Environmental Implications Research Articles

Economic Erosion: Examining Germany's Decline as a Business Destination

This study delves into the complex web of causes that have contributed to Germany's gradual decline as a sought-after business location. This scholarly work methodically examines a variety of internal and external variables shaping the country's economic environment, thus providing a comprehensive picture of the significant challenges currently faced by the German economy. The study methodically analyzes key variables such as labor market dynamics, regulatory frameworks, demographic changes and infrastructure improvements to uncover the root causes of this decline. The results of this research are of enormous importance for the formulation of strategic, precise policy initiatives aimed at revitalizing the German economy, strengthening its resilience and restoring its position as a global beacon for industry recruitment and retention. Using a strong mixed methods approach, this study leverage the synergy of primary data collected through surveys, interviews and case studies, and secondary data derived from government reports, academic publications and economic indicators. This multi-layered technology makes it easier to recognize observable patterns and develop concrete, realistic plans that will lead Germany to long-term economic development and prosperity. This research is a component of efforts to revitalize Germany's economic strength and restore its reputation as a leading commercial center, and provides useful information for policymakers, industry executives and academics alike. The comprehensive analysis presented in this study has far-reaching implications for the larger European economic environment and contributes to the global discourse on sustainable economic development and renewal

Exploring expert perceptions towards emerging pollutants and their impacts in reused wastewater and agriculture

Water sustainability involves several natural and human spheres conditioning the availability and quality of water resources and life conservation. Regarding water quality, currently emerging pollutants (EPs) are a key topic at global scale since they are difficult to remove by traditional water treatment systems. In this context, this work aims to evaluate experts’ perception of several EPs issues with a special focus on semi-arid Mediterranean areas where EPs are negatively impacting water, environmental, and agricultural systems as, in these areas, effluents from water treatment plants are widely reused in the irrigation of crops, urban gardens, and golf courses or directly discharged on natural streams. Particularly, a detailed survey composed of questions about EPs regulation, risk insight, equipment, social and economic impacts, was performed collecting 437 responses. Main results suggested that EPs existence may pose a significant risk and a destabilizing factor in wastewater reuse, with negative impacts to crop irrigation, being managers the class with more concern followed by scientifics and administratives. New EPs regulations raises uncertainty amongst experts since 29 % considered positive its creation, while 20 % estimated this fact as regular and 14 % as negative. As well, although the combination of technologies to improve EPs removal generated agreement, aspects like the treatment charges at water treatment plants or the price/bill of EPs-free water were features of ambiguity. Within EPs elimination, the three expert groups highlighted that technologies impacts in the sustainability spheres will be positive on public health (87 % of responses), social trust (75 %), and environmental sustainability (76 %). Likewise, 88 % of experts concurred that the future of wastewater reuse relies on a combination of technologies. These findings offer valuable information to water legislators and policymakers to manage water resources, especially in semi-arid areas due to the final use of treated effluents and, therefore, the great implications for agriculture, environment and human health.

Preliminary Study on The Characteristics of Effluent From A Cachoeiro de Itapemirim – ES and Analysis of Possible Biotechnological Treatments

Purpose: The objective of this research was to organize and evaluate physical-chemical parameters of the industrial dairy effluent and to propose viable alternative treatments using biotechnological methods, aiming not only to prepare the effluent for disposal but also to generate value-added products Theoretical framework: With the growth of the population, the food industry sector expands exponentially. Brazil ranks among the top five milk producers globally, with the dairy industry being a significant producer of effluent, generating between 1.1 m³ and 6.8 m³ of effluent per cubic meter of processed milk. Dairy wastewater carries a high pollutant load and requires treatment prior to discharge into water bodies. There is an increasing demand for converting waste into raw materials, prompting research into biotechnological treatments that not only prepare effluent for disposal but also yield products from such waste. Method/design/approach: The data on wastewater characteristics were provided by the dairy itself, and the physicochemical aspects of the effluents over 19 months were interpreted, establishing relationships among key parameters, as well as the ratios BOD/COD, BOD: N and COD: N. The survey of biotechnological treatments was conducted through bibliographic research on Google Scholar, Scielo, Web of Science, and Scopus databases. Results and conclusion: Through the analysis and correlations of the physicochemical characteristics of effluents from the Cachoeiro dairy, it is evident that this type of effluent is rich in low biodegradability organic matter, as the BOD5/COD ratio was less than 0.15 in over 79% of the samples, indicating that physical-chemical treatment is the most appropriate approach for this effluent. The linear correlation coefficient between BOD5 and COD was 0.6, suggesting a weak correlation that does not allow one parameter to be accurately predicted from the other. According to the literature, it is possible to derive biofuels, bioplastics, single cell protein, organic acids, polysaccharides, biosurfactants, and other products from dairy effluent, while also meeting environmental requirements Research implications: Evaluation of optimal treatments based on effluent characteristics and suggestion of alternative treatments aiming to utilize wastewater as a raw material for obtaining secondary products complementary to the industry's focus, in addition to compliance with current disposal regulations. Originality/value: Development of relationships to assist in evaluating effluent treatments and identification of treatments that can reuse this substantial volume of generated waste.

