Search Results (473)

Heavy metals represent long-lasting contaminants that pose significant risks to both human health and ecosystem integrity. Originating from both natural and anthropogenic activities, they bioaccumulate in organisms through the food web, leading to widespread and long-lasting contamination. Industrialization, agriculture, and urbanization have exacerbated soil and water contamination through activities such as mining, industrial production, and wastewater use. In response to this challenge, biochar produced from waste materials such as sewage sludge has emerged as a promising remediation strategy, offering a cost-effective and sustainable means to immobilize heavy metals and reduce their bioavailability in contaminated environments. Here we explore the potential of phosphate-enriched biochar, derived from sewage sludge, to adsorb and stabilize heavy metals in polluted soils. Sewage sludge was pyrolyzed at various temperatures to produce biochar. A soil incubation experiment was conducted by adding phosphate-amended biochar to contaminated soil and maintaining it for one month. Heavy metals were extracted using a CaCl₂ extraction method and analyzed using atomic absorption spectrophotometry. Results demonstrated that phosphate amendment significantly enhanced the biochar’s capacity to immobilize heavy metals. Amending soils with 2.5 wt% phosphate-enriched sewage sludge biochar led to reductions in bioavailable Cd (by 65–82%), Zn (40–75%), and Pb (52–88%) across varying pyrolysis temperatures. Specifically, phosphate-amended biochar reduced the mobility of Cd and Zn more effectively than unamended biochar, with a significant decrease in their concentrations in soil extracts. For Cu and Pb, the effectiveness varied with pyrolysis temperature and phosphate amendment, highlighting the importance of optimization for specific metal contaminants. Biochar generated from elevated pyrolysis temperatures (500 °C) showed an increase in ash content and pH, which improved their ability to retain heavy metals and limit their mobility. These findings suggest that phosphate-amended biochar reduces heavy metal bioavailability, minimizing their entry into the food chain. This supports a sustainable approach for managing hazardous waste and remediating contaminated soils, safeguarding ecosystem health, and mitigating public health risks. Full article

Human activities and river course change have a complex reciprocal interaction. The river channel is altered by human activity, and these alterations have an impact on the activities and settlements along the riverbank. Understanding the relationship between urbanization and changes in river morphology is crucial for effective river management, safeguarding the urban environment, and mitigating flood hazards. In this context, this study has been conducted to investigate the interrelationship between morphological dynamics, built-up growth, and urban flood risk along the Manohara River in Kathmandu Valley, Nepal. The Sinuosity Index was used to analyze variation in river courses and instability from 1996 to 2023. Built-up change analysis is carried out using supervised maximum likelihood classification method and rate of change is calculated for built-up area growth (2003–2023) and building construction between 2003 and 2021. Flood hazard risk manning was carried out using flood frequency estimation method integrating HEC-GeoRAS modeling. Linear regression and spatial overlay analysis was carried out to examine the interrelationship between river morphology, urban growth, and fold hazed risk. In recent years (2016–2023), the Manohara River has straightened, particularly after 2011. Before 2011, it had significant meandering with pronounced curves and bends, indicating a mature river system. However, the SI value of 1.45 in 2023 and 1.80 in 2003 indicates a significant straightening of high meandering over 20 years. A flood hazard modeling carried out within the active floodplain of the Manohara River shows that 26.4% of the area is under high flood risk and 21% is under moderate risk. Similarly, over 10 years from 2006 to 2016, the rate of built-up change was found to be 9.11, while it was 7.9 between 2011 and 2021. The calculated R² value of 0.7918 at a significance level of 0.05 (with a p value of 0.0175, and a standard error value of 0.07877) indicates a strong positive relationship between decreasing sinuosity and increasing built-up, which demonstrates the effect of built-up expansion on river morphology, particularly the anthropogenic activities of encroachment and haphazard constructions, mining, dumping wastes, and squatter settlements along the active floodplain, causing instability on the river course and hence, lateral shift. The riverbank and active floodplain are not defined scientifically, which leads to the invasion of the river area. These activities, together with land use alteration in the floodplain, show an increased risk of flood hazards and other natural calamities. Therefore, sustainable protection measures must be prioritized in the active floodplain and flood risk areas, taking into account upstream–downstream linkages and chain effects caused by interaction between natural and adverse anthropogenic activities. Full article

