Landfill Material Research Articles

Utilization of coalmine overburden-furnace slag and fly ash mixed cement-treated subbase/base course material for sustainable flexible pavements: mechanical performance and environmental impact.

The scarcity of conventional aggregates with tremendous growth in highway construction and the indiscriminate dumping of industrial waste materials in precious landfills has become a huge global concern. This study is aimed at utilizing wastes from various industries, including coalmine overburden (OB) dump, basic oxygen furnace (BOF) slag, and fly ash to produce suitable and sustainable cement-treated subbase/base course layers (CBSB/CTB) for flexible pavement construction. Response surface methodology was used to optimize the composition of the blended material considering unconfined compressive strength (UCS) and Poisson's ratio. Results demonstrated that 50% OB dump, 40% slag, 5% fly ash, and 5% cement achieved a 7-day UCS of 4.84MPa and Poisson's ratio of 0.25, in line with IRC:37-2018 guidelines. X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) analysis confirmed the presence of ettringite crystals, calcium-silicate-hydrate (C-S-H), and calcium-aluminosilicate-hydrate (C-A-S-H) gels which are the source of strength development in the blend. Further, a soaked California bearing ratio (CBR) of 136.08% and flexural strength of 2.06MPa after 7days and 28days of curing, respectively, demonstrates the overall strength of the stabilized waste. Approximately 4% weight loss was observed after wet-dry durability tests, indicating exceptional performance of the optimal blend in inclement weather conditions. Furthermore, the environmental impact of the blended material was studied through a leaching study. Fly ash had a high zinc (Zn) level, while BOF slag showed a rich concentrationof chromium (Cr), manganese (Mn), and iron (Fe) in the acid digestion test. In spite of this, the toxicity characteristics leaching procedure (TCLP) test indicated that the levels of heavy metals that leached from the stabilized material stayed considerably below the permissible limits set forth in Indian Standard, IS:10500 (2012). Finally, cost analysis showed a 51.6% reduction in construction cost with cement-treated industrial wastes instead of granular base/subbase made with conventional aggregates. The study recommends the suitability of the stabilized waste material as an alternate construction material for large-scale field applications, which could encourage the construction of flexible pavements that are environmentally benign, economical, and sustainable.

Thermal removal of binder from waste glass wool intended for recycling

AbstractGlass wool waste constitutes a large amount of waste both in the production process and after the demolition of buildings. The storage of these materials in landfills is associated with their large volume and low mass which results from their low density. Considering the principle of a life cycle assessment, the possibility of recycling this type of waste should be ensured. The basic problem with the recycling process is the removal of the binder that connects the glass wool fibres before returning it to the production process. The paper presents the results of research on the process of heat treatment of glass wool with various temperatures and heating rates. The process of sinter formation and the possibilities of avoiding their formation were analysed. For this purpose, a series of tests in the field of thermal analysis were carried out, in which the temperature ranges in which heat was released were identified. Furthermore, a series of tests were carried out on cube samples with dimensions of 20 × 20 × 20 mm in a chamber furnace. Based on the research conducted, assumptions were developed for the heat treatment process of glass wool waste, which allows the removal of organic substances and prevents the formation of sinters.

Permeability Characteristics of Improved Loess and Prediction Method for Permeability Coefficient

Due to its unique geotechnical properties, loess presents itself as a cost-effective and energy-efficient material for engineering construction, aiding in cost reduction and environmental sustainability. However, to meet engineering specifications, loess often requires enhancement. Evaluating its permeability properties holds significant importance for employing improved loess for construction materials in landfills and artificial water bodies. This study investigates the influence of dry densities, grain size characteristics, grain size distribution, and admixture contents and types on the permeability of improved loess, focusing on the Malan and Lishi loess. The falling head permeability test was conducted to analyze how each factor affects the permeability of the improved loess. The findings indicate that the permeability coefficient decreases with increased dry density and admixture content. Conversely, it demonstrates a linear increase with the average grain size (d50), restricted grain size (d60), and the product of the coefficient of uniformity and coefficient of curvature (Cu × Cc). The primary influencing factor is the type of admixture, followed by Cc and d60. Furthermore, this study developed a predictive model for permeability using a support vector machine (SVM), surpassing the predictive accuracy of linear regression and neural network models. The model provides a robust prediction for the permeability of superior loess material.