Environmental Implications of Sculpture Landscape in Ancient Cities with Reference to Enugu, Nigeria

The study aimed to examine the environmental implications of landscape sculptures in Enugu, with the objective of examining the historical record and awareness of the cultural connotation of Landscape sculptures to the city development. Based on a qualitative approach, this study examines six landscape sculptures situated in the central business district of the city. The study employs mainly the primary sources of data which include; site visits and interviews, focus group discussions, and secondary data such as Archives and internet search engines. Using a purposive and simple random sampling technique, a sample size of 60 community elders and youth were interviewed through focus group discussion (FGD), and oral interview with the aid of a questionnaire. Data were qualitative and quantitative analysed. Findings identified six major landscape sculptures without and with cultural connotations; the Otigba Statue, the White Lion statue, and the status of Park Lane hospital, while others; were sculptures of the three wise monkeys, coal miners, and Edward Anike statue. Findings discovered that more than 90% of the youth are not aware of the historic record and connotation of the landscape sculptures in the city. Keys findings show non-marketable values of environmental implication. The Chi-square result (X2 = P-Sig > 0.05) shows that the environmental implications of the sculpture landscape have no statistical relationship to the economic value of city development, but the non-marketable values show a positive implication of environmental and social implications to city development. The study suggests public enlightenment to enhance landscape sculpture preservation. Further examination of landscape sculpture preservation techniques should be considered for sustainable city development.

Bio-inspired synthesis of Cm-Ag/NiO nanocomposites: Enhanced photocatalytic degradation of textile dyes

This study successfully syntheses Cm-Ag/NiO nanocomposites (NCs) using an eco-friendly approach with Cucumis maderaspatanus L. leaf extract, highlighting a promising avenue for sustainable nanomaterial development. The nanocomposites were calcined at temperatures ranging from 300 to 700 °C to optimize their bandgap, achieving a value of 2.94 eV as determined by UV-Tauc plots. Characterization techniques revealed a face-centered cubic structure via X-ray diffraction, while transmission electron microscopy (TEM) showed uniformly spherical NCs with an average particle size of 7.1 nm. X-ray photoelectron spectroscopy (XPS) confirmed the elemental composition and oxidation states, while thermogravimetric analysis (TGA) and zeta potential measurements indicated robust thermal and colloidal stability. Photocatalytic experiments demonstrated degradation efficiencies of 83.16 % for the textile dye BB41 and 90.19 % for ROM2R under optimized conditions, with degradation kinetics following a first-order reaction model. Additionally, degradation products were identified via LC-MS, and toxicity was evaluated using ECOSAR software, shedding light on the environmental implications of our photocatalytic process. These findings establish Cm-Ag/NiO NCs as highly effective photocatalysts and sustainable solutions for addressing dye pollution in wastewater treatment, paving the way for innovative applications in environmental remediation.

