakes. Agricultural runoff, industrial effluents, and untreated municipal wastewater emerge as primary pollution sources. These contaminants drive eutrophication, biodiversity loss, and the decline of fisheries, thereby undermining livelihoods and exacerbating water insecurity. Invasive species such as water hyacinth further degrade aquatic habitats, while sedimentation alters hydrological dynamics. The review highlights the flowing impacts of pollution on ecosystem services, including disruption of water supply, economic loss, and health risks. It also identifies knowledge gaps and emphasizes the need for integrated watershed governance, investment in wastewater treatment technologies, adoption of sustainable agricultural practices, and enhanced community participation. The review underscores the urgency of adopting a multisectoral response grounded in Integrated Water Resources Management (IWRM), emphasizing collaborative governance, technological innovation, and community-led stewardship as pathways to restore and sustain the health and services of lake ecosystems in the CRV.
Advances in biomass valorization for sustainable biofuel production assisted by ionic liquids: processes, challenges, and industrial perspectivesRai, Suveena; Kanthakere, Sandesh; Puttur, Ujwal
doi: 10.1007/s11356-026-37479-4pmid: 41670766
The increasing global demand for sustainable and renewable energy sources has intensified interest in biofuels derived from lignocellulosic biomass. However, technical, economic, and environmental challenges continue to limit the large-scale commercialization of biofuels. This review focuses on recent advancements in biomass pretreatment, specifically the role of ionic liquids as green solvents for effective biomass fractionation. The use of ionic liquids improves the efficiency of biomass deconstruction. However, the issues related to cost, recyclability, and degradation during recovery must be addressed to support industrial adoption. This review also explores various ionic liquid recovery techniques, including distillation, membrane separation, adsorption, and aqueous biphasic systems, highlighting their efficiencies and limitations. Through this review, potential strategies for improving techno-economic feasibility and reducing environmental impact are highlighted, contributing to the broader understanding of sustainable biofuel production. The insights presented aim to support future developments in the field by identifying areas for research and innovation.
Visible light-powered eco-friendly Fe3O4/g-C3N4 nanocomposites for rapid malachite green degradationMahich, Sanju; Shekhawat, Kundan Singh; Gupta, Shubham; Kumar, Anuj; Swami, Sanjay Kumar; Mathur, Jaya; Devra, Vijay; Singh, Amanpal
doi: 10.1007/s11356-026-37454-zpmid: 41615609
Malachite Green (MG), a widely used textile dye, is a toxic and non-biodegradable product commonly found in industrial wastewater. In this work, Fe3O4/g-C3N4 nanocomposites showed as an eco-friendly photocatalyst, effectively degrading the persistent pollutant to support sustainable wastewater treatment. Fe3O4 nanoparticles (NPs) were synthesized using a green route with Camellia sinensis (green tea) leaf extract method and integrated with g-C3N4, to form a hetero-structured photocatalyst. X-ray diffraction (XRD) analysis confirmed the successful formation of Fe3O4 and the preserved structural integrity of g-C3N4 structure. UV–visible diffuse reflectance spectroscopy (UV–vis DRS) revealed that Fe3O4 and g-C3N4 nanocomposites exhibit enhanced visible-light absorption. Photoluminescence (PL) spectra indicated suppressed recombination of photogenerated charge carriers, implying improved charge separation. Field emission scanning electron microscopy (FESEM) revealed a crumpled, sheet-like morphology. Brunauer–Emmett–Teller (BET) and Barrett-Joyner-Halenda (BJH) analysis confirmed the mesoporous nature of the nanocomposites. Photocatalytic tests under visible light irradiation demonstrated a remarkable degradation efficiency of 99.20% for MG dye at pH 11, significantly outperforming the individual components. Liquid Chromatography-Mass Spectrometry (LC–MS) confirmed the presence of intermediate products, supporting a stepwise degradation mechanism of MG dye through demethylation and oxidative reactions.Graphical Abstract[graphic not available: see fulltext]
Plasma-enhanced electrostatic precipitation (PE-ESP) of restaurant smoke emissionsZhang, Boxin; Schrock, Derek; Pavin, Fuoad; Livchak, Andrey; Thomas, Mark; Murthy, Sunil; Singleton, Dan; Cronin, Stephen B.
