Search Results (10)

This study reports a successful selective waste collection initiative led by UFSC’s Araranguá campus in a municipality without a recycling system. The initiative, named “Recicla UFSC Ara”, was structured around three main components: (i) the installation of color-coded bins for recyclable waste (including paper, plastic, metals, and polystyrene) and non-recyclable waste in indoor and common areas; (ii) the establishment of a Voluntary Delivery Point (PEV) to gather specific recyclable materials, such as glass, electronics waste, plastic bottles, writing instruments, and bottle caps; and (iii) the execution of periodic educational community-focused campaigns aimed at encouraging participation from both the university and the broader local community. Recyclables were manually sorted and weighed during regular collection rounds, and contamination rates were calculated. Quantitative data collected from 2022 to 2025 were analyzed using descriptive statistics and one-way ANOVA to assess waste generation and contamination trends. Gathered recyclables were directed to appropriate partner institutions, including local “Ecoponto”, non-profit organizations, and corporate recycling programs. The study also conducted a literature review of similar university-led waste management programs to identify standard practices and regional specificities, providing a comparative analysis that highlights both shared elements and distinctive contributions of the UFSC model. Results demonstrate a significant volume of waste diverted from landfills and a gradual improvement in waste disposal practices among the university community. Targeted communication and operational changes mitigated key challenges, improper disposal, and logistical issues. This case underscores the role of universities as agents of environmental education and local sustainable development. Full article

There are still many unmanaged landfills around the world that pose significant potential environmental problems. One of the largest unmanaged landfills in Europe, which has been used for more than 40 years to deposit waste from Serbia’s capital, Belgrade, is the Vinča landfill. A revitalization and extension of this landfill was proposed that would allow its sustainable operation in the future. The revitalization project considered building a capping layer on the surface of the current landfill, which will close it and which will serve as a liner on the bottom of the new landfill. The use of a composite system including a HDPE geomembrane is considered in the project. New landfill settlements were predicted using the FEM method utilizing a Hardening-soil constitutive model for subgrade. Both immediate settlements of subgrade caused by waste deposition and primary consolidation settlement were calculated. The results show that a substantial increase in the settlement of the geomembrane subgrade can be expected during the primary consolidation period, due to the high rate of filling compared to the permeability of the subgrade. The total settlement of the new landfill in its crown is expected to be between 2.73 and 4.52 m. The axial force in the geomembrane will not exceed the tensile strength of the membrane at any time during or after the new landfill operation. Full article

The growing population and urbanization rates in developing countries causes huge pressure on the construction sector to aid the equivalent infrastructure growth. Natural resources are essential to attain the required infrastructure needs. The demand in the construction sector for materials causes significant environmental effects due to the higher consumption rate of finite natural resources. To address such an issue, the study focuses on the landfill capping application demand in Vietnam, based on its extensive landfill presence in its current state and their need to be closed in the years ahead. The study considers utilization of secondary raw materials arising from industrial or anthropogenic waste as an alternative material as a landfill mineral sealing layer, to replace the dependence on conventional clay and bentonite. The selected alternative materials were tested to satisfy the permeability conditions for the landfill sealing layer standards, where results indicated very low permeability values for the mixtures, meeting German quality requirements which require k ≤ 5 × 10⁻⁹ m/s for landfill class I (landfills without further environmental requirements) and k ≤ 5 × 10⁻¹⁰ m/s for class II (conventional landfill for non-hazardous waste) for sealing layers of landfills. Further, the various mixes of alternative mineral layers in a life cycle analysis for a functional unit of one hectare landfill mineral sealing layer resulted in lower environmental footprints than the conventional layer. The results of the mineral sealing layer showed that the higher bentonite composition of about 20% in the mix ratio and transport distance of 65 km for the ashes increased the overall environmental footprint of the mix. In this case, mix 6 and mix 7, having 20% bentonite, tended to possess higher impacts, despite the alternative ashes holding zero allocation, along with the 65 km transportation distance associated with ashes. The avoidance factor over the alternative mixes has an effective approximate 25–50% Global Warming Potential (GWP) impact reduction. There was a significant mineral resource scarcity impact reduction on the use of secondary raw materials. Full article

