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Global warming caused by greenhouse gas (GHG) emissions is a global problem. Solid municipal waste landfills are the third largest source of artificial methane emissions. Methane is one of the greenhouse gases contributing to global warming. The net zero emissions target was set to strike a balance between emissions and anthropogenic GHG disposal by 2050. Methane emissions from active or closed landfills may be reduced by methane oxidation, which is developed as a coating over these landfills. Methane (CH4) is an important gas that causes greenhouse effects on Earth and has an atmospheric warming potential of 28 times higher than carbon dioxide (CO2). The aim of this study is to find out whether cellulose in the biocover contributes to improving the performance of biocover and to decreasing methane emissions. An experiment was conducted in laboratory conditions that studied the effectiveness of biocover developed in the laboratory. Three experimental columns were created with a diameter of 160 mm and a height of 1500 mm. An active compost saturated with water at a thickness of 500 mm was used as a source of methane, a permeable layer of sand at a thickness of 300 mm was further applied and finally covered with biocover. The first biocover consisted of 50% of fine fraction waste, 50% of clay soil. The second biocover consisted of 40% of fine fraction waste, 40% of clay soil and 20% cellulose (shredded paper). Measurements were performed with the CRDS device, Picarro G2508. The measurements were taken weekly for 5 months. [ABSTRACT FROM AUTHOR]

Solid municipal waste landfills are the third largest source of man-made methane emissions. Methane is one of the greenhouse gases contributing to global warming. The capture of methane emissions in the waste sector is addressed by collecting it and using it for energy production. Methane emissions from active or closed landfills can be reduced by methane oxidation, which is developed as a covering over these landfills. It is usually composed of a gas distribution layer that favours micro-organisms that consume methane. The aim of this study is to find the most appropriate composition of the biocover in which filling material waste is used. In laboratory conditions, an experiment was conducted that studied the effectiveness of the biocover developed in the laboratory. Three experimental columns were created at a height of 160 mm and 1500 mm. A active compost saturated with water at a thickness of 500 mm was used as a source of methane, a permeable layer of sand at a thickness of 300 mm was further formed and finally covered with biocover. The biocover was composed of 60% of fine fraction waste, 20% soil and 20% compost, of the total volume. The experiment was created on 6 June 2022 and the first measurements were made two weeks later with CRDS equipment Picarro G2508. Measurements were made weekly for 4 months. The results of the study show that methane is released more forcefully after the first two months of application of the biocover. This is related to compost in the biocover, which has started to decompose actively, that methane oxidising micro-organisms develop on average after two months. [ABSTRACT FROM AUTHOR]

Landfill and dump remediation and waste recovery are often needed as circular economy approach is more and more demanding. Complicated solutions are needed to conserve the landfill space as well as overall reduction of the amount of landfilled material is not an easy task because of the different content of contaminants. Primitive soil excavating and transporting to hazardous waste landfills is not the best solution anymore. Series of experiments using landfill mined fine fraction of waste considering complex forming stability of contained copper and lead were performed. Experiments have shown that stability constants overall are enough convincing that inert fine fraction of waste with added soil of various percentage amounts are appropriate for stabilizing the heavy metals. Cation exchange capacity, selective ion electrode potentiometry and extraction experimental procedures were used in order to calculate stability values and determine free exchange cations of Pb and Cu. The fine fraction of waste combined with soil organics are stabilizing Pb and Cu meaning these will not be leaching out from the dumpsite if material is used as biocover. [ABSTRACT FROM AUTHOR]

The growing population of the planet and the population's desire for ever-higher welfare standards have contributed to a linear economy-based consumer society model that is one of the main reasons for the increased volume of waste. Global sustainability, mitigation of climate change, and the reduction of pollution are strongly related to the waste management issue, and there is a need to switch from linear economy models to the circular economy. The maintaining solution for keeping and storing waste over the last century has been landfilling as its costs are the lowest. A sustainable approach such as landfill mining (LFM) can be applied to recover rare earth elements (REEs) and other valuable metals from waste that make fundamental assets in terms of economy and essential for developing industrial technologies. This study investigated concentrations of REEs and other metals in waste material. Samples from Ida-Virumaa (Estonia) landfilled waste fine fraction were taken to estimate the element concentration proceeded through sequential extraction. Additionally, the method of clay modification was developed that may serve as a sorbent to extract the REEs from the inert landfill fine fraction waste using hydroxyapatite modified clay. The amount of REEs might become of industrial interest if a feasible landfill mining approach for remediation of landfills and degraded industrial soils is applied together with innovative recovery methods, e.g., sorption by modified clays. [ABSTRACT FROM AUTHOR]