Biogenic volatile organic compounds emissions, atmospheric chemistry, and environmental implications: a review

Biogenic volatile organic compounds emissions, atmospheric chemistry, and environmental implications: a review

Personal noise exposure patterns and health implications in urban work environments

Noise-induced hearing loss remains a preventable occupational health concern, contingent on timely detection and mitigation of excessive workplace noise. However, the lack of effective identification of at-risk workers often results in the neglect of safety measures that could prevent hearing loss. To address this, personal noise exposure measurements, using noise dosimeters, were conducted on 50 individuals across diverse urban work environments, including work from home, offices, outdoor settings, and mixed-use spaces. The results demonstrated significant variations in noise exposure levels among different environments. Outdoor and mixed-use environments exhibited the highest average dose percentages, while home-based workers had the lowest exposure. A strong correlation between noise levels above 80 dB and increased dose percentages emphasized the need to reduce high-noise exposure times. Additionally, the study integrated quantitative dosimeter measurements with qualitative data from a questionnaire survey to provide a holistic understanding of the participants' perception on noise pollution. Traffic emerged as the primary source of noise pollution, with a substantial number of respondents experiencing stress and ear infections attributed to noise exposure. The research underscores the importance of personalized noise dosimetry in assessing health implications, emphasizing the need for awareness and preventative measures to mitigate health risks in urban work environments.

Potential use of district heating networks and the prospects for the advancements within urban areas of Nottingham as a case study

Buildings in urban areas significantly contribute to global energy consumption, necessitating solutions to reduce energy demands and mitigate environmental impacts. This study investigates district heating networks in urban areas, using Nottingham as a case study. A literature review addresses key barriers to decarbonising building energy in the UK, focusing on: (1) Information, engagement, and behaviour, (2) Strategy, policy, and regulation, (3) Infrastructure, (4) Supply chain and skills, and (5) Distribution of costs and impacts. The study examines the network's location, current processes, energy performance, and potential future impacts. Heat mapping and energy flow assessments identify areas for energy savings, guiding system optimisation. The findings suggest that increasing the energy output from the heat station to the network can enhance performance. The analysis highlights the potential of a life cycle perspective for district heating networks, proposing a framework that considers all stages from material sourcing to system utilisation. This approach helps assess environmental impacts, including greenhouse gas emissions and resource depletion, identifying opportunities to improve resource efficiency and reduce environmental impacts. By evaluating current sustainability goals and regulatory compliance, the study provides insights into the environmental and social implications of the district heating network's operations, pinpointing areas for improvement. It emphasises the need for continuous optimisation and innovation throughout the network's life cycle. The potential of a full life cycle assessment (LCA) approach is highlighted to evaluate four main future advancements: (1) heating network with added energy storage, (2) advanced system operations through model predictive control (MPC) for demand prediction, (3) general network improvements, and (4) network expansion. Overall, this study aims to enhance the sustainability, efficiency, and resilience of district heating networks, contributing to the transition towards sustainable energy systems while ensuring environmental and economic viability over time.

Sustainable digital fashion in a metaverse ecosystem

The fashion industry ranks among the top polluters globally, yet the emergence of virtual worlds offers a chance for brands to switch to digital clothing as a greener option. This research explores whether the metaverse can enhance sustainability in fashion or worsen environmental issues, especially those linked to non-fungible tokens (NFTs). We introduce a game theory model to analyze the strategic dynamics between brand manufacturers and digital fashion platforms, factoring in platforms' abilities to reduce emissions. The model uncovers how these uncertainties influence pricing, investment, and performance outcomes. Our analysis is supported by a case study on DressX, a prominent digital fashion platform, showing that digital fashion brings technological innovation and environmental advantages. Platforms with greater emission reduction capacities and their collaborators witness increased revenues. However, information asymmetry complicates strategic decision-making, and the environmental implications of digital technologies underpinning the metaverse remain a critical concern. Platforms with advanced capabilities gain a competitive edge by managing costs effectively, whereas manufacturers profit at the platforms' expense. However, there is a strategic equilibrium that benefits both sides. Our study indicates that maximizing the environmental benefits of digital fashion demands responsible actions from all stakeholders, including careful technology selection, clear communication of capabilities, cost management, and strategic cooperation. Our game theory approach, combined with a real-world case study, provides a unique perspective on the strategic and environmental dynamics of digital fashion in the metaverse, contributing to the growing body of literature on sustainable fashion and digital ecosystems.

