Tesi sul tema "Coal mine soils"

Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains 149 p. : ill. (some col.), map (part col.). Vita. Includes abstract. Includes bibliographical references (p. 66-71).

A 5 -year experiment was conducted from 1978 through 1982 on the Black Mesa Coal Mine, Kayenta, Arizona, to study plant species best suited for coal mine reclamation and the effects of fertilizer on selected species. Five plant species were broadcast seeded on coal mine soil (spoils) and unmined soil. Prior to planting, 560 kg /ha of 16-20-0 fertilizer were applied on one -half of each site while the other half received no fertilizer. Immediately after planting, sprinkler irrigation water was applied on all plots, as needed, for the first two years. After two years, fertilizer and irrigation were discontinued on both soil materials and all plant species received only natural rainfall for the following three years. Coal mine soil contained more total soluble salts, nitrogen, potassium, sodium, and organic matter than did unmined soil; however, unmined soil had a higher pH and contained more phosphorous than did coal mine soil. Plant growth measurements were recorded for each plant species in October of each year. In general, plants grew better and produced more forage in unmined soil than they did in coal mine soil. All plant species grew better, yielded more forage, and produced a more satisfactory ground cover when they were fertilized than they did when they were not fertilized. Plant species differed greatly in general growth, forage yield, and percent ground cover within soil materials and within fertilizer treatments. Crested wheatgrass (Agropyron cristaturn L.), western wheatgrass (Agropyron smithii Rydb.), and vernal alfalfa (Medicago sativa L.) grew better, yielded more forage, and produced a more complete ground cover than did Indian ricegrass (Oryzopsis hymenoides Ricker) or fourwing saltbrush (Atriplex canescens Pursh). In general, the reclamation of unmined soil with fertilizer and a combination of natural rainfall and sprinkler irrigation during the first two years and with perennial grasses was more successful than the reclamation of coal mine soil with no fertilizer and with legumes or shrubs in the semiarid environment in the southwestern United States.

Current reclamation research following surface mining in the Appalachian coal region seeks to measure carbon (C) and nutrient accumulation and retention under forest vegetation to better understand the role of reforestation in the re-establishment of these ecosystem services. This study capitalized on the Controlled Overburden Placement Experiment (COPE), a 29-year-old reclamation research installation in southwestern Virginia, to estimate long-term mine soil C sequestration potentials and nutrient capitals after different reclamation strategies. The COPE includes two studies, a rock mix study (RM) comparing topsoil substitutes created from different ratios of local overburden [pure sandstone (SS), pure siltstone (SiS), 2:1 SS to SiS, 1:1 SS to SiS, and 1:2 SS to SiS], and a surface amendment study (SA) comparing organic amendments [control (CON), natural topsoil (TS), sawdust (SD), and 22 Mg ha-1 (22B), 56 Mg ha-1 (56B), 112 Mg ha-1 (112B) and 224 Mg ha-1 (224B) of biosolids] on a common 2:1 SS to SiS topsoil substitute. In the RM, overburden selection significantly affected soil nitrogen (N) and C concentrations as well as many other soil chemical [e.g., available phosphorus (P), pH, and other macro- and micronutrients) and physical (e.g., sand, silt and clay contents) properties.    C sequestration rates were also significantly different and ranged from 0.13 to 0.47 Mg C ha-1 yr-1. Many of the differences demonstrated relationships with the mineral make-up of the RM treatment. The SA mine soils also differed significantly in many properties after 29 years, including N, C, and many other nutrient concentrations and contents. C sequestration rates were also significantly different with the SD and 224B treatments having negative sequestration rates, and the remaining treatments ranging from 0.23 to 0.80 Mg C ha-1 yr-1. Collectively, the results demonstrate that topsoil substitutes and surface amendments show divergent trends in soil C and nutrient dynamics after nearly three decades of development and stress the importance of post- mining reclamation based on available materials and reclamation goals.
Master of Science

[Truncated abstract] Many soil properties are involved in supporting the growth of plants and in limiting soil degradation. The present study was carried out to provide a basis for minimising environmental impact by providing a firm understanding of the soil properties that affect plant growth for soils developed from mining waste from the Wesfarmers Premier coalmine at Collie. The purpose of this study was to provide an understanding of the soil materials and to identify the potential interactions between soil properties and plants for soils developed on coalmine materials at the Premier mine, Collie. This research was to identify the nature of the manmade soils so as to determine if soil forming processes are active, to determine soil acidity including pH buffering capacity and the lime requirement of soils, to measure water retention characteristics and soil available water for plant growth, to relate soil properties to possible effects on plant growth, and to identify management strategies to improve soil conditions and overcome plant growth constraints. Seventy-seven manmade horizons from pits in 18 constructed soils, ranging from 9 to 21-years old, were analyzed throughout this study. These samples are classified based on soil depth, layer (topsoil and subsoil), and age of soil since rehabilitation. The methods for doing most of the analyses follow the Australian Soil and Land Survey handbook by Rayment and Higginson (1992). The results are presented quantitatively and soil properties are compared to provide information on pedogenic processes, the extent of soil development, the ability of the soils to resist degradation and to provide an indication of soil parent materials

The Star Fire Coal Mine is a large strip mining operation (10,000 acre permit) that produces mine spoil consisting of sandstones, shales, siltstones, and underclays of the Pennsylvanian Breathitt Formation. Chemical analysis of groundwater from the saturated mine spoil show unusually high magnesium concentrations, with magnesium constituting between 27 and 47 percent of the major cations. Excess magnesium in water is detrimental to plant metabolism, and its content in groundwater may limit its use for irrigation and other uses during a post-mining land use plan. Petrological methods (thin section point count analysis and x-ray diffraction) and geochemical methods (electron microprobe analysis and water extraction experiments) were performed to determine the source of magnesium in sandstone and shale samples of the Breathitt Formation. Based on mineral percents and concentrations of magnesium found in samples used for waterrock interaction samples, magnesium-rich siderite was found as the primary contributor of magnesium to the groundwater.
Department of Geology

Surface coal mining is a large-scale disturbance that disrupts soil properties that requires reclamation. Reclamation monitoring and success typically focuses on vegetation communities, but soil monitoring may improve our understanding of barriers to reclamation success. In this study, we assessed biological presence in stockpiled soils using seed viability screening and phospholipid fatty acid analysis. We found microbial communities had distinct shifts in structure, declines in overall abundance of organisms with increased stockpile depth, and that total seedling emergence was lower in stockpiled soils than the reference site. In addition, we measured carbon pools, vegetative cover, and other edaphic properties in a chronosequence of reclaimed mine land (chapter two) in order to quantify how reclamation affects soil properties. We found disturbance affected all soil properties at every treatment (years since reclamation) and that all soil carbon pools measured were significantly (p <0.005) lower than that of the reference site.
North Dakota Industrial Commission Lignite Energy Counsel

The environmental impact and sustainability of irrigation with coal-mine water was investigated from an agricultural point of view on different coal-mines in the Republic of South Africa. Field trials were carried out on a commercial and plot scale, on sites that could offer a range of soil, crop, weather conditions and water qualities such as gypsiferous, sodium sulphate and sodium bicarbonate waters. Crop production under irrigation with gypsiferous mine water is feasible on a field scale and sustainable if properly managed. No symptoms of foliar injury due to centre pivot sprinkler irrigation with gypsiferous water were observed. The presence of high Ca and Mg in the water suppressed plant uptake of K. This could be corrected by regular application of K containing fertilizers. The bigger problem experienced was waterlogging due to poor site selection, especially during the summer months. The problem is not related to the chemistry of the gypsiferous water used for irrigation. Pasture production with Na2SO4 rich mine effluent was also feasible, at least in the short term, but would need a well-drained profile and large leaching fraction to prevent salt build up. Forage quality was not affected by the Na2SO4 water used. NaHCO3 water was of very poor quality for irrigation and is not recommended for irrigation. Salt tolerant crops that are not susceptible to leaf scorching can be produced with this water, but only with very high leaching fractions and careful crop management. Regular gypsum application will be required to prevent structural collapse of the soil. Most of the salts applied will leach from the soil profile, and will probably need to be intercepted for treatment or reuse. The Soil Water Balance (SWB) model was validated successfully. The model predicted crop growth, soil water deficit to field capacity and soil chemistry reasonably well, with simulated results quite close to measured values. Soluble salts have to be leached from the soil profile, so that crop production can be sustainable, but will externalize the problem to the receiving water environment. To assess the environmental impact of irrigation with coal-mine water, it is valuable to develop a tool that can assist with prediction of offsite effects. SWB was validated for runoff quantity and quality estimations, and was found to give reasonable estimates of runoff quantity and quality. SWB also predicted the soil water and salt balance reasonably well. This gives one confidence in the ability of the model to simulate the soil water and salt balance for long-term scenarios and link the output of SWB to ground and surface water models to predict the wider impact of large scale irrigation. This will also link the findings of this work to other research oriented towards the management of mine water and salt balances on a catchment scale. It will also help authorities make informed decisions about the desirability and consequences of permitting mine water irrigation on a large scale. Irrigation with gypsiferous mine water can be part of finding the solution to surplus mine water problems. Appropriate irrigation management of mine water is essential for the long-term sustainability of irrigation.
Thesis (PhD)--University of Pretoria, 2009.
Plant Production and Soil Science
unrestricted

