Environments: 10 Years of Science Together

Sewage sludge management is a key concern in today’s world. Improper disposal can lead to various environmental issues including air, water and soil pollution. Among the available technologies, thermal treatments, particularly pyrolysis, are gaining interest for their ability to reduce sewage sludge volume and to recover materials and energy from it. This study explored the influence of some relevant parameters in the thermal pyrolysis process. The design of experiment, named central composite design, was accounted to optimize temperature, heating rate and residence time in order to maximize the biochar yield and its CO₂ adsorption capacity. A two-factor interaction model provided a satisfactory interpretation of the results. Within the studied ranges, maximum values of 47.8 wt% and 0.514 mol CO₂/kg were obtained for the yield and CO₂ adsorption capacity, respectively. Two significant experiments were repeated in a different pyrolysis system highlighting how other factors (e.g., reactor geometry, granulometry, etc.) can influence the quantity and the quality of produced biochar. The biochar obtained under the best pyrolysis conditions was characterized by a surface area of 124 m²/g and an ash content of 61 wt%. Lastly, the theoretical energy balance showed that the drying process is the main energy-intensive step in the pyrolysis of sewage sludge. Full article

The aim of this work was to determine the content of heavy metals in soil and, for the first time, in wild Cortaderia nitida, and to discuss its potential as a metal phytoremediator plant. We sampled sediments (bulk and rhizosphere) and C. nitida (roots and shoots) in three nearby spots with different land uses (urban, industrialized and agricultural) along the Chibunga river basin (Ecuador). We analyzed the physico-chemical parameters in soil and heavy metal contents in soil and plants. The agricultural sediments showed the highest conductivity and redox potential, but the lowest pH. Among all the metals analyzed in soil and plants, we only found significant values of Zn and Fe. We observed clear differences in patterns of Zn distribution throughout soil and plants among the three areas sampled, thus suggesting that soil properties played an important role in Zn compartmentalization. Also, C. nitida demonstrated effective Zn translocation from roots to shoots, especially in farmlands (translocation factors between 1.64 and 2.51). Together with the results obtained for other Cortaderia species in metal-polluted areas, this study proposes C. nitida as a candidate to further study its metal phytoremediation potential and encourages this research in heavy metal-enriched soils. Full article

Landfills for disposing of solid waste are designed, located, managed, and monitored facilities expected to comply with government regulations to prevent contamination of the surrounding environment. After the average life expectancy of a typical landfill (30 to 50 years), a large investment in the construction, operation, final closure, and 30-year monitoring of a new site is needed. In this case study, we provide a holistic explanation of the unexpected development of elevated temperature landfills (ETLFs), such as that in the city of Bristol (United States) on the border of the states of Virginia and Tennessee, including the initial role played by coal ash. Despite the increasing frequency of ETLF occurrence, there is limited knowledge available about their associated environmental problems. The study uses mixed (qualitative, quantitative, and mapping) methods to analyze (1) the levels of odoriferous reduced sulfur compounds, ammonia, and volatile organic compounds (VOCs) emitted, (2) the ratio of methane to carbon dioxide concentrations in five locations, which dropped from unity (normal landfill) to 0.565, (3) the location of gas well heads with gradients of elevated temperatures, and (4) the correlation of the filling rate (upward of ~12 m y⁻¹) with depth for registered events depositing coal ash waste. The work identifies spatial patterns that support the conclusion that coal ash served as the initiator for an ETLF creation. The case of the city of Bristol constitutes an example of ETLFs with elevated temperatures above the regulatory United States Environmental Protection Agency (EPA) upper threshold (65 °C), having alongside low methane emissions, large production of leachate, land subsidence, and a large production of organic compounds. Such landfills suffer abnormal chemical reactions within the waste mass that reduce the life expectancy of the site. Residents in such communities suffer intolerable odors from fugitive emissions and poor air quality becomes prominent, affecting the well-being and economy of surrounding populations. Conclusive information available indicates that the Bristol landfill has been producing large amounts of leachate and hazardous gases under the high pressures and temperatures developed within the landfill. A lesson learned, which should be used to prevent this problem in the future, is that the early addition of coal ash into the landfill would have catalyzed the process of ETLF creation. The work considers the public health risks and socioeconomic problems of residents exposed to emissions from an ETLF and discusses the efforts needed to prevent further incidents in other locations. Full article

