Search

Greece committed to the European Green Deal plans to complete mining operations by the end of 2028 and to transition from coal-based electricity to renewable energy sources (RES). The mine closure under the principles of effective strategic planning of the post-mining land uses constitutes an integral part of this transition. This research aims to simulate land use changes in the Ptolemais lignite mining area from 2023 to 2030 using a cellular automata-based (CA) calibrated model. The model analyzed three distinct scenarios with directions of agriculture development, industrial growth, and nature and biodiversity conservation. Five areas' topographic-morphologic characteristics (slope, distance from roads, predetermined RES, future lakes, and cities) were assessed through the Analytic Hierarchy Process (AHP) to calibrate the model for each scenario. A fuzzification algorithm was developed in a Geographical Information System (GIS) environment to generate a land use suitability map for each scenario. The generated suitability maps were imported into the simulation model, serving as transition rules for each scenario. The study's findings revealed that each scenario diachronically derives different land use types of distribution. The scenario-based approach has proven to be a valuable tool for simulating the dynamic transitions of post-mining land uses, offering significant assistance to decision-makers in planning new land use. [ABSTRACT FROM AUTHOR]

Timetables for energy transition vary across EU Member States. The planning for dealing with the consequences of the transition in affected regions also varies. Under the pressure of the ten-year economic crisis, Greece is one of the few countries that has committed to stop using lignite in electricity generation, achieving 80% by 2023 and definitively by 2028. Apart from its environmental impact, the country assessed using lignite in electricity generation as unprofitable and damaging to the Greek economy. Simultaneously, it formulated a national energy transition plan for the country's lignite areas. The plan also provides support for existing enterprises and incentives for new enterprises. European and domestic financial instruments accompany the support incentives. The compressed timetable is ambitious and demanding, entailing risks of project failure. As one of the first Member State projects to be completed in 2028, its outcome will shape an ambient atmosphere, positive or negative, for other Member States' projects as well. Based on the transition plan and the timelines to which Greece has committed, this research examines the reanimation of rural areas involved in lignite mining from the perspective of entrepreneurship and financial support instruments. The findings revealed that while there is strong social consensus around the design that incorporates best practices, the basis for the completion schedule has unrealistic elements that will have potentially negative consequences for the restoration of the areas that the energy transition affects. The present study highlights the risks for entrepreneurship that tight schedules pose in the context of lignite area redevelopment. [ABSTRACT FROM AUTHOR]

To achieve sustainable development, the energy transition from lignite burning to renewable energy resources for electric power generation is essential for Greece. Wind and solar energy have emerged as significant sources in this transition. Surprisingly, numerous studies have examined the potential for onshore wind based on land eligibility, while few studies on open-field photovoltaic (PV) installations have been conducted. Therefore, based on the Specific Framework for Spatial Planning and Sustainable Development for Renewable Energy Sources (SFSPSD-RES), along with insights from previous relevant studies, this work conducts a land eligibility analysis of onshore wind and open-field PV installations in Greece using the software Geospatial Land Availability for Energy Systems (GLAES 1.2.1) and ArcGIS 10.2. Additionally, through an in-depth exploration of wind and solar PV energy potential in decommissioned lignite mines integrated with wind power density (WPD) and global horizontal irradiation (GHI) maps, this study compares the suitability of wind versus solar as energy sources for the decarbonization of Greece. Overall, despite the greater spatial eligibility for onshore wind turbines compared to open-field PV power plants, the relatively lower wind energy potential and operational limitations of wind turbines lead to the study's conclusion that solar energy (PV) is more suitable for the decarbonization of Greece. [ABSTRACT FROM AUTHOR]

Greek lignite reserves are mainly located in the northwestern part of the country (Region of Western Macedonia, Greece), reaching a total of 5 billion tons. Considering that Greece is planning to stop burning lignite for electricity production, the recovery of the CH4 trapped in lignite coalbed reservoirs can be a valuable alternative for power generation and may help to reduce the direct emissions of methane during mining activities. The aim of the present study was to evaluate the LCBM in the Region of Western Macedonia, Greece (Ptolemaida basin). In order to assess the LCBM that could be extracted, three samples were collected from an active mine and were subjected to desorption experiments at different temperatures (25 °C, 50 °C, 100 °C, and 150 °C) by channeling high purity Ar gas at 1 atm of pressure. According to the results, the highest amount of CH4 was extracted during the desorption process at 50 °C, while the total amount of CH4 from all three samples was 0.82 m3/kg, confirming the presence of CH4 in the lignite deposits. Finally, a SWOT analysis was carried out that shows the strengths and opportunities against the weaknesses and threats of a potential LCBM exploitation in Greece, while also taking into account the social, economic, and environmental nexus. [ABSTRACT FROM AUTHOR]

Entering the coal phase-out era, major priorities of the Greek lignite mining industry are sustainable mine closure, land reclamation, and planning for long-term and sustainable land repurposing scenarios. A holistic and digitally enabled approach to water management could lead to effective strategic planning in the coal phase-out era. This research proposes an integrated approach to evaluate the hydrological profile of a large and complex open pit lignite mining area based on remote sensing data. This framework included processing of satellite images in different bands and an evaluated digital elevation model of an ≈170 km2 area within the Ptolemais Basin, northern Greece, that has extensive surface lignite mining. Several spectral (SMI, RIP, NDVI, NDWI, MNDWI) and topographic (SPI, TWI, LS) indices were investigated, providing details of spatial and temporal variations in the terrestrial water cycle. The analysis permitted the hydrological characteristics of the study area to be mapped with sufficient accuracy. Water bodies, low-flowing streams, water flow direction, vegetation cover, erodible areas, locations with water accumulation, and areas with high soil moisture were identified. A major additional outcome of this research was the construction of flood-susceptibility maps introducing several hydrological parameters in a fuzzy model. The results indicated several areas inside the mining area with high flood susceptibility. These results were subsequently validated through PPC flood event reports during heavy rainfalls and events reported in the National River Basin Management plans. Using high-resolution digital elevation models and remote sensing data processing to identify hazards, like flooding, could improve land use planning and water management strategies. [ABSTRACT FROM AUTHOR]

The lockdown implemented to tackle the spread of the COVID-19 pandemic had a positive impact on air quality. Globally, studies have shown that air pollutant levels decreased temporally during the restriction measures. In this study, we evaluated the impact of COVID-19 restrictions on the air quality of Western Macedonia, Greece, using the concentrations of PM2.5 and PM10 along with meteorological data from the Air Quality Monitoring Stations (AQMS) operated by the Lignite Center of Western Macedonia. In Western Macedonia, previous studies have identified a general reduction in air pollutant levels during the last decade due to the coal phase-out plan for power generation. During the lockdown, the levels of PM2.5 and PM10 decreased further. The reduced emissions from the local mining activities and lignite-fired power plant electricity generation, as well as the weather conditions, seem to contribute to improving air quality. [ABSTRACT FROM AUTHOR]