Highly acidic and metal-rich runoff from coal storage facilities can have a dramatic impact on local surface and ground water quality. In order to identify important reactions governing metal transport within subsurface environments subject to infiltration of coal pile runoff, samples of uncontaminated subsoil and aquifer materials adjacent to the D-Area coal stockpile runoff containment basin at the Department of Energy's Savannah River Site were collected and subjected to leaching with the acidic, metalliferous coal pile runoff. Columns were packed to bulk densities of 1.5 Mg m³ and subjected to steady, saturated flows of 0.2 and 1.3 cm h⁻¹, Effluent was collected and multicomponent transport through the subsoil and aquifer materials evaluated. Observed transport was then related to soil chemical and mineralogical properties. Mass balance calculations, a sequential dissolution scheme in which column leaching was terminated and elements partitioned to aqueous, M NH₄CI, and ammonium oxalate in the dark (Ox)-extractable phases, and mineralogical and surface chemical analyses were used to identify important chemical processes and mineralogical alterations.
Ph. D.

Species prescriptions are developed for revegetating abandoned acidic coal overburden seepage sites in the Collie region of Western Australia. The research involved selecting appropriate plant species and determining successful methods of enhancing revegetation. Candidate species were screened for tolerance to acidic overburden materials, local climate conditions and metal toxicity. Methods tested included improving spoil conditions and trialing an alternative method for seeding.Twelve species of native plants were tested for tolerance in two acid overburden materials in pot and field trials. Eucalyptus robusta is the most tolerant, Eucalyptus camaldulensis and Eucalyptus cladocalyx are highly tolerant, Eucalyptus rudis and Melaleuca hamulosa demonstrate potential, provided adequate soil moisture is available.An important growth restriction factor in acid soils is the presence of free aluminium ions. A glasshouse trial performed on seven species for tolerance to aluminium toxicity revealed E. robusta as most tolerant and E. camaldulensis and Kunzea ericifolia a highly tolerant. E. rudis and M. hamulosa are moderately tolerant, but E. cladocalyx and Eucalyptus diversicolor are very sensitive to aluminium.Various methods were trialed to increase growth of seedlings transplanted on to acidic overburden sites. Both commercial cow manure and slow-release fertiliser tablets increase growth, whereas commercial potting mix and lime do not. Inoculation of plants with the ectomycorrhiza fungus Pisolithus tinctorius increases the amount of infection in roots but does not enhance plant growth.Supplementary fertilisation is necessary to maintain growth (nitrogen) and restore chlorophyll production (phosphorus) in fast growing eucalypt seedlings planted into typical acidic spoils. Poor levels of nutrient availability in such acidic sites appear to be the primary factor in ++
retarding growth. In the absence of supplementation, foliage reddening is observed in several species.An alternative method of seeding dumps is fascining. Prepared dump surfaces may be covered with capsule-laden branchwood of myrtaceous species. Material of the locally available Kunzea ericifolia is effective in producing many seedlings. Subsequent seedling growth is enhanced with fertiliser and lime addition.

This study investigates coal discard cover soil fertility and its potential for degradation, particularly in terms of its salinisation and acidification potential. Seven rehabilitated coal discard dumps in the Witbank, Ermelo and Newcastle regions were used as study areas. All areas were rehabilitated with a cover soil layer, revegetated and annually fertilised with nitrate fertilisers, super phosphate, kraal manure and lime. Performance guideline for pH of 5.5-(6.5 i0.5)-7.5 and electrical conductivity guideline of preferably less than 200 mS.rn-' but not higher than 400 mS.m-' were set based on literature information. Soil chemical data from a three-year fertilisation programme were used to assess the fertility of the cover soil surface (0-150mm). Data collected over a three year period as well as additional electrical conductivity and pH measurements from the cover soil surface, subsoil, cover soil/coal contact zone and underlying coal itself were used to assess the occurrence of salinisation and acidification of the cover soil. The soil fertility varied significantly among dumps as well as over the three years. Results indicated an increase in ammonium acetate extractable macro elements (calcium, magnesium and potassium). With the exception of manganese, no micro-element toxicities were recorded. Iron concentrations were slightly elevated in some of the sandy cover soil layers. No increase in soluble nitrogen (nitrate and ammonium) was found and most soluble nitrogen was in the form of nitrates. In general the Bray extractable phosphate increased during the study period. It can be predicted that with the following fertiliser programme increases of exchangeable macro-elements as well as available phosphorus can be expected. The study could not indicate an increase in adsorbed or available nitrogen. Organic carbon was initially not analysed therefore no comments can be made whether organic matter increased. Four of the seven dumps surveyed had comparably similar organic carbon levels to the background samples. Overall the fertiliser programme increased the electrical conductivity and decreased the acidity of the cover soil surface. Acidity and salinity was in general not a problem at the surface of the cover soil and pH was even slightly higher in cover soil samples. The acidity and especially salinity increased at the subsoil and so did the sulphate concentrations. Calcium and magnesium sulphate were predominantly responsible for higher electrical conductivity measurements. The percentage exchangeable sodium was also predominantly less than 2% indicating that sodicity is not currently a problem in cover soil. Soil fertility was satisfactory for vegetation growth and macroelement concentrations were in the correct ratio although calcium was slightly high. An elevated sulphate concentration, in comparison to the natural grassland soils, as well as a high salinity and high acidity in the subsoil layers indicate that salinisation and acidification could deteriorate without proper management. A slightly acidic cover soil can also be attributed partially to its natural acidic pH due to the wellweathered and leach property of burrow pit. Higher than recommended salinity levels were found in subsoil samples but the occurrence of acidification of the subsoil was more dump specific. In relation to acidity and salinity guidelines only the cover soil of one dump was concerning and the larger dumps subsoil acidity and salinity were elevated. The following management strategies are proposed: a) The acidification potential, and therefore the pyrite content of the coal discard must be considered during decisions making on the rehabilitation method (clay barriers), topsoil depth, maintenance and mine closure potential. b) The occasional monitoring of the subsoil's and coal contact acidity is recommended, although not much can be done to stop acidification after cover-soil placement. c) To ensure a more sustained from of nitrogen supplementation over the long term the use of selected legumes should be investigated. Research in Europe and Australia suggested that nitrogen fixation could contribute substantially to the nitrogen for plant uptake. d) The physical properties of the topsoil (bulk density 8 soil compaction) are also being neglected and needs to be assessed occasionally and interpreted together with chemical analyses. Observations in other studies indicate that this could be the most fundamental problem for vegetation growth and not necessarily soil fertility, since soil physical properties could have a major impact on root development. Key words: Coal discard, mine rehabilitation, soil fertility, topsoil degradation, salinisation, and acidification
Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2004.

A 3-year experiment was conducted in the greenhouse at Tucson, Arizona to study the effects of three soil materials, three mulching treatments, and two soil moisture treatments on the growth and forage production of western wheatgrass (Agropyron smithii Rydb.) when used in the reclamation of coal mine spoil. The three mulching treatments were: (1) No mulch. (2) Barley (Hordeum vulgare L.) straw mulch, and (3) Russian thistle (Salsola kali L.) mulch. The two soil moisture treatments consisted of: (1) Optimum (60 cm total) and (2) Stressed (30 cm total). There were significant differences in number of stems per pot, plant height, and forage yield between soil materials, mulching treatments, and soil moisture treatments. The Gila loam soil, barley straw mulch, and optimum soil moisture treatment produced the highest number of stems per plot, the tallest plants, and the highest yield of forage. Plants were more vigorous and produced more forage when soil mulch (incorporated organic matter mulch) was used than when soils were not mulched. Barley straw and Russian thistle were of similar value as mulching materials. Within soil materials and within mulching treatments forage yields were significantly higher with optimum soil moisture than they were when moisture was limited.

Surface coal mining has taken place in North Dakota for many decades. Upon the mining process, the mined lands need to be reclaimed to a better state than pre-mining. The reclamation process is a timely and costly procedure. Currently, most reclamation strategies focus only on above ground biomass. Our research entailed two different studies, the first looking into vegetative species composition and canopy cover of reclaimed mine lands, and the second focuses on belowground properties affected by soil compaction over a 40 year reclamation gradient. Species composition and canopy cover did not increase over 40 years (p> 0.05). Soil compaction did not decrease, and rooting depths and soil water content range did not increase over the reclamation gradient (p> 0.05). Relative plant community patch size and soil health on reclaimed lands over four decades indicate the landscape-level success of the current ecosystem-based reclamation strategy.
BNI Coal

Surface coal mine reclamation is challenged by alterations in soil characteristics, compaction being the most plant-yield reducing. Superabsorbent polymers (SAPs) ability to retain large volumes of water gives them the potential to alter soil properties. Laboratory objectives were to determine how SAPs alter water retention, liquid limit (LL), evaporation, saturated hydraulic conductivity (Ksat), and compression across five soil series. Increasing SAP application rates to 0.2% significantly increased plant available water (PAW), stage one evaporation duration, LL, stage two evaporative water loss, and significantly decreased stage one evaporative water loss, Ksat, and compression for various soil series. Field study investigated how SAP, deep ripping (R) and mulch (M) impacted penetration resistance and spring wheat yield (Triticum aestivum). Application of 0.04% SAP improved yields similar to R. Penetration resistance decreased with R, and SAP application showed reduction similar to R. While SAPs show potential as a reclamation tool, application longevity needs evaluation.