A study was conducted to determine if the odor profile of Bos taurus manure could be altered by the addition of the simple saccharides glucose, lactose, and sucrose. Sucrose was added to manure slurry at 0, 12.5, 25, 50, or 125 g L⁻¹, while glucose and lactose were added at 0, 6.45, 13.2, 26.4, or 65.8 g L⁻¹. One hundred mL slurries were incubated in capped bottles at 30 °C for four weeks. Biogas production was measured throughout the incubations, and the pH and concentrations of short-chain fatty acids were measured at the end of the incubations. Odor compounds of the final manure slurries were isolated by stir bar sorptive extraction and identified by stir bar gas chromatography/mass spectroscopy. Unamended manure had high concentrations of the typical manure malodorants phenol, p-cresol, p-ethylphenol, indole, and skatole. The addition of the sugars decreased these malodors in a dose-dependent manner. The addition of sugars shifted odor production to aliphatic esters including ethyl butyrate and propyl propanoate. The sugar-amended manure therefore had a different odor profile than the unamended manure did. The addition of sugar also caused the accumulation of short-chain fatty acids and, thus, decreased the pH of the manure. The production of lactic acid was particularly enhanced at high concentrations of sugar, suggesting that lactic acid bacteria could be responsible for changes in the odor profile. Future research will investigate if the addition of lesser concentrations of sugars or agricultural and food wastes rich in carbohydrates can reduce manure malodor. Full article

This study assesses the adoption and operational effectiveness of Environmental Management Systems (EMSs) in Italian wineries, focusing on ISO 14001:2015. It evaluates commitment, planning, communication strategies, emergency preparedness, and employee training practices. Using a comprehensive survey-based methodology, the research elucidates the dynamics of EMS implementation across various scales of winery operations. The research reveals a strong commitment among wineries to environmental objectives such as waste reduction and efficient electricity and water use. However, significant deficiencies were identified in EMS policy implementation, emergency preparedness, and the uptake of ISO 14001:2015 certification, with larger wineries showing more robust engagement in environmental training than smaller ones. The study incorporates five key performance indicators (KPIs) and a predictive model using logistic regression and Random Forest to analyze the likelihood of ISO 14001 certification based on the analyzed variables. The model highlights established processes, environmental policies, and frequent reviews as significant predictors of certification. These findings contribute original value by identifying critical leverage points and barriers affecting EMS effectiveness within the wine sector. The research uncovers nuanced interactions between the scale of operations and management engagement influencing EMSs’ success. It proposes novel, survey-based KPIs essential for assessing EMS performance in wineries, demonstrating their practical utility in pinpointing areas for improvement. The research limitations include potential biases from varying participation rates among surveyed wineries, affecting extrapolation to the broader Italian wine industry. Despite these limitations, the study provides substantive practical implications, suggesting that wineries can enhance both environmental sustainability and a competitive edge by addressing gaps in EMS implementation. Full article

Global fire activities, which are getting worse due to climate change, cause both environmental and human health hazards. Firefighters, being the first responders, are frequently exposed to heat which may impact their immune system and overall health. However, the nature of the impact of chronic heat exposure on immune function has not been studied in-depth in firefighters. In this study, 22 firefighters exposed to “heavy-smoke fires (structural fires)”, categorized as the “high-exposure group” (>0.15 structural fires/week) and “low-exposure group” (<0.15 structural fires/week), were sampled. Peripheral blood was examined for immune cell profile based on total and differential cell counts, immune function based on the transcriptional expression of drivers of innate and adaptive immunity and key inflammation mediators, and heat stress marker HSP70. The white blood cell (WBC) count, mean corpuscular volume, mean corpuscular hemoglobin, and absolute and segmented neutrophil counts decreased below the normal range in both exposure groups. The gene transcript levels for toll-like receptors (TLR2, TLR4, but not TLR7) and their adaptor protein MYD88 were lower whereas those for T-cell transcription factors (RORC/RORγ, FoxP3) and inflammatory mediators (TNF-α, Granzyme-B) were higher in the “high-exposure group”, indicating mixed response; however, the ratios between pro-inflammatory and anti-inflammatory transcription factors of adaptive immunity, namely T-bet/FoxP3 (Th1/Treg) and RORC/FoxP3 (Th17/Treg), were lower. Collectively, decreased immune cell landscape, downregulated key innate immunity receptors, and Tregs’ dominance suggested that chronic heat exposure in firefighters dysregulated innate and adaptive immunity, skewed towards an overall immunosuppressive condition with inflammation. Full article

