Search Results (440)

The contamination due to coastal landfill is a growing environmental concern, particularly in fragile marine ecosystems, where leachate can mobilize toxic elements into soil, water, air, and sediment. This study aims to assess the impact of a coastal landfill in Al-Qunfudhah, western Saudi Arabia, on nearby coastal sediments by identifying the concentration, distribution, and ecological risk of potentially toxic elements (PTEs) using geospatial and multivariate analysis tools. The results indicate significant accumulation of Pb, Zn, Cu, and Fe, with Pb reaching alarming levels of up to 1160 mg/kg in the landfill area, compared to 120 mg/kg in the coastal sediments. Zn contamination also exhibited substantial elevation, with values reaching 278 mg/kg in landfill soil and 157 mg/kg in coastal sediment. The enrichment factor values indicate moderate to severe enrichment for Pb (up to 73.20) and Zn (up to 6.91), confirming anthropogenic influence. The contamination factor analysis categorized Pb contamination as very high (CF > 6), suggesting significant ecological risk. Comparison with sediment quality guidelines suggest that Pb, Zn, and Cu concentrations exceeded threshold effect levels (TEL) in some samples, posing potential risks to marine organisms. The spatial distribution maps revealed pollutant migration from the landfill toward the coastal zone, emphasizing the necessity of monitoring and mitigation strategies. As the first comprehensive study on landfill-induced PTEs contamination in Al-Qunfudhah, these findings provide essential insights for environmental management and pollution control policies along the Red Sea coast. Full article

This study aims to investigate the processes associated with mass movements and their relationship with the behavior of the Amazon River delta-estuary (ADE) wetlands. The methodological approach involves using water spectral indices and ground-penetrating radar (GPR) to diagnose areas of soil water saturation and characterize regions affected by mass movements in Amazonian cities. It also involves identifying areas of critical saturation content and consequent mass movements. Analysis of risk and land use data revealed that the affected areas coincide with zones of high susceptibility to mass movements induced by water. The results showed the following: the accumulated annual precipitation ranged from 70.07 ± 55.35 mm·month⁻¹ to 413.34 ± 127.51 mm·month⁻¹; the response similarity across different sensors obtained an accuracy greater than 90% for NDWI, MNDWI, and AWEI for the same targets; and a landfill layer with a thickness variation between 1 and 2 m defined the mass movement concentration in Abaetetuba city. The interaction between infiltration, water saturation, and human-induced land alteration suggests that these areas act as wetlands with unstable dynamics. The analysis methodology developed for this study aimed to address this scenario by systematically mapping areas with mass movement potential and high-water saturation. Due to the absence of geological and geotechnical data, remote sensing was employed as an alternative, and in situ ground-penetrating radar (GPR) evaluation was suggested as a means of investigating the causes of a previously observed movement. Full article

Per- and polyfluoroalkyl substances (PFASs) are emerging pollutants of global concern due to their high environmental persistence and bioaccumulative characteristics. This study investigates PFAS concentrations in soils from China through an extensive literature review, covering soil samples from seventeen provinces and the years from 2009 to 2024. It was found that the total concentration of PFAS in soil ranged from 0.25 to 6240 ng/g, with the highest contamination levels observed in coastal provinces, particularly Fujian (620 ng/g) and Guangdong (1090 ng/g). Moreover, Fujian Province ranked the highest among multiple regions with a median PFAS concentration of 15.7 ng/g for individual compounds. Ecological risk assessment, focusing on areas where perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate (PFOS) were identified as the primary soil PFAS compounds, showed moderate ecological risk from PFOA in Shanghai (0.24), while PFOS posed a high ecological risk in Fujian and Guangdong, with risk values of 43.3 and 1.4, respectively. Source analysis revealed that anthropogenic activities, including PFAS production, firefighting foam usage, and landfills, were the primary contributors to soil contamination. Moreover, soil PFASs tend to migrate into groundwater via adsorption and seepage, ultimately entering the human body through bioaccumulation or drinking water, posing health risks. These findings enhance our understanding of PFAS distribution and associated risks in Chinese soils, providing crucial insights for pollution management, source identification, and regulation strategies in diverse areas. Full article

