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Mining produces significant amounts of solid mineral waste. Mine waste storage facilities are often challenging to manage and may cause environmental problems. Mining waste is often linked to contaminated mine drainage, including acidic waters with more or less elevated concentrations of trace metals such as lead. This work presents a study on the mobilization of lead from waste from two typical mining sites: Zeida and Mibladen, two now-closed former Pb–Zn mines in the Moulouya region of Morocco. Our research investigates the mobilization potential of Pb from the waste of these mines. The study involved acid–base neutralization capacity tests (ANC–BNC) combined with geochemical modeling. Experimental data allowed for the quantification of the buffering capacity of the samples and the mobilization rates of lead as a function of pH. The geochemical model was fitted to experimental results with thermodynamic considerations. The geochemical model allowed for the identification of the mineral phases involved in providing the buffering capacity of carbonated mining waste (Mibladen) and the meager buffering capacity of the silicate mining waste (Zeida). These cases are representative of contaminated neutral drainage (CND) and acid mine drainage (AMD), respectively. The results highlight the consistency between the ANC–BNC experimental data and the associated modeling in terms of geochemical behavior, validating the approach and identifying the main mechanisms involved. The modeling approach identifies the dissolution of the main solid phases, which impact the pH and the speciation of lead as a function of the pH. This innovative approach, combining ANC–BNC experiments and geochemical modeling, allowed for the accurate identification of mineral phases and surface complexation phenomena, which control the release of lead and its speciation in drainage solutions, as well as within solid phases, as a function of pH.
Clémentine Drapeau; Rabei Argane; Cécile Delolme; Denise Blanc; Mostafa Benzaazoua; Rachid Hakkou; Thomas Baumgartl; Mansour Edraki; Laurent Lassabatere. Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling. Minerals 2021, 11, 606 .
AMA StyleClémentine Drapeau, Rabei Argane, Cécile Delolme, Denise Blanc, Mostafa Benzaazoua, Rachid Hakkou, Thomas Baumgartl, Mansour Edraki, Laurent Lassabatere. Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling. Minerals. 2021; 11 (6):606.
Chicago/Turabian StyleClémentine Drapeau; Rabei Argane; Cécile Delolme; Denise Blanc; Mostafa Benzaazoua; Rachid Hakkou; Thomas Baumgartl; Mansour Edraki; Laurent Lassabatere. 2021. "Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling." Minerals 11, no. 6: 606.
Although plot-scale erosion experiments are numerous, there are few studies on constructed landforms. This limits the understanding of their long-term stability, which is especially important for planning mined land rehabilitation. The objective of this study was to gain insight into the erosion processes in a 30 × 30 m trial plot on a mine waste rock dump in tropical northern Australia. The relationships between rainfall, runoff and suspended and bedload sediment export were assessed at annual, seasonal, inter-event and intra-event timescales. During a five-year study period, 231 rainfall–runoff–sediment export events were examined. The measured bedload and suspended sediments (mainly represented in nephelometric turbidity units (NTU)) showed the dominance of the wet season and heavy rainfall events. The bedload dominated the total mass, although the annual bedload diminished by approximately 75% over the five years, with greater flow energy required over time to mobilise the same bedload. The suspended load was more sustained, though it also exhibited an exhaustion process, with equal rainfall and runoff volumes and intensities, leading to lower NTU values over time. Intra-event NTU dynamics, including runoff-NTU time lags and hysteretic behaviours, were somewhat random from one event to the next, indicating the influence of the antecedent distribution of mobilisable sediments. The value of the results for supporting predictive modelling is discussed.
Shahla Yavari; Neil McIntyre; Thomas Baumgartl. An Empirical Analysis of Sediment Export Dynamics from a Constructed Landform in the Wet Tropics. Water 2021, 13, 1087 .
AMA StyleShahla Yavari, Neil McIntyre, Thomas Baumgartl. An Empirical Analysis of Sediment Export Dynamics from a Constructed Landform in the Wet Tropics. Water. 2021; 13 (8):1087.
Chicago/Turabian StyleShahla Yavari; Neil McIntyre; Thomas Baumgartl. 2021. "An Empirical Analysis of Sediment Export Dynamics from a Constructed Landform in the Wet Tropics." Water 13, no. 8: 1087.
Rehabilitated soils from post mining fields are considered to have poor soil structure, low nutrient content and microbial activity. Soil development during rehabilitation is a complex biogeochemical process influenced by the inherent properties of the substrate used for the rehabilitation. Besides disturbed soil properties, in Australia soil rehabilitation success is also influenced by climatic conditions like high evaporation rate which affects rebuilding of soil system functions. There are several studies looking into the development of soil properties post rehabilitation in temperate climates, however, the intertwined development of soil structure, quality and quantity of soil organic matter (SOM) after the rehabilitation under water stressed environment is not clear until now.
In this study, we used a space-for-time chronosequence approach in the rehabilitated open-cast mine site at Yallourn (Victoria, Australia) to elucidate the development of soil structure and soil organic matter after rehabilitation. We selected five different fields with increasing rehabilitation ages (2, 3, 10, 21 and 39 years) and two mature soils that are used as grazing land. In each field, we sampled 6 independent locations with stainless steel cylinders (100 cm3) at two depths of 0-4 cm and 10-14 cm. All samples were analysed for bulk density, organic carbon (OC) and total nitrogen (TN) concentration. Selected samples were wet sieved into four aggregate size classes of <63 µm, 63-200 µm, 200-630 µm and >630 µm. Each aggregate size class was characterized by OC and TN concentration. The chemical composition of the SOM of selected samples was characterized using solid-state 13C NMR spectroscopy.
