The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Paul L. Younger - One of the best experts on this subject based on the ideXlab platform.
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An object-oriented particle tracking code for pyrite oxidation and pollutant transport in mine Spoil Heaps
Journal of Hydroinformatics, 2007Co-Authors: Cj Gandy, Paul L. YoungerAbstract:A physically based contaminant transport model, POTOMAC (Pyrite Oxidation products Transport: Object-oriented Model for Abandoned Colliery sites), has been developed to simulate the pyrite oxidation process in mine Spoil Heaps and the subsequent transport of the reaction products. This is believed to represent the first particle tracking model created using object-oriented technology and has proved capable of simulating the large time scales (on the order of centuries) required for this application. The model conceptualises a Spoil Heap as a series of ‘columns’, each representing a portion of the unsaturated zone, where active weathering and precipitation of secondary minerals takes place. The columns are then connected to a saturated zone, beneath the water table, where the contaminants are transported to the Heap discharge. A form of particle tracking, the ‘random walk method’, is used to transport both the oxidant, oxygen, and the products, ferrous iron and sulfate. The subsequent oxidation of ferrous iron and precipitation of ferric oxyhydroxide is incorporated to provide an iron ‘sink’, where iron is effectively removed from the transport process. The application of POTOMAC to a case study, the Morrison Busty Spoil Heap in County Durham, UK, has produced encouraging results.
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effective remediation of grossly polluted acidic and metal rich Spoil Heap drainage using a novel low cost permeable reactive barrier in northumberland uk
Environmental Pollution, 2006Co-Authors: A P Jarvis, Patrick Orme, Mahmoud Moustafa, Paul L. YoungerAbstract:Abstract A permeable reactive barrier (PRB) for remediation of coal Spoil Heap drainage in Northumberland, UK, is described. The drainage has typical chemical characteristics of pH 1400 mg/L as CaCO 3 , [Fe] > 300 mg/L, [Mn] > 165 mg/L, [Al] > 100 mg/L and [SO 4 ] > 6500 mg/L. During 2 years of operation the PRB has typically removed 50% of the iron and 40% of the sulphate from this subsurface Spoil drainage. Bacterial sulphate reduction appears to be a key process of this remediation. Treatment of the effluent from the PRB results in further attenuation; overall reductions in iron and sulphate concentrations are 95% and 67% respectively, and acidity concentration is reduced by an order of magnitude. The mechanisms of attenuation of these, and other, contaminants in the drainage are discussed. Future research and operational objectives for this novel, low-cost, treatment system are also outlined.
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growth of phragmites australis cav trin ex steudel in mine water treatment wetlands effects of metal and nutrient uptake
Environmental Pollution, 2004Co-Authors: Lesley C Batty, Paul L. YoungerAbstract:The abandoned mine of Shilbottle Colliery, Northumberland, UK is an example of acidic Spoil Heap discharge that contains elevated levels of many metals. Aerobic wetlands planted with the common reed, Phragmites australis, were constructed at the site to treat surface runoff from the Spoil Heap. The presence of a perched water table within the Spoil Heap resulted in the lower wetlands receiving acidic metal contaminated water from within the Spoil Heap while the upper wetland receives alkaline, uncontaminated surface runoff from the revegetated Spoil. This unique situation enabled the comparison of metal uptake and growth of plants used in treatment schemes in two cognate wetlands. Results indicated a significant difference in plant growth between the two wetlands in terms of shoot height and seed production. Analyses of metal and nutrient concentrations within plant tissues provided the basis for three hypotheses to explain these differences: (i) the toxic effects of high levels of metals in shoot tissues, (ii) the inhibition of Ca (an essential nutrient) uptake by the presence of metals and H+ ions, and (iii) low concentrations of bioavailable nitrogen sources resulting in nitrogen deficiency. This has important implications for the engineering of constructed wetlands in terms of the potential success of plant establishment and vegetation development.