Biomass and other solid wastes create potential environmental and health hazards in our modern society. Conversion of the wastes into energy presents a promising avenue for sustainable energy generation. However, the feasibility of the approach is limited by the challenges in material handling because of the special properties of the materials. Despite their critical importance, the complexities of material handling often evade scrutiny until operational implementation. This paper highlights the challenges inherent in standard solid material-handling processes, preceded by a concise review of common solid waste typologies and their physical properties, particularly those related to biomass and biowastes. It delves into the complexities of material flow, storage, compaction, agglomeration, separation, transport, and hazard management. Specialised characterisation techniques essential for informed process design are also discussed to mitigate operational risks. In conclusion, this paper emphasises the necessity of a tailored framework before the establishment of any further conversion processes. Given the heterogeneous nature of biomaterials, material-handling equipment must demonstrate adaptability to accommodate the substantial variability in material properties in large-scale production. This approach aims to enhance feasibility and efficacy of any energy conversion initiatives by using biomass or other solid wastes, thereby advancing sustainable resource utilisation and environmental stewardship. Full article

This study examines the progress, challenges, and successes in implementing Sustainable Development Goal 12 (SDG12), focusing on responsible consumption and production, using Qatar as a case study. The State has integrated Sustainable Consumption and Production (SCP) into national policies, established coordination mechanisms, and implemented action plans aligned with SDG12 targets. Achievements include renewable energy adoption, waste management reforms, and sustainable public procurement, though challenges persist in rationalizing fossil fuel subsidies, addressing data gaps, and enhancing corporate sustainability reporting. Efforts to reduce food loss and waste through redistribution programs highlight the country’s resilience, despite logistical obstacles. The nation has also advanced hazardous waste management, environmental awareness, and sustainable tourism policies, though gaps in data systems and policy coherence remain. Qatar’s approach provides a valuable local-to-global example of balancing resource-dependent economies with sustainability goals. Its strategies and lessons offer potential adaptability for other nations, especially those facing similar challenges in achieving SDG12. By strengthening data systems, enhancing policy integration, and fostering regional and international cooperation, Qatar’s efforts underscore the importance of aligning economic growth with environmental stewardship, serving as a blueprint for global sustainability initiatives. Full article

The sustainable management of Municipal Solid Waste (MSW) relies heavily on community participation in separating it at the source and delivering it to collection systems. These practices are crucial for reducing pollution, protecting ecosystems, and maximizing resource recovery. However, in the Global South context, with conditions of socioeconomic vulnerability, community participation in the sustainable management of MSW remains limited, highlighting the need to generate context-specific interventions. MSW includes items such as household appliances, batteries, and electronic devices, which require specialized handling due to their size, hazardous components, or material complexity. This study implemented a Community-Based Social Marketing approach during the research and design phases of an intervention focused on promoting source separation and management of hard-to-manage MSW in five municipalities within the administrative region of Norte de Santander (Colombia), which borders Venezuela. Using a mixed-methods approach, we collected data from 1775 individuals (63.83% women; M _age = 33.48 years; SD = 17.25), employing social mapping, focus groups, semi-structured interviews, participant observation, and a survey questionnaire. The results show that the source separation and delivery of hard-to-manage MSW to collection systems are limited by a set of psychosocial, structural, and institutional barriers that interact with each other, affecting communities’ willingness and capacity for action. Furthermore, a prediction model of willingness to engage in separation and delivery behaviors showed a good fit (R2 = 0.83). The strongest predictors were awareness of the negative consequences of non-participation and perceived environmental benefits, with subjective norms contributing to a lesser extent. Based on these results, we designed a context-specific intervention focused on reducing these barriers and promoting community engagement in the sustainable management of hard-to-manage MSW. Full article