Green governance is an emerging field, attracting increasing attention from scholars, and governments have been using a range of policy tools to support the transition to green economy, including regulation; financial incentives; voluntary agreements; fiscal measures; public sector procurement; targeting to the deployment of clean energy technologies. Greece has little experience in developing comprehensive long-term energy and climate strategies; thus, it is imperative that governance and analytical underpinning of long-term energy and climate planning be improved, and investment needs and innovative financing instruments for clean energy technologies analysed. To investigate the critical issue of state and entrepreneurship synergies in the framework of the green economy, the present survey employed a web-based questionnaire distributed to 417 small and medium sized enterprises in Western Macedonia from September to December 2021. Data analysis involved an exploratory factor and logistic regression analysis, creating a statistical model with three independent factors describing basic tools of the green economy. The results showed that, in Greece, state environmental governance is often perceived as inadequate, scarce, or constrained by considerations of economic growth. In addition, the research indicates that government policies with regards to environmental law implementation are mainly restricted to the "command and control" regulatory model, which fails to address green innovation and entrepreneurship and promote synergies between the private sector and the State. The analyses demonstrate that if government revenues are heavily reliant on taxes and fines, their capacity to finance structural adjustment programs can be severely affected, and alternative approaches are necessary to achieve the green growth. [ABSTRACT FROM AUTHOR]

Inorganic arsenic (As), a carcinogenic element to humans, is among the most dangerous and flammable substances that coal-burning plants could release. When coal is burned, large portions of arsenic are captured on fly-ash (FA) particles, but it could also contribute significantly to stack emissions of fine fly-ash particles. The aim of this study was to evaluate the oral and respiratory bioaccessibility of arsenic in lignite fly-ash (LFA) samples, and their contribution to total As exposure. Arsenic bioaccessibility fractions via ingestion and inhalation showed significant differences, suggesting the presence of highly soluble As-bearing phases in the studied LFA samples. The bioaccessible As fractions (BAF%) in the simulated gastric fluids (UBM protocol, ISO 17924:2018) showed a range of 45–73%, while the pulmonary bioaccessibility rates in the simulated lung fluid (artificial lung fluid (ALF)) exhibited significantly enhanced levels ranging from 86% to 95%. The obtained arsenic bioaccessibility rates were compared with previous data for multiple environmental matrices such as soil and dust-related materials, revealing that LFA exhibited significantly higher bioaccessibility (%) for the inhalation pathway. [ABSTRACT FROM AUTHOR]

As part of the European Green Deal, the EU aims to become climate-neutral and reach net-zero greenhouse gas emissions by 2050. Lignite has long dominated the electricity system of Greece, providing cheap and reliable energy, given the abundant and low-cost domestic resources at the cost of increased emission. In line with its national and international commitments to climate action, Greece needs to urgently transform its energy system and overcome its technological lock-ins, paving the way for a net-zero emission economy by the mid-century. The Internet of Things plays a significant role in this direction, providing with its technologies the protection of the environment and creating new jobs. The smart bins constitute an interesting proposal for areas in the energy transition. This research work reflects the current situation in the region of Western Macedonia and proposes the smart bin project as a part of the solution in the transition to the post-lignite era. For this purpose, survey research has been conducted in the municipalities of Greece on waste management technology. [ABSTRACT FROM AUTHOR]

This study investigated the indoor environment quality (IEQ) of eight office buildings of interest due to: (a) their location at the region of Western Macedonia, Greece, which is an area characterized by aggravated air quality and is currently in a transition phase because of changes in the energy production strategy to reduce the use of lignite as an energy fuel; and (b) the survey's timing, characterized by new working conditions implemented during the COVID-19 pandemic period. In-site measurements were performed to identify the indoor air pollutants to which the occupants were exposed, while questionnaires were collected regarding the participants' perception of the working environment conditions, indoor air quality, and health symptoms. The statistical analysis results showed that the most-reported health symptoms were headache, dry eyes, and sneezing. The acceptance of new working conditions showed a significant correlation with their overall comfort and health perception. Occupants in offices with higher pollutant concentrations, such as NO2, benzene and toluene, were more likely to report health symptoms. The evaluation of the plausible health risks for the occupants of the buildings with carcinogenic and no-cancer models showed that health problems could exist despite low pollutant concentration levels. [ABSTRACT FROM AUTHOR]

The recent rise in prices of energy, electricity, NG, liquid fuels, combined with geopolitical developments highlight the biggest problem called the "energy transition to the decarbonization of the energy mix". Geopolitical developments and tensions are open to many interpretations. But everyone seems to agree on the energy transition, which is an insurmountable need to stem the climate crisis. It is a condition for our existence on the planet and our country and EU rightly aspire to be the first continent with energy neutrality by 2050. But such a vision will require huge investments of 100 billion till 2050, or 3bil/ year (McKinsey study 2021), and the right strategies and time to be implemented. Like any major structural change, the energy transition has risks such as, the transition to benefit few and create a new energy poverty regime, to make Greece a mere consumer of imported know-how and RES technology. The good development is, firstly transition to help country and its regions to produce high added value technologies in-home and secondly the speed of transition to be the best so that it didn't destroy the existing energy infrastructure long before new ones are ready to replace them. The transition requires a plan to be effective but also to benefit everyone. In this context, the National Energy and Climate Plan (NPEC) which was first formulated in 2018, needs to be reformed and to adopt the new objectives of the European Green Agreement and new strategies and actions in this direction. 1. Energy goals to be tackled in parallel with climate and social goals-easy access to energy for all, elimination of energy poverty 2. Decisively support the potential for strengthening the Energy Democracy through self-production and self-consumption of individuals and communities, while at the same time, the public sector and large companies will have to invest in the new smart technologies for offshore RES, new biofuels, green H2 3. Develop a scientifically proven framework for the promotion of RES and other energy infrastructure in terms of location, environmental impact and biodiversity protection, the faster development of RES, the promotion of smart electricity storage systems and new smart transport infrastructure 5. To pay balanced attention to investments in production of green energy and to savings with generous support in the upgrade of buildings quality, vehicles and in production process 6. The withdrawal of lignite plants should be done in relation to the development of new power production systems so that energy costs to remain at reasonable levels 7. The energy transition requires the involvement and support of the domestic potential universities, research centers, companies and organizations, local authorities so that the energy transition to upgrade the know-how and consequently the added value produced in our country. These are the issues analyzed in this monograph, mainly at the level of the EMTH region and less at the country level. [ABSTRACT FROM AUTHOR]