The practice in agriculture of spreading polyethylene (PE) film over the soil surface as mulch is a common, global practice that aids in conserving water, increasing crop yields, suppressing weed growth, and decreasing growing time. However, these films are typically only used for a single growing season, and thus, their use and non-biodegradability come with some serious environmental consequences due to their persistence in the soil and potential for microplastic pollution, particularly when retrieval and disposal options are poor. On the microscale, particles < 5 mm from degraded films have been observed to disrupt soil structure, impede water and nutrient cycling, and affect soil organisms and plant health. On the macroscale, there are obvious and serious environmental consequences associated with the burning of plastic film and its leakage from poorly managed landfills. To maintain the crop productivity afforded by mulching with PE film while avoiding the environmental downsides, the development and use of biodegradable polymer technologies is being explored. Here, the efficacy of a newly developed, water-dispersible, sprayable, and biodegradable polyester–urethane–urea (PEUU)-based polymer was compared with two commercial PE mulches, non-degradable polyethylene (NPE) and OPE (ox-degradable polyethylene), in a greenhouse tomato growth trial. Water savings and the effects on plant growth and soil characteristics were studied. It was found that PEUU provided similar water savings to the commercial PE-based mulches, up to 30–35%, while showing no deleterious effects on plant growth. The results should be taken as preliminary indications that the sprayable, biodegradable PEUU shows promise as a replacement for PE mulch, with further studies under outside field conditions warranted to assess its cost effectiveness in improving crop yields and, importantly, its longer-term impacts on soil and terrestrial fauna. Full article

Per- and polyfluoroalkyl substances (PFAS) have been reported to contaminate soil as a result of improper management of waste, wastewater, landfill leachate, biosolids, and a large and indiscriminate use of aqueous film-forming foams (AFFF), posing potential risks to human health. However, their high chemical and thermal stability pose a great challenge for remediation. As a result, there is an increasing interest in identifying and optimizing very effective and sustainable technologies for PFAS removal. This review summarizes both traditional and innovative remediation strategies and technologies for PFAS-contaminated soils. Unlike existing literature, which primarily focuses on the effectiveness of PFAS remediation, this review critically discusses several techniques (based on PFAS immobilization, mobilization and extraction, and destruction) with a deep focus on their sustainability and scalability. PFAS destruction technologies demonstrate the highest removal efficiencies; however, thermal treatments face sustainability challenges due to high energy demands and potential formation of harmful by-products, while mechanical treatments have rarely been explored at full scale. PFAS immobilization techniques are less costly than destruction methods, but issues related to the regeneration/disposal of spent sorbents should be still addressed and more long-term studies conducted. PFAS mobilization techniques such as soil washing/flushing are hindered by the generation of PFAS-laden wastewater requiring further treatments, while phytoremediation is limited to small- or medium-scale experiments. Finally, bioremediation would be the cheapest and least impactful alternative, though its efficacy remains uncertain and demonstrated under simplified lab-scale conditions. Future research should prioritize pilot- and full-scale studies under realistic conditions, alongside comprehensive assessments of environmental impacts and economic feasibility. Full article

The extensive environmental pollution caused by petroleum-based plastics highlights the urgent need for sustainable, economically viable alternatives. The practical challenge of enhancing polyhydroxybutyrate (PHB) production with cost-effective agro-industrial residues—rice-bran and corn-flour hydrolysates—has been demonstrated. Bacillus bingmayongensis GS2 was isolated from soil samples collected at the Pirana municipal landfill in Ahmedabad, India, and identified through VITEK-2 biochemical profiling and 16S rDNA sequencing (GenBank accession OQ749793). Initial screening for PHB accumulation was performed using Sudan Black B staining. Optimization via a sequential one-variable-at-a-time (OVAT) approach identified optimal cultivation conditions (36 h inoculum age, 37 °C, pH 7.0, 100 rpm agitation), resulting in a PHB yield of 2.77 g L⁻¹ (66% DCW). Further refinement using a central composite response surface methodology (RSM)—varying rice-bran hydrolysate, corn-flour hydrolysate, peptone concentration, and initial pH—significantly improved the PHB yield to 3.18 g L⁻¹(74% DCW), representing more than a threefold enhancement over unoptimized conditions. Structural validation using Fourier Transform Infrared spectroscopy (FTIR) and Proton Nuclear Magnetic Resonance spectroscopy (¹H-NMR) confirmed the molecular integrity of the produced PHB. That Bacillus bingmayongensis GS2 effectively converts low-cost agro-industrial residues into high-value bioplastics has been demonstrated, indicating substantial industrial potential. Future work will focus on bioreactor scale-up, targeted metabolic-engineering strategies, and comprehensive sustainability evaluations, including life-cycle assessment. Full article

