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Acid mine drainage (AMD) is one of the most important global causes for polluted water. It occurs in mining areas due to oxidation of sulfide minerals. Depending on hydrological conditions, wetlands are considered suitable for passive treatment of AMD. The aim of the study was to characterize the long-term retention performance of a drained wetland, Briesener Niedermoor, in an iron and sulfate contaminated catchment area. The site is located in the Lusatian lignite mining district, Germany. Hydrological and hydrochemical measurements as well as time series of groundwater and surface water were evaluated and saturation conditions of iron species were determined using Phreeqc Interactive and EH–pH diagrams for the Fe–S–K–O–H system. Progressing peat degradation due to drainage leads to a hydraulic behaviour of the wetland that is more comparable to a rain bog than a fen, and thus to more pronounced oxic conditions. Groundwater feeds the wetland with significant loads of iron and sulfate, which are temporally stored in the wetland. At low surface water discharge, iron is removed and weak acidic pH is buffered by the dominant phase of schwertmannite (Fe8O8(OH)6SO4), usually during summer months. In winter, greater water availability initializes a high source strength from the wetland, that cannot be retarded. Thus, only during summer, there is a retention potential; in winter, the retention potential is not strong enough to prevent an inflow of iron and sulfate. Only a significant rewetting of the wetland may result in a restoration of the retention potential of the wetland Briesener Niedermoor. [ABSTRACT FROM AUTHOR]

The purpose of this study is to determine the groundwater quality of the Gadilam River basin on the basis of Geographic Information Technology (GIS) taxonomy evaluation and risk assessment and statistical analysis. The Gadilam River originates from the district of Kallakurichi and flows into the district of Viluppuram finally confluence at Bay of Bengal in the district of Cuddalore. Groundwater supplies are serving the entire drinking needs of the residents of the Gadilam River basin, and pollution of its toxic elements has been raised in recent years. A total of 120 groundwater samples, excluding reserved forest areas, were obtained from the Gadilam River basin. 50 samples of the Archaean formation, 34 samples of the Quaternary formation, 35 additional Tertiary formation samples and one Cretaceous formation sample. During the monsoon season (Nov. 2018), groundwater samples were taken, which is after the Gaja cyclone's diastral effects. At the time of the sample acquisition, pH, EC and TDS were measured using the Elico field kit. Using the Atomic Absorption Spectrometer, the heavy metals Zn, Cr, Cu, Pb, Co, Fe, Mn and Ni were analyzed. The spatial distribution maps of the GIS shows that in all the samples the concentrations of chromium, lead, cobalt, nickel are high (above the permitted limit). In 93.40%of the area, the manganese concentrations are higher, dropping under the unauthorized cap for human use in compliance with WHO requirements. In addition, statistical analysis indicates that groundwater pollution of the roots of Pb and Cr is from foreign sources and geogenic origin cannot be avoided. The country's rocks and industrial effluents can trigger Zn and Co. The anthropogenic operations may be due to Cu. The taxonomy diagram showing all groundwater samples is classified as 'near neutral high metal.' Industrial waste, household sewage, has boosted the emission of heavy metals. Groundwater risk assessment study of heavy metals using SMCE approach reveals that dense residential area in the Archaean formation, lineaments intersection with river portion and sea shore area in Quaternary formation and nearby SIPCOT industry and Lignite mining area in Tertiary formation is noted in the 'Extreme risk dangerous' areas. [ABSTRACT FROM AUTHOR]

Forecast model for soil movements caused by dewatering – Development and previous application in the Rhenish lignite mining area A model based on soil mechanics principles was developed to map current soil movements and to forecast further soil movements caused by dewatering. To date, the model has been applied at more than 30 points in the Rhenish lignite mining area, both within the framework of the evidence required under mining law by RWE Power AG and within the framework of environmentally relevant investigations by the Landesamt für Natur, Umwelt und Verbraucherschutz NRW. The soil movement behaviour observed and measured since the 1950s can be mapped qualitatively and quantitatively very well and future soil movements can be forecasted based on this. Uncertainties that still exist with regard to the uplift behaviour of cohesive soils can be further reduced by continuous measurements and recalibration, thus continuously improving the forecast. Furthermore, the model can be easily adapted to new boundary conditions, e.g. as a result of the coal phase‐out decided by the Federal Government, and can also in principle be transferred to other lignite mining areas or adapted for other applications. [ABSTRACT FROM AUTHOR]