The studied soils have a strong temporal dynamic and variability as determined for the soil properties bulk density and SOM stocks. Aggregate fractionation showed that large macroaggregates (>630 µm) were the most abundant size class fractions in each rehabilitation field, representing 95-75% of the total soil mass. SOM played an important role in the formation of large macroaggregates, where the highest contribution to total OC content was observed. It became evident that plant derived carbon had a decisive role in the structural formation, because O/N-alkyl-C and alkyl-C chemical shift regions represented the highest relative intensities throughout the chronosequence.
Tiia Haberstok; Evelin Pihlap; Franziska Bucka; Tabea Klör; Thomas Baumgartl; Ingrid Kögel-Knabner. Soil structural development in a rehabilitated open-cast mine site in south-east Australia. 2021, 1 .
AMA StyleTiia Haberstok, Evelin Pihlap, Franziska Bucka, Tabea Klör, Thomas Baumgartl, Ingrid Kögel-Knabner. Soil structural development in a rehabilitated open-cast mine site in south-east Australia. . 2021; ():1.
Chicago/Turabian StyleTiia Haberstok; Evelin Pihlap; Franziska Bucka; Tabea Klör; Thomas Baumgartl; Ingrid Kögel-Knabner. 2021. "Soil structural development in a rehabilitated open-cast mine site in south-east Australia." , no. : 1.
The variation of water content has a significant effect on the engineering behaviour of clayey soils. This is in particular of high importance to infrastructure projects such as open pit mine rehabilitation. During the construction of open pit mines, the natural ground water level needs to be lowered for the feasibility of mining activities. This dewatering causes significant shrinkage and development of cracks amongst the deposits of cohesive soils. In order to design a rehabilitation plan, it is critical to investigate the shrinkage and desiccation cracks occurred within and around open pit mines as the result of dewatering. This study aims at identifying the shrinkage and crack development patterns using an experimental approach and utilizing image analysis. Three different types of clays were studied to this end. Physical properties including liquid limit, plastic limit and linear shrinkage of clays were determined. Soil samples were put in circular moulds of 150 mm diameter and 5 to 25 mm thickness. The variation of water content, while desiccating, was monitored. In addition, a digital camera was used to capture the initiation and propagation of desiccation cracks. Crack and shrinkage intensity factors were determined and analysed against various soil properties. The results obtained in this study could potentially lead to developing models to predict crack propagation patterns in various soils. This will ultimately result in more realistic and reliable future designs of infrastructures, such as mine rehabilitation.
Mohammadjavad Yaghoubi; Thomas Baumgartl. Evaluation of Shrinkage and Desiccation Crack Propagation Patterns in Clays for the assessment of their suitability in landform rehabilitation. 2021, 1 .
AMA StyleMohammadjavad Yaghoubi, Thomas Baumgartl. Evaluation of Shrinkage and Desiccation Crack Propagation Patterns in Clays for the assessment of their suitability in landform rehabilitation. . 2021; ():1.
Chicago/Turabian StyleMohammadjavad Yaghoubi; Thomas Baumgartl. 2021. "Evaluation of Shrinkage and Desiccation Crack Propagation Patterns in Clays for the assessment of their suitability in landform rehabilitation." , no. : 1.
Pyrite and calcite are mineral phases that play a major role in acid and neutral mine drainage processes. However, the prediction of acid mine drainage (AMD) or contaminated neutral drainage (CND) requires knowledge of the mineral composition of mining waste and the related potential for element release. This paper studies the combination of acid–base neutralizing capacity (ANC–BNC) with geochemical modeling for the characterization of mining waste and prediction of AMD and CND. The proposed approach is validated with three synthetic mineral assemblages: (1) siliceous sand with pyrite only, representing mining waste responsible for AMD, (2) siliceous sand with calcite and pyrite, representing calcareous waste responsible for CND, and (3) siliceous sand with calcite only, simulating calcareous matrices without any pyrite. The geochemical modeling approach using PHREEQC software was used to model pH evolution and main element release as a function of the added amount of acid or base over the entire pH range: 1 < pH < 13. For calcareous matrices (sand with calcite), the results are typical of a carbonated environment, the geochemistry of which is well known. For matrices containing pyrite, the results identify different pH values favoring the dissolution of pyrite: pH = 2 in a pyrite-only environment and pH = 6 where pyrite coexists with calcite. The neutral conditions can be explained by the buffering capacity of calcite, which allows iron oxyhydroxide precipitation. Major element release is then related to the dissolution and precipitation of the mineral assemblages. The geochemical modeling allows the prediction of element speciation in the solid and liquid phases. Our findings clearly prove the potential of combined ANC–BNC experiments along with geochemical modeling for the characterization of mining waste and the assessment of risk of AMD and CND.
Clémentine Drapeau; Cécile Delolme; Clément Vézin; Denise Blanc; Thomas Baumgartl; Mansour Edraki; Laurent Lassabatere. ANC–BNC Titrations and Geochemical Modeling for Characterizing Calcareous and Siliceous Mining Waste. Minerals 2021, 11, 257 .
AMA StyleClémentine Drapeau, Cécile Delolme, Clément Vézin, Denise Blanc, Thomas Baumgartl, Mansour Edraki, Laurent Lassabatere. ANC–BNC Titrations and Geochemical Modeling for Characterizing Calcareous and Siliceous Mining Waste. Minerals. 2021; 11 (3):257.
Chicago/Turabian StyleClémentine Drapeau; Cécile Delolme; Clément Vézin; Denise Blanc; Thomas Baumgartl; Mansour Edraki; Laurent Lassabatere. 2021. "ANC–BNC Titrations and Geochemical Modeling for Characterizing Calcareous and Siliceous Mining Waste." Minerals 11, no. 3: 257.