Background: The global burden of chronic diseases has been increasing, with evidence suggesting that diet and exposure to environmental pollutants, such as per- and polyfluoroalkyl substances (PFAS) and heavy metals, may contribute to their development. The Dietary Inflammatory Index (DII) assesses the inflammatory potential of an individual’s diet. However, the complex interplay between PFAS, heavy metals, and DII remains largely unexplored. Objective: The goal of this cross-sectional study was to investigate the associations between diet operationalized as the DII with individual and combined lead, cadmium, mercury, perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) exposures using data from the National Health and Nutrition Examination Survey (NHANES) 2017–2018. Methods: Descriptive statistics, a correlational analysis, and linear regression were initially used to assess the relationship between the variables of interest. We subsequently employed Bayesian kernel Machine regression (BKMR) to analyze the data to assess the non-linear, non-additive, exposure–response relationships and interactions between PFAS and metals with the DII. Results: The multi-variable linear regression revealed significant associations between the DII and cadmium and mercury. Our BKMR analysis revealed a complex relationship between PFAS, metal exposures, and the DII. In our univariate exposure–response function plot, cadmium and mercury exhibited a positive and negative linear relationship, respectively, which indicated a positive and negative relationship across the spectrum of exposures with the DII. In addition, the bivariate exposure–response function between two exposures in a mixture revealed that cadmium had a robust positive relationship with the DII for different quantiles of lead, mercury, PFOA, and PFOS, indicating that increasing levels of cadmium are associated with the DII. Mercury’s bivariate plot demonstrated a negative relationship across all quantiles for all pollutants. Furthermore, the posterior inclusion probability (PIP) results highlighted the consistent importance of cadmium and mercury with the inflammatory potential of an individual’s diet, operationalized as the DII in our study, with both showing a PIP of 1.000. This was followed by PFOS with a PIP of 0.8524, PFOA at 0.5924, and lead, which had the lowest impact among the five environmental pollutants, with a PIP of 0.5596. Conclusion: Our study suggests that exposures to environmental metals and PFAS, particularly mercury and cadmium, are associated with DII. These findings also provide evidence of the intricate relationships between PFAS, heavy metals, and the DII. The findings underscore the importance of considering the cumulative effects of multi-pollutant exposures. Future research should focus on elucidating the mechanistic pathways and dose–response relationships underlying these associations in a study that examines causality, which will enable a deeper understanding of the dietary risks associated with environmental pollutants. Full article

Recently exposed reservoir sediments, prone to colonization by invasive species, provide novel settings to test hypotheses related to soil conditions and propagule supply as potential drivers of plant assembly in disturbed ecosystems. We used a dam removal site in southwestern Wisconsin to examine the relationship between the physiochemical properties of dewatered sediments, seeding density, and plant community assembly. The plant communities from five seed densities (1000, 500, 250, 125, and 0 seed m⁻²) were annually assessed over four years. We hypothesized (1) that the native aboveground biomass and the proportion of native to invasive (non-seeded species) aboveground biomass would increase with the seeding density and (2) that the diversity of seeded native species would increase with a higher seeding density. We found evidence that sowing at least 500 seeds m⁻² of prairie species increased their abundance, establishment, and plot diversity compared to non-seeded plants that persisted four years after seeding (p < 0.05). The seeding density treatments led to the assembly of two distinct communities: “native” and “invasive”. The “native” community, assembled in plots seeded with at least 500 seeds m⁻², had a greater aboveground biomass and diversity (i.e., richness) of seeded plants compared to plots with lower seed densities, and its productivity was positively related to this richness. In the “weedy” community, the diversity of invasive species had no relationship to their aboveground biomass, likely because these species share similar traits (i.e., redundancy) and may have performed similar functions within the plant community. These findings suggest that the seeding density interacted with the disturbed soil resources to increase the diversity and productivity of seeded native species and may serve as a positive feedback mechanism for the establishment of native communities in dewatered sediments. Full article