The article describes the application of the artificial ground freezing method for sinking the shafts of the now-defunct Bach lignite mine in Cybinka (Lubusz Province). It was probably the only instance of such a procedure in lignite mining in Poland. The text presents the origins of this method, patented in 1863 by F.H. Poetsch, and the examples of mines where this technique was implemented, with particular emphasis on the Polish lands. The course of freezing the Bach V and Bach VI shafts and the problems that occurred at the very beginning of their exploitation are described in detail. As a result of errors made during the drilling of freezing holes, both shafts were completely flooded with groundwater. The paper also aims to analyse the causes of this mining disaster. [ABSTRACT FROM AUTHOR]

The current study attempts to characterize the samples from Kapurdi, Giral and Sonari lignite mines of Barmer Basin within Rajasthan Tertiary Lignite deposits using petrographic and geochemical techniques. The data generated has been studied in order to better understand the geochemical properties, hydrocarbon potential, depositional environment and paleo-climatic condition of the paleo-mires of these lignites. The proximate analysis of the samples reveals that the average ash content of the Barmer Basin is 11.93 %, the average moisture content is 14.08 %, average volatile matter yield is 42.03 % and the average fixed carbon is 31.95 %, which suggesting that the physical properties of lignite are dominated by volatile matter on dry basis. The ultimate investigation reveals the chemical properties of the lignite with the average carbon content found to be 58.79 wt%, hydrogen value 3.83 wt%, nitrogen percentage 1.60 wt% and sulphur content 2.75 wt%. This clearly indicates high sulphur concentration in Barmer lignite deposits, based on dry basis. The lignite samples subjected to FTIR studies identified aliphatic C H group, aromatic C O group, hydroxyl O H and Aldehyde HC O group. The Rock-Eval pyrolysis studies have been carried out to know the coalification profile of the deposits and hydrocarbon source rock potential. The varying behaviour between brown coal lithotype are primarily reflected by changes in oxygen index values, whereas hydrogen index values demonstrate a more pronounced correlation with coal type rather than the level of maturation. The results show the average total organic carbon (TOC) 47.29 %, S 1 peak 2.18 mg HC/g, S 2 peak 88.70 mg HC/g, S 3 peak 19.22 % mg CO 2 /g, T max 410.53 °C, hydrogen index 219.2 mg HC/g TOC and oxygen index 46.33 mg CO 2 /g TOC. According to petrographic investigations, the huminite macerals dominate followed by liptinite and inertinite maceral groups in mineral matter-free basis. In all the three different lignite mines, the huminite group dominates with preserved sub-maceral ulminite indicating less transformation of structured plant matter. Reconstruction of depositional environment and paleo-climatic condition of the paleo-mires has been attempted by using organic petrographic indices. The high gelification index (GI) and low tissue preservation index (TPI) values suggest a prolonged wet environment during the decomposition of organic material, accompanied by a gradual subsidence process. The ground water influence index (GWI) and vegetation index (VI) denote ombrotrophic to mesotrophic hydrological conditions of basin at the time of deposition. • The study provides lignite's physical and chemical properties. • Rock-Eval pyrolysis provides coalification profile and hydrocarbon potential. • Petrographic analysis indicates the dominance of huminite macerals in the lignite. • Pyrite in lignite indicates anoxic conditions and marine influence during lignite evolution. • Barmer Basin lignites are thermally immature and have good hydrocarbon potential. [ABSTRACT FROM AUTHOR]

Land slide in an opencast mine is a common phenomenon. It not only obstructs the mining operation but also incurs heavy economic losses as a cost of the removal of debris to facilitate mining work. Often, it also leads to the loss of valuable human lives. This problem is attributed mainly due to groundwater movement within the mines. Most suitable solution to this problem lies in the delineation of potential groundwater zones in order to pumping out groundwater to keep the sub-surface geological formations in almost dry land slide zone. Tadkeshwar lignite mine, located in Surat district of Gujarat state, India is one such mine which is facing land slide problem because of movement of groundwater in a segment of the mine. This paper describes the results of electrical resistivity tomography (ERT) carried out in the mine lease area to locate groundwater potential zones. These results are then used for the selection of suitable sites to drill bore wells for dewatering in and around land slide zone in order to prevent landslide. [ABSTRACT FROM AUTHOR]