doi: 10.1007/s11356-026-37448-xpmid: 41615610
The remediation of nanoscale particulate matter generated during restaurant cooking processes presents a unique challenge, characterized by higher flow rates than most engines but at significantly lower pollutant concentrations. As such, it combines the worst aspects of both scenarios. We present a novel solution to this persistent challenge using transient plasma generated by high-voltage (20 kV) nanosecond pulse discharge. This approach has recently demonstrated potential for enhancing electrostatic precipitation (ESP) in capturing oil-based aerosol particles from restaurant emissions and diesel particulates.(Jang, Yoo et al. 2023) However, prior studies have been limited to small-scale systems operating at low flow rates (~ 2.8 CFM, i.e., 0.0013 m3/s). Here, we report particulate matter (PM) mass concentrations plotted over 7-min cooking cycles with 24 hamburgers at 1000X higher flow rates than those reported previously. At flow rates of 2000 and 3000 cubic feet per minute (CFM), i.e., 0.94 m3/s and 1.416 m3/s, we achieve 93.7% and 86.9% reduction in PM, respectively. This system uses a total of 805 Watts of electrical power, which is less than 5% of a typical rooftop blower power (i.e., 18 kW). This system provides the additional benefit of reducing odor. The PE-ESP enables the system to operate at significantly higher flow rates (3000 CFM, i.e., 1.416 m3/s) than current filter-based technologies without creating a large backpressure on the fan (i.e., blower). In fact, our system produces a pressure drop of just 0.85 inches of water gauge (inwg) (212 Pa) at 2000 CFM (0.94 m3/s) and 1.91 inwg (476 Pa) at 3000 CFM (1.416 m3/s), which is considerably lower than current filter-based technologies and well below the blower limit, which can only tolerate a pressure drop of up to 10 inwg (2494 Pa) and represents a relatively firm design constraint. This plasma-enhanced approach demonstrates the potential for deploying such a system to restaurants to improve the efficacy of the remediation of smoke.
Deciphering hydrological drought controls on atrak river discharge predictability: a multiscale dynamic assessmentBehroozi, Mohammad; Fattahi, Mohammad Hadi; Sayadi, Abolghasem
doi: 10.1007/s11356-025-37387-zpmid: 41619092
Hydrological drought, a persistent challenge in Iran, profoundly impacts water resources, particularly river discharge patterns critical for effective management. This study aims to quantify how hydrological drought shapes the chaotic, multiscale, and predictable dynamics of Atrak River discharge from 1978 to 2018, using an integrated approach of chaos theory, multifractal analysis, and cross-correlation techniques. Daily discharge data and monthly drought indices were used, with monthly data applied for dynamic analysis. Cross-correlation revealed drought intensifies sensitivity to initial conditions and randomness, with delayed effects (lag = 2 months for Lyapunov Exponent [LE]-SDI; lag = -3 for Approximate Entropy [ApEn]-SDI). Sensitivity analysis showed outlier removal shifts CC lags and directions, reduces LE by 74.5% on average, and narrows multifractal spectra (Δα smaller, left-truncation delayed to 41 years), confirming cleaner detection of intrinsic chaos. Autocorrelation-adjusted CC (prewhitening) yielded non-significant p-values (> 0.05) at all lags, indicating apparent delays partly reflect serial dependence. Bootstrap resampling (B = 1000) showed high LE uncertainty in short (31-point) segments, decreasing with longer series, and more chaotic months post-outlier removal. Sample Entropy validated ApEn, confirming moderate-to-low irregularity and seasonal predictability (lowest in June, highest in January). Multifractal spectra revealed a 41-year flood cycle and 25-year drought cycle. These findings improve drought and discharge forecasting models, enabling precise water allocation and reservoir management strategies to mitigate drought impacts in Iran.