Surface mining operations require a comparison of post-mining erosion rates with pre-mining soil loss to ascertain if remedial measures are needed. In this study the Universal Soil-Loss Equation (USLE) was modified to reflect conditions of western rangelands to develop a procedure for estimating pre-mining soil loss rates. The modification used back-calculation for the C-Factor and an adjusted R-Factor based on storm size. Soil loss simulation based on stochastic precipitation patterns is appropriate to the site--the La Plata mine area in northern New Mexico--and increases the flexibility of the USLE as a soil loss predictor for western rangelands.

Thesis (MSc)--Stellenbosch University, 1997.
ENGLISH ABSTRACT: The activity of iron-oxidizing bacteria, for example, Thiobacillut. ferrooxidans, in the outer layers of coal waste dumps results in the oxidation of pyrite with the formation of large volumes of acid mine drainage. The process requires atmospheric oxygen and moisture. Acid mine drainage may possibly be controlled by creating unfavourable environmental conditions in dumps for the iron-oxidizing bacteria. The present research investigated the possibility of inhibiting these bacteria and consequently acid formation in coal waste dumps by means of different dump construction techniques. Physical and chemical conditions, acid formation and populations of four groups of bacteria which might produce acid were studied in the outer layers of ten differently constructed pilot scale coal waste dumps at the Kilbarchan Mine near Newcastle, Kwazulu-Natal, from September 1993 to July 1995. Dump covers consisting of a 30-cm or 70-cm layer of Estcourt soil of low permeability covered with 70 cm or 30 cm, respectively, of more permeable Avalon soil produced anaerobic conditions in the dumps throughout most of the 22 months of the test period, as did a cover of 70 cm compacted plus 30 cm uncompacted Avalon soil alone. An uncoMpacted 30-cm or compacted 50- cm Avalon soil cover proved ineffective in causing prolonged anaerobic conditions. Uncovered dumps showed only slight reduction of oxygen in the coal waste after heavy rains. Pockets of acidity were detected on several occasions in the coal waste below the 50-cm Avalon soil layer from the time of construction and progressively increasing acidity in the uncovered dumps and the waste below the 30-cm Avalon soil cover. Iron-oxidizing bacterial populations of the T. ferrooxidans type have tended to be higher in the uncovered dumps and Avalon soil-covered dumps showing acidification than in the non-acidified dumps covered with 1 m of Avalon soil or Avalon and Estcourt soil. Associated populations of iron-oxidizing bacteria of the Metallogenium type, acidophilic and non-acidophilic thiosulphate-oxidizing bacteria were generally low in the coal waste of the dumps. Thus, five of the soil covers, all with a thickness of 1 m, but not covers with a thickness of 0.5 m or less, proved effective for almost 2 years in inhibiting the diffusion of oxygen to the underlying coal waste in the pilot scale dumps and also appeared to suppress the populations of iron-oxidizing bacteria believed to be implicated in acid formation in the coal waste. These results suggest that coal waste dumps in South Africa should be covered with soil layers of 0.5-1.0 m thick to prevent the generation of acid mine drainage.
AFRIKAANSE OPSOMMING: Die aktiwiteit van ysteroksiderende bakteriee soos Thiobacillus ferrooxidans, in die buitenste lae van steenkoolafvalhope, veroorsaak die oksidasie van piriet met die gevolg dat groot volumes suur mynafloopwater gevorm word. Hierdie proses benodig suurstof en vog. Suur mynafloopwater kan moontlik beheer word deur 'n situasie te skep waar die toestande in die hope ongunstig is vir die ysteroksiderende bakteriee. Die huidige navorsing het die moontlikheid ondersoek om hierdie bakteriee te inhibeer deur verskillende afvalhoopontwerpe op die proef te stel en sodoende suurvorming in steenkoolmynhope te beperk. Die fisiese en chemies kondisies, suurvorming en populasies van vier verskillende bakterie-groepe wat dalk by suurvorming betrokke is, is vanaf September 1993 tot Julie 1995 bestudeer in die buitenste lae van tien verskillend gekonstrueerde loodsskaalafvalhope by die Kilbarchan myn naby Newcastle in KwaZulu-Natal. Afvalhoopbedekkings bestaande uit 'n 30-cm of 70-cm Estcourt grond met 'n lae permeabiliteit bedek met'n 70-cm of 30-cm laag van meer deurlaatbare Avalon grond het anaerobe kondisies veroorsaak. Ongekompakteerde 30-cm en gekompakteerde 50-cm Avalon grondlae het egter nie bestendige anaerobe kondisies in die hope veroorsaak nie. Die onbedekte hope het aerobics gebly met slegs effense dalings van suurstofkonsentrasies gedurende en na swaar reens. Geisoleerde monsters uit die steenkoolafval onder die 50-cm Avalon grondlaag het vanaf die begin van die toetsperiode tekens van suurvorming getoon. Die onbedekte steenkoolafval en die van die sel met 'n 30-cm Avalon grondlaag het met verloop van tyd al hoe meer suur geword. Die ysteroksiderende bakterie-populasies van die T. ferrooxidans tipe het geblyk om in die onbedekte en Avalon grondbedekte hope wat tekens van suurvorming getoon het hoer te wees as in die hope wat met 'n 1-m laag Avalon grond of Avalon en Estcourt grond bedek is en geen tekens van suurvorming getoon het nie. Ysteroksiderende bakteriepopulasies van die Metallogenium tipe, nieasidofiele en asidofiele tiosulfaatoksiderende populasies was oor die algemeen laag in die steenkoolafvalhope. Vyf van die grondlae wat alma! 1 m dik was het dus geblyk om effektief te wees in die bekamping van die infiltrasie van suurstof na die onderliggende steenkoolafval in die loodskaalhope. Dit lyk asof daardie lae die ysteroksiderende populasies betrokke by suurvorming onderdruk het. Die 0.5-m grondbedekking het egter nie so 'n sterk onderdrukkende effek op die suurstofinfiltrasie of die bakteriepopulasie gehad nie. Na aanleiding van hierdie resultate blyk dit dat steenkoolafvalhope in Suid-Afrika met minstens 0.5 tot 1..0 m grond bedek moet word om effektief die probleem van suur mynafloopwater te bekamp.

