Search Results (332)

This paper presents the potential use of calcined cement–asbestos waste as an additive in cement mortars. Due to its harmful asbestos content, cement–asbestos waste poses a significant environmental challenge. One method of disposal is high-temperature calcination, which degrades the structure of asbestos fibers and removes their carcinogenic properties. After appropriate thermal treatment, this material can be used as a mineral additive in cement mixtures. This study analyzed the physical and chemical properties of the calcined waste and its impact on the basic strength parameters of cement mortars. The results indicate that, with appropriate dosing, calcined cement–asbestos waste can serve as a useful additive or filler without significantly impairing—and in some cases even improving—the mechanical properties of the mortars. The developed solution aligns with the principles of the circular economy, enabling the safe and effective management of hazardous waste. Full article

Municipal solid waste incineration fly ash (MSWI FA) is recognized as a hazardous solid waste due to its enrichment in toxic heavy metals and high leaching potential. This review systematically summarizes the current understanding of heavy metal occurrence in MSWI FA and associated environmental risks. Solidification and stabilization methods, such as cement-based curing and chemical immobilization, are widely applied due to their cost-effectiveness and operability, though their long-term stability and recovery potential remain limited. Thermal treatment technologies, including sintering, vitrification, thermal separation, and molten salt processes, have shown excellent performance in reducing volume and enhancing the immobilization or recovery of heavy metals. However, these methods are often limited by high energy demands and operational complexity. Recently, emerging technologies such as electrodialysis, bioleaching, and electrokinetic remediation have demonstrated promising capabilities for selective metal recovery under relatively mild conditions. Nevertheless, these novel approaches remain at an early stage of development and have thus far been validated only at the laboratory or pilot scale. Overall, integrating multiple treatment technologies while advancing resource-oriented and low-carbon approaches will be essential for the sustainable management of MSWI FA. Full article

In order to recycle plastic waste back to food contact materials (FCMs), it is necessary to identify hazardous substances in plastic packaging that pose a toxicological risk. Printing inks on plastics are not yet designed to withstand the high heat stress of mechanical recycling processes and therefore require hazard identification. In this study, virgin polypropylene (PP) foils were printed with different types of inks (UV-cured, water-based) and colour shades. Thermal analysis of printed foils and pigments was performed using differential scanning calorimetry (DSC). Samples were then thermally treated below and above measured thermal events at 120 °C, 160 °C, 200 °C or 240 °C for 30 min. Subsequently, migration tests and miniaturised Ames tests were performed. Four out of thirteen printed foils and all three pigments showed positive results for mutagenicity in miniaturised Ames tests after thermal treatment at 240 °C. Additionally, pre-incubation Plate Ames tests (according to OECD 471) were performed on three pigments and one printed foil, yielding two positive results after thermal treatment at 240 °C. These results indicate that certain ink components form hazardous decomposition products when heated up to a temperature of 240 °C. However, further research is needed to gain a better understanding of the chemical processes that occur during high thermal treatment. Full article

As potable water becomes limited, alternative water sources, such as reclaimed wastewater, for crop irrigation have gained attention. However, reclaimed wastewater for irrigation may expose edible crops to compounds of emerging concern (CECs), which may include pharmaceutics, hazardous waste, and volatile substances. Of these CECs, carbamazepine (CBZ) is of particular interest because only 7% of CBZ is filtered out during traditional wastewater treatment processing methods. Two trials were designed to evaluate the uptake and partitioning of CBZ in lettuce grown in a deep-water culture system (DWC) at low and high concentrations. The first trial (0 µg L⁻¹, 12.5 µg L⁻¹, 25 µg L⁻¹, and 50 µg L⁻¹) of CBZ had few effects on lettuce (Lactuca sativa var. capitata) growth, and low concentrations of accumulated CBZ were found in lettuce tissues. As a result, increased concentrations of CBZ were used in the second trial (0 mg L⁻¹, 21 mg L⁻¹, 41 mg L⁻¹, and 83 mg L⁻¹). Greater amounts of CBZ accumulated in plant tissues and the application of higher rates of CBZ negatively affected the growth and overall health of the lettuce. Further research is needed to determine the impacts of CECs on plant uptake and growth, as well as the environmental conditions. Full article