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Effect of a Clay Cap on oxidation of Pyrite withinMine Spoil
Quarterly Journal of Engineering Geology and Hydrogeology, 2003Co-Authors: Cj Gandy, Paul L. YoungerAbstract:Polluted discharges from perched groundwater systems in mine Spoil Heaps are a significant cause of water pollution in many parts of the world. Oxidative weathering and dissolution of sulphide minerals, particularly pyrite, which is widespread within Coal Measures strata, frequently results in surface water discharges rich in iron, sulphate, aluminium and acidity. Reducing the availability of oxygen to mineral surfaces should limit the amount of oxidation taking place and, therefore, reduce the concentrationsof contaminants in percolating waters. A pollutant-generating portion of a Spoil Heap in County Durham, UK, was covered with a clay cap in February 1998, and subsequent monitoring has shown a significant reduction in the concentrations of contaminants in the water discharging from the Spoil Heap to a nearby constructed wetland treatment system. This allows the wetland to receive better quality water, thereby extending its future life and making it even more sustainable.
Mahmoud Moustafa - One of the best experts on this subject based on the ideXlab platform.
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Assessing perched aquifer vulnerability using modified DRASTIC: a case study of colliery waste in north-east England (UK)
Hydrogeology Journal, 2019Co-Authors: Mahmoud MoustafaAbstract:DRASTIC is a commonly used approach for delineating areas that are vulnerable to contamination. This study examines the suitability of DRASTIC for evaluating the vulnerability of groundwater inside a colliery Spoil-Heap to contamination. The standard DRASTIC approach was modified according to the environmental conditions of Spoil Heaps that introduce contaminants to the environment. The parameter layers used in DRASTIC are depth to water, net recharge, aquifer media, soil media, topography, impact of the vadose zone and hydraulic conductivity. The values of the hydrogeological parameters used in DRASTIC were obtained from eight exploration boreholes drilled in a Spoil Heap in Northumberland, England (UK). The estimated DRASTIC vulnerability score was then mapped. Sensitivity analysis of the DRASTIC parameters and validation were implemented. The results indicated that, contrary to the DRASTIC assumptions, the contaminants were not introduced at ground surface, but instead were mainly initiated in the soil, vadose and aquifer zones. Consequently, these zones should receive high values of DRASTIC weights and rates. Zones characterized by low permeability and low recharge represent contaminant hot spots inside the Spoil Heap, and both parameters in these areas should also receive high values of weights and rates. Sensitivity analysis revealed that the soil, vadose zone, aquifer media, hydraulic conductivity and net recharge are the most controlling parameters with respect to vulnerability. The produced vulnerability map has a high degree of compatibility with the measured contaminant concentrations in the Spoil. Thus, the standard DRASTIC approach should be modified before its application to mining waste Spoil Heaps.
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Deconvolution analysis of slug test in engineered treatment system for contaminated groundwater
Modeling Earth Systems and Environment, 2018Co-Authors: Mahmoud MoustafaAbstract:Most current approaches for analysis overdamp slug test require parameters that are highly uncertain. Applying these approaches could give an error in the estimated hydraulic conductivity. A novel permeable reactive barrier (PRB) was designed and installed to treat contaminated groundwater seeps from Spoil Heap contaminate natural water stream. Accurate estimation of hydraulic conductivity of the reactive media placed inside thePRB is a vital for evaluating treatment process. Current work examines deconvolution, and traditional approaches to analyze slug test in a reactive media where precipitation and dissolution process are prevailing. A number of slug and pumping tests were carried out in the same boreholes drilled inside the reactive media. The slug testes were analyzed with traditional and deconvolution approaches. The hydraulic conductivity (K) values obtained from both approaches were compared with that from pumping test. (K) values from deconvolution approach could be comparable to that from pumping test if saturated thickness is the same at the test time. Deconvolution analysis for slug tests overcome drawbacks of tradtional analysis of slug test as it does not use uncertain parameters in the analysis. Deconvolution analysis for slug tests carried out in reactive media is recommended over traditional approaches to have better estimate of reactive media permeability which changes over time due to precipitation and dissolution processes.