Geophysical and geoenvironmental engineering assessment of contaminated workstation soils in a metamorphic environment

This study aims to employ the electrical method, multi-pollution indices, and statistical optimization to establish a common ground for the utilization of contaminated soil as construction material and for agricultural purposes. Two samples each were taken at a depth of 0.5 m and 1.0 m from the eatery, auto-mechanic, car wash, and transformer workstations and at a control site in Akungba-Akoko, southwestern Nigeria. The concentrations of the following geochemical parameters were analyzed: Cr, Pb, Zn, Cd, Mn, and Cu. The resistivity distribution of the workstations’ subsurface layers was determined using Schlumberger vertical electrical sounding (VES). The generated geoelectrical sections revealed four geoelectric layers (topsoil, weathered layer, partially weathered/fracture bedrock, and bedrock) with two curve types: HA (50%) and AA (50%) across the workstations. The topsoil resistivity values (65–184 Ωm) from the VES results suggest moderately rich organic matter and averagely very fine-grained sand. The concentrations of the heavy metals in all the soil samples are within the maximum allowable concentration as stipulated by the National Environmental Standards and Regulations Enforcement Agency in the soil and are suitable for farm activities. Similarly, the geotechnical tests of the Atterberg limit, grain size analysis, compaction, and CBR revealed that all the soil samples met the criteria of a good pavement design but with poor landfill material. Pearson's correlation coefficient revealed that a strong relationship between Igeo\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${I}_{geo}$$\\end{document}-PLI, Igeo\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${I}_{geo}$$\\end{document}-RI, PLI-RI, TSR-Fines, MDD-CBR, LL-MDD, and LL-CBR exists among the multi-pollution indices, the geotechnical properties of soil, and the resistivity distribution of the topsoil. This suggests similar levels of heavy metal pollution and a common source of anthropogenic activities throughout the four workshops and provides the link between geotechnical properties and resistivity distribution for future soil management strategies. The exposure of children and adults to multiple heavy metals through inhalation at the four workstations shows no significant non-cancer or cancer risks.

Waste Separation and Perceptions of Environmental Health in a College Floral Design Course

Industries have found themselves under a microscope because consumers are basing more of their purchasing decisions on a company’s sustainability practices. The floral industry is perceived as being environmentally friendly by consumers. However, based on waste production, the life cycle of fresh merchandise, and the carbon footprint of flowers shipped across the world, this purchasing assumption is not entirely true. To align with consumer perceptions and become more sustainable, the industry must adapt to include more sustainable practices. New and experienced florists alike must determine how they can make slight changes in their businesses to become more environmentally savvy. The purpose of this study was to investigate whether the introduction of more sustainable waste practices into a college floral design course influenced the students’ perceptions of environmental health. Two groups of students enrolled in the basic floral design course at Mississippi State University completed a survey about environmental health at the start and at the end of the semester. However, one group sorted their laboratory wastes into compostable material and landfill material. The results of this study indicated that students who separated their floral waste maintained the same level of environmental concern throughout the testing period, whereas the environmental health scores of those who did not separate their waste declined slightly. The results also indicated that the participants who did not separate their floral waste had lower mean scores at the beginning and at the end of the study. Finally, the results of this study indicated that students who separated floral waste were ranked as having high environmental concern compared to those who did not separate their floral waste in the laboratory.

(FA) Fly Ash And (CAD) Coal Ash Dams: A Potential Hotspot For Environmental Pollution Study Of Resources Emission And TheirConsequences Among Humans Inhabiting In Developmental Areas Of Over Bridges Across National Highway India

FA (FA) is a major output of Thermal Power Plants (TPP) formed when coal is burnt it produces Fly Ash (FA) trapped in Electrostatic Precipitator termed as EPA and left over at bottom of power plants. As per Government of India, this Fly ash can be directly used as better option for landfill material during any construction of Overbridges and Underpass in and around Maharashtra State. During our study, we do find apart of its major use as Land filler option it create havoc in environment. Study comprises two distinct methods Direct Observation and Line Transect Methods. To accomplish objective overall six villages were selected in and around site of construction. Our result suggest chemical contents of FA are extremely hazardous for local villagers it contains mercury,antimony , silica, aluminum oxide , ferric oxide and other oxides material acting as passive contributing factor in physical environment causing all three major types of pollution viz. air pollution ,water pollution , and soil pollution resultant consequences of human health problems .residing nearby construction highway areas .For sustainable power production there are recommended package and practices as measure to be adapted by Government of India .