In the coal phase-out era, achieving sustainable mine closure is significant and prioritizes targets for the mining industry. In this study, the already closed lignite mine of Kardia, North Greece, is investigated, where the mine void left is naturally filled with water. The viability of different repurposing land uses is evaluated, and the natural water level development inside the mine pit is investigated concerning its future uses. The potential for solar photovoltaic (PV) panels developed on mining land and its surrounding area is evaluated in combination with the application of pumped hydro storage (PHS) technology, utilizing pit lake water. Except for electricity system planning, other end-uses that offer multiple, mutually reinforcing and lasting benefits are investigated, such as recreation parks, terrestrial wildlife, aquaculture and agriculture. All repurposing scenarios are evaluated with regard to the spatiotemporal evolution of the lake, by generating forecasts of the dependent variables (rainfall and temperature) via linear (autoregressive integrated moving average) and non-linear (artificial neural network) models. The prediction of pit lake natural development redefines the new land use layout and the land repurposing decisions. This is essential for strategic planning, considering the Greek lignite mining industry's priority regarding transitioning from the current coal-based electricity to renewable energy sources (RES) technology. [ABSTRACT FROM AUTHOR]

Humic acids (HAs) and fulvic acids (FAs) are naturally occurring compounds that influence the fate and transportation of various compounds in the soil. Although HAs and FAs have multiple uses, the reports about their sorbent potential for environmental pollutants are scanty and sparse. In this study, HA and FA, isolated from lignite samples from two mines in Greece, were studied as sorbent materials for three active compounds of plant protection products, namely glyphosate (herbicide), cypermethrin (pyrethroid insecticide), and azoxystrobin (fungicide). According to the results, both HA and FA are promising sorbent materials for these active compounds, with HA achieving better sorption for cypermethrin and azoxystrobin, while FA was found to be more efficient for glyphosate. Moreover, their performance was not compromised by other components commonly found in commercially available herbicides/insecticides/fungicides. In addition, no significant leaching of the sorbed compounds was recorded. Finally, the two materials achieved similar sorption efficiency of the compounds from lake water. [ABSTRACT FROM AUTHOR]

The efficient and sustainable exploitation of energy resources may secure a sustainable economic growth for different regions. However, the peripheries are subject to social, economic, and political constraints, with limited power over energy management. The present work examines regional convergence in exploitation efficiency as synopsized in the GDP generated by energy and minerals in an era of the country's efforts to shut down the lignite-run power production. With the assistance of panel unit root tests, we confirm non convergence of the variables employed, an expected result given the fact that different energy sources are being used for energy production by each different periphery, generating different economic results. In the second stage the methodology employed is a Bayesian vector auto-regressive model (BVAR) with an informative prior on the steady state. The particular methodology outperforms the conventional VAR methodology due to limited degrees of freedom. The Impulse response analysis and the Variance Decomposition analysis confirmed interlinkages among the regions studied. This result implies that the growth generated by different energy and mineral resources are interconnected. Furthermore, the energy transition taking place in Megalopoli and West Macedonia, where the two greatest lignite industries were located until recently, affects the growth generated by energy and resource exploitation for all the other peripheries, according to our findings. The novelty of the present work stands on the concept to detect interlinkages of energy and resources-based growth for the peripheries in Greece with the assistance of the Bayesian Var. The results of the present work are significant, since our findings suggest to policy makers tools to promote economic growth generated by energy based on alternative energy sources, including the environmentally friendly ones, by taking into consideration the interlinkages established by the existing infrastructure and the conventional energy sources used. [ABSTRACT FROM AUTHOR]

The development of three-dimensional geological models has proven to be critical for conceptualizing complex subsurface environments. This is crucial for mining areas due to their various hazards and unstable conditions. Furthermore, three-dimensional (3D) models can be the initial step for the development of numerical models in order to support critical decisions and sustainable mining planning. This paper illustrates the results and the development phases of a 3D geological model within the boundaries of the Kardia lignite deposit in western Macedonia, Greece. It also highlights the usefulness of a Geographic Information System (GIS) methodology in the subsurface geological and hydrogeological analysis regarding the Underground Coal Gasification (UCG) methodology. In addition, the work focuses on the integrated geospatial framework that was developed to support the Coal-to-Liquids Supply Chain (CLSC) integration in unfavorable geological settings. A 3D subsurface geological model of the study area was developed to identify a suitable area for in situ coal conversion and UCG considering criteria related to specific coal thickness and depth. In this context, the suggested integrated geomodelling workflow can positively contribute to the implementation of conventional and innovative mining, saving time and reducing the cost to improve the quality of information needed to support decisions related to UCG implementation. [ABSTRACT FROM AUTHOR]

Lignite plays a dominant role for energy production in Greece, covering over 30% of the demand for electricity generation. Increased energy demand requires, additionally to alternative energy sources, an increase in energy supply from both old and new deposits. Due to the low quality of mined lignite, methods of upgrading in terms of power plants' efficiency and environmental performance need to be applied. In this work, the technique of Selective Size Reduction (SSR) was investigated for three deposits in North Greece, Amynteon, S. Field and Ahlada, in order to improve lignite quality through reduction of its mineral matter content. The variation of the qualitative characteristics of the grain fractions produced by SSR provided useful information on both the suitability of these fractions for combustion in the power plants of the area and the emissions of greenhouse gases. The results have shown that fractions, which were produced from the first stage of crushing, with recovery between 83% and 95%, had lower ash by 16.5–27% than the raw material and were of acceptable quality for combustion in the power plants of the area. Beneficiated fractions could give energy efficiency between 34% and 36% and a reduction in CO2 emissions up to 29%, originated from the decomposition of the carbonate minerals, contained in the mined lignite. As a result, the cost for buying CO2 certificates could be lowered up to 3€/MWh. [ABSTRACT FROM AUTHOR]

This study aims to investigate the lignite ash behavior during combustion for electricity generation and to predict the Ash Fusion Temperatures (AFTs) using ash chemical composition. The studied lignite samples were collected from the area of Ptolemais-Amyntaio at Western Macedonia district of Northwest Greece. Ash chemical composition and its AFTs were determined for all collected samples. Results indicated that the chemical composition of the ash varies significantly and is rich in CaO. AFTs, as well as, slagging and fouling indices derived from the chemical analysis results, showed the tendency for slagging and fouling fluctuates also significantly. The varying chemical composition and AFTs, requires frequent sampling and laboratory analysis. Since AFTs determination is a time-consuming laboratorial procedure, multiple linear regression models, capable to predict AFTs from ash chemical composition, were developed. The adjusted regression coefficients of the prediction models were around to 0.90, while the relative root mean square error was approximately 4%. [ABSTRACT FROM AUTHOR]

