The use of temperature profiles to estimate the pyritic oxidation rate in a waste rock dump from an opencut mine

Temperature distributions were measured in a dump of waste rock from an old opencut U mining operation in the Northern Territory of Australia. The 20 yr old dump contained pyritic material, averaging about 3% S, which is known to be oxidising. The temperatures were in the range 32 to 37°C for most of the dump, but ranged up to 56°C in one region. The temperature distributions were used to evaluate the heat source distributions which identify oxidation sites and are a direct measure of rates of oxidation within the dump. Oxidation occurred in the top 5 m of the dump and, at some sites, down to 15 m from the surface. Oxidation rates at the deep sites did not change over the 8 mo period from the end of one wet season to the beginning of the next.[a/b]     

Pot and field experiments on the suitability of lignite as soil improving agent

Effects of raw brown coal ("Kohletrübe"), brown coal modified with ammonia water, NH3, ("Ammonkohle") and composted brown coal ("Biomineraldünger") on plant yield and on selected soil fertility characteristics of a colloidpoor and a coal-bearing dump soil are tested in a pot and field experiment. The results confirm already published results. Therefore chemical modified nitrogen enriched brown coal is a humus fertilizer the influence of which sustained the water and nutrient storing capacity as well as the nutrient transformation ability of colloid-poor dump soils. Soil improving and yield increasing effects of coal fertilisation depend on particular conditions.     

重庆市煤矿开采区土壤侵蚀特征及水土保持模式研究

煤矿开采区土壤侵蚀属典型的人为加速侵蚀类型,重庆煤矿开采区典型土壤侵蚀主要集中在矸石山和塌陷区两个侵蚀地貌单元。矸石山土壤侵蚀特征主要表现为在时间上随堆积年限的增加,土壤侵蚀程度减小;在空间上山体坡度减缓、稳定性增强。根据矸石山的立地条件和主要限制因子特点确定其治理难度,并按极难治理型、难治理型、易治理型三类建立植被恢复型水土保持模式。塌陷区土壤侵蚀特征主要表现为过程缓慢、破坏作用强及影响范围大等特点,根据塌陷区土地复垦后的利用类型可分为农业复垦区、林业复垦区、建设复垦区,分别建立煤矸石充填复垦型水土保持模式。植物吸附和铺设粘土层的方法可改善矿区土壤和水体的重金属污染,提高生态环境质量。     

The sediment concentration–turbidity relation: its value in monitoring at Ranger Uranium Mine,Northern Territory,Australia

Some earlier studies of erosion of the schist-dominated waste rock dump of Ranger Uranium Mine, Northern Territory, Australia, used turbidity as a surrogate for sediment concentration. Subsequent detailed studies of the turbidity–sediment concentration relation for a number of sites on the waste rock dump, reported in this paper, demonstrate that turbidity cannot be used to accurately predict sediment concentration. The results of this experiment suggest that environmental monitoring of erosion at mines in the Kakadu region of Northern Australia should use direct methods of measurement of the sediment concentration in runoff, and that turbidity measurements will not provide sufficient accuracy to satisfy audits of environmental compliance to regulatory guidelines.     

Schwermetall- und Nährelementgehalte von Pflanzen und Bodenproben schwermetallhaltiger Halden im Raum Bleiberg in Kärnten (Österreich). II. Holzpflanzen

Heavy metal- and nutrient contents of plants and soil samples from metalliferous waste dumps in Bleiberg (Carinthia, Austria). II. Woody plants Needles, stem- and root-samples from coniferous trees (Norway spruce and Scots pine), taken from a waste dump habitat and an offmine-site in Bleiberg (Carinthia) were analysed on their macronutrient-and heavy metal-contents. No significant age dependent differences in N-and P-content of the two species were observed. The highest potassium levels occured in the youngest needle age group. The needles of the trees from the mining dump site show increasing Ca- and Fe- concentrations with increasing needle age. The Mn-contents of needles collected in offmine-sites were higher than those from the waste dump. The Mg-levels in the needles from both sites are remarkably low, a symptom of undersupplement. High Pb- and Zn-concentrations were determined in older needles of waste-dump-trees. Because of rather high Pb- and Zn-levels in the roots of the trees from this site a physiological transport barrier is assumed, which partly inhibits the upward lead transport; on the other hand lead is partly deposited in stem-wood of the two species. The heavy metal contents of roots from mining dump site are interpreted as an effect of high metal stress in the fine fraction of soil material.     