Thesis (MSc)--Stellenbosch University, 1998.
One copy microfiche.
ENGLISH ABSTRACT: The biologically catalysed oxidation of pyrite in the outer layers of coal waste dumps leads to the formation of acid mine drainage. The oxidation of pyrite to ferric iron and sulphate is a complex process involving various abiotic and biologically catalysed reactions. Pyrite is abiotically oxidized by ferric iron, with the formation of thiosulphate and ferrous iron. Thiosulphate decomposes to form various inorganic sulphur compounds. Bacterial catalysis of pyrite oxidation is achieved by iron-oxidizing bacteria oxidizing ferrous iron to ferric iron. Bacteria that oxidize sulphur compounds assist the catalysis by oxidizing thiosulphate and its decomposition products. Heterotrophic organisms may play a role by consuming organic substances inhibitory to the lithotrophic bacteria. Abiotic ecological factors, acid formation and populations of iron-oxidizing bacterial groups were studied in 10 differently constructed pilot scale coal waste dumps, as the second phase of a study which started in September 1993. Gas samples were withdrawn weekly from coal waste through permanently buried stainless steel probes, for analysis in the field using a portable oxygen/carbon dioxide meter. Samples of coal waste were extracted by auger for analysis of moisture, pH and microbial populations. The analyses of oxygen and pH can be recommended for the routine monitoring of rehabilitated waste dumps. Covers of Avalon soil 0.3 or 0.5 m thick, were not adequate to prevent acidification. Coal waste covered with 0.7 m compacted beneath 0.3 m uncompacted Avalon soil, showed a slow pH decline, but reached approximately pH 3 in 1997. Covers of compacted Estcourt soil beneath tmcompacted Avalon soil to a cover depth of 1 m were effective in preventing acidification and generally kept the coal waste anaerobic. However, all covers developed cracks during drought conditions in 1995, allowing aeration. Low pH of some samples from these dumps during 1995/1996 may have indicated the start of acidification. Bacteria oxidizing high concentrations of ferrous iron and considered to be Thiobacillus ferrooxidans, were monitored routinely, but may not have been the dominant iron-oxidizer, as population counts using media with a lower ferrous iron concentration were higher. The majority of the latter organisms could also not oxidize sulphur, hence were not T. ferrooxidans. The populations of the high ferrous iron-oxidizing bacteria were affected by pH, tending to be high in acidified and low in non-acidified coal waste. Investigations of microbial populations forming iron-oxidizing consortia in enrichment cultures from coal waste and acid drainage samples showed the presence of T. ferrooxidans, the heterotrophic bacterial genus Acidiphilium, fungi of the genus Penicillium, unidentified filamentous fungi, including Cladophialophora-like morphological types, and a yeast of the genus Dipodascus. In interaction studies, the Penicillium isolate had an inhibitory effect on T. ferrooxidans (subjected to organic compound stress), but the Cladophialophora-like fungi reduced inhibition by organics. Fungi have not previously been studied in detail as components of iron-oxidizing consortia, but the bacterial isolations agree with those elsewhere, indicating that appropriate conclusions from acid mine drainage research in other parts of the world can be applied in KwaZulu-Natal.
AFRIKAANSE OPSOMMING: Die biologies gekataliseerde oksidasie van piriet in die buitenste lae van steenkoolafvalhope lei tot die vorming van suur mynafloopwater. Die oksidasie van piriet tot ferri-yster en sulfaat is 'n komplekse proses wat abiotiese en biologies gekataliseerde reaksies insluit. Piriet word abioties deur ferri-yster geoksideer, met die vrystelling van tiosulfaat en ferro-yster. Tiosulfaat verval om verskeie anorganiese swawelverbindings te vorm. Bakteriese katalise van pirietoksidasie word deur ysteroksiderende bakteriee wat ferro-yster na ferri-yster oksideer, bewerkstellig. Bakteriee wat swawelverbindings oksideer maak 'n bydrae tot die katalise deur tiosulfaat en vervalprodukte daarvan te oksideer. Heterotrofe organismes mag ook 'n rol speel deur organiese verbindings wat die litotrofe bakteriee mag inhibeer, te verbruik. Abiotiese ekologiese faktore, suurvorming en bevolkings ysteroksiderende bakteriee is in 10 verskillend gekonstrueerde loodsskaal steenkoolafvalhope bestudeer, as die tweede fase van 'n studie wat in September 1993 begin het. Gas monsters is weekliks uit die steenkoolafval onttrek deur vlekvrye staal peilers wat permanent daarin begrawe is, en met behulp van 'n draagbare suurstoflkoolstofdioksiedanaliseerder in die veld ontleed. Monsters van die steenkoolafval is met behulp van 'n kleiboor vir die analise van vog, pH en mikrobepopulasies geneem. Die analise van suurstof en pH kan aanbeveel word vir die roetiene monitering van gerehabiliteerde afvalhope. Bedekkings van 0.3 of 0.5 m Avalongrond was nie voldoende om suurvorming te verhoed nie. Steenkoolafval wat met 0.7 m gekompakteerde en 0.3 m ongekompakteerde Avalongrond bedek is, het 'n stadige pH-daling getoon, maar het in 1997 ongeveer pH 3 bereik. Bedekkings van gekompakteerde Estcourtgrond onder ongekompakteerde A valongrond met 'n totale dikte van 1 m, was effektief in die voorkoming van suurvorming. Hulle het oor die algemeen die steenkoolafval anaerobies gehou, maar aile bedekings het tydens die droogte in 1995 krake ontwikkel, wat suurstof laat binnedring het. 'n Lae pH gedurende 1995/1996 by sommige monsters uit hierdie hope mag die begin van suurvorming aangedui het. Bakteriee wat hoe konsentrasies ferro-yster oksideer en wat as Thiobacillus ferrooxidans beskou is, was moontlik nie die dominante ysteroksideerder nie, aangesien bevolkingstellings waar 'n medium met 'n laer konsentrasie ferro-yster gebruik is, hoer bevolkings getoon het. Die meerderheid van laasgenoemde organismes kon ook nie swawel benut nie en dus nie T. ferrooxidans was nie. Die bevolkings van die hoe ferro-ysteroksiderende bakteriee is deur pH beInvloed, met 'n geneigdheid tot hoe bevolkings in suur en lae bevolkings in minder suur steenkoolafval. Ondersoeke na die rnilcrobebevollcings wat in ysteroksiderende konsortia in verryldngslculture vanaf steenkoolafval- en suur mynafloopwatermonsters voorgekom het, het die teenwoordigheid van 7'. ferrooxidans, die heterotrofe balcteriegenus Acidiphilium, fungi van die genus Penicillium, ongeIdentifiseerde fungi, insluitend Cladophialophora-agtige tipes en 'n gis van die genus Dipodascus aangetoon. By interaksiestudies het die Penicillium-isolaat 'n inhiberende effek op T ferrooxidans (onderworpe aan organiese verbindingstres) gehad, maar die Cladophialophora-agtige fungi het die inhibisie deur organiese verbindings verminder. Fungi is nog the in detail as komponente van ysteroksiderende konsortia bestudeer the, maar die isolasies van bakteried stem saam met die van elders wat aandui dat toepaslike gevolgtreldcings ten opsigte van suur mynafloopwatemavorsing vanaf ander dele van die wereld ook in KwaZulu-Natal toegepas kan word.