Automated vehicles and the urban parking paradigm: Environmental implications and Citizen preference

This study examines parking decisions in a future populated by automated vehicles (AVs), focusing on their energy implications. Using a multinomial logit model, preferences among cruising, garage parking, sending the AV home, and on-street parking in Santander, Spain, were evaluated. Home sending emerged as the favourite (52%) for its convenience, while garage parking was chosen by 36%, valued for security and environmental benefits. Cruising was least popular (6%), deterred by environmental concerns. Integrating survey data with traffic simulations, the research uncovered that cruising, despite its low preference, accounted for 16% of energy consumption due to empty trips. Surprisingly, sending AVs home, despite being the most popular, led to significant energy use, although it maintained a good consumption ratio. Garage parking, especially when located on city outskirts, was also inefficient. The study highlights the urgent need for strategies to mitigate inefficient parking behaviours, thereby enhancing the sustainability of AV-driven mobility.

Manufacturers’ digital transformation under carbon cap-and-trade policy: investment strategy and environmental impact

Digital transformation (DX) has become an important strategy for the sustainable development of traditional manufacturers. However, the impact of DX on the environment is still inconclusive, and whether it is beneficial for manufacturers to reduce total carbon emissions remains to be examined. Therefore, based on the carbon cap-and-trade policy, this paper employs a game-theoretic model to study the DX strategies of duopolistic manufacturers and to explore the influence of low-carbon policy on these strategies. Additionally, we compare the total carbon emissions before and after DX implementation by manufacturers, discussing the environmental implications of DX. And we innovatively segment the market into two scenarios: one with a low digital technology level and the other with a high digital technology level. Our research demonstrates that the appropriate DX strategy can not only boost manufacturers’ profits but also enhance their ability to withstand external shocks. In the scenario with a high level of digital technology, manufacturers can achieve greater profits and are more likely to reduce total carbon emissions, resulting in a win-win situation. Sensitivity analysis reveals that an increase in carbon trading prices encourages manufacturers to ramp up their investments, ultimately driving comprehensive DX. This study not only provides decision-making guidance for the DX of manufacturers, but also provides a direction for the government to promote DX and achieve carbon neutralization.

Environmental impact assessment of alternative technologies for production of biofuels from spent coffee grounds

AbstractIn the strategy to combat climate change that has been caused by the world's overdependence on fossil fuels, current research is focusing on the decarbonisation of the energy sector through the production of renewable cleaner energy, such as biofuels. Spent coffee grounds (SCGs), the waste stream of the coffee brewing industry, are a potential feedstock for the production of valuable products, including biofuels. However, the environmental implications for the valorisation of this valuable waste need to be investigated. This study assesses the environmental impacts of six biomass‐to‐fuel processing technologies using SCGs as a feedstock, with the aim of identifying the most environmentally friendly technology. A cradle‐to‐gate life‐cycle assessment (LCA) was conducted on fast pyrolysis, fermentation, anaerobic digestion (AD), hydrothermal liquefaction (HTL), gasification, and biodiesel production. The mass and energy balances obtained from Aspen Plus simulations served as the life‐cycle inventory data. Using the ReCiPe 2016 midpoint (H) and Eco‐Indicator 99 as the assessment methods, potential environmental impacts were calculated in OpenLCA software. Electricity generation and carbon dioxide emissions were the biggest contributors of environmental impacts. For each category, the maximum result was set to 100% and the results of the other variants were displayed in relation to this result. AD, with the smallest total weighted score (160), was the most environmentally friendly biomass‐to‐fuel processing route, while HTL, with the biggest total weighted score (893), was the worst. A sensitivity analysis indicated that the environmental performance of biofuel production from SCGs was highly influenced by energy input flows and the source of energy generation.

Towards a sustainable decision analysis approach for moisture-safe building envelope design

Energy-efficient building designs, notably through adding insulation, can reduce energy consumption and greenhouse gas emissions by over 40 %, but may also increase risk of condensation. Therefore, a comprehensive decision analysis approach is essential for selecting optimal building envelope assemblies while considering their hygrothermal, economic, and environmental implications. This study introduces a novel decision analysis method based on the inutility decision analysis (IDA) concept, in which the building envelope with the lowest inutility is considered the optimal choice. Initially, different building envelope assemblies were assessed through probabilistic hygrothermal analysis combined with a machine learning metamodel. Subsequently, the environmental and economic consequences associated with each assembly were quantified by integrating moisture-related damage into these assessments. Combining these outputs yielded inutility indices for the case studies, guiding the selection of the most optimal alternative. The results indicated that an external wall, with a minor risk of moisture-related failure, may outperform other alternatives when considering economic and environmental metrics. However, the final decision on the acceptability of such risk should rest with the customers or owners. Balancing the trade-off between performance longevity, cost, and occupants’ health is crucial.