To investigate the impermeability characteristics of composite geomembranes in rigid landfills, a three-dimensional finite element seepage analysis model, which incorporates a composite geomembrane, was established based on a case study of a rigid landfill project in Tongling. Utilizing the seepage mechanism of the composite geomembrane, the seepage distribution patterns of the hazardous waste leachate within the unit cell were computed under representative operating conditions. Different thickness amplification factor schemes for the equivalent treatment of the composite geomembrane were comparatively analyzed, considering both isotropic and anisotropic seepage conditions. The relationships between the seepage flow rate, velocity, and thickness amplification factor were determined. The results showed that the leachate experiences a rapid drop in the water head as it passes through the composite geomembrane, with a low seepage flow rate and velocity, highlighting the membrane’s significant impermeability effect. The finite element analysis indicated that thickness amplification of the composite geomembrane based on the flow equivalence is feasible to some degree, but treating the geomembrane as an anisotropic material during the equivalent process better approximates the actual conditions. Full article

While traditional disposal of solid waste from the global wine industry causes significant environmental burden and hazards, a range of value-added by-products can be produced from the grape marc. This review focuses therefore on crucial sustainability-enhancing technologies for pomace dewatering and separation, which constitute a mandatory stage in obtaining storage-stable by-products and final value-added commodities. A number of dryers and separators were considered for pre-treatment of wet grape marc and analysed in terms of their design characteristics, functionality, feasibility, throughput and efficiency. A multi-criteria decision analysis was carried out to compare, rank and select the equipment which is most suitable for the purpose. It was found out that the rotary drum dryer and the drum screen separator with internal blade rotor are the best candidates to fulfil the technology requirements, while the flowsheet that includes an initial separation followed by drying of the resulting fractions is a rather attractive option. Valorising grape waste worldwide contributes substantially to achieving the United Nations Sustainable Development Goals for responsible consumption and production, mitigating climate change, caring for health and well-being, preserving land life and combating hunger. 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

The treatment of antibiotic mycelial residue (AMR) has emerged as a critical challenge hindering the sustainable development of the biopharmaceutical industry. As a representative hazardous solid waste generated during antibiotic manufacturing processes, AMR may pose substantial risks to environmental safety. This review elucidates the properties and hazards of AMR while systematically reviewing current mainstream treatment technologies. Building upon the elucidation of underlying mechanisms, it further examines the application bottlenecks and research progress associated with different techniques. Through a comprehensive understanding of existing research achievements, this paper proposes future development strategies and perspectives for AMR treatment, highlighting that integrated multi-technology treatment approaches may represent the predominant developmental direction in this field. 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

Waste valorization involves reusing and recycling waste materials to create useful products such as materials, chemicals, fuels, or energy. The primary goal is the transition to a circular economy model while minimizing the impacts of hazardous waste. Adopting such policies appears to be a one-way path due to the continuous increase in the consumption of raw materials. According to recent projections, by 2050, 180 billion tonnes of materials will be consumed annually. Since natural resources cannot meet these requirements, new sources must be explored. Waste can serve as an alternative source and cover at least part of the needs that arise. In this work, good practices regarding waste valorization are presented. The case studies examined include the waste/by-products of ultrabasic rocks resulting in chromite and magnesite mining, as well as the tannery sludge produced after the corresponding wastewater treatment. 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