Runoff fraction and pollution levels in runoff from a waste rock dump undergoing pyritic oxidation

Measurements have been made of rainfall, runoff and pollution levels in runoff, on a waste rock dump in which soluble salts are produced by pyritic oxidation. The dump is overburden material from the opencut mining of White's uranium orebody at Rum Jungle in the Northern Territory of Australia where there is a pronounced wet/dry season cycle. Most of the data were collected in the 1975-76 and 1976-77 wet seasons with some from the 1977-78 wet season. Events monitored in the first two wet seasons accounted for about half the rainfall in each. The runoff fraction, which averaged 15.6% over the two seasons, ranged up to a maximum of 33 %. Calculations of the runoff fraction using measured sorptivities and hydraulic conductivities predicted an even lower runoff fraction than that observed. The SO₄ concentrations in runoff varied in a well defined way throughout the discharge events and showed no significant dependence on the history of rainfall on the dump. The average SO₄ level in runoff was 0.84 kg m^?3; Cu, Zn, Mn levels were respectively 1.0, 0.15, and 0.09% of the SO₄ levels. The annual Cu load in runoff was estimated to be 0.4 t which is much smaller than the estimated release of 39 to 53 t in water seeping through the dump.     

Soils of technogenic landscapes in the Far East: The Luchegorsk and Pavlovsk coal strip mines

Soils and vegetation developed on dump rock of coal strip mines located in different hydrothermic provinces of the Primorskii region have been studied. The formation of phytocenoses on dump rocks proceeds in several consecutive stages, during which the species diversity of vegetation and the total pool of vegetative organic matter regularly increase. This results in a progressive development of humus accumulation. In turn, it leads to the morphological, chemical, and physicochemical differentiation of the soil profiles. General and specific features of pedogenesis in the studied areas are described.     

Organic matter of subsoil horizons under broadleaved forest: Highly processed or labile and plant-derived?

Between 30 and 63% of the soil organic matter (SOM) is stored below 30 cm, making subsoil-SOM an important source and sink in the global carbon cycle. Nevertheless, detailed information on the composition of subsoil-SOM remains scarce. This study aims to evaluate the chemical composition of SOM in topsoil and subsoil horizons in broadleaved forests on acid loamy soils. Six sites were chosen in Northern Belgium under beech, oak and hybrid poplar, on Gleysols, Umbrisols, Cambisols and Albeluvisols on loamy Quaternary deposits. Analytical pyrolysis–gas chromatography/mass spectrometry (pyrolysis–GC/MS) was performed on the dialyzed alkaline extract, which represents between 41 and 90% of the total organic carbon for the selected sites. All extracts show a significant shift in chemical composition between the topsoil and the subsoil. While topsoil-SOM mainly differs according to input and nutrient status, subsoil-SOM shows high relative amounts of alkanes and alkenes or polysaccharides for coarse and fine textured soils respectively. Lignins, lignin-derived phenols or aromatics were not major contributors to subsoil-SOM, regardless of soil type. Furthermore, results show that very labile plant-derived molecules are present in the subsoil, i.e. long-chain aliphatics and (cellulose-derived) anhydrosugars. The organic matter signature of the subsoil samples was evaluated for typical indications of fresh material, decay, podzolisation and anaerobic processes, and indicates root input and stabilization of certain labile plant-derived compounds against microbial decay to be important in the subsoil.     

PARTITIONING OF HEAVY METALS IN PODZOL SOILS CONTAMINATED BY MINE DRAINAGE WATERS,DALARNA, SWEDEN

The discharge of acidic mine drainage waters onto a hillslope in Dalarna, central Sweden, has lead to the contamination of the podzol soils with Cu, Fe, Ni, Pb, Zn and sulfate. Samples from contaminated and reference soils have been collected for chemical and mineralogical analyses. Jarosite is identified by x-ray diffraction analysis as a precipitate in the upper horizons (A, E, B) of the contaminated soils, where the soil acidity (pH_KCl～2.6) promotes jarosite stability. The sequential chemical extraction of soil samples indicates that, in the reference A horizon, Cu, Pb, Ni and Zn are bound primarily to cation exchange sites and organic matter. In the A horizon of the contaminated soils closest to the rock dump, metal partitioning is dominated by the Fe oxide fractions, despite the high organic matter content; Pb is almost completely bound to crystalline Fe oxides, possibly adsorbed to Fe oxides or occuring in a jarosite solid solution. In the reference B and C horizons, Cu, Ni and Zn are primarily adsorbed/coprecipitated in the Fe oxide fractions, while Pb remains with a large fraction bound to organic matter. In the Fe-rich B horizon of the contaminated soils, the partitioning of the metals in cation exchange sites and to organic matter has greatly increased relative to the reference soils, resulting from the mobilization of organo-metal complexes down the profile.     