This paper assesses the potential of the circular economy (CE) policy ambitions of the port cities of Ghent (Belgium) and Amsterdam (The Netherlands). Both Ghent and Amsterdam are municipalities that potentially lend themselves ideally to set up a more local-oriented circular (re)production and (re)consumption system. Subsequently, both have the ambition that, in 2050, the CE will have become an achieved public value that influences all activities to be more circular in comparison with today. However, while having ambitious policies is important, we explain that a public value also requires alignment with the operational capacity used or needed to achieve this policy ambition. In this paper, we focus on the ‘negative’ CE operational capacity: landfills and incinerators. Our results show that the CE ambitions of Ghent are more realistic than Amsterdam. During the last few decades, Dutch waste management has been largely privatized. This led to a significant increase in incinerator capacity and a lowering of the incineration price. This differs from Flanders, which has a deliberate capping on the allowed incinerator capacity, keeping the price for incineration high. This increases the incentive for urban and maritime actors to climb the waste hierarchy, eventually thus making the port city (potentially) more circular as a whole. Full article

Mineral landfill liners require legally-fixed standards including a sufficiently-high available water capacity (AWC) and relatively low saturated hydraulic conductivity values (Ks). For testing locally available and potentially suitable materials with respect to these requirements, the soil hydraulic properties of boulder marl (bm) and marsh clay (mc) were investigated considering a defined compaction according to Proctor densities. Both materials were pre-compacted in 20 soil cores (100 cm³) each on the basis of the Proctor test results at five degrees of compaction (bm1–bm5; mc1–mc5) ranging between 1.67–2.07 g/cm³ for bm and 1.09–1.34 g/cm³ for mc. Additionally, unimodal and bimodal models were used to fit the soil water retention curve near saturation and changes in the pore size distribution (PSD). The structural peak of the PSD in the fraction of pore volume between −30 and −60 hPa was more pronounced on the dry side (bm1–2, mc1–2) than on the wet side of the Proctor curve (bm4–5, mc4–5). Therefore, the loss in structural pores can be attributed to an increasing dry bulk density for bm and an increasing gravimetric moisture content during Proctor test for mc. While the mc fulfils the legal standards with AWC values between 0.244–0.271 cm³/cm³, the Ks values for bm between 1.6 × 10⁻⁶ m/s and 3.8 × 10⁻⁷ m/s and for mc between 7.4 × 10⁻⁷ m/s and 1.2 × 10⁻⁷ m/s were up to two orders of magnitude higher than required. These results suggest that the suitability of both materials as landfill liner is restricted. Full article

The soil shrinkage behavior of mineral substrates needs to be considered for engineering long-term durable mineral liners of landfill capping systems. For this purpose, a novel three-dimensional laser scanning device was coupled with (a) a mathematical-empirical model and (b) in-situ tensiometer measurements as a combined approach to simultaneously determine the shrinkage behavior of a boulder marl, installed as top and bottom liner material at the Rastorf landfill (Northern Germany). The shrinkage behavior, intensity, and geometry were determined during a drying experiment with undisturbed soil cores (100 cm³) from two soil pits; the actual in-situ shrinkage was also determined in 0.2, 0.5, 0.8, and 1.0 m depth by pressure transducer tensiometer measurements during a four-year period. The volume shrinkage index was used to describe the pore size dependent shrinkage tendency and it was classified as low (4.9%) for the bottom liner. The in-situ matric potentials in the bottom liner ranged between −100 and −150 hPa, even during drier periods, thus, the previously highest observed drying range (pre-shrinkage stress) with values below −500 hPa and −1000 hPa was not exceeded. Therefore, the hydraulic stability of the bottom liner was given. Full article