Brown coal remains an important energy source in Europe, including countries such as Germany, Poland, the Czech Republic, and Greece. Open-pit mines disturb the environment in terms of air quality, hydrology, and chemical and biological transformations in rivers receiving mine waters. In the present study, we assessed the impact of mine waters from four brown coal open-pit mines on the contamination of river sediments. Chemical analysis included the quantification of 62 elements, including heavy metals (HMs) and rare earth elements (REEs). The contamination of sediments by HMs was evaluated using the contamination factor (CF), the pollution load index (PLI), and the Nemerow multi-factor index (PI). The potential toxic effects of HMs on aquatic organisms were assessed using the potential ecological risk index (PERI). Detailed analysis of chondrite-standardized concentrations of REEs was performed to describe the effects of mine water on their pattern in sediments. Cluster analysis (CA) and principal component analysis (PCA) were employed to divide study sites into groups and to evaluate the combined effect of sediment texture and site location on HMs and REEs in sediments. The study showed that after mine water discharge, there is a decrease in HM and REE concentrations in sediments. The decrease in each element's concentration in sites located 100 m downstream of the discharge was caused by washing out of the finest fractions of sediments by mine waters. [ABSTRACT FROM AUTHOR]

This study processes borehole data from the coal-bearing Kleidi basin (Ptolemais sedimentary basin, Western Macedonia, Greece) to unravel the timeline of the neotectonic configuration of the basin and correlate it with the neotectonics of the broader region. Coal (lignite) deposits preserve faulted sequences, and for this reason they are ideal locations for studying deformation patterns. Lithostratigraphic data acquired by previous investigations revealed a continuous stratigraphic sequence which spans from the Upper Miocene to the Middle Quaternary. These Neogene deposits demonstrate their maximum thickness towards the SE of the basin. Boreholes also revealed that in the subsurface, the basin is actually divided into two separate grabens on either side of a ridge of the alpine basement. Stratigraphic interpolations using the inverse distance algorithm-generated thickness rasters which, through successive derivation, allowed the discovery of normal faults. Repetition of the algorithm using the new structural constraints returned patterns of deformation in the southern part of the Kleidi basin different from those revealed in the northern part. The configuration of the southern part of the Kleidi basin seems to reflect the Late Miocene–Pliocene extensional event. In contrast, configuration of the northern part of the basin is compatible with a later extensional phase in Pliocene‒Quaternary. Both events are manifested in the tectonostratigraphy of the Ptolemais sedimentary basin and the broader area. [ABSTRACT FROM AUTHOR]

Mining operations can drastically affect the stability of nearby areas. A representative case for this has been the Mavropigi mine, a part of an open-pit lignite mining complex in northwestern Greece. Mavropigi is a vast excavation that has reached 150 m depth and has posed severe challenges and stability issues that caused problems in the area. In 2010, noteworthy surface tension cracks appeared near the excavation, leading to extensive monitoring and countermeasures, while various studies were conducted. The present work aims to revisit the case study of Mavropigi from a different than the previous perspectives. Previous studies were based only on continuum approaches, thus understating or ignoring the effect of discontinuities. Nevertheless, the area has an intense tectonic past and faults that interact with soil movements. In this work, advanced, discontinuous numerical modelling through the distinct element method was used to understand better the role of slope-fault interaction in the case study of Mavropigi and assess the faults' effect on the area's response. The results emphasised the influence of faults on ground movements. The fault's existence increases the impact of the mine operations on the surrounding area significantly and intensifies the possibility of structural damage in nearby constructions. The analysis confirms that the open-pit mine's effect on the surrounding area can be amplified under complex geological conditions, in this case, the presence of faults nearly parallel to the slope inclination. [ABSTRACT FROM AUTHOR]

The 2022 energy crisis augmented the European ambition for RES capacity expansion. However, beyond the issue of "how many" renewables, the research question that remains, is which capacity mixes achieve the emissions reduction, renewable integration, and energy autarky targets in a cost-effective way. This paper tries to answer this inquiry supported by two energy models and one decision support model. The analysis focuses on Greece, as an example country which opted for lignite phase out, turning to temporary heavy reliance on natural gas for power generation. The results indicate that even though from the energy and environmental targets' perspective, more wind turbines in the RES capacity mix yield better results, when incorporating the economic point of view, balanced wind and solar mixes enable the achievement of targets in a cost-effective way. The most cost-efficient mixes consist of 50–55% wind and 45–50% solar capacity, with cost per additional percentage of RES share in the generation mix, equal to 40 million €. Nevertheless, in order to materialize them in a timely manner, and limit the short-term dependency on imported gas, permitting simplification, tenders for large-scale projects and incentives for small-scale projects are needed to facilitate accelerated RES deployment. • A modelling framework allowing exploratory RES capacity expansion is presented. • Renewable energy sources and storage capacity mixes are explored. • Balanced wind and solar mixes achieve energy targets economically efficiently. • RES deployment pathways to 2030 based on different perspectives are analyzed. • Further policy action is needed to enable accelerated RES deployment. [ABSTRACT FROM AUTHOR]

The disposal of lignite spoil and tailings poses a major environmental problem in lignite mining sites which is associated with the oxidation of sulfide minerals contained in the primary ore. This process renders acidic effluents. Lignite mining in the Oropos Neogene basin, North Attica, Greece operated since the last century and ceased in the late 1960s. Piles of complex waste material are dispersed close to the mining sites. The high sulfur content and low Net Neutralization Potential, i.e. values < − 20 CaCO3 kg/t in most analyzed waste samples, indicate that the waste is prone to acid generation. The leachates (EN12457) from the lignite spoils showed high concentrations in Ni and Zn exceeding the EU regulatory limits for the non-hazardous wastes. GIS-based geochemical maps of the topsoil showed enrichment in Ni (Cr, V) associated with the regional geogenic enrichment but also local accumulation around the hot spot sites of lignite spoil heaps. [ABSTRACT FROM AUTHOR]