The landfilling of biodegradable waste is proven to contribute to environmental degradation. Much wood and lumber is discharged as waste from the cleared fields. These woody wastes are subsequently disposed of by burning. However, it would be preferable to dispose of them without combustion to avoid the release of carbon dioxide, one of the critical greenhouse gases. Instead of burning these woody wastes, we should recycle them as future resources. One solution to this problem is to make compost from the waste. Compost use in agriculture is increasing as both an alternative to landfilling for the management of biodegradable waste, as well as means of increasing or preserving soil organic matter. This research aimed to contribute to the identification of a system for managing the production and utilization of wood waste (Quercus rubra and Pinus sylvestris) compost for sustainable agriculture, with particular regards to carbon dioxide produced from both compost and combustion of wood. Compost of wood was implemented in two consecutive trials. The first was carried out in greenhouse experiment in 4 liter pot of Quercus rubra and Pinus sylvestris (QR and PS) moisted by compost and tap water and infected by tiger worm (Eisenia fetida, EF) and European night crawlers (Dendrobaena veneta, DV) at different mixed ratios with lake mud (LM). The second was conducted in greenhouse experiment in 40 liter pot of the successful wood and worm from the first compost trial (QR and EF respectively). The tested wood (QR) was mixed separately by lake mud and horse manure and irrigated by compost and tap water. The final product, successful wood compost (QR) produced from the first trial (4 liter pot) was utilized in different mixed ratios with coal mine tailings (tertiary sand) in greenhouse pot trial to study his effects on improving soil physical and chemical properties and some plant growth parameters of RSM 7.2.1 grass. The wood compost produced from the second compost experiment (40 liter pot) and other artificial component named Arkadolith® were used as soil amelioration in field experiments of different selected sites with extremely unsuitable characteristics (tertiary and quaternary sand in Lusatia lignite region, Germany). The soil in each site was sowed by RSM 7.2.1 and autochthonous grasses. Also, some vermicompost samples were selected to study its thermal stability which compared with a soil sample (Niedermoorgleys) by using thermogravimetric analysis technique. Further investigation was achieved to evaluate the effect of charcoal as a source of carbon on vermicompost stability. Moreover some selected vermicompost samples were used to examine its microstructure under scanning electron microscope which compared also with the same soil used in thermal analysis. The obtained results under all studied experiments can be arranged as follow: First compost trial, Cumulative amount of carbon dioxide produced during composting period was lower than that evolved by combustion of wood. The results showed composting of wood can reduce the emitted CO2 up to 50 % when compared with the amount of CO2 produced from combustion of wood. The effect of different studied factors on different studied parameters show that, QR wood compost have more responsive to decomposition processes and humification rate in comparison with PS wood compost. Under different infection worms, Eisenia fetida (EF) was better than Dendrobaena veneta (DV) in biodegradation rate. Compost water has had a better impact of tap water in all studied decomposition parameters. For example, The compost content of OM and total OC was decreased with the increase of the decomposition period in the treatments of compost water and EF worm, where this decrease was higher at mixed ratio of 1:3 (wood: mud, w/w). The total content of N in the final products takes reversible trend regarding to OM and C content. The high content of N was found in QR wood compost moisted by compost water and infected by EF worm. The content of both macro-and micro-nutrients was clearly positive affected by the studied factors. The content of these nutrients in QR wood compost was higher than that found in the compost of PS wood. Second compost trial, The observed data show that, the amount of CO2 produced by composting was lower than that evolved by combustion of wood. Composting of wood reduced CO2 emission up to 40 % of the combustion wood CO2. Cumulative amount of CO2 produced from wood compost treated by horse manure was higher than that fount in the other treated by LM. The compost of wood treated by horse manure has had a high decomposition rate in comparison with that treated by lake mud. The treatments left without worms during all composting period and moisted by compost water have a responsive effects but it was lower than that infected by worms. Total and available contents of N, P, K, Mg, Zn, and Cu in the compost treated by HM were higher than that found in compost treated by LM. The other nutrients (Ca, Fe, Cu, and Mn) take reversible trend, which it was higher in LM than HM treatments. Thermal and microstructure analysis, The selected vermicompost samples from both first and second compost experiments showed, up to 200° C temperature the mass loss was due to free water and bound water (It was in vermicompost samples higher than soil sample). Mass loss from 200 to 550° C is due to easily oxidizable organic forms and it was higher in vermicompost than soil. In this stage the soil OM seems to be more stable than vermicompost which can be explained by a more intensive bond between the organic and inorganic components. At higher temperatures (T> 550° C) no significant detectable was appeared of soil organic matter. In contrast, the vermicompost treatments showed a high proportion of stable groups, especially aromatic compounds. These statements seem to be importance particularly for the practical application of the wood compost in terms of their long-term effect in the soil. The application of charcoal, showed no additional stabilizing effect of vermicompost. Also, the data show that, vermicompost structure characterized with high homogeneity and ratio of surface area to volume compared to those in soil structure. First plant trials (greenhouse), Different compost mixed ratios had positive impact on different extreme soil physiochemical properties. At the end of experiment (42 days) compost increased soil water holding capacity, decreased soil bulk and particle density and increased total porosity. The used wood compost modified soil buffering capacity and soil acidity. The availability of soil macro and micro nutrients were increased after adding wood compost. The wood compost had a positive effect in some growth parameters like fresh and dry matter yield of the selected grass. High dry matter yield and nutrients uptake was achieved with higher rates of compost application (25.0% > 12.5% > 3.0% > 0.0 %, w/w). Second plant trials (field experiment), Regarding to the effect of wood compost (QR) and Arkadolith® component on tertiary and quaternary sand, at the end of grown season (6 month) most soil and plant characteristics of tertiary sand were improved and it was better than that in quaternary sand. This trend reveals to, physical and chemical properties of tertiary sand was better than that in quaternary sand, like organic matter content, CEC, WHC, TOC, available nutrients. In the both sites, the effects of different type of soil conditioners arranged as follow: the treatments treated with wood compost is the better followed by the other treated with both wood compost and Arkadolith. Wood compost increased soil pH, CEC, soil buffering capacity, OM content, and soil WHC in comparison with Arkadolith which make a small improvement of these properties in both sites. Finally, Different growth parameters (height, covering, fresh and dry matter yield) of the used grasses were clearly positive affected by wood compost, with the highest production inherent to the treatments treated by the high amount of wood compost.
Entsprechend der Zielstellung wurden zunächst verschiedene Varianten der Kompostierung von Holzsubstanz getestet, um eine optimale Technologie, die auch für Entwicklungsländer realisierbar ist, herauszufinden. Hierzu sind in Pflanztöpfe Holzspäne (Woodchips) von zwei verschieden Holzarten (Laub- und Nadelholz) gefüllt und mit verschiedenen natürlichen Stickstoffquellen gemischt worden. Diese Ansätze wurden regelmäßig mit Kompostwasser appliziert. Nach vier Wochen sind zwei verschiedene Wurmarten (Dendrobaena veneta und Eisenia fetida) hinzugegeben worden. Die Feuchthaltung erfolgte ab diesem Zeitpunkt durch Frischwasser. Die qualitativ beste Versuchsvariante ist im nächsten Schritt mit weiteren natürlichen Stickstoffquellen, die in Entwicklungsländern zur Verfügung gestellt werden könnten, getestet worden. Von allen Kompostvarianten sind im Labor eine Vielzahl von bodenphysikalischen (z.B. Dichte, Wasserhaltekapazität) und bodenchemischen Zustandsgrößen (z.B. Elektrische Leitfähigkeit, Totalgehalte biophiler Elemente, Bodenreaktion, organische Substanzgehalte, Kationenaustauschkapazität) bestimmt worden. Die Wiederum qualitativ beste Mischung ist in einer weiteren Versuchsreihe in verschiedenen Mengenverhältnissen mit tertiärerem Abraumsand des Braunkohlebergbaus gemischt worden. In diese Versuchsmischungen wurde die Grasmischung RSM 7.2.1 eingesät und regelmäßig bewässert sowie die Wuchshöhe gemessen. Nach 42 Tagen wurden das Gras geerntet und die biometrischen Parameter, die Nährstoffgehalte (pflanzenverfügbare Fraktionen), die Bodenreaktion, die effektive bzw. potentielle Kationenaustauschkapazität sowie die Pufferkapazitäten der Mischsubstrate bestimmt. Die nächsten Versuchsvarianten sind als Feldversuche in der Niederlausitz durchgeführt worden. Für ihre Realisierung wurde als weiterer Zuschlagsstoff Arkadolith® zugemischt. Die Plotflächen sind sowohl auf Abraumsanden des Tertiärs als auch Quartärs angelegt worden. In jeweils eine Subvariante ist RSM 7.2.1, in die andere eine autochthone Grasmischung eingesät worden. Diese Experimente wurden nach 6 Monaten beendet, die Bestimmung aller Parameter erfolgte in gleicher Weise wie bei den Gewächshausversuchen. Auf Basis aller Versuchsreihen konnten die besten Kompostqualitäten und ihre optimalen Herstellungsvarianten ermittelt werden. Eine weitere Aufgabe war es zu untersuchen, wie im Vergleich zur Verbrennung von Holzmasse die CO2-Emission in die Atmosphäre durch Holzkompostierung verringert werden kann. Hierzu wurde während der verschiedenen Kompostierungsvarianten die CO2-Freisetzung gemessen. Im Vergleich dazu ist jeweils die gleiche Masse an Holzsubstanz verbrannt worden. Die Ergebnisse zeigten, dass im Vergleich zu der thermischen Verwertung von Holsubstanz die CO2-Emission bis zu 50 % verringert werden kann. Dem Boden kann darüber hinaus energiereiche organische Substanz zugeführt werden, die eine Entwicklung der Bodenorganismen ermöglicht. Ein weiteres Experiment zielte darauf ab, die Stabilität der Holzkomposte zu bestimmen. Darüber hinaus sollte untersucht werden, ob durch die Zufuhr von pyrogenem Kohlenstoff eine Vergrößerung der Stabilität zu erreichen ist. Diese Untersuchungen wurden mit Hilfe der Thermogravimetrie vorgenommen. Alle wichtigen Kompostierungsvarianten sind sowohl mit verschiedenen Zusatzmengen als auch ohne Zusatz von pyrogenem Kohlenstoff vermessen worden. Als Vergleichssubstanz diente der Oberboden eines Niedermoorgleys, der naturgemäß einen relativ hohen Anteil an organischer Substanz aufweist. Die Ergebnisse zeigten, dass im Bereich niedriger Temperaturen die Wasserbindung im Naturboden fester ist. In der Fraktion der oxidierbaren organischen Substanz, im mittleren Temperaturbereich gemessen, ist die natürliche Bodensubstanz ebenfalls stabiler, was auf eine intensivere Bindung zwischen den organischen und anorganischen Bestandteilen, also auf stabilere organisch-mineralische Komplexe, schlussfolgern lässt. Im Bereich höherer Temperaturen (T> 550° C) waren im Naturboden keine nennenswerten organischen Bestandteile mehr nachweisbar. Hingegen wiesen die Kompostvarianten einen hohen Anteil stabiler Fraktionen, vor allem aromatische Verbindungen, auf. Diese Aussagen erscheinen vor allem für die praktische Anwendung der Holzkomposte in Hinblick auf ihre Langzeitwirkung bedeutsam. Der Zusatz von pyrogenem Kohlenstoff zeigte keine zusätzliche Stabilisierungswirkung.