Petroleum oily sludge (OLS), a hazardous by-product of the petroleum industry, and high-alkali lignite (HAL), an underutilized low-rank coal, pose significant challenges to sustainable waste management and resource efficiency. This study systematically investigated the combustion behavior, reaction pathways, and gaseous-pollutant-release mechanisms across varying blend ratios, utilizing integrated thermogravimetric-mass spectrometry analysis (TG-MS), interaction analysis, and kinetic modeling. The key findings reveal that co-combustion significantly enhances the combustion performance compared to individual fuels. This is evidenced by reduced ignition and burnout temperatures, as well as an improved comprehensive combustion index. Notably, an interaction analysis revealed coexisting synergistic and antagonistic effects, with the synergistic effect peaking at a blending ratio of 50% OLS due to the complementary properties of the fuels. The activation energy was found to be at its minimum value of 32.5 kJ/mol at this ratio, indicating lower reaction barriers. Regarding gas emissions, co-combustion at a 50% OLS blending ratio reduces incomplete combustion products while increasing CO₂, indicating a more complete reaction. Crucially, sulfur-containing pollutants (SO₂, H₂S) are suppressed, whereas nitrogen-containing emissions (NH₃, NO₂) increase but remain controllable. This study provides novel insights into the synergistic mechanisms between OLS and HAL during co-combustion, offering foundational insights for the optimization of OLS-HAL combustion systems toward efficient energy recovery and sustainable industrial waste management. Full article

Mining waste presents significant environmental and public health risks due to the potential release of toxic substances when improperly managed. In this study, four tailings samples were taken to evaluate the environmental risks in the Ponce Enríquez mining area in Ecuador. Chemical characterization and X-ray Fluorescence Spectrometry (XRF) were used to analyze the content of potentially toxic elements (PTEs) of interest (As, Cd, Cr, Cu, Ni, Pb, and Zn), and X-ray Diffraction (XRD) for mineralogical characterization. The contamination index (IC) was calculated to assess the potential hazard associated with the content of PTEs in the mining wastes. To assess environmental risks, leaching tests were carried out to evaluate the potential release of PTEs, and Acid-Base Accounting (ABA) tests were conducted to determine the likelihood of acid mine drainage formation. The results revealed that the PETs concentration exceeded the maximum permissible limits in all samples, according to Ecuadorian regulations: As, Pb, and Cd were identified as critical contaminants. Mineralogically, quartz was the dominant phase, followed by carbonates (calcite, dolomite and magnesite), phyllosilicates (chlorite and illite), and minor amounts of pyrite and talc. The IC indicated high to very high contamination risk levels, with As being the predominant contributor. Although leaching tests met the established limits for non-hazardous mining waste, the ABA test showed that all samples had a high potential for long-term acid generation. These results underscore the need for implementing management strategies to mitigate the environmental impacts and the development of plans to protect local ecosystems and communities from the adverse effects of mining activities. Full article

Municipal solid waste (MSW) and refuse-derived fuel (RDF) incineration generate over 20 million tons of residues annually in the EU. These include bottom ash (IBA), fly ash (FA), and air pollution control residues (APCr), which pose significant environmental challenges due to their leaching potential and hazardous properties. While these residues contain valuable metals and reactive mineral phases suitable for carbonation or alkaline activation, chemical, techno-economic, and policy barriers have hindered the implementation of sustainable, full-scale management solutions. Accelerated carbonation technology (ACT) offers a promising approach to simultaneously sequester CO₂ and enhance residue stability. This review provides a comprehensive assessment of waste incineration residue carbonation, covering 227 documents ranging from laboratory studies to field applications. The analysis examines reactor designs and process layouts, with a detailed classification based on material characteristics, operating conditions, investigated parameters, and the resulting pollutant stabilization, CO₂ uptake, or product performance. In conclusion, carbonation-based approaches must be seamlessly integrated into broader waste management strategies, including metal recovery and material repurposing. Carbonation should be recognized not only as a CO₂ sequestration process, but also as a binding and stabilization strategy. The most critical barrier remains chemical: the persistent leaching of sulfates, chromium(VI), and antimony(V). We highlight what we refer to as the antimony problem, as this element can become mobilized by up to three orders of magnitude in leachate concentrations. The most pressing research gap hindering industrial deployment is the need to design stabilization approaches specifically tailored to critical anionic species, particularly Sb(V), Cr(VI), and SO₄²⁻. Full article