Accurate scheduling of bauxite residue (red mud) deposition time is required in order to prevent the risk of storage facility failure. This study was conducted to precisely determine the hydraulic parameters of bauxite residue and investigate the capability of HYDRUS to accurately estimate the residue moisture profile and the timing for its deposition. The hydraulic properties of the bauxite residue profile were determined by solving an inverse problem. A one-dimensional hydrological model (HYDRUS-1D) was validated using a 300 mm long column filled with bauxite residue and exposed to a dynamic lower boundary condition. After numerical validation, the model was used to simulate the moisture profile of bauxite residue under the climatic conditions of an alumina refinery site in Queensland, Australia, as well as other scenarios (i.e., high (300 mm) and small (1.7 mm) rainfall events of the site). This study showed that the HYDRUS model can be used as a predictive tool to precisely estimate the moisture profile of the bauxite residue and that the timing for the re-deposition of the bauxite residue can be estimated by understanding the moisture profile and desired shear strength of the residue. This study revealed that the examined bauxite residue approaches field capacity (water potential −10 kPa) after three days from a low rainfall event (<1.7 mm) and after eight days from an intense rainfall event (300 mm) at the time of disposal. This suggests that the bauxite residue can be deposited every four days after low rainfall events (as low as 1.7 mm) and every nine days after high rainfall events (as high as 300 mm) at the time of deposition, if bauxite residue experiences an initial drying period following deposition.
Mandana Shaygan; Brent Usher; Thomas Baumgartl. Modelling Hydrological Performance of a Bauxite Residue Profile for Deposition Management of a Storage Facility. Water 2020, 12, 1988 .
AMA StyleMandana Shaygan, Brent Usher, Thomas Baumgartl. Modelling Hydrological Performance of a Bauxite Residue Profile for Deposition Management of a Storage Facility. Water. 2020; 12 (7):1988.
Chicago/Turabian StyleMandana Shaygan; Brent Usher; Thomas Baumgartl. 2020. "Modelling Hydrological Performance of a Bauxite Residue Profile for Deposition Management of a Storage Facility." Water 12, no. 7: 1988.
In the course of brown coal mining, large amounts of soil, interseam and overburden material are moved and translocated. Ceasing mining activities, the disturbed landscape needs to be restored and a rapid development of functional soils is of utter importance for the rehabilitation of those areas. Simple backfilling of the overburden material is not sufficient, above all in areas with semi-arid or arid climate due to the lack of water driving the formation of structure and rebuilding of organic carbon (OC) and nutrient pool. In order to accelerate soil development and rehabilitation, new approaches using mixtures of different substrates and OC sources are tested. Testing such rehabilitation mixtures in field scale is time and resource consuming. We present a rapid and easy to perform laboratory approach to evaluate the performance of artificial soil mixtures for rehabilitation regarding the development of chemical, biological and structural features. We tested six different mixtures used for a rehabilitation program at a coal mine in southern Australia composed with increasing complexity using overburden material, fly ash, paper mulch and brown coal. In addition, we investigated the effect of a fresh plant litter addition.
We performed a short-term laboratory incubation in microcosms for forty days at constant water tension. During the incubation, we monitored water content and microbial activity. After the incubation period, we evaluated soil structure formation by isolating water-stable aggregates and estimated pore sizes by calculating water-filled pore space. We investigated OC allocation in bulk soil, soil solution, aggregates and microbial biomass and calculated the microbial carbon use efficiency (CUE).
Our results showed that the more complex mixtures had a higher OC content and a wider CN ratio. Available nutrients in the soil solution were mainly provided by the additional components, because the overburden material alone showed very low element concentrations in the soil solution. The formation of water-stable aggregates was mainly driven by the addition of fresh plant litter and there was a predominant formation of large macroaggregates (0.63-30 mm), that stored >80% of the total OC. Microbial activity, as measured by CO2 release, was high in all mixtures with fresh plant litter addition, but the highest microbial CUE was observed in the full rehabilitation mixture. Thus, the full rehabilitation mixture is considered to support sustainable microbial growth and has the potential for a rapid soil development. Also, we identified the OC input to be the main driver of early soil development in artificial soil mixtures influencing nutrient supply, microbial development and structure formation.
The study suggests that the presented experimental design is a functional and efficient test system for assessing the rehabilitation potential of different substrates and rehabilitation mixtures in a short-term lab approach.
Franziska Bucka; Evelin Pihlap; Jara Kaiser; Thomas Baumgartl; Ingrid Kögel-Knabner. Testing the rehabilitation potential of post-mining soils: soil organic matter, microbial biomass and aggregate formation. 2020, 1 .
AMA StyleFranziska Bucka, Evelin Pihlap, Jara Kaiser, Thomas Baumgartl, Ingrid Kögel-Knabner. Testing the rehabilitation potential of post-mining soils: soil organic matter, microbial biomass and aggregate formation. . 2020; ():1.
Chicago/Turabian StyleFranziska Bucka; Evelin Pihlap; Jara Kaiser; Thomas Baumgartl; Ingrid Kögel-Knabner. 2020. "Testing the rehabilitation potential of post-mining soils: soil organic matter, microbial biomass and aggregate formation." , no. : 1.
Numerical modelling is a tool allowing the prediction of water flow and water balance based on material properties and time dependent input information at defined boundaries. Long time series are often required for a well informed assessment of the performance of a site. It has been shown that covers as a preferred option constructed in semi-arid and arid climates on mine sites to manage water flows and to prevent deep drainage have a characteristic bi-modal pore system largely caused by a large fraction of coarse rocks. Bi-modal water retention curves have been established for such covers which have proven to describe the response to precipitation with higher accuracy. Meteorological data as input information are in many cases only available on a daily basis if time series over decades are used for modelling. For a bi-modal pore system with often very high values for saturated hydraulic conductivity, a daily time-step may be to large to capture numerically the response in water flow. The objective of the presented work is the comparison of modelled deep drainage data for a specific cover design where hourly data are compared with daily input data. The latter were aggregated from the hourly information.