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Evaluating drastic method for assessing Spoil Heap groundwater contamination vulnerability
International Journal on Environmental Sciences, 2014Co-Authors: Mahmoud MoustafaAbstract:DRASTIC method used to assess groundwater contamination vulnerability based on different factors controlling contaminates transport at ground surface from agriculture and industrial activities to groundwater water table. This work evaluates DRASTIC method for assessing groundwater contamination vulnerability from acid water generation due to pyrite oxidation in Spoil Heap. The DRASTIC method assumptions and the factors used in this method were discussed to examine its suitability for assessing contamination vulnerability from acidic water in the Spoil Heap. Factors used in DRASTIC approach, depth to water, rainfall, aquifer media, surface topography, hydraulic gradient and hydraulic conductivities were collected from monitoring boreholes network in the Spoil Heap located in northern England. Not all drastic factors concepts applicable to Spoil Heap cases. DRASTIC method may be not suitable for assessing vulnerability to contamination due to acid water generation from Spoil Heap and it may give highly uncertain results if applied in Spoil Heap case.
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effective remediation of grossly polluted acidic and metal rich Spoil Heap drainage using a novel low cost permeable reactive barrier in northumberland uk
Environmental Pollution, 2006Co-Authors: A P Jarvis, Patrick Orme, Mahmoud Moustafa, Paul L. YoungerAbstract:Abstract A permeable reactive barrier (PRB) for remediation of coal Spoil Heap drainage in Northumberland, UK, is described. The drainage has typical chemical characteristics of pH 1400 mg/L as CaCO 3 , [Fe] > 300 mg/L, [Mn] > 165 mg/L, [Al] > 100 mg/L and [SO 4 ] > 6500 mg/L. During 2 years of operation the PRB has typically removed 50% of the iron and 40% of the sulphate from this subsurface Spoil drainage. Bacterial sulphate reduction appears to be a key process of this remediation. Treatment of the effluent from the PRB results in further attenuation; overall reductions in iron and sulphate concentrations are 95% and 67% respectively, and acidity concentration is reduced by an order of magnitude. The mechanisms of attenuation of these, and other, contaminants in the drainage are discussed. Future research and operational objectives for this novel, low-cost, treatment system are also outlined.
Bao-yang Sun - One of the best experts on this subject based on the ideXlab platform.
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effects of soil texture and gravel content on the infiltration and soil loss of Spoil Heaps under simulated rainfall
Journal of Soils and Sediments, 2020Co-Authors: Wenlong Wang, Mingming Guo, Hongliang Kang, Zhigang Wang, Jinquan Huang, Bao-yang SunAbstract:Large Spoil Heaps formed during construction projects have caused serious soil erosion and threatened ecological security. The recent researches on soil erosion of Spoil Heaps are based on one or several soil types, which can only represent the soil texture category within the limited area, but cannot be used in other larger scale areas. Soil texture and gravel are the main factors affecting infiltration and erosion processes of Spoil Heaps. The runoff plot dimensions were 5.0 m × 1.0 m × 0.5 m (length × width × depth). A series of rainfall experiments with a constant rainfall intensity of 1.0 mm min−1 and a slope gradient of 25° were conducted to investigate the effects of soil texture (sandy, loam, and clay) and gravel mass content (GC, 0%, 10%, 20%, and 30%) on the infiltration and erosion processes. The gravels are divided into 3 classes according to particle size 2–14 mm (small), 14–25 mm (medium), 25–50 mm (large), and the mass ratios were 30%, 50%, and 20%. The duration of each rainfall event was 45 min after runoff out of the plot. Results showed that there was a critical GC (10%) improving or controlling infiltration and soil loss. Infiltration rate of sandy Spoil Heap (SSH) decreased within 45 min, but it decreased first and then stabilized for loam Spoil Heap (LSH) and clay Spoil Heap (CSH). Soil loss rate (SLR) of SSH stabilized first and then increased, while it decreased and then stabilized for LSH and CSH. SLR at early stage (0–18 min) was 0.08–0.23 times than it was at later stage (18–45 min) for SSH, but it was 2.06–5.06 times and 1.46–1.95 times for LSH and CSH, respectively. The soil texture had a more significant effect on SLR (P < 0.05) than GC did. The effects of gravel on SLRs were dependent on soil texture. The greater the GC was, the lower the SLR was for the Spoil Heaps. Special attention should be paid to the later stage during rainfall events for SSHs and the early stage for LSHs and CSHs when considering erosion protection measures.