Commonly the product’s life cycle ends up with waste. Conventionally the remains go to the landfill, earlier times – a dumpsite, the least manageable waste disposal method. To ensure that lost to society materials are treated with high priority, the European Union (EU) has implemented the Circular Economy Action Plan, continuing the monitoring of old dumpsites. The hierarchy of waste management points at preventing raw material use at first sight, but the following steps point at material reuse and recycling. The material recovery and revitalisation of old forgotten dumpsites are related to a sustainable and circular economy based direction and the corresponding rules. Candidates for so-called landfill mining (LFM) should be evaluated on a country by country basis. The starting point is inspecting each dumpsite, evaluating prospective materials and space as the real estate benefit and landscapes revitalisation perspective. Another aspect is the emissions diminishment while an innovative approach of landfill closing is taken. A fine fraction of residual waste might be used as a cover – functional composite capping material. It would decrease methane gas emissions in the atmosphere. Last but not least is restoring ecosystem services by revitalising the dump structures as parks and recreation areas and/or transforming them to industry/logistic parks to diminish the need for new urban areas in virgin lands. This study aims to analyse the aspects compulsory when estimating old dumpsites revitalisation projects. [ABSTRACT FROM AUTHOR]

Resources are lost in dumps from the time civilization knows itself. Solid waste handling through ‘zero waste’ concept is important for disposed waste reuse/recycling. The challenge for future is landfill mining (LFM) – one of the approaches dealing with that approach. We can think of recycling of valuable components such as plastic, metals and even rare soil elements if we have the right technology. Fine fraction of waste derived from excavated, separated and screened waste is also a perspective of circular economy as this inert fraction may serve as methane degradation layer for covering the old as well as new landfills. It may reduce harmful CH4 emissions and diminish the raw material use for closure of dumping sites. The aim of this study is to give an outlook on opportunities and describe other benefits for circular economy from innovative construction technology of cover layer. Rejected material may contain up to 40–60% of dump site/landfill mass and we may have interest in: 1) estimation of fine fraction of waste as functional construction material; 2) watching environmental effects – possible leaching and emissions; 3) keeping dumpsite revitalization as the master plan idea. First studies revealed the potential of fine fraction of dumpsite material for sustainable covering layer development. This study is supported by the project No.1.1.1.2/VIAA/3/19/531 ‘Innovative technologies for stabilization of landfills – diminishing environmental impact and resources potential in frames of circular economy’. [ABSTRACT FROM AUTHOR]

Landfills (dumps) are places where the end of the life cycle of products can be found - useful material is dumped away from the sight creating contaminant flows around. Another problem is huge unexplored potential of resources recycling - we have limited knowledge also on useful elements and materials that are buried. The solution to overcome the limitations that provide remote sensing and traditional geodesy, proximal sensing techniques could be used. “Near surface geophysics” with operation at or just below the soil surface, significantly may contribute to give answers that traditionally are solved only after excavation. Geophysical methods are various, those can be active (i.e. create its own signal) or passive (i.e. register an existing signal); invasive (by inserting devices into the soil) or non-destructive. Some of these methods are static (e.g. a sequence of inserted electrodes), others can be used in a mobile way (e.g. pulled by a quad-bike). In general, their depth of exploration can vary from a few decimetres to some tens of metres. Thus in range of wide geophysical methodology spectrum almost all methods might be of use for unknown dump exploration depending on circumstances. In this paper, the aim is to macro-characterize anthropogenic geomorphological forms for contouring of old buried dumps by use of magnetometry, and geoelectric research methods to provide knowledge on approximate content of the dump. Protonmagnetometer was used in Eastern Latvia to determine unseen on surface dumpsite, buried in forest; induced polarisation and electric resistivity research was done in Southern Sweden for the macro-content analysis of dump hills composed of glass industry residuals and construction waste mixture. Geophysical surveying was performed to support site investigation with respect to landfill-related environmental problems, to enhance the opportunity for contouring of location of material mass and initially evaluate its physical properties. Results have shown good potential of geophysical surveying to spatially characterize landfill masses (location and dimensions) and to identify the internal structure of a landfill site, which already provides valuable information to estimate the landfill mining (material recovery) potential of landfills. [ABSTRACT FROM AUTHOR]

Production of refuse derived fuel from municipal solid waste in future shall play a strategic role in an integrated waste management system. The amount of landfilled biodegradable materials thus will be diminished according to provisions of the 1999 Waste Landfill Directive. The aim of this article is to evaluate cost effectiveness based on cost evaluation of the different complication of the waste pre-treatment equipment complectation and based on regenerable waste quantities in Latvia. The comparison of cost estimates is done in 3 scenarios considering potential waste quantities in Latvia: Scenario I - planned annual waste quantity is 20 kT; Scenario II - 40 kT and Scenario III - 160 kT. An increase in amount of waste and processing capacity means the decrease in costs of mechanical pre-treatment of 1 ton of waste. Thus, costs of mechanical sorting line under different scenarios with capacities of 10 t h-1, 20 t h-1 and 80 t h-1 are EUR 32 per t, EUR 24 per t and EUR 15 per t, respectively. Most feasible cost for a set of mechanical pre-treatment equipment for the capacity of 10 t h-1 is EUR 32 per t by using rotating drum screener with the following manual sorting. Mechanical pre-treatment equipment of unsorted municipal waste is economically nonbeneficial, when the use of fine (biologically degradable) fraction is not possible. As the sorting of biodegradable kitchen waste is not developed under the current waste management system in Latvia, the lines for mechanical pre-treatment of household waste would be better to install in landfills. [ABSTRACT FROM AUTHOR]