Environmental sustainability of closed-loop regeneration of NaHCO3 in CO2 utilization-driven desulfurization ash: From the perspective of integrated hybrid life cycle assessment

The closed-loop regeneration of NaHCO3 by treating sodium-based desulfurization ash (SDA) using CO2 in flue gas and ammonia by-products demonstrates an attractive perspective of low-cost sodium-based dry desulfurization (SDD) application. To push generation reuse of desulfurization ash into more practices, taking the application in coking plants as a case, this study first compares the environmental and economic performance of four scenarios of flue gas desulfurization (FGD) and desulfurization ash disposal by integrated hybrid life cycle assessment (IHLCA) with life cycle costing. Compared with process-based LCA, IHLCA captures more environmental impacts through the economic input-output (EIO) system, especially 36.40–67.89% of terrestrial ecotoxicity comes from the EIO system. Based on evaluation results of four scenarios, among the ten environmental impact categories (excluding photochemical oxidation), the SDD scenario with NaHCO3 regeneration by CO2 and ammonia (S2) is not only the most environmentally friendly route, but also has the lowest total hourly operating cost. These are mainly due to the offsetting effect of by-products replacing traditional chemicals on the total impact and avoiding landfill and raw material transportation. Furthermore, sensitivity analysis also shows that when technical parameters change, the environmental and economic performance of S2 still remains the best, except for the case when the NaHCO3 regeneration rate is 60%. The findings will be valuable for the selection and optimization of FGD in coking plants, incineration plants, and others.

Soil–water contamination assessment due to dumpsite-impacted leachates in a metamorphic environment

Environmental contamination is a complex issue that significantly impacts human health and ecological systems, especially in developing countries like Nigeria. This study explores the interplay between surface-subsurface soil-rock resistivity and subsurface geotechnical properties, along with multiple soil-water pollution indices at and around the Old Owo-Ikare road (OOIR) dumpsite in southwestern Nigeria. Water samples from five wells and one stream were collected and analyzed, alongside twelve soil samples from four trial pits at varied depths for geoenvironmental assessment. Analyzed hydrogeochemical parameters include Na, Ca, Mg, K, Cr, Pb, Zn, Ni, Mn, Fe, and cations (NO, SO4, Cl) in the water samples. Nine dipole-dipole electrical resistivity tomography (ERT) profiles and six Schlumberger vertical electrical sounding (VES) points were used to determine surface–subsurface resistivity distribution. Water analysis results showed elevated levels of K, Ni, Cr, and Pb concentrations. Geotechnical tests indicated that most dumpsite soil meets good landfill material criteria with low permeability (5.92×10−6 to 1.49×10−4cm/s). ERT and VES inverted models revealed four lithologic layers with two main curve types (HA and QA). Elevated heavy metal levels in the dumpsite soil and inverted resistivity models suggested leachate contamination in the topsoil and weathered bedrock units. Despite relatively lower heavy metal concentrations compared to other Nigerian and Ghanaian dumpsites, multi-pollution indices indicated significant contamination in both water and soil samples, posing moderate to very high environmental risks based on World Health Organisation standards. Additionally, human health risk assessment suggested a risk of cancer and non-cancer-related diseases from prolonged well water consumption. Therefore, ongoing monitoring and remediation efforts are essential to forestall imminent pollution in uncovered areas.