Clay smears in normal faults can form seals for hydrocarbons and groundwater, and their prediction in the subsurface is an important problem in applied and basic geoscience. However, neither their complex 3-D structure, nor their processes of formation or destruction are well understood, and outcrop studies to date are mainly 2-D. We present a 3-D study of an excavated normal fault with clay smear, together with both source layers, in unlithified sand and clay of the Hambach open-cast lignite mine in Germany. The faults formed at a depth of 150 m, and have shale gouge ratios between 0.1 and 0.3. The fault zones are layered, with sheared sand, sheared clay and tectonically mixed sand-clay gouge. The thickness of clay smears in two excavated fault zones of 1.8 and 3.8m² is approximately log-normal, with values between 5 mm and 5 cm, without holes. The 3-D thickness distribution is heterogeneous. We show that clay smears are strongly affected by R and R' shears, mostly at the footwall side. These shears can locally cross and offset clay smears, forming holes in the clay smear, while thinning of the clay smear by shearing in the fault core is less important. The thinnest parts of the clay smears are often located close to source layer cut-offs. Locally, the clay smear consists of overlapping patches of sheared clay, separated by sheared sand. More commonly, it is one amalgamated zone of sheared sand and clay. A microscopic study of fault-zone samples shows that grain-scale mixing can lead to thickening of the low permeability smears, which may lead to resealing of holes. [ABSTRACT FROM AUTHOR]

Problems with lowering of water table are common all over the world. Intensive pumping of water from aquifers for consumption, irrigation, industrial or mining purposes often causes groundwater depletion and results in the formation of cone of depression. This can severely decrease water pressure, even over vast areas, and can create severe problems such as degradation of agriculture or natural environment sometimes depriving people and animals of water supply. In this paper, the authors present a method for determining the area of influence of a groundwater depression cone resulting from prolonged drainage, by means of satellite images in optical, near infrared and thermal infrared bands from TM sensor (Thematic Mapper) and ETM+ sensor (Enhanced Thematic Mapper +) placed on Landsat 5 and Landsat 7 satellites. The research area was Szczercowska Valley (Pol. Kotlina Szczercowska), Central Poland, located within a range of influence of a groundwater drainage system of the lignite coal mine in Belchatow. It is the biggest lignite coal mine in Poland and one of the largest in Europe exerting an enormous impact on the environment. The main method of satellite data analysis for determining soil moisture, was the so-called triangle method. This method, based on TVDI (Temperature Vegetation Dryness Index) was supported by additional spatial analysis including ordinary kriging used in order to combine fragmentary information obtained from areas covered by meadows. The results obtained are encouraging and confirm the usefulness of the triangle method not only for soil moisture determination but also for assessment of the temporal and spatial changes in the area influenced by the groundwater depression cone. The range of impact of the groundwater depression cone determined by means of above-described remote sensing analysis shows good agreement with that determined by ground measurements. The developed satellite method is much faster and cheaper than in-situ measurements, and allows for systematic monitoring of the vast area in the vicinity of Belchatow lignite mine. Besides, this method could be useful as a helper in in-situ measurement allowing a significant reduction of the number of in-situ measurements by performing them only within problematic areas. Hence, the triangle method can be used as an effective supplement to field measurements. Although the research area is located in Poland, in the vicinity of lignite mine, the method of observation of depression cones provided in this study is universal and effective, and therefore could also be useful to an international audience. [ABSTRACT FROM AUTHOR]