Lignite has long dominated Greece's electricity system, boosting economic growth and energy security, given the abundant domestic resources. In line with its national and international commitments to climate action and sustainable development, the country is currently facing the urgent need to transform its energy system, overcome its technological lock-ins, and transition to a low-carbon economy. Drawing from the need to secure a sustainable transition that considers the impacts of a lignite phase-out on local economies, this study builds upon the Multi-Level Perspective framework and further focuses on the phase-out of the dominant fossil fuel, rather than solely exploring the phase-in of new technologies. By delving into the landscape that established lignite as the mainstream energy resource in Greece, as well as the factors sustaining its dominance despite niche technologies and innovations challenging the regime, we discuss how the envisaged decarbonization can be socially just and effective across multiple sustainability dimensions. [ABSTRACT FROM AUTHOR]

In Greece, 5.8 million tons of municipal solid wastes (MSW) are produced annually, of which 2.47 million tons are bio-wastes. Composting is an alternative treatment of bio-wastes instead of landfill. Two composting plants operate in Greece, one in Ano Liossia (capacity 1,200 tons/day, producing 120 tpd compost) and another in Chania (capacity 70,000 tons/year, producing 20,000 tpa compost). In addition, since 2018, the first integrated waste management plant was set off in the region of Kozani (capacity 120,000 tons/year). An alternative utilization of the compost, produced in the latter plant, was investigated in this study. In particular, instead of using compost as fertilizer, the energy recovery from this bio-waste was attested. Utilization of compost of MSW for energy production purposes has rarely been studied in the literature. Several blends of compost with lignite were prepared and their energetic potential was determined. Proximate analyses and gross calorific value (GCV) determination were conducted. Wastes and biomass- based fuels differ in many ways from fossil fuels. The CLOF sample revealed the highest GCV and the lowest ash content than all analyzed samples. Based on all analytical determinations, compost and its mixtures with lignite could be regarded suitable for energy recovery by thermal processes, such us combustion. Further studies should be done including emission analysis, ash deposition during combustion (corrosion, slagging and fouling). [ABSTRACT FROM AUTHOR]

Global brown coal resources are estimated to be extracted at around 512 million Mg. They are found in over a dozen countries, including primarily: Australia, China, the Czech Republic, Greece, Germany, Poland, Russia, the United States and Turkey. More than 80% of total brown coal production in the EU takes place in: Germany, Poland, Greece and the Czech Republic. This means that the majority of production still uses conventional fuels, including both hard coal and brown coal. Given the current energy needs in the context of brown coal reserves depletion and the impacts of the current climate and energy policies of the EU, it is very important that all new investments in mining and energy complexes based on brown coal resources must be prepared carefully to ensure high production efficiency and minimize negative environmental impacts. This article attempts to solve a problem involving the choice of the location of the opening cut to expose brown coal deposits. Due to the stratified nature of brown coal deposits and the associated open-cast mining technology used in a continuous mining system with bucket wheel excavators, belt conveyor systems and spreaders, the location of the opening cut is not completely random and the number of potential solutions is finite. The multifaceted technical, organizational, economic, social and environmental problems require a holistic approach to this research problem. Such an approach should take the different, often opposing, perspectives of the many stakeholders into account. These issues can be solved using mathematical tools designed for multiple-criteria decision support. With the proposed method, a ranking of alternatives can be created, depending on the predefined location of the opening cut. [ABSTRACT FROM AUTHOR]

Epoxy resin composites filled with pristine and organomodified fly ash were prepared and examined. The fly ash used is CaO-rich due to the origin of lignite from the northern Greece area and the power plants in Kozani. As matrix, the epoxy system with curing agent triethylenetetramine was used. A combination of mechanical stirring and ultrasonication was used for highly dispersed fly ash composites. SEM, FTIR spectroscopy and XRD measurements were used to study dispersion homogeneity, structure, degree of aggregation/agglomeration and interface formation of the matrix with the fly ash particles. The properties E′, E″ and relaxations α-(Tg) and β-(Τβ) of the composites were assessed by DMA. Also, DSC and TGA measurements were used to characterize the thermal properties. Interesting results concerning the effect of the surface organomodification of fly ash on the network formation and the thermomechanical properties of the composites were derived. XRD and FTIR measurements reveal that the functional groups present on the surface of fly ash particles play a dominated role to interface formation. DMA results show that the fly ash surface modification affects the thermodynamic properties of the composites. Additionally, there is evidence showing that the short-scale β-relaxation is also affected by the fly ash surface organomodification. [ABSTRACT FROM AUTHOR]

The underground mining is the only potential way for the utilization of the lignite reserves from an open pit exploitation which could remain unexploited due to high stripping ratios. This paper is dealing with the findings of a pilot scale underground exploitation that was developed in the Prosilio open pit coal mine in Northern Greece. The method used is the room and pillar mining method where the initial entry galleries are driven into the coal seam starting from the surface excavation face, as used in the highwall mining cases. The design of the mining scheme is presented in detail along with the building of the 3D numerical model which simulates the overall development of the pilot mine. The evaluation of the stability conditions is further discussed and analysed with the use of the results of the numerical model and through their validation with the findings and observations of the actual excavation's response. The mine scheme selected exhibited its flexibility in coping with the prevailing conditions and its performance, in terms of the stability conditions attained, further supporting the development of a large scale underground coal excavation. [ABSTRACT FROM AUTHOR]

The idea of the past gestures at an individual or collective's knowledge of events which occurred before the present. Given this spacious conceptual fitting, the past can appear to be a vaguely theorized knowledge space. But, what makes the past? Is it existent only to be manipulated by culture? Or is it a resource which can be located? This essay seeks to explore what the past is in a world rendered in a new materialist spirit. New materialisms challenge scholars to discard the divide between socially construction and materiality. Through the concept of "resource materialities," a genealogy will be constructed which links Science Technology Studies, the subfield STS of the Underground, and media theory together. Based on experience participant observing an archeological dig in Arkadia, Greece, this essay will then proceed to take seriously that the past is not a limitless symbolic resource by investigating two underground resources from which the past can be derived: ancient ceramic fragments and lignite coal deposits. The resulting account of the making of ceramic fragments as a knowledge resource and lignite as an energy resource intends to provide a description of the choreography required to produce these resources. Ultimately, this account provides evidence in support of the concept of "resource materialities." In the critical space following, this paper will discuss problems with the relationality of resources and recommend action. Lastly, this essay concludes by exploring the consequences of this conceptualization of past making. [ABSTRACT FROM AUTHOR]