Made available in DSpace on 2014-10-09T12:47:19Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:10:26Z (GMT). No. of bitstreams: 1 08354.pdf: 6557210 bytes, checksum: 0c6cea793150b2683fda13b9ec421168 (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

In South Africa, most of the surface coal mines are situated on the Highveld of the Mpumalanga Province. The mining industry plays a vital role and contributes to the economy of the country. Very often the mining activities change the physical nature of the soil which results in soil compaction. In mine soils, compaction is of great importance in plant growth and the environment because its high levels may adversely result in the degradation of soil structure, reduced nutrient distribution and reduced root growth, which eventually decreases plant growth. To ensure a productive vegetation, compacted mine soils has to be ameliorated effectively. A combination of practices is suggested to alleviate soil compaction, but some of them are costly and not ecologically stable particularly the use of conventional methods. Therefore, the challenge is to use the potential practices to ameliorate compacted soils. The proposed investigations, which are envisaged to solve harmful effects of soil compaction on plant growth, include biological activities, achieved through appropriate application of cattle manure and planting of pasture species. A review on literature, some studies indicate that the application of organic manure amendments such as cattle manure may overcome the negative effects of compaction, due to the beneficial effects on soil physical, chemical and biological properties in the zone of incorporation. Other studies has shown that pastures are linked with improvements in soil structure, soil organic matter content, rooting depths, consequently, reductions in bulk density. The focus of this study were to monitor the root biomass of irrigated Tall Fescue (F. arundinacea cv Dovey) and dryland Smuts Fingergrass (D. eriantha cv Irene) on mine soils, and to describe soil bulk density and soil nutrient concentrations in such soils. This study were also determining the effects of incorporating cattle manure into compacted (mine soils) and non compacted (agricultural soils) and evaluating its effects on the seedling growth rate, dry matter and root biomass production of Tall Fescue and Smuts Fingergrass. In addition, the influence of different rates of cattle manure on soil bulk density and nutrient concentration in such compacted soil was also measured. These parameters are relevant to the sustainable rehabilitation of mine soils. Based on the results obtained in this study, it was concluded that the use of two grass species, Tall Fescue and Smuts Fingergrass, with vigorous root systems have extended their roots in compacted mine soil layers over two growing seasons. Other results have demonstrated that application of cattle manure revealed a significant decrease in soil bulk density of compacted mine soils planted to Tall Fescue and Smuts Fingergrass. The bulk density was at a minimum in the 80 tha-1 cattle manure-treated plots and followed by the 40 tha-1 cattle manure treatment, and the maximum bulk density was recorded for the control treatment (0 tha-1). The application of cattle manure resulted in a large input of nutrients to the soil as compared to untreated control and significantly increased Tall Fescue and Smuts Fingergrass growth and production. This research has illustrated that use of plant roots and cattle manure as soil organic amendments to reduce soil compaction may be environmentally and economically beneficial leading to a more sustainable agricultural system. Copyright
Dissertation (MSc)--University of Pretoria, 2010.
Plant Production and Soil Science
Unrestricted

Thesis (Ph.D. (Agriculture)) -- University of Limpopo, 2018
Surface coal mining requires good and sound rehabilitation practices to re-establish productive land capability and land use after mine-closure. The vast majority of Mpumalanga’s coal deposits are located below high quality and productive arable land. Impacts on soil and land, associated with surface coal mining can reduce the possibility to re-establish the pre-mining land capability and productive potential. Stockpiled soils are excavated from the ground during mining activities, and piled on the surface of the soil for rehabilitation purposes. These soils are often characterized by low Soil Organic Matter (SOM) content, low fertility, and poor physical, chemical and biological properties, limiting their capability for sustainable vegetation growth. The aim of this study was to assess coal-mine stockpile soil quality and its impacts on vegetation using laboratory techniques and Reflectance Spectroscopy. Firstly, the impact of quality of coal-mine stockpile soils on sustainable vegetation growth and productivity was investigated. Soils were collected at three different depths (surface (0-25cm), mid (150-200cm) and deep (300-350cm)), as well as mixed (equal proportion of surface, mid and deep) from two stockpiles (named stockpile 1: aged 10 and stockpile 2:20 years) at the coal mine near Witbank in Mpumalanga Province, South Africa. Soils were amended with different organic and inorganic fertilizer. A 2 x 4 x 5 factorial experiment in a randomized complete block design with four replications was established under greenhouse condition. A grass species (Digiteria eriantha) was planted in pots with unamends and amended soils under the greenhouse condition at ambient temperatures of 26-280C during the day and 16.5-18.50C at night. Mean values of plant height, plant cover, total fresh biomass (roots, stems and leaves) and total dry biomass were found to be higher in the stockpile 1 than in stockpile 2 soils. On average, plants grown on soils with amendments yielded plant height that was 98.28% higher than plants grown on soil with no amendment. On average, height of plants grown on soil amended with poultry manure and lime was 44.65% higher compared to plants planted on soils amended with NPK + lime, compost and poultry manure. On average, mixed soils had better vegetation growth than soil from the individual depths. In total, dry biomass and plant height of plants grown on mixed soils was 33.56% and 22.34% higher than plants grown on surface, mid and deep soils. Mixing soils changes texture, which might affect other physical properties like water availability, infiltration rate and aeration and, to some extent, chemical properties.Secondly, the effect of soil amendments on enzyme activity of coal-mine stockpile soil was investigated. The activity of β-glucosidase, alkaline phosphatase, acid phosphatase and urease was analysed after harvest of grass species (Digiteria eriantha). The results show significantly high activity for β-glucosidase, alkaline phosphatase and urease when soils were amended with poultry manure + lime. Soils with no fertilizer yielded significantly low enzyme activity compared to soil amended with poultry manure+ lime, NPK + lime, sole application of poultry and in some instances compost application. β-glucosidase, urease and acid phosphatase mean values generally tend to decrease with an increase in soil depth. β-glucosidase activity for surface soil was found to be 18.06% higher than that of mid and deep soil. The stockpile depth plays a major role in biochemical activities of the soil; deep soils, in most cases, have decreased microbial biomass and enzyme activity due to oxygen and moisture availability. The results for the effect of organic and inorganic amendment on stockpile soil showed that on average, alkaline phosphatase activity following the application of poultry manure + lime was 17.69% higher than that of lime + inorganic fertilizers (NPK). On average, the acid phosphatase activity following the application of lime + NPK was 56.33% higher than that of poultry manure + lime, compost, soil with no fertilizer as well as sole poultry manure. Urease activity for soil with no fertilizer was found to be 84.70% lower than that of soil amended with poultry + lime. The increase in enzyme activity was attributed to change in soil pH due to application of amendments. A comparison of the two stockpiles indicated that, stockpile 2 (20-year old) had low enzyme activity compared to stockpile 1 (10-year old). The activity of β-glucosidase, acid phosphatase, alkaline phosphatase and urease was found to be 11.03%, 8.04%, 10.03% and 60.23% respectively, higher on stockpile 1, relative to stockpile 2 soils. When soils are stockpiled for a long period of time, microbial biomass is reduced and that affect enzyme activity because microbial biomass is considered as the primary source of enzymes in the soil. Thirdly, the capability to estimate coal-mine stockpile soil properties using Reflectance Spectroscopy was investigated. Soil from coal-mine stockpiles were air dried, crushed, sieved and analysed using laboratory methods. The following soil properties: exchangeable calcium (Ca), sodium (Na), magnesium (Mg), potassium (K), soil pH, organic carbon (OC), phosphorus (P) and clay content were analysed as they are important for vegetation re-establishment during rehabilitation. Spectral reflectance of the soil samples was measured using FieldSpec 3 Portable Analytical Spectral Device (ASD®) spectrometer. Partial Least Square Regression (PLSR) was used to estimate various soil properties, in combination with various spectral transformation techniques such as untransformed reflectance spectra, First Derivative Reflectance (FD) and Log transformed spectra Log (1/R). To assess the performance of various predictive models, R2 (Coefficient of Determination), Root Mean Squares Error of Validation (RMSEV) and Variable Importance in the Projection (VIP) values were computed. The results showed that pH and Ca were accurately estimated (R2=0.79 and 0.69 and RMSEV=0.52 and 0.89cmol/kg respectively) using Log (1/R) reflectance as compared to other soil properties achieving R2 less than 0.5. Ca has strong correlation with pH. Ca expressed in soil solutions is mostly related to pH, which is what was attributed to accurate prediction of both Ca and pH. Soil pH in most cases is directly influenced by calcium carbonate content in the soil. Although the performance of other soil properties was poor, they were highly correlated with pH and Ca except for K. K is soluble and mobile and is therefore subject to leaching in most soils resulting in low K concentrations. Low K concentrations results in higher variability and lower R2 values.Finally, the capability of Partial Least Square Regression and Reflectance Spectroscopy to estimate the effect of coal-mine stockpile soil on foliar nitrogen and phosphorus content was investigated. Grass samples were collected from coal-mine stockpile soils and the adjacent unmined soils at open-cast coal mine around Witbank area in Mpumalanga Province, South Africa. Samples were oven dried and analysed for foliar N and P concentration in the laboratory. Spectral reflectance of the dried grass samples were measured using Analytical Spectral Device (ASD) - FieldSpec 3. Partial Least Square.Regression (PLSR) was used to estimate N and P concentration, in combination with various spectral transformation techniques such as First Derivative Reflectance (FDR) and Log transformed spectra Log (1/R). The results show that stockpile soils appear to impact foliar N and P concentration as evidenced by low N and P concentration in the grass, sampled from stockpile soils compared to grass sampled from unmined soils. This was attributed to soil nutrient status of the study sites, as unmined sites had high soil nutrient content than stockpile soils. Foliar N concentration of grass sampled from stockpile soils and unmined soils can accurately be estimated without spectral transformation. FD yielded highest R2 for N and P estimation in grass sampled from both stockpile soils and unmined soils.Overall, the study shows that stockpiling affect soil quality, enzyme activity and vegetation growth. It further shows that soil amendments can improve soil quality and enzyme activity of coal-mine stockpile soils. Finally, Reflectance Spectroscopy can be used to estimate coal-mine stockpile soil properties, its quality and foliar N and P content as an indicator of vegetation nutrient stress.
National Research Foundation