The results from the numerical modelling showed that for environments with high intensity rainfall events the calculated amount of deep drainage was by up to 10% smaller for the aggregated daily input data compared to the hourly data.
The presentation will inform which rainfall events contributed primarily to the difference in the water balance parameters and to which extent a generalisation can be made on the choice or requirement to choose an appropriate time step for specific climatic conditions.
Thomas Baumgartl; Mandana Shaygan. The effect of the choice of time resolution on the prediction of deep drainage rates in rocky covers. 2020, 1 .
AMA StyleThomas Baumgartl, Mandana Shaygan. The effect of the choice of time resolution on the prediction of deep drainage rates in rocky covers. . 2020; ():1.
Chicago/Turabian StyleThomas Baumgartl; Mandana Shaygan. 2020. "The effect of the choice of time resolution on the prediction of deep drainage rates in rocky covers." , no. : 1.
Soil structure and soil organic matter (SOM) are closely linked characteristics describing the status of development of a soil. Their interactions affect various physical, chemical and biological soil properties and functions like water holding capacity, water infiltration, composition of the carbon pool and microbial activity. Rehabilitated soils from post mining fields are considered to have poor soil structure, low nutrient content and microbial activity. Besides disturbed soil properties, in Australia soil rehabilitation success is also influenced by climatic conditions like high evaporation rate which affects rebuilding of soil system functions. Although there are several studies looking into the development of soil properties post rehabilitation in temperate climates, the intertwined development of soil structure and quality and quantity of SOM during soil formation under water stressed environment is not clear until now.
In this study we used a space-for-time chronosequence approach in the rehabilitated open-cast mines at Yallourn Mine (Victoria, Australia) to elucidate the development of soil structure and soil organic matter after rehabilitation in a water limited environment. We selected five different fields with different rehabilitation ages (40, 22, 11, 4 and 3 years) and two mature soils that are used as grazing land. In each field we sampled 6 independent locations with stainless steel cylinders (100 cm3) at two depths of 0-4 cm and 10-14 cm. All samples were analysed for bulk density, organic carbon (OC) and total nitrogen (TN) concentration. Selected samples were wet sieved into four aggregate size classes of <63 µm, 63-200 µm, 200-630 µm and >630 µm. For detecting OC contribution to aggregate formation, OC and TN was measured from each aggregate size fraction. This system is temporarily highly dynamic and shows different developments for bulk density and SOM stocks, which had an effect on the structure of the microbial communities. Along the space-for-time chronosequence we can observe soil structure formation with ageing and a build-up of a OM, which has a positive effect on recovering soil functionality.
Evelin Pihlap; Franziska Bucka; Tiia Haberstok; Emily Scholes; Tabea Klör; Thomas Baumgartl; Ingrid Kögel-Knabner. Descriptors for soil development in a water limited environment of a rehabilitated open-cast mine site in south-east Australia. 2020, 1 .
AMA StyleEvelin Pihlap, Franziska Bucka, Tiia Haberstok, Emily Scholes, Tabea Klör, Thomas Baumgartl, Ingrid Kögel-Knabner. Descriptors for soil development in a water limited environment of a rehabilitated open-cast mine site in south-east Australia. . 2020; ():1.
Chicago/Turabian StyleEvelin Pihlap; Franziska Bucka; Tiia Haberstok; Emily Scholes; Tabea Klör; Thomas Baumgartl; Ingrid Kögel-Knabner. 2020. "Descriptors for soil development in a water limited environment of a rehabilitated open-cast mine site in south-east Australia." , no. : 1.
Freshly deposited tailings define finely crushed rock rarely altered by weathering processes. In modelling water flow and solute transport for saturated and unsaturated conditions in deposited tailings, the hydraulic parameters are essential required parameters. It has been proposed that these parameters vary as the materials evolve through weathering processes which transform minerals and hence chemical and physical properties. Several methods, destructive and non-destructive, have been used to determine the change of these parameters. The evaporation method as a non-destructive method, for deriving hydraulic parameters of porous media can be employed to monitor the overall changes in the pores as the properties of the porous matrix changes. In order to test this hypothesis, 25% of pyrite, 25% of dolomite, 35% of quartz and 15% of chlorite, reflecting typical acid producing, acid neutralising and inert minerals were mixed to form artificial tailings. The mineral admixture was mixed at a water content of 10% and allowed to equilibrate for two weeks before the start of the experiment. The mineral admixture was packed to a bulk density of 1.4 g/cm3. The hydraulic parameters for the near saturation state were measured using the simultaneous measurement of water content and water potential as a consequence of evaporation. The mineral admixture was subjected to 9 drying and wetting cycles over a period of 9 months. The hydraulic parameters were estimated using RETC and HYDRUS 1D. After 9 months of drying and wetting, there was a slight change in the bulk density of the material. This change had an overall effect on the subsequent hydraulic parameters. This study implies that feedback effects should be considered in modelling ageing of mine tailings.
Raphael Akesseh; Mansour Edraki; Thomas Baumgartl. Examining saturated and unsaturated hydraulic parameter changes as a result of geochemical reactions in tailings. 2020, 1 .
AMA StyleRaphael Akesseh, Mansour Edraki, Thomas Baumgartl. Examining saturated and unsaturated hydraulic parameter changes as a result of geochemical reactions in tailings. . 2020; ():1.
Chicago/Turabian StyleRaphael Akesseh; Mansour Edraki; Thomas Baumgartl. 2020. "Examining saturated and unsaturated hydraulic parameter changes as a result of geochemical reactions in tailings." , no. : 1.