The conventional Haber–Bosch process (HBP) for NH₃ production results in CO₂ emissions of almost 400 Mt/y and is responsible for 1–2% of global energy consumption; furthermore, HBP requires large-scale industrial equipment. Green or e-ammonia produced with hydrogen from alkaline water electrolysis using renewable energy and nitrogen from the air is considered an alternative to fossil-fuel-based ammonia production. Small-scale plants with the distributed on-site production of e-ammonia will begin to supplant centralized manufacturing in a carbon-neutral framework due to its flexibility and agility. In this study, a flexible small-scale NH₃ plant is analyzed with respect to three steps—H₂ generation, air separation, and NH₃ synthesis—to understand if milder operating conditions can benefit the process. This study investigates the aspects of flexible small-scale NH₃ plants powered by alkaline electrolyzer units with three specific capacities: 1 MW, 5 MW, and 10 MW. The analysis is carried out through Aspen Plus V14 simulations, and the primary criteria for selecting the pressure, temperature, and number of reactors are based on the maximum ammonia conversion and minimum energy consumption. The results show that: (i) the plant can be operated across a wide range of process variables while maintaining low energy consumption and (ii) alkaline electrolysis is responsible for the majority of energy consumption, followed by the ammonia synthesis loop and the obtention of N₂, which is negligible. Full article

Per- and polyfluoroalkyl substance (PFAS) contamination has emerged as a significant environmental concern, necessitating the development of effective degradation technologies. Among these technologies, ultrasonication has gained increasing attention. However, there is still limited knowledge of its scale-up or on-site applications due to the complexity of real-world conditions and its high energy consumption. Herein, we provide an overview of recent advancements in the ultrasonic degradation of PFAS toward hybrid technologies. This review contains information regarding the physical and chemical properties of PFAS, followed by an exploration of degradation challenges, the mechanisms of ultrasonication, and recent experimental findings in this field. The key factor affecting ultrasonication is cavitation intensity, which depends on ultrasonic frequency, power density, and PFAS structure. Its main advantages include the generation of reactive species without chemicals and the compatibility with other degradation technologies, while its main disadvantages are high energy consumption and limited applications to liquid-based media. We also highlight the integration of ultrasonication with other advanced oxidation processes (AOPs) to create hybrid systems for enhanced degradation of PFAS in order to significantly improve PFAS degradation efficiency, with enhancement factors ranging between 2 and 12. Finally, we discuss prospects for scaling up the ultrasonic degradation of PFAS and address the associated limitations. This review aims to deepen the understanding of ultrasonication technology in addressing PFAS contamination and to guide future research and development efforts. Full article

The One Health approach recognizes the interconnectedness between human, animal, and environmental health. Honeybees (Apis mellifera) embody this framework due to their crucial role in ecosystems, food production, and susceptibility to contaminants. Despite their suitability for a One Health approach, there is a lack of research showcasing the multidisciplinary impacts and contributions of bees. The objective of this work is to explore the application of the One Health approach to bees through a narrative review. This work highlights the contribution of bees to history and culture, economy, medicine, nutrition, food security, and the functioning of ecosystems. It also demonstrates that bee health is affected by land management, agricultural practices, environmental contaminants, nutritional resource availability, predators and diseases, weather, climate patterns, and beekeeping practices. This complex system is highly influenced by policy and beekeeping practices, which will benefit animal health directly and environmental and human health indirectly. Thus, the protection of bees should be prioritized. Full article