Lignite deposits of Bikaner-Nagaur basin, lie in Jayal block of Nagaur district of Rajasthan. The sandstone, shale, claystone and lignite sequence repeats at regular intervals. The lignite mines presently 30-40 meters deep below ground level filled up above lignite seams with the brine whenever interruption in dewatering occurs. The Tertiary formations hosting lignite deposits are mined by open cast mining having normal benching heights; along with continuous pumping out of saline groundwater by a battery of tube wells. Liithological samples from Kasnau yielded good assemblage of palynofossils of early Eocene age. The peculiarity of occurrences of rounded boulders and cobbles in near by area are indicative of a Palaeo-channel which could be related to some old river channel like Saraswati or its tributary Drishadwati. [ABSTRACT FROM AUTHOR]

Copyright of Mining Report is the property of GVSt,GesamtverbandSteinkohlee.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

On February 2011, two landslides took place in Çöllolar the lignite mine within 1 week. The first landslide, which occurred at the permanent slopes located in the southwest of the pit, resulted in one fatality and temporary cessation of production activities. Four days later, a second landslide, larger than the first, occurred in the temporary production slopes (northeast of the same pit). The second landslide, with a volume of about 50 Mm soil, resulted in ten fatalities including geological and mining engineers. In the present study, a series of numerical analyses were carried out using the finite element method and the limit equilibrium method to evaluate factors that caused the landslides. Three different depths were considered for the level of ground water table. The safety factors in the permanent slopes were found to be around one or less even if the level of groundwater table was relatively low. It was concluded that the first landslide at the permanent slopes happened possibly due to the high level of water table which was continuously fed by the Hurman River. On the other hand, despite relatively higher safety factors, the failure of the production slopes was triggered probably due to instability introduced by the first landslide. [ABSTRACT FROM AUTHOR]

• We investigated DOC production and losses in agro-managed temperate fens. • High seasonal fluctuation of DOC concentration in groundwater and soils. • Weather conditions are crucial determinants for DOC variability. • Open-pit mining did not affect short-term DOC production. Disturbance to peatlands via climate change and human activity affects their carbon storage potential. This leads to the loss of a significant part of their carbon stock as dissolved organic carbon (DOC) via fluvial pathways. The grassland fens in the Grójec Valley, Poland are dominated by organic soils, which degraded as a consequence of long-term agricultural use. Here, we assessed the seasonality of DOC production in these soils and its release to groundwater. To the best of our knowledge, this the first example of a seasonal DOC production assessment in agricultural fen soils that have also been affected by open-pit mining. All designated sites in the study area were under agricultural use (grasslands) and two of the sites were also located within predicted depression cones, caused by lignite mining operations. Samples were taken during the growing season (March–October) over three consecutive years 2017–2019. The observed DOC concentrations in the soils (1.00–4.99 g kg−1) and water (18.8–73.4 mg l−1) were similar to other studies conducted on agro-managed fens in central Europe. We found that the highest labile carbon concentrations in the soils and water occurred after dry/warm periods in the study area. However, the observed seasonal variability was especially evident in DOC concentrations in the groundwater, which indicates its dependence on weather conditions. Our preliminary assumption that DOC production and release would be greatest in sites located within predicted depression cones was not confirmed in this study. Overall, our results indicate that temperate grassland fens are endangered if future climate warming results in soil carbon losses via soil water deficiency and further acceleration of organic matter decomposition. [ABSTRACT FROM AUTHOR]

Oxygen and hydrogen stable isotopic compositions of precipitation, lake water and groundwater were used to quantitatively asses the water budget related to water inflow and water loss in natural lakes, and mixing between lake water and aquifer groundwater in a mining area of the Lignite Mine Konin, central Poland. While the isotopic composition of precipitation showed large seasonal variations (δ2H from−140 to+13 ‰ and δ18O from−19.3 to+7.6 ‰), the lake waters were variously affected by evaporation (δ2H from−44 to−21 ‰ and δ18O from−5.2 to−1.7 ‰) and the groundwater showed varying contribution from mixing with surface water (δ2H from−75 to−39 ‰ and δ18O from−10.4 to−4.8 ‰). The lake water budget was estimated using a Craig–Gordon model and isotopic mass balance constraint, which enabled us to identify various water sources and to quantify inflow and outflow for each lake. Moreover, we documented that a variable recharge of lake water into the Tertiary aquifer was dependent on mining drainage intensity. A comparison of coupled δ2H–δ18O data with hydrogeological results indicated better precision of the δ2H-based calculations. [ABSTRACT FROM AUTHOR]

The article focuses on the mining area of the Hambach opencast in Germany that lies in the centre of the Rhenish lignite area initiated in 1978. It notes the development of the Union 103 lignite underground project near the township of Morschenich of Hambach opencast mine aimed at achieving a largely independent raw material supply for the country. The characteristics of the mine workings in the said project including surface facilities, shafts and underground water system are also emphasized.