Lechaion in Corinth, Greece, is the largest ancient port in Greece. Harbour geoarchaeological investigations, based on 14C-dated palaeoenvironmental archives taken from a well-studied inner basin (Basin 3) and a still unknown outer basin (Basin 4), revealed anthropogenic lead excesses starting from the 12th century BCE, associated with brown coal fragments, for the first time discovered in such an ancient archaeological context. Given that historical sources trace the foundation of the port back to the 7th century BCE, these results attest to protohistoric industrial use of the site and push back its chronology by over five centuries. The existence of such ancient port activity not only extends the chronological horizon for harbour activity in the Corinthian area, but also provides new insights for the Late Bronze Age/Early Iron Age (LBA/EIA) transition, including potential trading routes that may have transited through Lechaion, likely spanning across the Gulf of Corinth and possibly even beyond, to western Mediterranean urban centers. • Earliest Evidence of Port-Related lead pollution in Bronze Age Greece • First discovery of brown coal in a stratigraphic context at the end of the Bronze Age • Lechaion's harbour archaeological chronology pushed back by at least 5 centuries • New perspectives on regional economy and trade during the LBA/EIA transition [ABSTRACT FROM AUTHOR]

The determination of the radionuclides of U- and Th-series as well as of K and Cs in soils and waters in a lignite mining area was performed. The measurements in the soils were undertaken by γ-ray spectrometry while the concentrations of U and U in waters and the isotopic ratio U/U were determined by α-ray spectrometry. Slight seasonal variation of the radioactivity was observed with high values in summer and low in winter. The estimated annual radiation dose from soil was lower than the worldwide average whereas in the case of water only one location showed increment in the internal radiation about 18 % of the worldwide average. [ABSTRACT FROM AUTHOR]

An approach for a plan to meet the energy needs of the state of Greece in conjunction with assumed responsibilities to confront global warming is presented. Time series of climate indicators like average temperature and rain precipitation together with energy consumption and CO 2 emissions are examined for stationarity and causality. Predictions of energy needs for the next 25 years and CO 2 emissions are made. With these predictions, production of energy from renewable sources like wind turbines and photovoltaic panels as well as from lignite with CO 2 capture and sequestration systems attached to power-generating units is formulated as an optimization problem with financial and environmental constraints. [ABSTRACT FROM AUTHOR]

Particulate matter (PM) is an important constituent of atmospheric pollution especially in areas under the influence of industrial emissions. Megalopolis is a small city of 10,000 inhabitants located in central Peloponnese in close proximity to three coal opencast mines and two lignite fired power plants. 50 PM 10 samples were collected in Megalopolis during the years 2009–11 for elemental and multivariate analysis. For the elemental analysis PIXE was used as one of the most effective techniques in APM analytical characterization. Altogether, the concentrations of 22 elements ( Z = 11–33), whereas Black Carbon was also determined for each sample using a reflectometer. Factorization software was used (EPA PMF 3.0) for source apportionment analysis. The analysis revealed that major emission sources were soil dust 33% (7.94 ± 0.27 μg/m 3 ), biomass burning 19% (4.43 ± 0.27 μg/m 3 ), road dust 15% (3.63 ± 0.37 μg/m 3 ), power plant emissions 13% (3.01 ± 0.44 μg/m 3 ), traffic 12% (2.82 ± 0.37 μg/m 3 ), and sea spray 8% (1.99 ± 0.41 μg/m 3 ). Wind trajectories have suggested that metals associated with emission from the power plants came mainly from west and were connected with the locations of the lignite mines located in this area. Soil resuspension, road dust and power plant emissions increased during the warm season of the year, while traffic/secondary, sea spray and biomass burning become dominant during the cold season. [ABSTRACT FROM AUTHOR]

During 2009 and 2010 electromagnetic (EM) soundings and a high-resolution magnetic survey were conducted to study the deeper structure of the peat–lignite deposit in the Philippi sub-basin in Northern Greece. The primary intention of investigating the basement structure of the Philippi sub-basin is to propose the ideal location for a deep and continuous paleoclimate drill site. Data were collected along a 12 km transect (NNE–SSW) through the largest extension of the basin from Krinides at the North to Eleftheroupolis at the South. We used a combined set of Radiomagnetotelluric (RMT), Time Domain Electromagnetic (TEM) and Audiomagnetotelluric (AMT) soundings to derive a 2D model of the electrical resistivity distribution versus depth using a joint inversion approach. This model was then cross correlated with a 2D forward model of magnetic anomaly data. The magnetic survey detected strong anomalies in the North that appeared to have been generated by the Philippi granitoid pluton. All three individual data sets support each other and have jointly been analyzed. From this study we yield an asymmetric graben model of the basin structure that shows maximum thickness (ca. 500 m) in the northern part of the basin leading to a reduction of the thickness to the South. The interface between the basin fill and the bedrock ascend steeply in the North. The overall assessment of the deeper basin structure reveals a detachment system that is in good accordance with previous findings. [ABSTRACT FROM AUTHOR]

In this paper, the application of 2D and 3D electrical resistivity methods in geotechnical investigations is explored through a case study in Northern Greece. These two methods were employed at a lignite surface mining operation where fracture zones and discontinuities have been recently observed close to the pit boundaries. The main aim of the geophysical survey was to estimate the inclination of the contact between the Neogene and Schist/Carbonate formations near the southern limits of the pit, as well as to estimate the thickness of the carbonate rocks on top of the Schist formations to evaluate the stability of the southern slopes. Synthetic data were initially generated to help plan an efficient electrical tomography survey, in a region with complex geology and irregular terrain. Three configurations (Wenner-Schlumberger and dipole-dipole or pole-dipole) proved essential in such conditions and helped improving the resolution of the resistivity section. The sections were then calibrated by boreholes. Finally, the geophysical survey provided invaluable data regarding the geometry of the bedrock and possible faults, which was essential for the slope stability calculations. [ABSTRACT FROM AUTHOR]

Abstract: High fluoride concentrations (>8mg/L) in the groundwater of the Plio-Pleistocene sediments are rare; however, this is the case around Aigion town, where teeth fluorosis has been detected since the 80s. Aiming to investigate the origin and the mobility mechanism of fluorine in groundwater and sediments a hydrogeological and geochemical research has been conducted. The hydrogeological research revealed that the Na–HCO3 water type of boreholes aligned along a fault and hosted in the confined aquifers display the higher fluoride content. The unconfined aquifer is mostly dominated by Na–Ca–Mg–HCO3–SO4 water, which displays much lower fluoride concentrations. The most permeable sectors of this aquifer host fresh water of Ca–HCO3 type. The geochemical research revealed significant amount of fluorine in the base of a lignite sequence hosted in the Plio-Pleistocene sediments. The Na–HCO3 water type represents a deep water circulation, proved by its elevated temperature and isotopic composition, carrying a significant load of fluorine and trace elements. During its uprise through faults and the Plio-Pleistocene sediments, part of its load is being deposited on the base of the lignite beds. Leaching experiments and mineralogical determinations in lignite samples revealed enrichment in fluorine at the bottom of the studied lignite sequence, where silicate minerals are dominant. This is due to either, the presence of F-bearing minerals or the presence of organic matter which can also absorb/adsorb fluorine. At the upper part of the sequence, where carbonates prevail, calcite is the major phase indicating the circulation of Ca–ΗCO3-rich fresh water. The Na–Ca–Mg–HCO3–SO4 water type could be considered as mixed water spending longer time in sediments of relatively low permeability and thus, dissolving fluorine and trace elements from clay minerals and organic matter. [Copyright &y& Elsevier]