Current mining methods used to extract coal from underground mine workings disturb the natural environment and the existing stable geological structures. As a result, the ingress of water into the mines increases and the quality of the water passing through the mine workings deteriorates, irrespective of the operational status of the mines. Water ingress is generated by regional aquifers, local aquifers, recharge from the surface through rainfall, natural drainage paths on the surface, and surface water bodies. The quality of water in the mines deteriorates as a result of contact with the remaining coal in the mine workings. Mining can therefore cause an increased influx of water into a mine and the degradation of this water. The solution to reducing the impact of mines on the environment is to prevent, or at least reduce, the amount of water entering the mines, and to manage this water to prevent further degradation in water quality. This study focused on afforestation with Eucalyptus viminalis trees to manage or inhibit ingress of water into underground mine workings. The hypothesis of this study was that a change in vegetation, from grassland to fast-growing and potentially high water-using trees like Eucalyptus. could possibly reduce the drainage of water below the root-zone and into the mine workings. The hypothesis was tested by estimating the components of the soil water balance for a grassland site and a Eucalyptus tree site. The research site was situated in Mpumalanga, (260 36' Sand 290 08' E, 1650 m a.m.s.l.), one of South Africa's major coal bearing areas. Although the Secunda area is a treeless environment and conditions are not optimal for forestry, some Eucalyptus species are suited for conditions (frost and periodic droughts) encountered in this area. The soil water balance of grassland and E. viminalis trees were studied through a field experiment and a long-term (30 years) modelling exercise. Total evaporation of the grassland site was estimated using the Bowen ratio energy balance technique. The transpiration of six representative E. viminalis trees were estimated using the heat pulse velocity technique. The soil water storage changes at both sites were determined from the soil water content, estimated using water content reflectometers. Measurements were performed in a smectic clay soil which resulted in measurements difficulties. Vertical cracks were formed under soil drying. To establish the importance of climate and plant growth on the drainage beyond the root-zone, the soil water balance of a grassland and an E. viminalis site were simulated over a 30-year period with the Soil Water Atmosphere Plant (SWAP) model. It was concluded from the comparative field experiment and modelling, that a change in vegetation from grassland to E. viminalis will reduce the drainage of water below the root-zone, especially under above-average rainfall conditions. The reduction in drainage beyond the root-zone at the E. viminalis sites, compared to the grassland site, was demonstrated in the modelling exercise and can be deduced from the total evaporation and soil water storage estimated at both sites. The results from the field experiment confirmed the modelling results and showed that usually there were higher transpiration rates for the E. viminalis tree site, compared to the grassland site. The higher transpiration rates for E. viminalis trees resulted in lower relative saturation of soil layers and lower profile soil water contents at the E. viminalis site, and higher daily soil water storage changes at the E. viminalis site compared to the grassland site. These differences were more pronounced during winter when the grassland was dormant. The results from the modelling exercise showed that an E. viminalis tree stand, with a closed canopy, reduced drainage below the root-zone compared to a grassland. The drainage at the grassland site contributed to up to 54 % of the rainfall, compared to the 43 % at the E. viminalis site. However, under below-average rainfall conditions the annual drainage at both sites, were similar. Further, the absolute magnitude of the drainage was similar to the total evaporation at the grassland site under certain conditions. The results not only suggest that a change in vegetation, from grassland to E. viminalis trees, would reduce the drainage beyond the root-zone, but that it may delay the onset of drainage. Under above-average rainfall conditions, the modelled drainage at the E. viminalis site only exceeded 20 mm, a month later than at the grassland site. The simulation results also showed that under conditions of aboveaverage rainfall, drainage occurs whenever the rainfall exceeds the long-term average rainfall, irrespective of the existing vegetation. However, when the rainfall is belowaverage drainage at both sites are limited to large rainfall events. This simulation showed that over a period of eight years, E. viminalis trees could potentially reduce the drainage by 1235 mm more than grassland, which is equivalent to 1540 m3 ha- I a-I, or 1.54 Me ha- I a-I. The annual average reduction in drainage below the root-zone caused by E. viminalis trees (1.79 Mf ha-1 a-\ is a small reduction when compared to the influx of water into mineworkings. E.g. the influx of water into a bord-and-pillar mine range between 0.5 and 4 Mt d-I per area mined and up to 17000 Mt d-I per area mined under high extraction mining (Hodgson and Krantz, 1998; Hodgson et aI., 2001). This work gave a comprehensive account of the differences in the soil water relations of grassland and E. viminalis trees overlying coal mine working. Few other studies in South Africa compared the total evaporation and soil water relations of grassland and E. viminalis trees in so much detail. State of the art monitoring techniques were used and produced valuable comparison of their use in expansive clay profiles. The work should contribute to management decisions focussed on limiting ingress of water into mine workings.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.

Soil organic matter (SOM) is highly important for soil quality and the global carbon cycle. SOM content is influenced by a complex interplay of many different factors such as time, climate, parent material, vegetation, and others. The effect of time is often studied using the chronosequence approach using a set of study sites differing in age but comparable in other soil-forming factors. The effect of other factors can be studied by comparing two or more chronosequences. An important assumption of these approaches is that the SOM quantification methods produce comparable results both among sites of each sequence and among different sequences. In this thesis, I explored the key factors in SOM accumulation and dealt with SOM quantification methods. I studied SOM accumulation in two model situations - in post-mining sites after open-cast coal and oil shale mining and in landslides in the Western Carpathians. The results of this thesis are summarized in one book chapter accepted for publication and four papers, out of which three have been published and one is prepared for publication in an international journal with impact factor. The key factor affecting the rate of SOM accumulation after a major disturbance is time. The accumulation rates found in the first 40 to 100 years in both post-mining sites...

To evaluate the outcomes of reclamation design, soil and plant community changes on an unmanaged, 15-year-old certified-reclaimed site were analysed and compared with an undisturbed reference location. Patterns were analysed using MRPP while change was measured with rmANOVA. Plant species were poor predictors of selected soil properties. Percent soil organic carbon increased (p = 0.032), while soil pH did not change. Overall plant community composition did not change in proportion of cover between a priori groups of seeded/unseeded species or between native/introduced species. Individual species did vary in amount of cover change between 1993 and 2007. A linear regression of richness versus area covered by native species determined that the Shannon index is not a suitable measurement for monitoring plant community change towards the reference ecosystem. These findings highlight the importance of initial design, and the potential additive role of landscape architects as part of reclamation planning.

碩士
國立中興大學
森林學系
88
The purpose of this study was to investigate soil chemical and biological properties influenced by Luchu pine (Pinus luchuensis) with ectomycorrhizae on coal mine spoils. The major investigation included soil chemical and soil solution properties and soil microbial biomass - N, P and S. The study site was located in Jing-Torng, Ping-Shi village, Taipei country, north Taiwan. The coal mine spoil was characterized by rugged topographies and fragile geological formation. These harshly physical conditions together with the large amount of aluminum and sulfate in soil would increase soil acidity. Therefore, vegetation was very difficult to service in this environment. In 1989, Luchu pines inoculated with Pisolithus tinctorius , as the plantation soil (PS), were planted and grow very well. However, those un-inoculated Luchu pines, as the bare-soil (BS), were all dead. In general, the pH of soil collected from both PS and BS are very acidic. Kjeldahl nitrogen, availability p and organic matter are also very low, but the amounts of inorganic S are very high. The amount of inorganic S in BS (173.85 g/g) is higher than those in PS (101.65 g/g). The result proves that mycorrhizal Luchu pines play a very important role in this high S-containing soil. Soil microbial biomass of PS, included microbial biomass-N, soil microbial biomass-P and soil microbial biomass-S, are significantly higher than those of BS. But the soil microbial biomass in coal mine spoils in this study was significantly lower than that in the normal forest soil. The seasonal variation of soil microbial biomass with season was low in the end of summer and in early autumn, and the highest microbial biomass was in winter. It was hypothesized that in plant growth season, much more nutrients were up taken from soil and caused soil microbial biomass lower than in other seasons. SO42-, K+-, Mg2+, Ca2+ and Al3+ concentrations in both PS and BS soil solution increased with depth of soil. The concentration of PO43- was too low to detect in this study soil. On the contrary the NO3- and F- ion concentrations decreased with the depth of soil. In coal mine spoils, soil solution had high SO42- and Al3+ concentrations decreased significantly when compared with those in 1995.