Soils in arid and semi-arid environments are threatened by salinization. A cost-effective and efficient way to reclaim saline land is through leaching. This will be most effective in situations where direct human impact is the cause for salinity, e.g., in environments affected by industrial use or land rehabilitation following mining. Irrigation, which is the most common means of achieving salt leaching, is not feasible for the reclamation of mine sites’ salt-affected soils located in remote areas, and thus, land reclamation largely relies on natural climatic conditions. This study was conducted to assess the effect of different climatic conditions of semi-arid environments on spatio-temporal salt leaching from brine-affected soil, and investigate the efficacy of the reduction of soil bulk density as a reclamation technique for saline land experiencing water scarcity. Three regions (represented by the Australian cities of Roma, Mount Isa, and Quilpie) representing semi-arid environments of Australia were selected, and their climatic scenarios (23 years) were applied to a validated HYDRUS-1D model. A brine-affected soil typical to Queensland, Australia, was chosen for this study. The investigations established that a greater number of individual high rainfall events resulted in a greater reduction of salinity in Roma (96%) and Mount Isa (93.31%) compared with Quilpie (58.75%), in which the soil salinity approached a level (−1) that was suitable for sustaining plant growth. Soil salinity reduced to 8 dS m−1 under the climatic conditions of the Quilpie region. This study also demonstrated that the success of salt leaching from a brine-affected soil is a consequence of a sensitive response to the depth of individual rainfall events rather than rainfall distribution and the total amount of rainfall, and is controlled by the physical properties of the soil. Where climatic conditions cannot solely assist with salt leaching, reclamation may be successful by reducing soil bulk density.
Mandana Shaygan; Thomas Baumgartl. Simulation of the Effect of Climate Variability on Reclamation Success of Brine-Affected Soil in Semi-Arid Environments. Sustainability 2020, 12, 371 .
AMA StyleMandana Shaygan, Thomas Baumgartl. Simulation of the Effect of Climate Variability on Reclamation Success of Brine-Affected Soil in Semi-Arid Environments. Sustainability. 2020; 12 (1):371.
Chicago/Turabian StyleMandana Shaygan; Thomas Baumgartl. 2020. "Simulation of the Effect of Climate Variability on Reclamation Success of Brine-Affected Soil in Semi-Arid Environments." Sustainability 12, no. 1: 371.
Coal mine spoils have the potential to create environmental impacts, such as salt load to surrounding environments, particularly when exposed to weathering processes. This study was conducted to understand the effect of physical and chemical weathering on the magnitude, rate, and dynamics of salt release from different coal mine spoils. Five spoil samples from three mines in Queensland were sieved to three different particle size fractions (6 mm). Two samples were dispersive spoils, and three samples were nondispersive spoils. The spoils were subjected to seven wet–dry cycles, where the samples were periodically leached with deionised water. The rate, magnitude, and dynamics of solutes released from spoils were spoil specific. One set of spoils did not show any evidence of weathering, but initially had higher accumulation of salts. In contrast, broad oxidative weathering occurred in another set of spoils; this led to acid generation and resulted in physical weathering, promoting adsorption–desorption and dissolution and, thus, a greater release of salts. This study indicated that the rate and magnitude of salt release decreased with increasing particle size. Nevertheless, when the spoil is dispersive, the degree of weathering manages salt release irrespective of initial particle size. This study revealed that the long-term salt release from spoils is not only governed by geochemistry, weathering degree, and particle size but also controlled by the water/rock ratio and hydrological conditions of spoils.
Melinda Hilton; Mandana Shaygan; Neil McIntyre; Thomas Baumgartl; Mansour Edraki. The Effect of Weathering on Salt Release from Coal Mine Spoils. Minerals 2019, 9, 760 .
AMA StyleMelinda Hilton, Mandana Shaygan, Neil McIntyre, Thomas Baumgartl, Mansour Edraki. The Effect of Weathering on Salt Release from Coal Mine Spoils. Minerals. 2019; 9 (12):760.
Chicago/Turabian StyleMelinda Hilton; Mandana Shaygan; Neil McIntyre; Thomas Baumgartl; Mansour Edraki. 2019. "The Effect of Weathering on Salt Release from Coal Mine Spoils." Minerals 9, no. 12: 760.
The quantification of percolation processes and deep drainage rates in cracking clays is challenging due to the existence of multiple flow pathways, including desiccation crack networks, and the effect of variability in antecedent soil moisture and rain event properties. While most previous research on this topic focuses on long‐term average rates, this study focusses on inter‐event dynamics. The study uses data from soil moisture sensors distributed vertically down 4 m profiles of Vertosol and Chromosol soils across 13 sites over an area of approximately 20 km2. The objectives were to estimate the temporal and spatial variability of deep drainage rates and to investigate the effect of antecedent soil moisture conditions and rain event properties on deep drainage rates and percolation dynamics. 35 deep drainage events over a 40‐month period contributed 78 % of the total deep drainage of 254 mm at 4 m depth. Average deep drainage estimates were about 15 % (ranging from 0 – 80 % between sites) of total rainfall and irrigation in the Vertosol and 8% (0 – 24 %) in the Chromosol. The event water travel times at 4 m depth were 0.25 – 38 hr and 14 – 39 hr in the Vertosol and Chromosol respectively. The event deep drainage rates averaged across sites were associated with event rainfall volumes (linear regression R2 = 0.40), with the effect of antecedent conditions evident only when looking at inter‐site differences. The percolation response time was strongly associated with higher rainfall intensities (R2 = 0.33) with no evidence from the linear regression of an antecedent moisture effect.