黄土高原公路弃土场侵蚀规律及其模拟研究

公路弃土场是道路侵蚀的重要单元之一,对其土壤侵蚀机理的研究与模拟是完善道路侵蚀模型、准确预测流域产沙量的基础。通过不同雨强(0.6~2.79 mm/min)的人工降雨实验对不同坡度(19.4%~78.1%)的弃土场坡面及坡度为30.6%的弃土场施工道路的土壤侵蚀规律进行了研究,并提出了弃土场土壤侵蚀预报方法。结果表明:弃土场土壤侵蚀速率与雨强呈较好的幂函数关系;小雨强下容重与侵蚀速率呈正相关,大雨强下容重与侵蚀速率呈负相关;弃土场坡面侵蚀量与坡度呈正相关,但侵蚀量随坡度的变化趋势与陡坡耕地有较大差异;使用EI30、容重及坡度等因子可以较好地预测弃土场土壤侵蚀量。     

海州露天煤矿排土场复垦区不同土地利用类型土壤入渗特征

为揭示排土场复垦区不同土地利用类型土壤的水源涵养功能,采用野外实地双环入渗试验和室内理化分析方法,系统地研究了海州露天煤矿排土场复垦区不同土地利用类型(乔木林地、灌木林地、农用地、荒草地)土壤入渗特性及其影响因素。结果表明:不同土地利用类型下的土壤初始入渗率、稳定入渗率和累计入渗量均表现为乔木林地灌木林地农用地荒草地;不同土地利用类型下土壤入渗过程的拟合优度存在差异,G-P综合模型、Kastiakov模型、Horton模型的平均拟合优度依次为0.926,0.908,0.905。G-P综合模型相对误差为79.21%~123.69%,更接近排土场复垦区土壤入渗的实际过程,可作为排土场复垦区土壤入渗过程的预测模型;不同土地利用类型下土壤初始入渗率与非毛管孔隙度呈显著正相关,稳定入渗率和累计入渗量与非毛管孔隙度、砾石含量和部分根系特征呈显著正相关;采用主成分分析评价的土壤入渗能力排序为乔木林地灌木林地农用地荒草地,初始入渗率、稳定入渗率、14min入渗率和累积入渗量的主成分方差累积贡献率为99.047%,较好地表达了土壤入渗能力。     

大型排土场“径流分散”水蚀控制模式及其设计探讨——以山西省安太堡大型露天煤矿排土场为例

 以安太堡露天煤矿排土场16年水土保持实践为基础,通过调查观测,对半干旱黄土区大型排土场水蚀控制进行分析研究。初步提出排土场“径流分散”水蚀控制模式,将排土场划分为若干径流分散单元,使暴雨径流在各单元间均匀分散,避免暴雨径流大量汇集造成的冲蚀和灌缝,并在分散单元内实施径流调节和进行合理的植被配置,同时在径流关键汇集路径设置排水主渠,以抵御特大暴雨对分散单元的破坏。根据排土场径流小区1993—2002年定位观测和试验资料,对典型径流分散单元的挡水埂和植被配置进行初步设计。该径流分散模式可操作性强,不仅能有效控制半干旱区排土场水蚀,而且有利于排土场植被的快速建立和恢复。     

The nature and spatial variability of lowland savanna soils: Improving the resolution of soil properties to support land management policy

A fresh approach is presented to address the increasingly urgent need for alternative land management strategies in savannas. We illustrate how fine‐scale information of soil characteristics can be used to enable a more precise delimitation of sites suitable for different forms of land stewardship, including agro‐pastoral activities, forestry, biodiversity and tourism. By collating data from previous soil surveys, and augmenting this with targeted new surveys, we produce the first national data set of soil properties for the lowland savannas of Belize. Most of these soils are typical of savanna soils worldwide, that is acidic (mean surface pH = 5.7), nutrient‐poor (mean surface total exchangeable bases [TEB] = 3.4 cmol kg^?1) and coarse‐textured (mean surface clay = 13.0%). Nevertheless, there is a marked spatial variability across the country in these soil properties. Some soils exhibit unusually high subsurface clay fractions (max = 73%), whilst other sites have exceptionally high pH in lower horizons (max = 8.4). Cluster analysis is used to group sites with similar soil properties. Across 79 sites, there is a clear division between soils with high clay percentages and those with coarser textures. These are sub‐divided into five groups based on further differences in parent material, chemical properties and site characteristics. Mapping the locations of these groups enables more specific land use recommendations to be made. This ability to make targeted land use recommendations from fine‐scale soil information represents an advance over the previous national land use policy, where all savanna lands were considered unsuitable for any form of agriculture. This approach could be applied to marginal savannas worldwide.     