Mineral temporary capping systems of landfills are required to accomplish the long-term coverage prerequisites or to use them as a basis layer prior to later permanent sealing. Such a capping system for a municipal waste landfill in Rastorf (Northern Germany) was developed and tested for its sealing capability on the basis of observed and simulated water balance components for the period between 2008 and 2015, considering observed local weather data and complemented by the Hydraulic Evaluation of Landfill Performance (HELP 3.95 D) model. The modeling results of this case study could be improved by the correction of previously used global solar radiation data due to the consideration of exposure and inclination angle of landfill surface areas. The model could positively be validated by comparing observed and simulated outflow (surface runoff and lateral drainage) data with R² values ranging between 0.95 and 0.99, as well as for the leachate rates with R² values of 0.78–0.87. The statistical-empirical HELP model was found useful in predicting the leachate generation of a temporary landfill capping system for specific soil and site conditions, even if only a restricted set of observed data was available. Full article

The effects of compaction on soil shrinkage behavior need to be considered for engineering long-term durable mineral liners of landfill capping systems. For this purpose, a new three-dimensional laser scanning device was coupled with a mathematical-empirical model to simultaneously determine the shrinkage behavior of a boulder marl (bm) and a marsh clay (mc). Therefore, both materials were precompacted in 200 soil cores (100 cm³) on the basis of the Proctor test results with five different degrees of compaction (bm1-bm5; mc1-mc5). Thus, the shrinkage behavior, intensity, and tendency were determined during a standardized drying experiment. The volume shrinkage index was used to describe the pore size dependent shrinkage tendency and was classified as high to very high (11.3–17.7%) for the marsh clay and medium (5.3–9.2%) for the boulder marl. Additionally, only the boulder marl (bm2), compacted up to 88% of Proctor density, could be installed as landfill bottom liner in drier locations if the local matric potentials did not exceed the previously highest observed drying range (i.e. values below −300 hPa), to avoid crack formation and generation. Full article

Methane is one of the most important gaseous hydrocarbon species for both industrial and environmental reasons. Understanding and quantifying methane emissions to atmosphere is therefore an important element of climate change research. Range-resolved infrared differential absorption Lidar (DIAL) measurements provide the means to map and quantify a wide range of different methane sources. This paper describes the DIAL measurement technique and reports the application of an infrared DIAL system to field measurements of methane emissions from active and closed landfill sites. This paper shows how the capability of the DIAL to measure the spatial distribution of methane plumes enables DIAL vertical scans to spatially separate and independently quantify emissions from different sources. It also allows DIAL horizontal scans carried out above the surface to identify emission hot-spots. An overview of the landfill emission surveys carried out over the last decade by the National Physical Laboratory (NPL) DIAL system is presented. These surveys were part of research projects and commercial works aimed to validate the method and to provide reliable information on the methane emissions measuring the total site and area-specific emissions from active areas, capped areas, and gas engine stacks. This work showed that methane emissions are significantly higher for active sites than closed sites due to the methane emitted directly to air from the uncapped active areas. On active sites, the operational tipping areas generally have higher emission levels than the capped areas, although there is considerably variation in the emission from different capped areas. The information obtained with DIAL measurements allow site operators to identify significant fugitive emission sources and validate emissions estimates, and they allow the regulators to revise and update the emission inventories. Operators’ remediation actions driven by DIAL measurements have also been shown to considerably decreased total site methane emission. Full article

The paper presents the current situation of the waste management system of the megacity Ho Chi Minh in Vietnam, and the options for waste and land recycling in a low income country. Generally, there is a large potential for circular economy in the city as the main proportion of the waste flows are recyclables. Due to the missing selective collection system, this potential is not used in the full extend yet, even if the collection of the entire waste volumes is envisaged in the National Waste Management Strategy by 2025. The waste stocks are the landfill locations in the region of Ho Chi Minh City (HCMC), two of them being in operation and two of them already being closed. A special focus is given to the landfill Gò Cát, which was subject to an option analysis in terms of waste and land recycling options. The results indicate that there are several reuse options: the use of the landfill material in a waste-to-energy process after landfill mining, the reuse of the re-gained land in case of landfill mining, the reuse of the capped landfill for energy crop cultivation, and the gasification in a biogas plant in case of a remaining landfill. Full article