Copyright of Annals of 'Constantin Brancusi' University of Targu-Jiu. Engineering Series / Analele Universităţii Constantin Brâncuşi din Târgu-Jiu. Seria Inginerie is the property of Universitatea Constantin Brancusi din Targu-Jiu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

PERSEAS research team in cooperation with Public Power Corporation (PPC-DEH) of Greece, installed, operates and maintains four R.E.MO.S. Monitoring telemetric stations (MTS) in the plant of the mines of Kardia and Notio Pedio in Western Macedonia, Greece. Two of the MTS monitor the stagnant surface waters in the bottom-pit of the mines, while the other two monitor ground water in specific well positions. The monitoring parameters are water temperature - Tw, electrical conductivity of water - ECw, pH, water level - H and discharge - Q. This study is focused on: a) The goodness-of-fit test, of the time series data to the normal distribution, using the Kolmogorov- Smirnov (KS) [1], non-parametric test of hypotheses; b) The assessment of the water quality and quantity monitoring daily data, based on approximately 2.5 years of monitoring period (2007-2009); c) The trend existence for the monitoring parameters, according to the method of the least squares estimator, apart from temperatures which present periodicity; d) The best fitting of a trend line using test statistics and student's distribution. It was found that "R.E.MO.S." network of water quality and quantity parameters in Western Macedonia lignite mines, is operating properly and serious technical problems have been confronted successfully. [ABSTRACT FROM AUTHOR]

The oxidation of pyrite results in sulphate concentrations from 1,300 to 2,000 mg/l in the dump water of the open cast mine Inden, which is located in Germany. Under near-neutral pH and reduced redox conditions, precipitation of siderite (FeCO) retains up to 85% of the pre-liberated ferrous iron, so that iron concentrations in the dump water are relatively low as compared to the concentrations of sulphate. The highly mineralised dump water will enter the aquifer system northwards of Inden during the next centuries. This area is used intensely for water extraction. Model calculations show that there will be no problem of acidification in the adjacent aquifer system and, therefore, no problem of high heavy metal concentrations during the next centuries. The most important problem will be high sulphate concentrations in the groundwater. Besides dispersion and diffusion, there are no chemical mechanisms that lower the sulphate concentrations downstream. On the basis of the simulations, sulphate plumes of about 1-2 km in width and up to 15 km in length are expected. Within the core of these plumes, sulphate concentrations will be above the drinking water limits. [ABSTRACT FROM AUTHOR]

In the paper there are described the geology and hydro-geological conditions of the lignite deposits of Oltenia zone, the methods used for the dewatering of the aquiferous horizons, techno-logy for the drill hole completion without filter for the tension release of the collecting aquiferous horizon, the open casts where they have been used and the results obtained throughout the time. [ABSTRACT FROM AUTHOR]

Water conservation and water management practices have been adopted at Neyveli to ensure proper hydrologic balance. These practices are important because ground water pumping is a prerequisite for lignite mining in the Neyveli basin. This paper delineates some of these practices and the scientific studies undertaken by the Neyveli Lignite Corporation to develop and implement them. Optimal water utilization would be achieved by maintaining the ground water recharge (input) and the ground water extraction (output) ratio in the basin. [ABSTRACT FROM AUTHOR]

Dewatering in deep opencast mines generally focuses on extraction of seepage water from the phreatic zones above the ore/mineral deposits and storm water that collects in mine pits. But at the Neyveli lignite deposit in the Cuddalore District, there was a danger of the mine floor bursting due to the hydrostatic head pressures in the underlying thick confined aquifers, a problem not previously encountered anywhere in India. Hydrogeological studies established the feasibility of mining the lignite by maintaining a constant cone of depression (pressure relief) in the surrounding aquifers below the mine by continuous pumping through a pre-planned network of wells. This depressurizing process had to be designed to tackle multi-layered confined aquifers and water table conditions. This paper traces the multi-faceted evolution in developments to control ground water at the Neyveli Mines. [ABSTRACT FROM AUTHOR]