Water regeneration in PVC production is a key issue to consider, given the high freshwater consumption rate of the process. This research evaluates the inherent safety of poly(vinyl chloride) (PVC) production via suspension polymerization by implementing mass and energy integration strategies in combination with wastewater regeneration under a zero-liquid-discharge (ZLD) approach. The impact of these integrations on process safety was examined by considering the risks associated with the handling of hazardous materials and critical operations, as well as the reduction in waste generation. To this end, the Inherent Safety Index (ISI) methodology was employed, which quantifies hazards based on factors such as toxicity and flammability, enabling the identification of risks arising from system condition changes due to the implementation of sustainable water treatment technologies. Although the ISI methodology has been applied to various chemical processes, there are few documented cases of its specific application in PVC plants that adopt circular production strategies and water resource sustainability. Therefore, in this study, ISI was used to thoroughly evaluate each stage of the process, providing a comprehensive picture of the safety risks associated with the use of sustainable technologies. The assessment was carried out using simulation software, computer-aided process engineering (CAPE) methodologies, and information obtained from safety repositories and expert publications. Specifically, the Chemical Safety Index score was 22 points, with the highest risk associated with flammability, which scored 4 points, followed by toxicity (5 points), explosiveness (2 points), and chemical interactions, with 4 points attributed to vinyl chloride monomer (VCM). In the toxicity sub-index, both VCM and PVC received 5 points, while substances such as sodium hydroxide (NaOH) and sodium chloride (NaCl) scored 4 points. In the heat of reaction sub-index, the main reaction scored 3 points due to its high heat of reaction (−1600 kJ/kg), while the secondary reactions from PVA biodegradation scored 0 points for the anoxic reaction (−156.5 kJ/kg) and 3 points for the aerobic reaction (−2304 kJ/kg), significantly increasing the total index. The Process Safety Index scored 15 points, with the highest risk found in the inventory of hazardous substances within the inside battery limits (ISBL) of the plant, where a flow rate of 3241.75 t/h was reported (5 points). The safe equipment sub-index received 4 points due to the presence of boilers, burners, compressors, and reactors. The process structure scored 3 points, temperature 2, and pressure 1, reflecting the criticality of certain operating conditions. Despite sustainability improvements, the process still presented significant chemical and operational risks. However, the implementation of control strategies and safety measures could optimize the process, balancing sustainability and safety without compromising system viability. Full article

As photovoltaic (PV) installations expand globally, effective recycling of end-of-life crystalline silicon solar cells has become increasingly important, including the recovery of valuable metals such as silver (Ag) and aluminium (Al). Traditional nitric acid-based chemical leaching methods, although effective, present environmental challenges due to the generation of hazardous nitrogen oxide (NO_x) emissions. To address these concerns, this study investigated alternative hydrometallurgical leaching strategies. Two selective treatments (NaOH for Al, and NH₃ + H₂O₂ for Ag) and one simultaneous treatment (HNO₃ + H₂O₂) were evaluated for metal recovery efficiency. All methods demonstrated high recovery efficiencies, achieving at least 99% for both metals within 60 min. The investigated methods effectively suppressed NO_x emissions without compromising leaching efficiency. These findings confirm that hydrometallurgical leaching techniques incorporating hydrogen peroxide can achieve efficient and environmentally safer recovery of silver and aluminium from solar cells, providing valuable insights into the development of more sustainable recycling practices for photovoltaic waste management. Full article

Growing requirements in the field of environmental protection and waste management result in the need to search for new and effective methods of recycling various types of waste. From the perspective of technical and natural sciences, the disposal of hazardous waste, which can lead to environmental degradation, is of utmost importance. A particularly hazardous waste is asbestos, used until recently in many branches of the economy and industry. Despite the ban on the production and use of asbestos introduced in many countries, products containing it are still present in the environment and pose a real threat. This paper presents the results of research related to the process of asbestos neutralization, especially the chrysotile variety, by the thermal decomposition method. Changes in the mineralogical characteristics of asbestos waste were studied using the following methods: TG-DTA-EGA, XRD, SEM-EDS and XRF. The characteristics of the chrysotile asbestos sample were determined before and after thermal treatment at selected temperatures. The second part of the study focuses on the kinetic aspect of this process, where the chrysotile thermal decomposition process was measured by two techniques: ex situ and in situ. This study showed that the chrysotile structure collapsed at approximately 600–800 °C through dehydroxylation, and then the fibrous chrysotile asbestos was transformed into new mineral phases, such as forsterite and enstatite. The formation of forsterite was observed at temperatures below 1000 °C, while enstatite was created above this temperature. From the kinetic point of view, the chrysotile thermal decomposition process could be described by the Avrami–Erofeev model, and the calculated activation energy values were ~180 kJ mol⁻¹ and ~220 kJ mol⁻¹ for ex situ and in situ processes, respectively. The obtained results indicate that the thermal method can be successfully used to detoxify hazardous chrysotile asbestos fibers. Full article