Irrigation Water Management and Food Security in Nigeria

Food security remains a persistent challenge in Nigeria, a country with a rapidly growing population and a heavy reliance on rain-fed agriculture. Effective irrigation water management is crucial to improving agricultural productivity and addressing this critical issue, particularly in the face of climate change and increasing water scarcity. This study investigates the current state of irrigation water management and its impact on food security in Nigeria. The research employs a mixed-methods approach, combining an extensive literature review with field surveys, interviews, and focus group discussions with key stakeholders, including farmers, water resource managers, policymakers, and subject matter experts. The findings reveal significant gaps in Nigeria's existing irrigation water management system, including outdated infrastructure, inefficient water distribution, limited access to irrigation technology, and poor coordination among relevant government agencies and agricultural extension services. The study explores the multifaceted relationship between irrigation water management and food security, highlighting the impact of water availability, quality, and accessibility on crop yields, livestock production, and overall agricultural output. The analysis also examines the socioeconomic and environmental implications of poor irrigation water management, such as reduced farm incomes, food price volatility, and environmental degradation. Based on the research findings, the study proposes a comprehensive framework for sustainable irrigation water management in Nigeria. This framework emphasizes the integration of technological innovations, policy reforms, institutional strengthening, and community-based approaches to enhance the efficiency, equity, and resilience of the irrigation system. Key elements of the framework include modernizing irrigation infrastructure, promoting precision agriculture techniques, improving water governance and stakeholder coordination, and enhancing the capacity of farmers and water user associations. The implications of this study are far-reaching, as it provides policymakers, development agencies, and agricultural practitioners with a thorough understanding of the critical role of irrigation water management in achieving food security in Nigeria. The proposed framework offers a roadmap for the implementation of sustainable irrigation practices, which can contribute to increased agricultural productivity, improved rural livelihoods, and enhanced national food security. The findings of this research also offer valuable insights for other developing countries facing similar challenges in the realm of irrigation water management and food security.

Addressing the Lemons Problem in Environmental Sustainability:Greenwashing and E-Waste Challenges in African Markets

The "lemons problem," as conceptualized by Akerlof in 1970, depicts the adverse effects of information asymmetry in markets wherein sellers are more informed than buyers, consequently causing the leakage of low-quality commodities. This paper explains how this phenomenon plays out in an environmental sense more specifically, through the disguise of greenwashing and e-waste overflowing into African nations. False claims of sustainability by company’s dupe customers and lead to environmental degradation. The agriculture and energysectors are put under the scanner, showing the damage done by monoculture practices and the fraudulent promotion of genetically modified organisms. The importation of electronic waste and used vehicles into Africa serves to underscore the serious health and environmental implications of such exploitation. To answer this, there is the need to first introduce the EPR model where the responsibility of dealing with waste management will be passed to the producers who will be forced to be responsible and sustainable.

A systematic evidence map protocol for mapping global exposure to bisphenols and their alternatives and social and environmental justice implications

BackgroundBisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Stricter regulations around the use of BPA have led many manufacturers to switch to other bisphenol chemicals with similar functions such as bisphenol S and F. Even though exposure to BPA, other bisphenol chemicals and bisphenol alternatives poses a health risk for humans, very little is known about the granular exposure levels of different populations around the world. AimThis systematic evidence map (SEM) will identify human studies reporting concentrations of bisphenols and their alternatives measured in human bio-samples with the aim to chart the global human exposure levels by country and population characteristics to identify research gaps and discuss any social and environmental injustice implications. Search strategy and eligibility criteriaMEDLINE®, Embase and Web of Science (WoS) databases as well as grey literature sources will be searched using predefined search strings. The database search results will be supplemented by backward and forward citation tracking on included studies. A scoping exercise conducted during planning identified 90 bisphenol chemicals and alternatives used in plastics. These include BPA, other bisphenol chemicals with/without similar functions to BPA as well as alternatives with similar functions to bisphenol chemicals. Eligible studies must report concentrations of at least one relevant bisphenol chemical/alternative measured in human bio-samples. Study selectionOnly primary studies published in English since 2010 will be considered. The title, abstract and keywords will be screened by the DistillerAI tool and two independent reviewers. Grey literature will be screened by two reviewers for inclusion and exclusion. The full text of the included studies will then be screened by two independent reviewers. Study appraisalStudy quality will not be evaluated in this SEM. Data extraction and codingData extraction and coding will be performed by two independent reviewers. Parameters of interest will include the following: study characteristics (e.g., year of publication, sampling timepoints and study design), population information (e.g., country, age, sex, ethnicity, number of participants) and exposure information (sources of exposure, bio-sample analyzed, chemical name, concentration, and detection frequencies). Synthesis and visualizationThe results will be presented using a narrative summary, tables, bar plots and color-coded maps. The interactive database will be available on a dedicated freely accessible website. Systematic map protocol registry and registration numberThis protocol has been registered on Open Science Framework (OSF) and is available at https://doi.org/10.17605/OSF.IO/MNWTD.