As byproducts generated by commercial and domestic food-related processes, FOGs (fats, oils, and grease) are the leading cause of sewer pipe blockages in the US and around the world. Grease trap waste (GTW) is a subcategory of FOG currently disposed of as waste, resulting in an economic burden for GTW generators and handlers. This presents a global need for both resource conservation and carbon footprint reduction, particularly through increased waste upcycling. Therefore, it is critical to better understand current GTW handling practices in the context of the urban food–energy–water cycle. This can be accomplished with firsthand data collection, such as onsite visits, phone discussions, and targeted questionnaires. GTW disposal methods were found to be regional and correspond to key geographical locations, with landfill operations mostly practiced in the Midwest regions, incineration mainly in the Northeast and Mid-Atlantic regions, and digestion mainly in the West of the US. Select GTW samples were analyzed to evaluate their potential reuse as low-cost feedstocks for biodiesel or renewable diesel, which are alternatives to petroleum diesel fuels. Various GTW lipid extraction technologies have been reviewed, and more studies were found on converting GTW into biodiesel rather than renewable diesel. The challenges for these two pathways are the high sulfur content in biodiesel and the metal contents in renewable diesel, respectively. GTW lipid extraction technologies should overcome these issues while producing minimum-viable products with higher market values. Full article

We review and draw distinctions between positions held by various federal agencies, tribal agencies, and civil society organizations to identify distinct stakeholder scenarios for salmonid recovery in the Columbia River Basin. We view the Columbia River Basin through a resilience lens from the point of view of the resident endangered salmonid populations. Using the resilience concept of multiple stable states we describe a stability landscape for the basin as a social–ecological system. We use a shared stability landscape as a common locus for mapping and comparing multiple scenarios representing distinct stakeholder perspectives of pathways towards salmon recovery. We found that the potential of using this approach goes well beyond the specifics of the Columbia River Basin. Full article

A review of the last 399 years (1624–2023) on fin whales (Balaenoptera physalus) in the Mediterranean Sea was conducted, based on an extensive compilation of records published in the scientific literature, technical reports, public databases, journals, and social media. A total of 10,716 sightings and 575 mortality events have been computed, analysed by semesters and mapped in order to compare the summer–winter seasons especially and their implications on migration–residence. Visual and acoustic detections, feedings, migrations, primary production areas (chlorophyll), threats and causes of death and their relations have been addressed, and a mini-review on heavy metals and pollutants has been carried out on fin whales in the Mediterranean Sea. Mortality events were most frequent between November and April, coinciding with the decreased sighting period. Ship strikes posed the greatest threat, peaking between May and October, when marine traffic tends to increase in the Mediterranean Sea. Two populations coexist in the Mediterranean Sea, one resident and the other migratory, the latter using the Strait of Gibraltar for its biannual movements. Two areas with a presence of calves (up to 7 m in length) between October and February were detected: one scattered in the northern Mediterranean and the Strait of Gibraltar and its surroundings. A critical zone for collisions has been established according to the results for fin whales in the Mediterranean Sea. Full article

Arsenic (As) is considered one of the most toxic chemicals to both human and environmental health. Mining activities represent one of the main anthropogenic sources of As; the concentration of As in mine soil can reach 9300 mg kg⁻¹. To overcome the major issue of soil As pollution, soil restoration is required. Biological restoration approaches are generally more cost-effective and environmentally sustainable than physical and chemical methods. In particular, phytoremediation, an environmentally friendly technique based on the use of plants to uptake contaminants from soil, has been successfully implemented to restore As-contaminated soils at mine sites. However, mine soils are generally depleted in essential plant nutrients, such as nitrogen (N). Recent research suggests that phytoremediation can be combined with other techniques (physical, chemical, and biological) to enhance the N content and plant biomass. The aim of this review is to assess the current state of knowledge in the field of the restoration of arsenic-impacted mine site soils, focusing on phytoremediation. We critically assess recent work examining the potential of the co-application of amendments with phytoremediation and identify promising technologies and key research gaps. More studies are required to test the effectiveness of using various soil additives to enhance the phytoremediation of As, not only in pot-scale experiments but also in the field, to enable an improved management strategy for mine site restoration in the future. Full article