In Neyveli, Tamilnadu, India, a deep-seated multi-layered confined aquifer is being continuously pumped to permit safe mining of lignite. This paper highlights the various ground water recharge studies undertaken to quantify the potential of recharging the Neyveli hydrogeological basin to maintain the regional ground water balance. GIS studies were used to analyze artificial recharge in the Neyveli basin, commencing from the deep water table zone (recharge area) in the western upland part, the confined aquifer zone closer to the active mining area, and the confined zone further away in the east, down-dip and closer to the coast. [ABSTRACT FROM AUTHOR]

Abstract: In the Lower Lusatian lignite mining district, large areas have been mined and recultivated. An even larger area has been affected by groundwater lowering. The specific characteristics of catchments disturbed by lignite mining are presented for the Schlabendorf/Seese region, where a close relation between water issues and open-cast lignite mining exists. In general, this relationship starts prior to mining and persists even after the land is reclaimed. The most obvious feature of this post-mining landscape is the large number of forming post-mining lakes. A further feature is the recovery of the groundwater table. Dry streams and springs now are starting to flow again, and areas with a formerly deep groundwater table are now directly influenced by rising groundwater. The disturbance causes various acidification phenomena. The aeration of pyrite-bearing material leads to a drastic deterioration of the groundwater quality, which affects receiving streams and lakes. Thus there is the tendency for some parts of post-mining lakes to become acid. Additionally, in the marginal areas of the groundwater recovery, acidification of streams occurs, causing water quality problems in ponds and lakes located downstream. The development of each individual water body with respect to water quantity and quality depends on its specific hydrogeological and hydrological setting. The region is experiencing dynamic changes, and shows that the future development of the post-mining catchments is difficult to predict. [Copyright &y& Elsevier]

Mining activities in the Rhineland lignite mining area in Germany have led to increased mineralisation and acidity of groundwater due to the oxidation of sulfide minerals. The potential benefit of adding alkaline substances (crushed limestone and a mixture of fly ash and crushed limestone) to the overburden spoil was investigated using laboratory columns and pilot-scale field experiments. The latter tests were each conducted with 13 metric tons of overburden. A considerable improvement in water quality (decreased sulfate, iron, trace elements and acidity) was found in both scales of experiment. Similar improvements are expected in the limed overburden dump of the Garzweiler lignite mine. [ABSTRACT FROM AUTHOR]

Heavy rainfall and slow movement of the cyclone Tamara caused record floods in May 2014 across Serbia. As a result, levees were breached, a large portion of the open-pit lignite mine Tamnava–West Field was flooded and a flood lake was created. Due to an active hydraulic link with aquifers, the water table rose and the amount of stored groundwater increased dramatically. Based on in situ surveys and hydrodynamic modeling, three distinct periods of the groundwater regime are identified and the flood impact on the groundwater regime in the study area quantified. The paper describes correlations between flood lake water levels and the water table, and shows calculated groundwater volumes as a result of flooding and those of residual groundwater after dewatering of the open-pit mine. This extreme historical flood in Serbia had disastrous economic and social consequences, given that the studied open-pit mine supports more than 25% of Serbia’s electric power output. The assessment of the flood wave and its impact on the groundwater regime is an important example of the groundwater system response to an extreme rainfall and flood event. The paper presents the operating algorithm which leads to the approach of assessing the impact of floods on increasing the volume of accumulated groundwater. The paper presents a developed methodology for groundwater level status exploration in the wider area of open-pit mine Tamnava-West Field during the flooding that occurred in this mine. The developed method encompasses the creation and calibration of a groundwater model and fate and transport model for groundwater state prior to the flooding, a verification model for groundwater level during the extreme floods and a control verification model which corresponds to the period after the passing of the flood wave. The applied operational algorithm offers reliable bases for adopting a strategy for groundwater management during floods. [ABSTRACT FROM AUTHOR]