Bodenentwicklung und Schwermetallgehalte einer Straßenkehrichtdeponie

Soil development and heavy metal contents of a street sweepings dump Soils from an unsealed street sweepings dump of the city of Kiel are inhomogeneous in their properties and in their distribution pattern. The deposited material is contaminated with copper, zinc, lead, and at lower concentrations with cadmium. The high pH-values lead to predominating immobility of heavy metals. However, heavy metals bonded in organic complexes are liable to be leached into the underground because of a high portion of large pores in these soils. Since there are only few other possible bonding mechanisms than organics, after the leaching of lime, pH decline, and mineralization of organic matter mobilization of heavy metals may be predicted. Thus, in the unsealed dump a danger of groundwater pollution with heavy metals remains. The site should be treated accordingly permanently after closing.     

Genotoxicity of snow in the Montreal metropolitan area

Snow is capable of scavenging particle-bound, mutagenic organic pollutants from the atmosphere. Between storms snow can act as a mechanical filter for airborne particulates and dry atmospheric fallout can contribute to contamination of the snowpack. In urban areas snow cover can store contaminants and provide a sensitive, time integrated record of local air contamination. We examined the genotoxicity of snow collected from 14 sites in the Montréal metropolitan area. Snow contaminants were extracted using dichloromethane and the genotoxicity of the extracts measured using the SOS Chromotest. Only one extract elicited a positive response in the absence of a metabolic activation mixture. Sites which provided genotoxic samples are diverse in nature. Some sites are adjacent to highways and might be expected to receive genotoxic contaminants from internal combustion vehicles. Extracts of snow from regional dump sites were not genotoxic. Mean ambient carbon monoxide and nitrogen dioxide levels were significantly higher at sites which provided genotoxic snow samples. The mean ambient concentration of suspended particulates at the positive sites was not significantly different from the concentration at the negative sites. However, a significant linear relationship was identified between the SOS response inducing potency (SOSIP) of the genotoxic samples and the ambient level of suspended particulates. The results presented confirm the presence of genotoxic material in urban snow and demonstrate that the SOS Chromotest can be used to rapidly screen complex environmental extracts for genotoxicity. High ambient levels of carbon monoxide, nitrogen dioxide measured at positive sites, and the relationship between SOSIP and the concentration of airborne particulate matter, suggests that the putative genotoxicants are fuel combustion by-products. This conclusion, while supported by previous research on atmospheric, particle-bound mutagens, is still speculative.     

Sulfate Reduction in a Lake and the Groundwater of a Former Lignite Mining Area Studied by Stable Sulfur and Carbon Isotopes

Water, Air, &; Soil Pollution - The isotopic and chemical composition of water and dissolved sulfur and carbon compounds from a flooded lignite-mining lake and a dump site in Central Germany...     

高速公路建设中不同类型弃土场的土壤流失特征

 以沪蓉西高速公路(上海至成都高速公路西段)湖北宜长段(宜昌至长阳县)弃土场为研究对象,通过观测天然降雨、土壤、植物和土壤流失量等因子,探讨不同类型弃土场的土壤流失特性。结果表明:1)降雨量与降雨强度的乘积(PI)和次降雨造成的单位面积土壤流失量(E)之间,表现出较好的一元正线性相关关系。在不考虑影响坡面土壤流失的其他因素的前提下,随着降雨量和降雨强度乘积的增加,土壤流失量逐渐加大。2)采取工程措施和生物措施综合防护,可以有效减少弃土场的土壤流失量。3)弃土场表土物质组成对土壤流失起着重要作用,表土受雨水冲刷,砾石含量会逐渐增大,土壤流失量逐渐减小。     

Use of electron spectroscopy to reveal structural differences between humus acids from virgin and arable gray forest soils

Issues related to the information stored in the electronic spectra of humus acids were considered. The spectrum recording procedure for revealing even small structural changes in the chromophore groups containing the C=C and C=O bonds is discussed. The effect of methods used for separation and purification of humus acids on their spectral and chemical properties is described. Differences in the polarizability and reactivity of humus substances from virgin and arable gray forest soils are revealed.