The treatment of wastewater and the utilization of the by-products of these processes are an important part of the circular economy. The sewage sludge, a result of wastewater treatment, could be used as a material for plant nutrient supply and/or soil-improving products. The city of Nyíregyháza, Hungary, with 120,000 citizens, has a well-planned water treatment plant operated by Nyírségvíz Ltd., which, in cooperation with the Research Institute of Nyíregyháza, developed a municipal sewage sludge compost (SSC). The closed loop of sewage water treatment and the agricultural utilization of its by-product has been developed and managed. The compost product called Nyírkomposzt was planned for acidic sandy soils. Beyond the agronomic benefits, the sustainable and environmentally sound utilization of SSC reduces sewage sludge disposal. This active involvement of a water utility company demonstrates the potential of cross-sectoral cooperation in solving environmental problems. The quality of the compost fits the Hungarian legislation. To study the effects of 0, 9, 18, and 27 t ha⁻¹ doses of compost on acidic sandy soil, a long-term small plot experiment was started in 2003. The cumulative effects of the regular (every third year, last treatment before sampling in 2021) application of the SSC showed positive changes in basic soil properties, depending on the doses used. Increasing values were found in the case of pH from 4.5 to 6, plant available P₂O₅ from 240 to 690 ppm, and plant available K₂O from 180 to 200 ppm. The plant-available zinc and copper content also increased. Soil organic matter and total N content stabilized at around 0.9% and 0.08%, respectively. The grain yields of winter rye also increased in both investigated years. The yields of 18 t ha⁻¹ treatment were about two times higher compared to the control, but only in 2022 was the difference significant. Our findings underscore the potential of well-planned SSC applications to improve the fertility of ploughed, acidic sandy soil, taking into account the theory of the circular economy by utilizing wastes and decreasing landfilling. Full article

For the first time, the deposition area of heavy metals and other trace elements (Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, P, Pb, S, Sr, Sb, V, Zn, and Hg) on the territory surrounding a landfill of domestic (municipal) waste at the 9th km of the Vilyuisky tract of Yakutsk within a radius of 51 km was assessed using the method of moss biomonitors and ICP-OES as an analytical technique. Mosses were analyzed for radionuclide content (⁴⁰K, ¹³⁷Cs, ²¹² Pb, ²¹⁴Pb, ²¹²Bi, ²¹⁴Bi, ²⁰⁸Tl, ⁷Be, and ²²⁸Ac) in a number of selected samples by semiconductor gamma spectrometry. The results of the examination of moss samples by ICP-OES indicate the presence of large amounts of toxic Ba and metal debris (Al, Co, Cr, Fe, S, and Pb) at the landfill. In addition, it is shown that the investigated samples contain elements such as Cd, Co, Cr, Cu, Cu, Mn, Ni, Pb, Sr, V, Zn, and Hg. The method of gamma spectrometry revealed that the studied samples contain such radioactive elements as ¹³⁷Cs, daughter products of ²³⁸U and ²³²Th. Detection of the same heavy metals and radionuclides in the atmospheric air of the city and in the vegetation near the landfill may indicate that one of the sources of environmental pollution may be products of incineration of the landfill contents at the 9th km of the Vilyuisky tract. Full article

The transformative trajectory of urban development in the contemporary era has engendered a substantial escalation in construction waste generation, particularly in China, where it constitutes approximately 40% of the total solid waste stream. Traditional landfill disposal methodologies pose formidable ecological challenges, encompassing soil contamination, groundwater pollution, and significant greenhouse gas emissions. Furthermore, the unsustainable exploitation of natural sandstone resources undermines energy security and disrupts ecological balance. In response to these pressing issues, an array of scholars and researchers have embarked on an exploratory endeavor to devise innovative strategies for the valorization of construction waste. Among these strategies, the conversion of waste into recycled aggregates has emerged as a particularly promising pathway. However, the practical deployment of recycled aggregates within the construction industry is impeded by their inherent physico-mechanical properties, such as heightened water absorption capacity and diminished compressive strength. To surmount these obstacles, a multitude of enhancement techniques, spanning physical, chemical, and thermal treatments, have been devised and refined. This paper undertakes a comprehensive examination of the historical evolution, recycling methodologies, and enhancement strategies pertinent to recycled aggregates. It critically evaluates the efficacy, cost–benefit analyses, and environmental ramifications of these techniques, while elucidating the microstructural and physicochemical disparities between recycled and natural aggregates. Furthermore, it identifies pivotal research gaps and prospective avenues for future inquiry, underscoring the imperative for collaborative endeavors aimed at developing cost-effective and environmentally benign enhancement techniques that adhere to the stringent standards of contemporary construction practices, thereby addressing the intertwined challenges of waste management and resource scarcity. Full article