From an occupational health perspective, if not stored, handled, and disposed of properly, laboratory chemicals exhibit hazardous properties such as flammability, corrosion, and explosibility. Additionally, they can also cause a range of health effects in handlers, including irritation, sensitization, and carcinogenicity. Additionally, the chemical waste generated during the planned assay is a significant byproduct and, if left untreated, can cause detrimental effects on both living organisms and non-living elements when released into the environment. Chemically, laboratory waste contains reagents, organic and inorganic compounds, and diagnostic stains. These agents are more toxic and hazardous than residential waste and affect the personnel handling them and the environments in which they are released. Considering this, it is crucial to adhere to waste management regulations during the various stages including generation, segregation, collection, storage, transportation, and treatment. This is extremely important and necessary if we are to avoid harm to individuals and environmental contamination. This review encompasses the examination of laboratory medical waste, various categories of chemical waste, and strategies to minimize and ensure the safe disposal of these toxic agents. As far as the authors are aware, this is the first review that focuses on the effects of laboratory-generated chemical wastes and environmental ethics. This is a neglected topic in healthcare education, and this review will serve as a valuable resource for students. Full article

Mobile phone waste management is a growing environmental challenge, with improper disposal contributing to resource depletion, pollution and missed opportunities for material recovery. This study presents the findings of a dual-purpose survey (11,163 respondents) conducted in a wide academic context in Italy, aimed at both assessing mobile phones disposal behaviors and knowledge and raising awareness through structured educational prompts about sustainable e-waste management. The results reveal significant behavioral patterns and knowledge gaps across demographic groups. While most respondents (90.6%) own one phone, males tend to have more than females. Phones are replaced every 3–5 years by 48.8% of users and every 1–3 years by 36.7%, with students tending to replace them earlier. Only 20.2% replace their phone when irreparable while 46% replace them due to high repair costs. A large majority (92.3%) store old devices at home, forming an estimated urban mine of 29,799 unused phones. The awareness of hazardous components is higher than that of critical raw materials, with males more informed than females and students in scientific fields displaying greater awareness than those in humanities and health disciplines. The awareness of official take-back programs is particularly low, especially among younger generations. Notably, 90% reported increased awareness from the educational survey and 93.1% expressed willingness to use an on-campus e-waste collection system. These results highlight the role of universities as catalysts for sustainable behavior, supporting the design of targeted educational strategies and policy actions in line with circular economy principles and Sustainable Development Goal 12 “Responsible consumption and production”. Full article

Augmented consumerism has propelled electronic innovation, leading to unprecedented growth in e-waste. Mishandling of e-waste poses environmental and human health hazards that necessitate a review of existing technologies and regulatory frameworks for effective e-waste management. Over the years, advancements in e-waste treatment technologies have addressed challenges uncovered in conventional e-waste treatment methods. This review comprehensively discusses valorization, regulations, and the environmental and health hazards imposed by e-waste mismanagement. The review adopted the novel VIRE framework to justify the research question and followed PRISMA analysis to filter the research basket. This study highlights that progressive policy frameworks are less efficient until inhibiting factors for successful implementation are addressed, especially in developing countries. The informal sector dominates in impeding the successful implementation of e-waste regulations, requiring integration with the formal sector as an initiative to reduce unlawful e-waste handling. Moreover, e-waste holds significant potential for economic value through precious metal recovery. An integrated approach of thermal techniques followed by bioleaching could be a cost-effective alternative for enhanced metal recovery from e-waste. There exists ample opportunity for further advancement in treatment technologies through the integration of discrete techniques, reframing regulatory frameworks to minimize unauthorized processing, and cooperative international agreements for collective action on sustainable e-waste management. Full article

This study introduces CO₂ laser surface vitrification as an innovative method for managing copper mining tailings, offering a sustainable solution to critical challenges in mineral processing. This technique transforms tailings into a stable and impermeable layer, immobilizing hazardous metals contained within them. By achieving vitrification at the surface level and operating at temperatures around 1200 °C, the process significantly reduces energy consumption compared to traditional vitrification methods, making it suitable for large-scale applications in remote mining sites. Detailed geochemical and mechanical analyses confirmed the formation of a dense vitreous matrix with high hardness (7.19–7.48 GPa) and reduced permeability, ensuring compliance with stringent environmental regulations. However, the brittle nature of the vitrified layer underscores the need for further research to enhance mechanical resilience. This work positions CO₂ laser vitrification as a transformative approach for integrating energy-efficient technologies into mineral processing, addressing key environmental concerns while advancing the sustainable management of mining waste. Full article