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Effects of soil texture and gravel content on the infiltration and soil loss of Spoil Heaps under simulated rainfall
Journal of Soils and Sediments, 2020Co-Authors: Wenlong Wang, Mingming Guo, Hongliang Kang, Zhigang Wang, Jinquan Huang, Bao-yang Sun, Ke Wang, Guan-hua Zhang, Yun BaiAbstract:Large Spoil Heaps formed during construction projects have caused serious soil erosion and threatened ecological security. The recent researches on soil erosion of Spoil Heaps are based on one or several soil types, which can only represent the soil texture category within the limited area, but cannot be used in other larger scale areas. Soil texture and gravel are the main factors affecting infiltration and erosion processes of Spoil Heaps. The runoff plot dimensions were 5.0 m × 1.0 m × 0.5 m (length × width × depth). A series of rainfall experiments with a constant rainfall intensity of 1.0 mm min−1 and a slope gradient of 25° were conducted to investigate the effects of soil texture (sandy, loam, and clay) and gravel mass content (GC, 0%, 10%, 20%, and 30%) on the infiltration and erosion processes. The gravels are divided into 3 classes according to particle size 2–14 mm (small), 14–25 mm (medium), 25–50 mm (large), and the mass ratios were 30%, 50%, and 20%. The duration of each rainfall event was 45 min after runoff out of the plot. Results showed that there was a critical GC (10%) improving or controlling infiltration and soil loss. Infiltration rate of sandy Spoil Heap (SSH) decreased within 45 min, but it decreased first and then stabilized for loam Spoil Heap (LSH) and clay Spoil Heap (CSH). Soil loss rate (SLR) of SSH stabilized first and then increased, while it decreased and then stabilized for LSH and CSH. SLR at early stage (0–18 min) was 0.08–0.23 times than it was at later stage (18–45 min) for SSH, but it was 2.06–5.06 times and 1.46–1.95 times for LSH and CSH, respectively. The soil texture had a more significant effect on SLR (P
Mateusz Rawlik - One of the best experts on this subject based on the ideXlab platform.
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Slope exposure and forest stand type as crucial factors determining the decomposition rate of herbaceous litter on a reclaimed Spoil Heap
CATENA, 2019Co-Authors: Mateusz Rawlik, Marek Kasprowicz, Andrzej M. Jagodziński, Katarzyna Rawlik, Cezary KaźmierowskiAbstract:Abstract Chemical composition of plant litter, properties of the soil, and climatic conditions are the major factors determining rate of organic matter decomposition. Although the process of decomposition in degraded areas plays a significant role in accumulation of soil organic carbon (SOC), this issue is poorly studied. SOC content is a crucial factor determining the success of land restoration. We measured rates of decomposition of the grass Calamagrostis epigejos, the dicotyledonous N-fixer Medicago sativa, the dicotyledonous non-N-fixing Cirsium arvense and cellulose paper as a standard carrier in forest stands on a reclaimed Spoil Heap of the opencast lignite mine in Belchatow (central Poland). We considered the 10 cm topsoil particle size distribution and pH as factors that can affect the rate of organic matter decomposition and soil organic carbon content. Rate of litter decomposition was slowest for the grass (mean half decay time 2.6 years), while the N-fixing litter was not decomposed faster than the dicotyledonous non-N-fixing litter (mean half decay time of both species 0.9 years). Cellulose was decomposed most quickly (mean half decay time 0.8 years). Decomposition rate was faster under the canopy of Robinia pseudoacacia (deciduous N-fixing tree species, mean half decay time 0.9 years), whereas the rate of decomposition under Pinus sylvestris (coniferous canopy) was not slower than under Betula pendula (deciduous non-N-fixing tree species, mean half decay time under both species 1.5 years). Irrespective of litter type, decomposition was faster on the northern slope (mean half decay time 0.9 years) than on the southern slope (1.6 years). The plots where decomposition was faster (under R. pseudoacacia and on the northern slope) were characterized by higher SOC content (1.95% and 1.96%, respectively) than the plots under B. pendula (1.15%), P. sylvestris (1.29%), and those located on the southern slope (0.97%).
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Canopy tree species determine herb layer biomass and species composition on a reclaimed mine Spoil Heap.