The effect of leachates on the physical and engineering properties of subsoil varies across different rock types and depth layers

Waste disposal on land is a major environmental issue that affects groundwater through soil. The aim of this study is to evaluate and compare the physical and engineering properties of subsoil at varying depths from different dumpsites and to determine the effects of leachates and parent rock types on these soil properties. Thirty-six subsoil samples were obtained from twelve trial pit profiles at depths of 0.5 m, 1.0 m and 1.5 m respectively. These soil samples were subjected to both geotechnical index and strength tests. Grain size analysis, linear shrinkage, CBR and compaction tests revealed that many of the soil samples from dumpsites and their environs met the criteria of a good landfill material. All the soil samples have low permeability that ranges from 2.07 × 10–6 to 1.49 × 10–4. Liquid limit, plasticity index and MDD values were higher in the control samples while the dumpsite soils became more permeable. The results of grain size analysis, linear shrinkage and CBR revealed that there was no significant difference in the properties of dumpsite and control soils. All the soil samples have TDS and EC values below 1000 ppm and 1000 µS/cm, except for trial pit 1, suggesting that the soil has a low risk of leaching contaminants into groundwater. For analysis of variance and Pearson’s correlation coefficient, the P values of some parameters such as pH, EC, TDS, CBR, OMC, MDD, SG, LS, PI and LL were significant at a 0.05 level of significance. The following pairwise parameters: pH-MDD, TDS-CBR, EC-CBR, OMC-MDD and TDS-EC recorded strong positive correlation values for the three dumpsites. The statistical analyses reveal that the soil's properties were only slightly influenced by parent rock types and can be used to limit contaminant flow into the groundwater in the short term.

Valorization of the Residual Fraction of Coal Tailings: A Mineral Circularity Strategy for the Clay Ceramic Industry in the Carboniferous Region of Santa Catarina, Southern Brazil.

Mineral extraction of coal in the carboniferous region of southern Santa Catarina (Brazil) plays a significant role in the regional economy. However, this activity has severe environmental impacts, with approximately 65% of the extracted mineral being discarded as a rejected material (deposited in landfills). The identification of the technological potential of these materials, based on the geological aspects of the extraction site and the beneficiation operations applied to obtain coal, provides the opportunity to add value to different residual fractions that can be reused. Thus, waste valorization, the main objective of this work, has recently become a strategy for the application of these minerals in the production of clay ceramics using a systematic approach named CPQvA, which means "classification, potentiality, quantity/viability, and applicability". The use of these materials as secondary mineral sources can avoid the deposition of these materials in industrial landfills and help to reduce the pressure on landfills, which receive an average of four million tons of material annually. In this study, the residual fraction, part of the tailing from coal beneficiation, known as coal fines, was evaluated for formulation valorization in clay ceramics. This residual fraction was classified as non-hazardous (class II-A, non-inert). X-ray fluorescence spectrometry, X-ray diffraction, and thermogravimetric analysis were performed to characterize the moisture content, particle-size distribution, and coal content to be used in the development of different formulations using the residual fraction of coal tailings (ranging from 0 to 40%) that are of technological interest to the sector. Processing parameters, such as firing at different temperatures (750, 800, 850, and 900 °C), were also correlated with these formulations. The results were compared with those of a reference ceramic formulation from the local productive arrangement of Morro da Fumaça (Arranjo Produtivo Local Cerâmica Vermelha de Morro da Fumaça). The various relationships between the materials were characterized in terms of their thermal shrinkage, water absorption, and mechanical resistance. Leaching and solubilization environmental tests revealed that both the industrial standard formulation and formulations with the application of the residual fraction were classified as non-hazardous materials. Thus, the method of using a mining residual fraction in the formulation of clay ceramics proved to be beneficial for the circular economy in the regional mineral sector through productive and environmental gains; the primary mineral resource and energy consumptions and the impacts related to waste generation were reduced. The results of this study can be applied to similar situations in other parts of the world.

Utilization of Rubber Wood Ash–Clay Mixes as Bottom Liner Material in Solid Waste Landfills: Engineering Properties and Microstructural Characteristics

Utilization of Rubber Wood Ash–Clay Mixes as Bottom Liner Material in Solid Waste Landfills: Engineering Properties and Microstructural Characteristics

Biosolid Mixtures Applied in Tropical Soils and Their Effect on Coriandrum sativum and Ocimum basilicum Nutritional Uptake