The processing of dimension stones for the construction sector involves transforming rock blocks into slabs via sawing and polishing. This process generates a fine-grained waste composed largely of rock powder derived from the processed rock. Several studies indicate that the rock powder produced as a processing waste can release Ca, Mg, and K. However, alongside the release of macronutrients, there is the possibility of releasing undesirable constituents, such as Na, which is also a component of the minerals forming silicate rocks. This study aimed to analyze the risk of salinization that these materials may cause to soil if applied without a thorough evaluation of their composition. Samples were analyzed in terms of physical, chemical, and mineralogical parameters; exchangeable inorganic constituents; percentage of exchangeable sodium; and sodium adsorption ratio. The data indicate that residues stored in landfills in a random and unsorted manner do not fully meet the criteria established by Brazilian regulations for soil remineralizers. However, their characteristics suggest good potential for use in the agricultural sector, although this would require blending with other agricultural inputs and/or segregating residues from certain types of rocks to comply with current regulations. Full article

This study aims to obtain findings on the internal water behavior, the presence of water channels, and the degree of washout due to rainfall infiltration in Japanese municipal solid waste (MSW) final disposal sites. Electrical resistivity tomography (ERT) monitoring and undistributed waste sampling for X-ray computed tomography (X-ray CT) analysis were conducted in the field. The study sites were targeted at Site A, which is mainly composed of non-combustible residues, and Site B, which is mainly composed of incineration ash. The time-dependent resistivity distributions obtained from real-time ERT monitoring were effective for us to understand the water content distribution after water infiltration during water injection tests. As a result, the global flow behavior and the local water channel flow were determined. In addition, X-ray CT analysis of the undisturbed waste samples obtained from the sites clarified the different pore structures, indicating the possibility of more advanced washing out at Site A than at Site B. Furthermore, the soil cover layer and gas extraction wells had a significant effect on the resistivity structure with respect to water flow behavior. Since soil cover layer and gas extraction wells are significant factors affecting waste stabilization by washout, it is suggested that these factors should be considered in the design and maintenance of landfills. Full article

Resource depletion and environmental degradation have resulted from the substantial increase in the use of natural aggregates and construction materials brought on by the growing demand for infrastructure development. Road building using mining waste has become a viable substitute that reduces the buildup of industrial waste while providing ecological and economic advantages. In order to assess the appropriateness of several mining waste materials for use in road building, this study investigates their engineering characteristics. These materials include slag, fly ash, tailings, waste rock, and overburden. To ensure long-term performance in pavement applications, this study evaluates their tensile and compressive strength, resistance to abrasion, durability under freeze–thaw cycles, and chemical stability. This review highlights the potential of mining waste materials as sustainable alternatives in road construction. Waste rock and slag exhibit excellent mechanical strength and durability, making them suitable for high-traffic pavements. Although fly ash and tailings require stabilization, their pozzolanic properties enhance subgrade reinforcement and soil stabilization. Properly processed overburden materials are viable for subbase and embankment applications. By promoting the reuse of mining waste, this study supports landfill reduction, carbon emission mitigation, and circular economy principles. Overall, mining byproducts present a cost-effective and environmentally responsible alternative to conventional construction materials. To support broader implementation, further efforts are needed to improve stabilization techniques, monitor long-term field performance, and establish effective policy frameworks. Full article