The Science of the total environment, 2018Co-Authors: Mateusz Rawlik, Marek Kasprowicz, Andrzej M. Jagodziński, Cezary Kaźmierowski, Remigiusz Łukowiak, Witold GrzebiszAbstract:According facilitative models of succession, trees are great forest ecosystem engineers. The strength of tree stand influences on habitat were tested in rather homogenous conditions where heterogeneity of site condition was not an important influence. We hypothesized that canopy composition affects total aboveground vascular herb layer biomass (THB) and species composition of herb layer plant biomass (SCHB) more significantly than primary soil fertility or slope exposure. The study was conducted in 227 randomly selected research plots in seven types of forest stands: pure with Alnus glutinosa, Betula pendula, Pinus sylvestris, Quercus petraea and Robinia pseudoacacia, and mixed with dominance of Acer pseudoplatanus or Betula pendula located on hilltop and northern, eastern, western, and southern slopes on a reclaimed, afforested post-mining Spoil Heap of the Belchatow Brown Coal Mine (Poland). Generalized linear models (GLZ) showed that tree stand species were the best predictors of THB. Non-parametric variance tests showed significantly higher (nearly four times) THB under canopies of A. glutinosa, R. pseudoacacia, B. pendula and Q. petraea, compared to the lowest THB found under canopies of P. sylvestris and mixed with A. pseudoplatanus. Redundancy Analysis (RDA) showed that SCHB was significantly differentiated along gradients of light-nutrient herb layer species requirements. RDA and non-parametric variance tests showed that SCHB under canopies of A. glutinosa, R. pseudoacacia and mixed with A. pseudoplatanus had large shares of nitrophilous ruderal species (32%, 31% and 11%, respectively), whereas SCHB under B. pendula, Q. petraea, mixed with B. pendula and P. sylvestris were dominated by light-demanding meadow (49%, 51%, 51% and 36%, respectively) and Poaceae species. The results indicated the dominant role of tree stand composition in habitat-forming processes, and although primary site properties had minor importance, they were also modified by tree stand species.
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Differentiation of herb layer vascular flora in reclaimed areas depends on the species composition of forest stands
Forest Ecology and Management, 2018Co-Authors: Mateusz Rawlik, Marek Kasprowicz, Andrzej M. JagodzińskiAbstract:Abstract Spoil Heaps, resulting from open-pit mining, are deprived of soil cover. A common method of reclamation for such sites is afforestation aimed at creating whole forest ecosystems. Forest stands planted on soilless areas make it possible to determine the effects of different tree taxa on the species composition of flora. The study focused on the vascular species of herb layers in young forest stands formed by Alnus glutinosa, Betula pendula, Pinus sylvestris, Quercus petraea and Robinia pseudoacacia, and mixed stands dominated by Acer pseudoplatanus or Betula pendula. The study included 227 randomly selected plots across the afforested Belchatow Brown Coal Mine Spoil Heap. Species composition of the herb layer was composed mainly of synanthropic species (over 70%), and was clearly related to the overstory tree species composition of forest stands. TWINSPAN divided sample plots into two groups that developed under the canopy of stands formed by: (1) Betula pendula, Pinus sylvestris or Quercus petraea, or mixed stands with Betula pendula, or (2) Alnus glutinosa or Robinia pseudoacacia, or mixed stands dominated by Acer pseudoplatanus. The first group was dominated by meadow species (25.8%), while the second had higher richness of ruderal (18.6%) and forest-edge species (14.1%). Plant species associated with fertile and moist forest habitats were more frequent in the second group (Alnus-Robinia), whereas species of acidic and dry forests occurred only in the first group (Betula-Pinus). Non-parametric tests on Ellenberg’s indicator values showed that forest stands of Betula-Pinus group created habitat conditions for light-demanding species with low fertility requirements, whereas forest stands of Alnus-Robinia group created habitat conditions for nitrophilous and shade-tolerant plant species. Our data revealed that tree species composition of forest stands is a key factor shaping herb layer conditions and – as a consequence – herb layer species composition despite of initial habitat variability on the Spoil Heap. These results highlight a key role of forest stand composition in the development of herb layer richness on post-industrial habitats.
Wenlong Wang - One of the best experts on this subject based on the ideXlab platform.