Agricultural soils are degraded worldwide as result of anthropogenic activities; environmental contamination; and excessive use of chemicals, fertilizers, and pesticides. Scientists are concerned about this problem; during the past few years sewage compost and sludge have been used as alternatives to improve the soil’s physical and chemical characteristics. Recycling solid waste residues can be a cost-effective way to reduce landfill material disposal and improve macro and micronutrients’ availability in agricultural soils. In this study, two types of biosolids (compost and sludge) were added to tropical soils (coloso and voladora series) to improve the nutritional content in two edible herbs (basil and coriander). Soil mixtures were made by volume percentage; compost was constant, at 25%, and soil and sludge were incorporated in different proportions to complete the 100% (25 comp/75 soil, 25 comp/62.5 soil/12.5 sludge, 25 comp/50 soil/25 sludge and 25 comp/37.5 soil/37.5 sludge). pH and electrical conductivity were measured in soil mixtures. Basil and coriander were cultivated in pots for 30 days at an open greenhouse (5 replicates per soil mixtures). Germination percentage, stems’ length, total chlorophyll (SPAD 502), acid digestions of plant tissues and an ICP-OES analysis were performed for both plants cultivated in all the soil mixtures. In voladora soil, the pH increased from 4.55 ± 0.10 to 5.64 ± 0.22 and EC from 0.0563 ± 0.0003 dS/m to 1.39 ± 0.01 dS/m in a 25% comp/37.5% soil/37.5% sludge mixture. In the coloso soil, the pH increased from 6.38 ± 0.13 to 6.82 ± 0.07 and electrical conductivity from 0.117 ± 0.001 to 1.310 ± 0.009 dS/m in 25% compost/37.5% soil/37.5% sludge mixture. Significant differences (p < 0.05) were found in the chlorophyll content and stem length for both plants. The highest chlorophyll value was in basil leaves from a 25% compost/50% soil/25% sludge mixture (43.20 ± 074) compared to the coloso soil (26.99 ± 0.43). In the voladora soil, the highest chlorophyll content was in a 25% compost/37.5% soil/37.5% sludge mixture (39.97 ± 0.83). In coriander leaves, the highest chlorophyll content was 33.01 ± 0.84 in the 25% compost/62.5% coloso/12.5% sludge mixture. In the voladora soil, chlorophyll content in leaves did not show a significant difference between treatments. Larger basil stems were found at 25% compost/75% voladora mixture (17.50 ± 2.39 cm) and in a 25% compost/62.5% coloso/12.5% sludge mixture (9.95 ± 0.71 cm) compared to control plants (3.45 ± 0.18 cm). Greater coriander stems were observed in a 25% compost/50% voladora/25% sludge mixture (2.43 ± 0.11 cm) and in a 25% compost/50% coloso/25% sludge mixture (2.17 ± 0.10 cm) compared to control plants (2.05 ± 0.07 cm). Macro and micronutrient content in plants increased with biosolids’ incorporation to soils. Mg content in basil leaves increased from 8.61 ± 0.70 mg/g in the voladora soil to 10.31 ± 0.60 mg/g in a 25% compost/37.5% soil/37.5% sludge mixture. In coriander leaves, Mg increased from 6.91 ± 0.06 mg/g in a 25% compost/75% soil mixture to 9.63 ± 0.02 mg/g in a 25% compost/50% soil/25% sludge mixture. The Mn uptake by basil leaves increased from 0.076 ± 0.005 mg/g in the coloso soil to 0.152 ± 0.019 mg/g in a 25% compost/75% soil mixture. In coriander leaves, Mn increased from 0.357 ± 0.002 mg/g in a 25% compost/75% soil mixture to 0.651 ± 0.006 mg/g in a 25% compost/37.5% soil/37.5% sludge mixture.

Deterioration modes, mechanisms, and effects of flexible landfill facilities disposing hazardous waste