This study assesses the extent of heavy metals (HMs) contamination and the associated ecological risks in soils surrounding waste landfills at the former Boruta Dye Industry Plant in Zgierz, Poland. Soil samples were collected during two sampling campaigns (summer 2023 and winter 2024) from 13 locations. Concentrations of Cu, Ni, Zn, Pb, and Cd were measured, and contamination levels were evaluated using several indices: geoaccumulation index (I_geo), pollution index (PI), pollution load index (PLI), Nemerow integrated pollution index (NIPI), ecological risk factor for a single metal (E_rⁱ), index of potential ecological risk (ERI). The highest I_geo value (10.95) was recorded for Cu in the area of the old landfill, which had been in operation for 90 years. The average PI values were Cu—120.97, Pb—52.46, Cd—46.70, Zn—22.19, and Ni—5.38, indicating considerable (3 ≤ PI < 6) to high (PI ≥ 6) contamination levels. The NIPI values, in descending order, were Cu (2102.2) > Pb (270.7) > Zn (88.3) > Cd (62.8) > Ni (21.5), all reflecting high (NIPI >3) contamination levels. The highest PLI was 5.10, with all remaining values exceeding the contamination threshold (PLI >1). The E_rⁱ value for Cu reached 14,852.75, indicating an extremely high (E_rⁱ ≥ 320) ecological risk. The average ERI value across the study area was 1347.2, suggesting a severe (ERI ≥ 600) ecological threat. These findings confirm that the industrial landfills associated with the dye plant constitute a critical pollution hotspot. The results underscore the urgent need for ongoing environmental monitoring, risk mitigation, and site remediation to prevent further environmental degradation and potential contamination of nearby water bodies. Full article

The main objective of this study is to assess the environmental life cycle of the materials, components, and elements of a mono-Si photovoltaic power plant towards their sustainable development. Currently, photovoltaic installations are considered to be environmentally friendly systems that produce “green” energy. During their exploitation, no pollutants are emitted into the environment. However, the processes of manufacturing and post-used management of their materials, components and elements are associated with both high demand for energy and matter, as well as with emissions of harmful substances into the atmosphere, water, and soil. For this reason, from the perspective of the entire life cycle, photovoltaic power plants may contribute to the deterioration of human health, the reduction in the quality of the environment, and the depletion of non-renewable fossil resources. Due to these potential threats, it was considered appropriate to conduct a Life Cycle Assessment of a real 2 MW photovoltaic power plant located in northern Poland, in terms of compliance with the main assumptions of sustainable development. The analysis was conducted using the Life Cycle Assessment (LCA) methodology (the ReCiPe 2016 model). Impacts on the environment was assessed in three areas: human health, ecosystem quality, and material resources. Two scenarios were adopted for the post-used management of materials, components, and elements: landfill disposal and recycling. Based on the conducted research, it was found that, among the assessed groups of photovoltaic power plant components (photovoltaic modules, supporting structure, inverter station, and electrical infra-structure), photovoltaic modules have the highest level of harmful impact on the environment (especially the manufacturing stage). The use of recycling processes at the end of their use would reduce their harmful impact over the entire life cycle of a photovoltaic power plant and better fit with the main principles of sustainable development. Full article

The emphasis on sustainable and environmentally friendly practices in geotechnical engineering has generated interest in alternative soil stabilizing techniques. The present study examines the application of xanthan gum (XG) and guar gum (GG) to enhance the strength of a sand–bentonite composite and explore their potential for use as landfill liners or impervious barriers. The mixtures, consisting of 25% bentonite and 75% sand, were treated with XG and GG concentrations of different percentages (0.5%, 1%, 2%, and 3% by dry mass). The test results indicated that a 2% addition was optimal for both biopolymers. Using this optimum value of XG and GG significantly increased the unconfined compressive strength (UCS) by almost 3-fold compared to the strength of untreated samples. Meanwhile, XG demonstrated a slightly higher impact on strength attributed to its robust gel-forming and binding properties. Comparisons between the two biopolymers highlighted XG’s superior performance, with UCS improvements of up to 20% over GG-treated samples. These results underscore the potential of biopolymers as effective, sustainable alternatives to traditional stabilizers, providing both mechanical enhancements and environmental benefits. The present study contributes valuable insights into green soil stabilization techniques, supporting the development of more sustainable construction practices. Fourier Transform Infrared Spectroscopy (FTIR) was conducted to analyze the chemical interactions between sand–bentonite mixtures and biopolymers, which possibly provide insights into the bonding mechanisms responsible for the observed improvements in mechanical and volumetric behavior. Full article