Tracing potentially toxic elements in button mushroom cultivation and environmental implications: Insights via stable lead (Pb) isotope analysis

Elevated levels of potentially toxic elements (PTEs) have been frequently detected in substrates used for cultivating edible mushrooms. However, the distribution and accumulation pathways of PTEs within mushrooms and their cultivation substrates remain inadequately understood. This study specifically aims to clarify these aspects of button mushrooms (Agaricus bisporus). A systematic analysis was conducted on the distribution of PTEs (As, Cd, Cr, Cu, Ni, Pb, and Zn) and stable Pb isotope fingerprints across various components of the button mushroom cultivation systems, including the cultivation substrates (a mixture of wheat straw, chicken manure, soil, and additives), fruiting bodies (MR), and spent mushroom substrate (SMS). The methodology involved inductively coupled plasma mass‒spectrometry for PTE quantification and Pb isotope ratio analysis for source identification. The results demonstrated that wheat straw and additives were the main contributors to the endogenous accumulation of PTEs in MR, accounting for 35.0% and 33.2% of Pb accumulation, respectively. Furthermore, MR, wheat straw, and soil together contributed to more than 67% of the Pb loads in SMS. The study also revealed that the occurrence of PTEs in these substrates is predominantly driven by exogenous sources, particularly the significant contribution from anthropogenic activities. Overall, these findings provide valuable biogeochemical insights into the accumulation pathways and patterns of PTEs in button mushroom cultivation systems, with potential applications for cleaner food management and environmentally sustainable practices.

Cyclic voltammetry analysis of mercuric chloride redox reactions with orange G dye

This study investigates the redox behavior of bulk and nano mercuric chloride (HgCl2) using cyclic voltammetry in the presence and absence of Orange G dye, employing 0.1 M KCl as the supporting electrolyte at room temperature. The effects of varying scan rates on electrode processes and redox reaction kinetics were analyzed, revealing that the choice of electrode material, specifically a glassy carbon electrode, significantly influences reproducibility and sensitivity. The study has implications for various applications, including environmental and analytical chemistry. The interaction between mercuric chloride and Orange G was characterized through specific scan rates, highlighting distinct redox peaks and current changes. This research underscores cyclic voltammetry as a powerful technique for probing redox reactions, electroactive species, and complexation processes. Additionally, the determination of complexation stability constants and Gibbs free energies provides valuable insights into the nature of these interactions, paving the way for future applications in environmental and analytical chemistry.Environmental Implication: The redox behaviour of hazardous substance mercuric chloride in the presence of orange G dye has been studied, and the results have important environmental implications. By studying the electrode processes and redox reaction kinetics using cyclic voltammetry, researchers can gain a better understanding of how mercuric chloride behaves in different environmental conditions.The environmental implications of this research are significant. Understanding how mercuric chloride interacts with organic dyes can inform strategies to mitigate mercury pollution, a pressing issue in environmental chemistry. The findings contribute to the broader goal of developing effective remediation strategies for contaminated ecosystems.