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effects of soil texture and gravel content on the infiltration and soil loss of Spoil Heaps under simulated rainfall
Journal of Soils and Sediments, 2020Co-Authors: Wenlong Wang, Mingming Guo, Hongliang Kang, Zhigang Wang, Jinquan Huang, Bao-yang SunAbstract:Large Spoil Heaps formed during construction projects have caused serious soil erosion and threatened ecological security. The recent researches on soil erosion of Spoil Heaps are based on one or several soil types, which can only represent the soil texture category within the limited area, but cannot be used in other larger scale areas. Soil texture and gravel are the main factors affecting infiltration and erosion processes of Spoil Heaps. The runoff plot dimensions were 5.0 m × 1.0 m × 0.5 m (length × width × depth). A series of rainfall experiments with a constant rainfall intensity of 1.0 mm min−1 and a slope gradient of 25° were conducted to investigate the effects of soil texture (sandy, loam, and clay) and gravel mass content (GC, 0%, 10%, 20%, and 30%) on the infiltration and erosion processes. The gravels are divided into 3 classes according to particle size 2–14 mm (small), 14–25 mm (medium), 25–50 mm (large), and the mass ratios were 30%, 50%, and 20%. The duration of each rainfall event was 45 min after runoff out of the plot. Results showed that there was a critical GC (10%) improving or controlling infiltration and soil loss. Infiltration rate of sandy Spoil Heap (SSH) decreased within 45 min, but it decreased first and then stabilized for loam Spoil Heap (LSH) and clay Spoil Heap (CSH). Soil loss rate (SLR) of SSH stabilized first and then increased, while it decreased and then stabilized for LSH and CSH. SLR at early stage (0–18 min) was 0.08–0.23 times than it was at later stage (18–45 min) for SSH, but it was 2.06–5.06 times and 1.46–1.95 times for LSH and CSH, respectively. The soil texture had a more significant effect on SLR (P < 0.05) than GC did. The effects of gravel on SLRs were dependent on soil texture. The greater the GC was, the lower the SLR was for the Spoil Heaps. Special attention should be paid to the later stage during rainfall events for SSHs and the early stage for LSHs and CSHs when considering erosion protection measures.
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Effects of soil texture and gravel content on the infiltration and soil loss of Spoil Heaps under simulated rainfall
Journal of Soils and Sediments, 2020Co-Authors: Wenlong Wang, Mingming Guo, Hongliang Kang, Zhigang Wang, Jinquan Huang, Bao-yang Sun, Ke Wang, Guan-hua Zhang, Yun BaiAbstract:Large Spoil Heaps formed during construction projects have caused serious soil erosion and threatened ecological security. The recent researches on soil erosion of Spoil Heaps are based on one or several soil types, which can only represent the soil texture category within the limited area, but cannot be used in other larger scale areas. Soil texture and gravel are the main factors affecting infiltration and erosion processes of Spoil Heaps. The runoff plot dimensions were 5.0 m × 1.0 m × 0.5 m (length × width × depth). A series of rainfall experiments with a constant rainfall intensity of 1.0 mm min−1 and a slope gradient of 25° were conducted to investigate the effects of soil texture (sandy, loam, and clay) and gravel mass content (GC, 0%, 10%, 20%, and 30%) on the infiltration and erosion processes. The gravels are divided into 3 classes according to particle size 2–14 mm (small), 14–25 mm (medium), 25–50 mm (large), and the mass ratios were 30%, 50%, and 20%. The duration of each rainfall event was 45 min after runoff out of the plot. Results showed that there was a critical GC (10%) improving or controlling infiltration and soil loss. Infiltration rate of sandy Spoil Heap (SSH) decreased within 45 min, but it decreased first and then stabilized for loam Spoil Heap (LSH) and clay Spoil Heap (CSH). Soil loss rate (SLR) of SSH stabilized first and then increased, while it decreased and then stabilized for LSH and CSH. SLR at early stage (0–18 min) was 0.08–0.23 times than it was at later stage (18–45 min) for SSH, but it was 2.06–5.06 times and 1.46–1.95 times for LSH and CSH, respectively. The soil texture had a more significant effect on SLR (P