A series of pot trials were undertaken to test the growth of indigenous grasses (Themeda triandra and Cynodon dactylon) on mine capping soil, treated with various soil ameliorants. The capping soils were obtained from open cast coal mines (Optimum Mine and Syferfontein Mine) in the Mpumalanga Highveld, south of Witbank. However, because mine soil was not available at the commencement of the project, the initial pot trial used soil from the Umlazi Landfill in Durban. The trials were the Umlazi Landfill Trial, Microbe Trial, Legume Trial and Fly Ash Trial. For the Umlazi Landfill Trial, landfill top and subsoil was used along with fertilizer, sewage sludge, K-humate, lime and microbes. The soil ameliorant treatments for the Microbe trial were Trichoderma harzianum (Eco'T), Bacillus subtilis Strain 69 (B69) and Bacillus subtilis Strain 77 (B77), for the Legume Trial, Medicago sativa, phosphorus and/or potassium were applied. For the Fly Ash Trial, lime and fly ash were introduced. From the Landfill trial it was shown that fertilizer and sewage sludge significantly increased the above ground, below ground and total biomass of T. triandra, further, there were no significant treatment differences between fertilizer and sludge. The lime treatment for this trial, surprisingly, significantly reduced below ground biomass but the application of microbes (B69 and BcoT) alleviated this negative effect. However, in the Microbe Trial the microbes (BcoT, B69 and B77) had a negative or no effect on the biomass of T. triandra and C. dactylon. In the Legume Trial it was shown that the above ground biomass of T. triandra was significantly reduced when grown with M. sativa. The Fly Ash Trial revealed that the lime and fly ash treatments had no effect on the biomass of M. sativa and T. triandra, and they did not maintain a reduction in soil acidity. The results therefore indicated that either organic fertilizer or sewage sludge could be used to significantly improve the growth of T. triandra. It was also suggested that lime not be applied to soils with an acid saturation of approximately 1%, as this could retard plant growth. The application of microbes and the growth of a legume with grass, although both have been recorded to have beneficial effects in aiding plant growth, in the short-term however, the application of T. harzianum, B. subtilis Strain 69 and 77 applied to the soil while growing T.triandra and C. dactylon and the growth of M. sativa with T. triandra is not recommended.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

A dissertation submitted to the Faculty of Engineering, University of Witwatersrand, in fulfillment of the requirements for the degree of Master Science in Engineering
The Electricity Supply Commission of South Africa (Eskom) have identified open cast coal mine backfill areas as potential disposal sites for the large volumes of coal ash produced by their power stations. As Eskom's power stations are mainly situated in agricultural and coal rich areas of the provinces of Mpumalanga and the Free State, the sterilisation of substantial areas of agricultural soil and coal deposits is thus reduced. The construction of a tailings dam or dump on uncompacted open cast mine backfill creates various problems related to the settlement of the backfill. The scale of the operation, the large particle size and heterogeneous nature of the backfill and its method of placement complicates the prediction for settlement of the backfill. Areas in excess of 74 000 ha could be subjected to opencast mining in Mpumalanga and for future development of these areas more information regarding the magnitude and mechanics of mine backfill settlement is required. This dissertation describes two large scale field tests in which the settlement of mine backfiil was studied during the construction of a test section of an ash tailings dam and the construction of a dry ash dump.
Andrew Chakane 2019

The Fording River, Greenhills and Line Creek Operations are three surface coal mines located adjacent to each other in the Fording and Elk River valleys of southeastern British Columbia. These mines are operated by Elk Valley Coal Corporation, and produce high-quality metallurgical coal. Active programs of reclamation research have been conducted on all three properties. One of the primary objectives of this research has been to evaluate the feasibility of reclamation directly on coal waste, as opposed to reclamation utilizing an overlying capping material. This paper reports on the results, both historic and recent, of this research, and presents conclusions on the success of this practice, as well as future directions for confirming this success.

The generation of large quantities of mine wastewater in South African coal mines and the needs for a cost effective, as well as an environmentally sustainable manner of mine water disposal, have fostered interests in the possibility of utilizing mine water for irrigation. Such a possibility will not only provide a cost-effective method of minimizing excess mine drainage, as treatment using physical, chemical and biological methods can be prohibitively expensive, but will also stabilize the dry-land crop production by enhancing dry season farming. Considering the arid to semi-arid climate of South Africa, the utilization of mine water for irrigation will also boost the beneficial exploitation of the available water resources and relieve the increasing pressure on, and the competition for, dwindling amounts of good quality water by the various sectors of the economy. The disposal of excess gypsiferous mine water through irrigation has been researched in a few collieries in the Witbank area. In this study, the assessment of the impacts of using gypsiferous mine water for irrigation were carried out in parts of the Upper Olifants basin upstream of Witbank Dam, using the ACRU2000 model and its salinity module known as ACRUSalinity. The study area was chosen on the bases of locations of previous field trials and the availability of mine water for large-scale irrigation. The primary objectives of the study were the development of relevant modules in ACRU2000 and ACRUSalinity to enable appropriate modelling and assessment of the impact of large-scale irrigation with mine water and the application of the modified models to the chosen study area. The methodology of the study included the modifications of ACRU2000 and ACRUSalinity and their application at three scales of study, viz. centre pivot, catchment and mine scales. The soils, hydrologic and salt distribution response units obtained from the centre pivot scale study were employed as inputs into the catchment scale study. The soils, hydrologic and salt distribution response units obtained from the catchment assessment were in turn applied in similar land segments identified in the mine used for the mine scale study. The modifications carried out included the incorporation of underground reservoirs as representations of underground mine-out areas, multiple water and associated salt load transfers into and out of a surface reservoir, seepages from groundwater into opencast pits, precipitation of salts in irrigated and non-irrigated areas and the incorporation of a soil surface layer into ACRUSalinity to account for the dissolution of salts during rainfall events. Two sites were chosen for the centre pivot scale study. The two sites (Syferfontein pivot of 21 ha, located in Syferfontein Colliery on virgin soils; Tweefontein pivot of 20 ha, located in Kleinkopje Colliery on rehabilitated soils) were equipped with centre pivots (which irrigated agricultural crops with mine water), as well as with rainfall, irrigation water and soil water monitoring equipment. The pivots were contoured and waterways constructed so that the runoff could leave the pivots over a weir (at Tweefontein pivot) or flume (at Syferfontein pivot) where the automatic monitoring of the quantity and quality of runoff were carried out. The runoff quantities and qualities from the pivots were used for verification of the modified ACRU2000 and ACRUSalinity. The catchment scale study was on the Tweefontein Pan catchment, which was a virgin area mainly within the Kleinkopje Colliery, draining into the Tweefontein Pan. The data on the water storage and qualities in Tweefontein Pan, as well as the soil water salinities in the irrigated area located within the catchment were used for verification of results. In the catchment scale study, different scenarios, including widespread irrigation on virgin and rehabilitated soils, were simulated and evaluated. For the mine scale study, the Kleinkopje Colliery was used. The colliery was delineated into 29 land segment areas and categorized into seven land use types, on the basis of the vegetation and land uses identified in different parts of colliery. The centre pivot and catchment scale studies indicated that the impacts of irrigation with low quality mine water on the water resources are dependent on the soil types, climate, the characteristics and the amount of the irrigation mine water applied, whether irrigation was on virgin on rehabilitated soils and the status of the mine in terms of whether a regional water table has been re-established in an opencast mining system or not. The studies further indicated that the irrigation of agricultural crops with low quality mine water may lead to increases in soil water salinity and drainage to groundwater, but that the mine water use for irrigation iii purposes can be successfully carried out as most of the water input onto the irrigated area will be lost through total evaporation and a significant proportion of the salt input, both from rainfall and irrigation water, will either be precipitated in the soil horizons or dissolved in the soil water of the soil horizons. By irrigating with a saline mine water therefore, the salts associated with the low quality mine water can be removed from the water system, thereby reducing the possibility of off-site salt export and environmental pollution. On-site salt precipitation, however, may lead to accumulation of salts in the soil horizons and consequent restriction of crop yields. Therefore, efficient cropping practices, such as leaching and selection of tolerant crops to the expected soil salinity, may be required in order to avoid the impact of long-term salinity build up and loss of crop yields. The simulated mean annual runoff and salt load contribution to Witbank Dam from the Kleinkopje Colliery were 2.0 x 103 MI and 392 tons respectively. The mean annual runoff and salt load represented 2.7% and 1.4% of the average water and salt load storage in Witbank Dam respectively. About 45% of the total water inflow and 65% of the total salt load contribution from the study area into Witbank Dam resulted from groundwater storage. From the scenario simulations, the least salt export would occur when widespread irrigation is carried out in rehabilitated areas prior to the re-establishment of the water table due to a lower runoff and runoff salt load. It may therefore be a better water management strategy in active collieries if irrigation with mine water is carried out on rehabilitated soils. In conclusion, this research work has shown that successful irrigation of some (salt tolerance) crops with low quality mine water can be done, although increases in the soil water salinity of the irrigated area, runoff from the irrigated area and drainage to the groundwater store can occur. Through the modifications carried out in the ACRU2000 model and the ACRUSalinity module in this research work, a tool has been developed, not only for application in the integrated assessment of impact of irrigation with mine water on water resources, but also for the integrated assessment and management of water resources in coal-mining environments in South Africa.
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.