Dynamic performance and lifespan predictions are essential for understanding the whole life-cycle emissions and environmental impacts of landfills. However, there are knowledge gaps regarding the major failure modes and mechanisms in flexible hazardous waste landfills (FHWLs) and their potential effects on the service life of landfills. These issues limit the advancement of related research. In this study, focusing on flexible landfills, failure mode, mechanism, and effects analysis was conducted to identify the major failure modes, mechanisms, and impacts that may occur in landfills under extremely harsh chemical and stress conditions. The results indicate that there are approximately 33 major components and materials in landfills, corresponding to 35 potential failure modes and more than 60 underlying failure mechanisms. Notably, the failure of the drainage media in the drainage system is concerning and challenging to recover from. In contrast, the failure of the high-density polyethylene geomembrane (HDPE GMB) in the liner system (LS) is considered serious and is prone to occur, but it is also difficult to detect. Therefore, these two failure modes were identified as critical factors affecting the degradation of the performance and longevity of FHWLs. Finally, due to their high probability of occurrence and severe impacts, stress damage (physical damage) and oxidative aging were identified as the main degradation modes of HDPE GMB, the core material in FHWLs. This study provides key insights into performance prediction targets, failure modes, and failure mechanisms for further research on long-term landfill performance and life prediction. It prompts the government and stakeholders to re-examine the rationality behind the positioning of landfills, such as the assumptions of unlimited service and solid waste management endpoints. Therefore, it calls for a reassessment and optimization of the full life cycle emissions of landfills and related waste.

A Review on the Impact of Fly Ash on the Resistance of Ultra-High Performance Concrete to Acid and Sulfate Attacks

A huge amount of fly ash (FA) was generated every year and dumped in landfills in large quantities and leading to environmental pollution issues. The use of FA in normal concrete and ultra-high performance concrete (UHPC) can reduce pollution in both cases, namely, reduce the accumulation of FA as waste material in landfills and reduce the cement production that generates around 7% of total carbon dioxide (CO2) emissions. This study is a comprehensive review to find out the effect of FA on some durability properties of UHPC, namely acid and sulfate attacks. The results indicate that the use of FA has a positive effect on the increase in the resistance of UHPC samples against acid and sulfate attacks. It is recommended to use nano-FA in the treatment of corrosion and carbonation of UHPC.

Chemical recycling of green poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based air filters through hydrolysis

Sustainable alternatives based on biodegradable polymers, such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), can potentially reduce the environmental impact generated by the massive disposal of face masks. However, the destination of this biodegradable material in post-consumer landfills or composting consumes energy and does not necessarily reduce environmental damage. Therefore, it is necessary to find ways to return this material to the chemical chain, such as chemical recycling through hydrolysis. In this context, the present work aimed to produce face masks by solution blow spinning (SBS) from solutions containing 4, 6, and 8 m/v% of PHBV and assess the polymer recyclability through hydrolysis. The filters were subjected to hydrolytic reactions in aqueous solutions with pH values of 4, 7, and 10 at 40, 60, and 80 °C for three weeks based on a standard statistical design of experiments (DoE). The fibers produced with solutions containing 4 m/v% of polymer provided the highest weight loss of 68 wt% after three weeks immersed in an aqueous solution (pH = 4 at 80 °C), exhibiting the lowest environmental impact during the chemical recycling process. The ANOVA analyses showed that the fiber diameter was the most significant factor during the recycling reactions, evidencing that materials should be designed to promote the principles of the circular economy. Based on the obtained results, it can be concluded that PHBV-based face mask filters can promote the principles of the circular economy if polymer fibers are correctly designed. Finally, they can also potentially reduce the environmental damage of face mask disposal as long as the recycling process is in place with a proper collection and sorting system.

PAHs and organophosphorus substances in burnt landfill material as a potential source of water and soil pollution

PAHs and organophosphorus substances in burnt landfill material as a potential source of water and soil pollution

Comparative carbon footprint estimation of three types of wooden door: A case study from China

As one of the most vital wood-based products, the carbon footprint of wooden doors has received increasing attention in recent years. The studies on the carbon footprints of different types of wooden doors are few. In this study, the cradle-to-grave carbon footprints of three types of wooden doors produced in China were comparatively analyzed. Models used for calculating the total life-cycle carbon footprint of a wood-based composite door, a solid wood composite door, and a solid wood door were developed. Considering the biogenic carbon storage and its delayed emissions, the wood-based composite door, solid wood composite door, and solid wood door featured carbon footprints of 0.379, 0.257, and −0.277 kg CO2 e per kg product, respectively. The solid wood door exhibited a negative carbon footprint, indicating that its carbon storage was higher than the carbon emission during the life cycle stage. The raw material acquisition (38%–66%) and the transportation stages (23%–38%) of the three types of wooden doors were the main contributors to the total carbon footprints (excluding the biogenic carbon). The product manufacturing stage released relatively small emissions (11%–24%). The waste disposal treatment at the end-of-life phase, the degradation of wood materials in landfills, and their service life displayed significant impacts on the carbon footprints of the three types of wooden doors. Fiberboard, laminated veneer lumber, sawn lumber, finger-jointed lumber, and electricity were identified as the main emission hotspots. This study provides guidelines for low-carbon development in the wooden door industry.