Sven Arnold; Nevenka Bulovic; Neil McIntyre; Warren K. Finch; Joshua R. Larsen; Lucy P. Reading; Thomas Baumgartl. Event‐based deep drainage and percolation dynamics in Vertosols and Chromosols. Hydrological Processes 2019, 34, 370 -386.
AMA StyleSven Arnold, Nevenka Bulovic, Neil McIntyre, Warren K. Finch, Joshua R. Larsen, Lucy P. Reading, Thomas Baumgartl. Event‐based deep drainage and percolation dynamics in Vertosols and Chromosols. Hydrological Processes. 2019; 34 (2):370-386.
Chicago/Turabian StyleSven Arnold; Nevenka Bulovic; Neil McIntyre; Warren K. Finch; Joshua R. Larsen; Lucy P. Reading; Thomas Baumgartl. 2019. "Event‐based deep drainage and percolation dynamics in Vertosols and Chromosols." Hydrological Processes 34, no. 2: 370-386.
Environmental information is acquired and assessed during the environmental impact assessment process for surface‐strip coal mine approval. However, integrating these data and quantifying rehabilitation risk using a holistic multi‐disciplinary approach is seldom undertaken. We present a rehabilitation risk assessment integrated network (R2AIN™) framework, that can be applied using Bayesian networks (BNs), to integrate and quantify such rehabilitation risks. Our framework has seven steps, including key integration of rehabilitation risk sources and the quantification of undesired rehabilitation risk events to the final application of mitigation. We demonstrate the framework using a soil compaction Bayesian network (BN) case study in the Witbank Coalfield, South Africa and the Bowen Basin, Australia. Our approach allows for a probabilistic assessment of rehabilitation risk associated with multi‐disciplines to be integrated and quantified. Using this method, a site's rehabilitation risk profile can be determined before mining activities commence and the effects of manipulating management actions during later mine phases to reduce risk, can be gauged, to aid decision making. This article is protected by copyright. All rights reserved
Vanessa D. Weyer; Alta De Waal; Alex Lechner; Corinne J. Unger; Tim G. O'Connor; Thomas Baumgartl; Roland Schulze; Wayne F. Truter. Quantifying rehabilitation risks for surface‐strip coal mines using a soil compaction Bayesian network in South Africa and Australia: To demonstrate the R2AIN Framework. Integrated Environmental Assessment and Management 2019, 15, 190 -208.
AMA StyleVanessa D. Weyer, Alta De Waal, Alex Lechner, Corinne J. Unger, Tim G. O'Connor, Thomas Baumgartl, Roland Schulze, Wayne F. Truter. Quantifying rehabilitation risks for surface‐strip coal mines using a soil compaction Bayesian network in South Africa and Australia: To demonstrate the R2AIN Framework. Integrated Environmental Assessment and Management. 2019; 15 (2):190-208.
Chicago/Turabian StyleVanessa D. Weyer; Alta De Waal; Alex Lechner; Corinne J. Unger; Tim G. O'Connor; Thomas Baumgartl; Roland Schulze; Wayne F. Truter. 2019. "Quantifying rehabilitation risks for surface‐strip coal mines using a soil compaction Bayesian network in South Africa and Australia: To demonstrate the R2AIN Framework." Integrated Environmental Assessment and Management 15, no. 2: 190-208.
Poor soil physical conditions associated with low hydraulic conductivity and infiltration can limit salt leaching and reclamation; hence, land revegetation. Soil physical amendments such as wood chips and fine sand may be used to remediate the soil physical conditions and improve salt leaching, thus assisting with revegetation. To evaluate the success of soil amendments for the reclamation and revegetation of a saline-sodic soil under a typical climatic condition of a semi-arid environment, a water and solute transport model (HYDRUS-1D) was used. Synthetic climatic scenarios were generated using LARS-WG. Soil profiles (1 m depth) amended separately with 20% wood chips and 40% fine sand at the surface (0–10 cm) were defined for the simulation. A non-amended soil profile, which had physical properties of a disturbed soil, was used as a control. Salt leaching was more successful in the non-amended soil profile compared with the amended soil profiles. The likelihood and the success of Atriplex halimus L. seed germination were also higher in the non-amended soil (67.7%) compared with wood chips (13.98%) and fine sand (6.7%) amended soils. This study indicates that the addition of 20% wood chips and 40% fine sand to the depth of 10 cm of a saline-sodic soil may not be an effective approach for reclamation and revegetation under the semi-arid climatic conditions. This study suggests that a reduction in soil bulk density is sufficient to provide suitable conditions for successful land reclamation and revegetation in the investigated climatic conditions.
Mandana Shaygan; Lucy Reading; Sven Arnold; Thomas Baumgartl. Modeling the effect of soil physical amendments on reclamation and revegetation success of a saline-sodic soil in a semi-arid environment. Arid Land Research and Management 2018, 32, 379 -406.
AMA StyleMandana Shaygan, Lucy Reading, Sven Arnold, Thomas Baumgartl. Modeling the effect of soil physical amendments on reclamation and revegetation success of a saline-sodic soil in a semi-arid environment. Arid Land Research and Management. 2018; 32 (4):379-406.
Chicago/Turabian StyleMandana Shaygan; Lucy Reading; Sven Arnold; Thomas Baumgartl. 2018. "Modeling the effect of soil physical amendments on reclamation and revegetation success of a saline-sodic soil in a semi-arid environment." Arid Land Research and Management 32, no. 4: 379-406.