Hazardous medical waste (HMW) presents significant environmental and public health challenges, particularly in the context of rising healthcare demands and the global push for sustainable resource management. This study investigates the evolution of HMW management through a bibliometric and thematic analysis of 1703 articles published between 2020 and 2025, retrieved from the Web of Science database. Using VOSviewer, co-occurrence mapping and term clustering reveal six major conceptual domains, including thermal treatment technologies, operational optimization, environmental indicators, and behavioral dimensions. This study adds value by applying a dual bibliometric–thematic lens to provide new insights into the operational, technological, and sustainability dimensions of HMW. The analysis identifies a gradual shift from traditional disposal methods to circular models focused on resource valorization through pyrolysis, gasification, and sterilization. Lean management principles—such as process efficiency, waste minimization, and the promotion of recovery and reuse—emerge as complementary to circular economy goals. Additional visualizations outline international collaboration trends, highlighting established research hubs and emerging contributors. The findings emphasize the role of data-driven decision tools, sustainability assessment methods, and cross-sectoral integration in enhancing medical waste systems. Full article

Heavy metals in lead refining waste slag pose persistent environmental risks, challenging conventional treatment methods that struggle to balance long-term stabilization with resource recovery potential. To address this issue, we developed a sustainable stabilization strategy. The simultaneous and long-lasting stabilization of Zn, Pb, and As heavy metals in lead refining waste slag was achieved by using an Fe-S(II) stabilizer, and the leaching toxicity of Zn, As and Pb was less than 1 mg/L, which is lower than the concentration limit of the Identification standards for hazardous wastes–Identification for extraction toxicity (GB5085.3-2007). The samples were analyzed by characterization before and after stabilization, and it was found that Fe-S(II) formed a protective layer of sulfide capsule on the surface of the samples. This stabilization mechanism, which has been termed the “nucleation-capture-sulfide encapsulation” process, involves after the oxidation of Fe⁰ to form a core–shell structure for trapping metal ions, where the external oxide layer undergoes mineralization via S(II) sulfide reduction. This microencapsulation-based passivation not only ensures long-term heavy metal immobilization but also preserves the slag’s potential for secondary resource recovery, aligning with circular economy principles. By minimizing environmental leakage risks while retaining metal reclamation feasibility, this approach offers a green and sustainable solution for heavy-metal-laden industrial waste management. Full article

The combustion of hard coal and lignite in power and combined heat and power plants generates significant amounts of coal fly ash (CFA), a waste material with variable properties. CFA naturally contains radionuclides, specifically naturally occurring radioactive materials (NORMs), which pose potential radiological risks to the environment and human health during their storage and utilization, including their incorporation into building materials. Although global research on the radionuclide content in CFA is available, there is a clear gap in detailed and current data specific to Central and Eastern Europe and notably, a lack of a systematic analysis investigating the influence of installed power plant capacity on the concentration profile of these radionuclides in the generated ash. This study aimed to fill this gap and provide crucial data for the Polish energy and environmental context. The objective was to evaluate the concentrations of selected radionuclides (²³²Th, ²²⁶Ra, and ⁴⁰K) in coal fly ash samples collected between 2020 and 2023 from 19 Polish power and combined heat and power plants with varying capacities (categorized into four groups: S1–S4) and to assess the associated radiological risk. Radionuclide concentrations were determined using gamma spectrometry, and differences between groups were analyzed using non-parametric statistical methods, including PERMANOVA. The results demonstrated that plant capacity has a statistically significant influence on the concentration profiles of thorium and potassium but not radium. Calculated radiological hazard assessment factors (Ra_eq, H_ex, H_in, IAED) revealed that although most samples fall near regulatory limits (e.g., 370 Bq kg⁻¹ for Ra_eq), some exceed these limits, particularly in groups S1 (plants with a capacity less than 300 MW) and S4 (plants with a capacity higher than 300 MW). It was also found that the frequency of exceeding the annual effective dose limits (IAEDs) showed an increasing trend with the increasing installed capacity of the facility. These findings underscore the importance of plant capacity as a key factor to consider in the radiological risk assessment associated with coal fly ash. This study’s outcomes are crucial for informing environmental risk management strategies, guiding safe waste processing practices, and shaping environmental policies within the energy sector in Central and Eastern European countries, including Poland. Full article