LOCALLY CHARACTERISED REPETITIVE ILLEGAL LANDFILLS CLASSIFICATION

Illegal dumping of waste material is present in almost all local communities in Bosnia and Herzegovina, including in the areas of urban and rural local communities of the City of Tuzla. Uncontrolled waste dumping at the landfields, as the illegal dumping, are created by dumping different types of waste material in areas that are not intended for waste material disposal. These are areas that are usually next to roads with less traffic, or in the immediate vicinity of roads where access is possible for motor vehicles with a lower load capacity. Illegal landfills have a direct negative impact on the living environment from several aspects. Primarily, watercourses and soil are polluted, the ambient space is disturbed, and by attracting animals, there is the possibility of infections that are dangerous for the population. Waste materials in illegal landfills are often deliberately set on fire, which causes additional problems of air pollution with smoke and gases resulting from combustion, as well as the possibility of fire outbreaks, especially in forest areas. In the current practice, illegal waste landfills did not have scientific and professional interest because they are often of a temporary nature and were not considered interesting from the aspect of the scientific approach to defining landfills by different classifications. This paper defines the classification of illegal landfills in the spheres of data processing possibilities of interest for the treatment of illegal waste landfills, and the experimental definition of the classification was confirmed on the example of the recording and analysis of illegal waste landfills in the local community of Kiseljak, City of Tuzla in the phase of implementing the project „Inclusive development of Kiseljak community for improvement of social and economic aspect of citizens, emphasizing Roma population“, finance by Foundation of Tuzla community, Tuzla. The basis of the classification is made up of repetitive local waste landfills, while permanent regional waste landfills are not the subject of research and classification since there are already known classifications for permanent waste material landfills. Consent for the publication of the paper was given by the Tuzla Community Foundation, which financed the referral research within the project "Inclusive development of the Kiseljak community, for the improvement of the social and economic aspects of the citizens' life, especially the Roma", implemented by the Tuzla Community Foundation in partnership and financial support of the Freudenberg Foundation and the German Federal Ministry for External Development (BMZ).

Assessment of natural radioactivity of Vietnamese steel slag for using as landfill material

Assessment of natural radioactivity of Vietnamese steel slag for using as landfill material

New opportunities for the development of construction and demolition waste in the construction industry in Hong Kong under the circular economy framework

Hong Kong's overall construction waste accounts for approximately 23% of its total solid waste. As the aging rate of buildings accelerates in Hong Kong, the number of buildings reaching 50 years old is projected to increase from 8,700 in 2020 to 13,900 by 2030. Recently, deteriorating older buildings have become potential sources of construction and demolition waste, leading to a significant rise in the total amount of construction waste. Traditionally, Hong Kong has managed construction waste by using it as landfill material or burying it, but such practices are unsustainable in a city where land resources are scarce. To alleviate the growing volume of construction and demolition waste, a circular economy approach emerges as a solution. However, there is a lack of research on implementing a circular economy model that treats construction and demolition waste as secondary building materials in the construction industry. This study focuses on the Tseung Kwan O landfill site as a case study, analyzing predominantly concrete waste generated from existing construction waste. The research explores how abandoned concrete can be effectively recycled and repurposed as a material. Additionally, it examines the integration of circular economy principles into the industry. The study concludes that incorporating recycled concrete aggregate (RCA) as a component in the construction industry's circular economy is feasible and environmentally beneficial. The establishment of a comprehensive management system for construction and demolition waste is a crucial first step towards realizing a circular economy in Hong Kong. This research provides a framework for formulating waste management policies in the construction sector, enhancing collaborative processes among stakeholders, and aiding relevant authorities in regulating construction activities.