Electron-only Reconnection and Ion Heating in 3D3V Hybrid-Vlasov Plasma Turbulence

We perform 3D3V hybrid-Vlasov simulations of turbulence with quasi-isotropic, compressible injection near ion scales to mimic the Earth’s magnetosheath plasma, and investigate the novel electron-only reconnection, recently observed by NASA’s Magnetospheric Multiscale mission, and its impact on ion heating. Retaining electron inertia in the generalized Ohm's law enables collisionless magnetic reconnection. Spectral analysis shows a shift from kinetic Alfvén waves to inertial kinetic Alfvén and inertial whistler waves near electron scales. To distinguish the roles of inertial scale and gyroradius (d i and ρ i), three ion beta (β i = 0.25, 1, 4) values are studied. Ion-electron decoupling increases with β i, as ions become less mobile when the injection scale is closer to ρ i than d i, highlighting the role of ρ i in achieving an electron magnetohydrodynamic regime at sub-ion scales. This regime promotes electron-only reconnection in turbulence with small-scale injection at β i ≳ 1. We observe significant ion heating even at large β i, with Q i/ϵ ≈ 69%, 91%, and 96% at β i = 0.25, 1, and 4, respectively. While ion heating is anisotropic at β i ≤ 1 (T i,⊥ > T i,∥), it is marginally anisotropic at β i > 1 (T i,⊥ ≳ T i,∥). Our results show ion turbulent heating in collisionless plasmas is sensitive to the separation between injection scales (λ inj) and ρ i, β i, and finite-k ∥ effects, necessitating further investigation for accurate modeling. These findings have implications for other collisionless astrophysical environments, like high-β plasmas in intracluster medium, where processes such as microinstabilities or shocks may inject energy near ion-kinetic scales.

Long-term interaction of metals and phosphate with ferrihydrite in artificial seawater and implications for past and present environments

The FeIII hydroxide ferrihydrite (Fh) is highly reactive towards dissolved metals and other aqueous compounds. This reactivity suggests a possible role for Fh in environmental remediation and in controlling ambient concentrations of metals and nutrients in both modern and ancient aqueous environments. Though the reactivity of Fh towards a variety of aqueous compounds has been determined in previous studies, its reactivity under seawater-like conditions has not been systematically explored. Since solution chemistry can have a profound effect on the uptake of metals and oxyions through its effects on the surface chemistry of Fh and the speciation of metals in solution, the dearth of experiments under seawater-like conditions translates into a knowledge gap of metal-Fh interactions in natural marine systems. Furthermore, metal- and nutrient-Fh interactions have been investigated under dissimilar conditions, making a quantitative comparison of these interactions difficult. Lastly, the fate of the aqueous metals and nutrients taken up by Fh upon its aging has been examined in only a few studies and mostly for a duration up to ∼8 months.We bridged these gaps in a series of adsorption and co-precipitation experiments of various metals and phosphate with Fh, in seawater-analog solutions, at circumneutral pH (pH 7.5 and 8.0) and 25 °C. We quantified the effect of interaction with Fh on the aqueous concentrations of CdII, CoII, CrVI, CuII, MnII, MoVI, NiII, VV, UVI, ZnII, and phosphate (PO43−). The experimental results are provided as uptake percentages (quantified as the metal:Fe ratio in the solid phase relative to the metal:Fe ratio added) at different metal:Fe ratios and as a series of partition coefficients of the studied metals and PO43− between aqueous solution and Fh. Additionally, aging experiments of up to ∼4 years in duration were used to determine the potential effects of grain coarsening, surface modification and mineral transformation on the uptake of the metals and PO43−. Uptake of CrVI, MoVI and UVI was negligible in both the adsorption and co-precipitation experiments. Uptake of VV and PO43− by co-precipitation was as much as twice their uptake by adsorption, and we suggest that stabilization of colloidal Fh with a large surface area explains these findings. For CuII, NiII, CoII, MnII, and CdII differences in uptake between the co-precipitation and adsorption experiments were less pronounced, and we ascribe these differences to relatively minor incorporation of these metals into Fh. No significant transformation of Fh to more stable phases was observed under our experimental conditions and duration. Nevertheless, the uptake of several metals and phosphate was affected by Fh aging. Approximately 75% of the PO43− initially taken up by co-precipitation with Fh was released, as was approximately 30% of the VV. A pronounced increase in the uptake of MnII may be related to its oxidation and precipitation as MnIII,IV oxides. For other metals the changes in uptake were less pronounced.We discuss the mechanisms of metal and PO43− uptake by Fh, the effects of solution composition on uptake, and the implications of our findings for modern and ancient natural environments and for environmental remediation.