The Kozani-Ptolemais-Amyntaio basin constitutes the principal coal field of Greece. Approximately 50 % of the total power production of Greece is generated by five power stations operating in the area. Lignite samples, together with the corresponding fly ash and bottom ash were collected, over a period of 3 months, from the power plant of Amyntaio and analyzed for their content in 16 trace elements. The results indicate that Y, Nb, U, Rb, Zr, Ni, Pb, Ba, Zn, Sr, Cu, and Th demonstrate an organic affinity during the combustion of lignite, while V has an inorganic affinity. Three elements (Co, Cr, and Sc) show an intermediate affinity. [ABSTRACT FROM AUTHOR]

Abstract: The energy balance of Greece is strongly dependent on imported oil. The rather late introduction of natural gas has increased the diversity of the energy mix while the share of renewable sources in primary energy supply still needs to increase according to the existing potential. Yet, Greece as one of the most of the EU developed countries encounters a serious task: the need to increase its electricity production of almost 5% per year but at the same time to reduce the CO2 emissions according with the National and International (20-20-20) regulations and allocation plans. Therefore reducing CO2 emissions has become a major priority for national government. In addition, from 2013, there will be the full implementation of the wholesale market in the European Trading Scheme (ETS) which is currently in the last stages of a transition phase.In Greece electricity is mainly generated from lignite, thus making the electricity sector one of the main contributors to GHG emissions with a level above 40% of the total country and higher than the corresponding average of the rest of the EU countries. The possible implementation of Carbon Capture and Storage (CCS) technologies would then become very decisive due to the large use of the lignite as fuel in the country electricity mix. CCS technology has the potential of increasing the flexibility on the achievement greenhouse gas emissions reduction by allowing to continue to use fossil fuels, which still guarantees feasibility in the energy sector. This work presents a roadmap with the modeling of the main technologies associated to the CCS and its implementation into the Greek energy system considering existing National and International Strategic energy plans under different scenarios. The implementation of CCS technologies would have a large influence on the national electrical power production, having the responsibility for large shares of the emissions reduction that can potentially achieved in this sector. For this purpose, TIMES (The Integrated MARKAL/EFOM System) has been chosen as the principal tool for building a techno-economic model of the Greek energy system and its possible evaluation over time (2040). [Copyright &y& Elsevier]

Several lignite samples were collected from boreholes of the Amynteo opencast lignite mine, northern Greece. Organic geochemical characteristics were investigated with the help of various analytical techniques, comprising Gas Chromatography (GC) and Gas-chromatography-Mass Spectrometry (GC-MS), Fourier Transform Infrared Spectroscopy (FTIR), solid-state Nuclear Magnetic Resonance (NMR) and Electron Paramagnetic Resonance (EPR) spectroscopy, petrographical measurements as well as determination of bulk parameters. In the low rank (Rr = 0.21%) Amynteo lignites, huminite is the most abundant maceral group, inertinite has relatively low percentages and liptinite concentrations are rather high. Carbon Preference Index (CPI) reveals the predominance of odd-numbered, long-chained aliphatic hydro-carbons, which is related to a higher terrestrial plant input. The Pr/Ph ratio suggests that reducing conditions were persistent during peatification. Gymnosperm biomarkers such as isoprimarane, abietane, phyllocladane and sandaracopimarane, as well as angiosperm indicators (lupane) and hopanoid compounds with bacterial origin were identified. Analyses of the aromatic fractions revealed the presence of naphthalene, alkyl benzenes and phenols, pyrene, cadalene, cadinane, fluoranthene and dibenzofurane. Based on the FTIR analysis, aliphatic and oxygen containing structures were prevailed over the aromatic moieties. The intensity of the mineral bands was preferentially increased in the FTIR spectra of insoluble material. According to NMR analysis, the aliphatic carbons (0-50 ppm) have higher proportions comparing to aromatic carbons (100-160 ppm). The aromaticity fraction is low (fa = 0.32), as expected for these low rank coals. The presence of free organic radicals and Fe and Mn paramagnetic ions was revealed by EPR. In summary, the combined application of complementary analytical techniques allowed a deep inside into the geochemical characteristics of Amynteo lignites. [ABSTRACT FROM AUTHOR]

Abstract: The mobility of inorganic pollutants is of key concern for a range of industrial and engineering applications of fly ash produced during the combustion of lignite in power generation. This paper investigates the role that the geochemical features of lignite, the ash composition and the partitioning of elements during combustion play in determining leaching properties of lignite fired by-products. The work is based on surveys on three lignite-fired power plants in Greece. Calcium-rich ashes show a high abatement potential for SO2 and other gaseous pollutants. For most elements, the concentrations in the parent lignite and the ashes follow the same trend. Relative enrichments in Cd, Co, Cr, Cu, Mo, Ni, Pb, U, V, W, Zn fingerprint the regional and local geological settings of the lignite basins. The total and leachable concentrations of highly volatile elements are strongly influenced by the interaction with ubiquitous free lime. A broad array of elements is highly insoluble in alkaline ash, while a few oxyanionic-forming elements display substantial mobility. Their mode of occurrence in the parent lignite plays a primary role in the leaching of combustion ashes. The outcomes of this study may assist in addressing the impact of co-firing high ash or high Ca alternative fuels on the leaching properties of combustion by-products. [Copyright &y& Elsevier]