Brine, produced as a by‐product of oil extraction, when contained in evaporation ponds can cause soil salinization in the vicinity of these ponds. Native halophytes may assist revegetation and rehabilitation of these salt‐affected soils. This study was conducted to investigate the revegetation and rehabilitation potential of brine‐affected land using native halophytes (Tecticornia pergranulata (J.M.Black) K.A.Sheph. & Paul G.Wilson, Sclerolaena longicuspis (F.Muell.) A.J.Scott and Frankenia serpyllifolia Lindl). Soil samples from adjacent bare and vegetated areas of brine‐affected land were compared to assess the physico‐chemical properties associated with the vegetation cover. The salt contents of the halophytes, plant bioaccumulation, bioconcentration, and translocation factors were measured to evaluate remediation capacity of the species. We hypothesized that the halophytes reduce the ions' concentrations and thus soil salinity and sodicity. The examined halophytes were associated with a reduction in salinity and sodicity by an average of 38.5% and 33% in the top 10 cm of the soil, respectively. T. pergranulata had the highest shoot Na+ content (98 g/kg dry wt), bioaccumulation (14.21), and translocation (23.09) factors for Na+ that indicated the higher remediation potential of this species. Despite the high remediation potential of the examined species, halophytes are not able to reduce the salt content of the landscape to create conditions for the growth of glycophytes. However, the salt‐affected land can be revegetated by halophytes, and halophytes probably provide a stable vegetation cover for the landscape in ecological succession. An improvement in soil physical properties is required for revegetation success.
Mandana Shaygan; David Mulligan; Thomas Baumgartl. The potential of three halophytes (Tecticornia pergranulata , Sclerolaena longicuspis , and Frankenia serpyllifolia ) for the rehabilitation of brine-affected soils. Land Degradation & Development 2018, 29, 2002 -2014.
AMA StyleMandana Shaygan, David Mulligan, Thomas Baumgartl. The potential of three halophytes (Tecticornia pergranulata , Sclerolaena longicuspis , and Frankenia serpyllifolia ) for the rehabilitation of brine-affected soils. Land Degradation & Development. 2018; 29 (6):2002-2014.
Chicago/Turabian StyleMandana Shaygan; David Mulligan; Thomas Baumgartl. 2018. "The potential of three halophytes (Tecticornia pergranulata , Sclerolaena longicuspis , and Frankenia serpyllifolia ) for the rehabilitation of brine-affected soils." Land Degradation & Development 29, no. 6: 2002-2014.
Large-scale open cut mining has occurred within the Bowen Basin for over four decades, transitioning from shallow mining depths and limited spoil elevation to increased mining depths, pre-stripping and increasingly elevated mesa-like landforms. As a result of this evolution, the stabilization of modern constructed landforms is no longer assured through the establishment of vegetation alone. The selection of resilient fragmental spoil types for the construction of final landform surfaces, and as cladding for stabilizing steep erosive batters, is a practical methodology that has the potential to significantly improve rehabilitation outcomes, by increasing surface rock cover, roughness and infiltration and reducing erodibility. An understanding of the properties and behavior of individual spoil materials disturbed during mining is required. Relevant information from published literature on the geological origins, lithology and weathering characteristics of individual strata within the Bowen Basin Coal Measures (and younger overlying weathered strata) has been reviewed, related to natural landforms and applied to the surface stability of major strata types when disturbed by mining. A spoil classification derived from geological characteristics and weathering behavior of identifiable lithologic components has been reviewed and refined, demonstrating the application of use of geological information. This classification system is a tool for the allocation of spoil types and use of categories which have application in pre-mine feasibility investigations, landform design and material selection and placement. The logic of classifying materials based on their stability in the natural landscape has wider relevance to other mining areas where elevated landforms of sedimentary material are constructed.
Bevan Emmerton; Jon Burgess; Joan Esterle; Peter Erskine; Thomas Baumgartl. The application of natural landform analogy and geology-based spoil classification to improve surface stability of elevated spoil landforms in the Bowen Basin, Australia-A review. Land Degradation & Development 2018, 29, 1489 -1508.
AMA StyleBevan Emmerton, Jon Burgess, Joan Esterle, Peter Erskine, Thomas Baumgartl. The application of natural landform analogy and geology-based spoil classification to improve surface stability of elevated spoil landforms in the Bowen Basin, Australia-A review. Land Degradation & Development. 2018; 29 (5):1489-1508.
Chicago/Turabian StyleBevan Emmerton; Jon Burgess; Joan Esterle; Peter Erskine; Thomas Baumgartl. 2018. "The application of natural landform analogy and geology-based spoil classification to improve surface stability of elevated spoil landforms in the Bowen Basin, Australia-A review." Land Degradation & Development 29, no. 5: 1489-1508.
Ecosystem services mapping is becoming increasingly popular through the use of various readily available mapping tools, however, uncertainties in assessment outputs are commonly ignored. Uncertainties from different sources have the potential to lower the accuracy of mapping outputs and reduce their reliability for decision-making. Using a case study in an Australian mining region, this paper assessed the impact of uncertainties on the modelling of the hydrological ecosystem service, water provision. Three types of uncertainty were modelled using multiple uncertainty scenarios: (1) spatial data sources; (2) modelling scales (temporal and spatial) and (3) parameterization and model selection. We found that the mapping scales can induce significant changes to the spatial pattern of outputs and annual totals of water provision. In addition, differences in parameterization using differing sources from the literature also led to obvious differences in base flow. However, the impact of each uncertainty associated with differences in spatial data sources were not so great. The results of this study demonstrate the importance of uncertainty assessment and highlight that any conclusions drawn from ecosystem services mapping, such as the impacts of mining, are likely to also be a property of the uncertainty in ecosystem services mapping methods.
Zhenyu Wang; Alex Mark Lechner; Thomas Baumgartl. Ecosystem Services Mapping Uncertainty Assessment: A Case Study in the Fitzroy Basin Mining Region. Water 2018, 10, 88 .