Concentrations of chromium, copper, and lead were determined in soil and plant specimens collected from the area of coal power plant (CPP), A. Dimitrios, the largest CPP in Greece located on the eastern part of Ptolemais basin, Macedonia. Two cultivated plants ( Brassica oleracea var. capitata L. and Zea mays L.) and two non-cultivated plants ( Rumex acetosa L. and Verbascum phlomoides L.) were chosen. The mean heavy metal content in the soil is described in the descending order of Cr>Pb>Cu, while for the plant material, the order was Cr>Cu>Pb. Stations in the vicinity of the CPP showed a distinctly high load of Cr in the soil, whereas for the other metals, no such correlation has been noted. Unexpectedly, high levels of chromium and copper have been found in plant samples of the control station (Grevena) where there is no significant point source of air pollution by particulate matter. In general, roots revealed a higher metal concentration than that of the other plant organs. This is more obvious in B. oleracea var. capitata for all metals studied. Thus, B. oleracea var. capitata possesses the potential for phytoremediation of soils contaminated by metals since this plant is removable together with its roots from the contaminated soil. The most contaminated leaves showed a variation in surface roughness. In V. phlomoides the non-glandular, branched candelabrum-like trichomes on the leaf epidermis effectively trapped and retained a considerable number of particles. In contrast, the waxy cuticle of R. acetosa, which forms a smooth sheet over the epidermal cells, enabled the fast removal of particles by rain or wind. In the case of Z. mays, seeds accumulated the lowest amount of all metals. [ABSTRACT FROM AUTHOR]

Twenty-six lignite samples, from eleven different basins of Greece, were examined as a precursor material to produce activated carbons. Two different experimental procedures were compared, a physical one, using CO2 as the activation agent after carbonization in N2, and a chemical one where lignites impregnated with KOH were thereafter activated. Raw materials and activated products were characterized using a variety of analytical techniques, including ultimate, proximate analysis, and X-ray diffraction. Specific surface areas and pore size distributions were also determined by means of liquid nitrogen isotherms. It was found that the obtained surface area and texture of the activated lignites depend mainly on the nature of the precursor material. The inorganic content had a negative effect on the developed surface area and the pore volume of the CO2 activated carbons. This effect was minor for the KOH activated samples, due to leaching reactions. Regardless of the activation procedure, the samples exhibited a quite similar pore texture consisting of narrow micropores and narrow mesopores. Especially for the KOH activated carbons, the mesopores occupied the higher portion of the total pore volume. [ABSTRACT FROM AUTHOR]

Abstract: The Achlada and Mavropigi lignite deposits in northern Greece provide the main coal source for the next generation of Greek power plants. A comparative characterization of these two lignite deposits is presented, covering the coal rank and the features of the maceral components, based on detailed coal petrography, and the mineralogical and geochemical features of the coals and their ashes, based on XRF and XRD analyses. The data are used to interpret the palaeoenvironments of the lignite beds, as well as factors that may affect their burnout behavior. Both deposits have a lignite C rank. The Mavropigi lignite is mainly a matrix lignite lithotype, whereas the Achlada deposit consists both of matrix and xylite-rich lithotypes. The Achlada lignite was formed in a fluviatile environment, mainly in the abandoned channels of a meandering river system during flooding periods; hence it is enriched in inorganic matter, with ash values >30wt.%. The Mavropigi lignite formed in a reed-marsh environment under limno-telmatic conditions, and displays ash values <30wt.%. The inorganic matter of the two deposits is different in composition due to the contrasting environments, and these differences should be taken into account in optimizing their utilization for power production. A preliminary assessment indicates that the Achlada lignite may have more favorable slagging and fouling properties than the Mavropigi lignite, although experimental studies are required for more solid conclusions to be reached. [ABSTRACT FROM AUTHOR]

Abstract: The effect of glass addition on the processing, physical properties and microstructure of lightweight aggregate made from lignite coal fly ash from the Megalopolis power station in Greece has been investigated. Fly ash/glass mixes have been rapidly sintered at temperatures between 1040 and 1120°C in a rotary furnace, and the density, water absorption and pellet strength determined. Sintering 60:40 fly ash:waste glass mixes at 1120°C produced lightweight aggregate with a mean density of 1.35g/cm3, water absorption of ∼16% and crushing strength of 7.3MPa. Major crystalline phases in sintered materials were quartz (SiO2), albite (NaAlSi3O8), moissanite (SiC), hematite (Fe2O3), wollastonite (CaSiO3) and diopside (CaMg(Si2O6)). The work indicates that Megalopolis fly ash combined with waste glass can be used to manufacture lightweight aggregate with properties comparable to commercially available products. Fly ash and glass are potential resources that are currently waste materials in Greece. The processing involving pelletising and sintering in a rotary kiln is similar to that required for other commercially available lightweight aggregates manufactured from shales, clays and slate, and therefore processing costs are expected to be similar. However, avoiding the costs and environmental impacts associated with importing lightweight aggregate or using pumice makes the production of FA/glass lightweight aggregate a viable option. [Copyright &y& Elsevier]

Abstract: In this paper the development and the application of a fuzzy expert system for the evaluation of the exploitable reserves of multiple-layer lignite deposits, mined by continuous surface methods, is presented. The exploitable reserves are determined decisively by the structure of these deposits, as well as by the limitations of the used mining systems. In practice, thin layers of lignite and interbedded waste layers are grouped under specified assumptions regarding thickness and ash content, to form the exploitable blocks. Moreover, the decision for excavating such a block is made under subjective constraints of different importance, or by using uncertain data. Advances in fuzzy inference systems (FIS) have provided a new approach to the evaluation of multiple-layer lignite deposits. FIS have the ability to handle imprecise, incomplete or linguistically ambiguous information and incorporate them into decision-making processes. In the developed FIS (Mamdani type) new linguistic variables, related to working conditions, operators’ experience and production were involved. The FIS was used for the estimation of the exploitable reserves of the Southern Field lignite deposit, located in the area of Ptolemais (Greece). [Copyright &y& Elsevier]

Abstract: The removal of metal ions (Pb, Cd, Zn, and Cu) from spiked aqueous solutions using four lignite samples (TH2, TH7, MT2, and MT8) of different quality, from different areas in Greece, was investigated. Cation exchange capacity, humic and fulvic acid content, and the BET specific surface area of the samples were determined, proximate and ultimate analyses were conducted and the mineralogy of their low temperature ash was studied. Equilibrium and kinetic studies were performed in batch conditions. Competitive adsorption of the four elements examined was also investigated. It was observed that the four lignite samples were considerably effective in removing Pb, Cd, Zn, and Cu ions from aqueous solutions, with the sample MT2 being the most effective. Among the elements, Pb appeared to have the strongest affinity based on a mass uptake by lignite samples. The same behaviour was observed during the competitive adsorption experiments. Kinetic experiments proved that, in all cases, equilibrium was achieved within 45min. Sorption isotherm studies were conducted by varying the initial concentration of the elements. MATLAB software was used to fit experimental data to Langmuir and Freundlich equations. The data were better fitted to the Langmuir equation. Attempt was made to correlate the adsorption behaviour of the lignite samples with the mineralogy of their low temperature ashes and their content in humic and fulvic acids. [Copyright &y& Elsevier]