AMA StyleZhenyu Wang, Alex Mark Lechner, Thomas Baumgartl. Ecosystem Services Mapping Uncertainty Assessment: A Case Study in the Fitzroy Basin Mining Region. Water. 2018; 10 (1):88.
Chicago/Turabian StyleZhenyu Wang; Alex Mark Lechner; Thomas Baumgartl. 2018. "Ecosystem Services Mapping Uncertainty Assessment: A Case Study in the Fitzroy Basin Mining Region." Water 10, no. 1: 88.
Tailings rehabilitation, using soil-like properties with chemical and physical stability, can be influenced by surface forces on a particle scale and microstructure. Non-homogeneous structures, manifesting as particle aggregation, alter the permeability/porosity and improve the balance of aerated and water-filled pores that then favours plant growth. Polymer flocculation in tailings thickeners yields large, weak aggregates that are sheared in beds and on pumping. While low-level residual structure may remain, sizes are small and downstream polymer impacts are minor. However, high polymer dosages added in-pipe to high-solids streams lead to further water recovery on deposition, and while this process is poorly understood, it gives aggregates that are likely denser and stronger. If such structures persist, they could potentially offer closure and rehabilitation benefits in some applications. A high-solids (50 wt%) thickener underflow analogue (kaolin, silt, and fine sand) was treated with anionic polyacrylamide (PAM) polymers at elevated dosages (up to 1,000 g t-1) to establish if aggregate structures created during inline tailings flocculation survive or change over longer-term consolidation. Low and high molecular weight (MW) PAM polymers of fixed anionicity (30%) were tested. Focused beam reflectance measurement (FBRM) provided real-time monitoring of the aggregation state after polymer addition. The compressibility of the inline flocculated tailings was assessed over an eight week period. Variations in the size–density relationship of aggregate structures were determined over this period using an image analysis technique, revealing that the shorter polymer chains produced denser, more compact structures immediately after deposition, whereas the longer chains resulted in a much slower re-conformation of the partially adsorbed polymer, leading to additional densification over time. Eight weeks after deposition, inline flocculated tailings produced with the low MW polymer were characterised by a higher compressive yield stress compared with the high MW polymer, consistent with the formation of smaller, more rigid aggregate structures with the shorter chains. The potential impact of such structures on longer-term rehabilitation properties (e.g. metal/metalloid ion adsorption and surface exchange capacity) of the treated tailings is discussed.
Allan Costine; Fiona Benn; Phillip Fawell; Mansour Edraki; Thomas Baumgartl; John Bellwood. Understanding factors affecting the stability of inline polymer-amended tailings. Proceedings of the 21st International Seminar on Paste and Thickened Tailings 2018, 103 -116.
AMA StyleAllan Costine, Fiona Benn, Phillip Fawell, Mansour Edraki, Thomas Baumgartl, John Bellwood. Understanding factors affecting the stability of inline polymer-amended tailings. Proceedings of the 21st International Seminar on Paste and Thickened Tailings. 2018; ():103-116.
Chicago/Turabian StyleAllan Costine; Fiona Benn; Phillip Fawell; Mansour Edraki; Thomas Baumgartl; John Bellwood. 2018. "Understanding factors affecting the stability of inline polymer-amended tailings." Proceedings of the 21st International Seminar on Paste and Thickened Tailings , no. : 103-116.
Aggregation of tailings is instrumental for developing a physical environment permitting water infiltration, aeration, and root penetration. Previous research found that microaggregation of Cu-Pb-Zn tailings was stimulated by amendment of composted sugarcane residues. The present study aimed to identify organic functional groups in humic acids (HA) involved in the aggregation of Cu-Pb-Zn tailings, which were considered to be formed from long-term organic matter decomposition in the engineered tailing-soil. The adsorption of HA by the weathered (WT) and freshly deposited (FT) tailings was evaluated at a range of pH conditions in tailing-HA suspension. Humic acid adsorption decreased with increasing pH from 5.0 to 9.0. The FT was found to contain more oxy-(hydr)oxides, particularly poorly crystalline Fe and Al oxy-(hydr)oxides than the WT, which was one of the factors attributing to FT’s higher HA affinity. The Fourier transform infrared spectroscopy analysis of tailing particles before and after HA adsorption indicated that carboxylic and phenolic groups of HA preferentially interacted with tailing mineral particles, probably through ligand exchange, polyvalent cation bridge and electrostatic attraction. The pH-dependent HA adsorption indicated the potential role of functional groups of organic matters in microaggregation of Cu/Pb-Zn tailings. Moreover, the presence of abundant Al/Fe oxyhydroxides promoted organo-mineral interactions. The present findings will contribute toward developing field application to engineer functional Technosols from the tailings by selecting organic matter rich in functional groups. Copyright © 2017. . Copyright © by the Soil Science Society of America, Inc.
Mingrui Yuan; Zhi Ping Xu; Tuan A.H. Nguyen; Thomas Baumgartl; Longbin Huang. Interaction of Humic Acid with Cu/Pb-Zn Tailings of Different Degrees of Weathering. Soil Science Society of America Journal 2017, 81, 712 -722.
AMA StyleMingrui Yuan, Zhi Ping Xu, Tuan A.H. Nguyen, Thomas Baumgartl, Longbin Huang. Interaction of Humic Acid with Cu/Pb-Zn Tailings of Different Degrees of Weathering. Soil Science Society of America Journal. 2017; 81 (4):712-722.
Chicago/Turabian StyleMingrui Yuan; Zhi Ping Xu; Tuan A.H. Nguyen; Thomas Baumgartl; Longbin Huang. 2017. "Interaction of Humic Acid with Cu/Pb-Zn Tailings of Different Degrees of Weathering." Soil Science Society of America Journal 81, no. 4: 712-722.