基于小流域自然形态的废弃矿区地形重塑模拟

地貌重塑是废弃矿区土地复垦与生态重建的重要基础部分和重点研究的技术问题之一。该文根据流域地貌学及其自相似原理,利用ArcGIS技术重新规划了废弃矿区的子流域及沟道、计算了矿区邻近未干扰子流域地貌形态特征数据并作为参照的标准;在此基础上结合Geofluv模型重建了北京市房山区黄院废弃采石场的小流域地貌,探讨了基于小流域自然形态的废弃矿区地貌重塑原理与技术方法,分析了重塑后的与未干扰的子流域形态特征间关系。结果表明,重塑后子流域地貌形态是相对稳定的、自然的,并与未干扰的子流域形态特征比较相似;用地貌系统信息熵值判断出重塑后地貌起伏变化小,受侵蚀强度弱,水土流失趋向于非常缓和。该文研究成果为废弃矿区地貌重塑的研究提供了一种新思路。     

Multivariate analyses and spatial distribution of Manganese minerals in soils close to an abandoned Manganese mine

Four hundred soil samples were obtained from a 4 km² area close to the abandoned Kgwakgwe Mn oxide ore mine in order to investigate the environmental association of Mn minerals and concentrations in the soils. Manganese minerals and Mn concentrations in samples were identified by X‐ray diffractometry and atomic absorption spectrometry, respectively, and results statistically analysed. Bixbyte, Mn₂O₃; braunite, Mn⁺²MnSiO₁₂; ramsdellite, MnO₂; pyrolusite, β‐MnO₂ and cryptomelane, K_{2 − x}Mn₈O₁₆ were identified in soil samples at the study site but none of these minerals found in soil samples from the control site. Manganese concentrations in samples from the study area were significantly higher than those from the control site. Statistical data yielded seven clusters with distribution of the Mn minerals and concentrations as follows: cluster 1 dominated by Mn concentrations in soil, cluster 2 by none of the seven Mn minerals, cluster 3 by pyrolusite, cluster 4 by braunite, cluster 5 by cryptomelane, cluster 6 by bixbyite and cluster 7 by ramsdellite. Very weak associations of these minerals were depicted from their correlations. The clusters had a bearing on the spatial distribution of the different minerals. Comparing results obtained from the control site, and geological materials, to the soils from the study area, it is certain that Mn minerals and high Mn concentrations in soils originated from the surrounding geological materials. The mining activities most possibly have affected Mn concentrations' and minerals' occurrences in the soils at the study area. Copyright © 2009 John Wiley & Sons, Ltd.     

Evaluation of the potential toxicity (acute and chronic) of sediments from abandoned uranium mine ponds

Background, Aim and Scope  

The superficial aquatic system of the Cunha Baixa uranium mine area is comprised by the flooded mine pit (M), which receives the acidic mine effluent resultant from in situ leaching of pore ore, a pond where this effluent is neutralised (T), and a potential reference pond (Ref). As part of the first tiers of an ecological risk assessment that is being performed in this area, the aim of this work was to evaluate the potential sediment toxicity of these ponds.     

Growth and selenium uptake of range plants propagated in uranium mine soils

High soil selenium (Se) levels have been found in association with uranium deposits in Texas. A concern that high Se concentrations may be found in forages grown on reclaimed mine lands prompted this investigation. A native soil sampled near the mining area, and overburden materials sampled from two Se enriched uranium mine spoil sites were compared in a plant growth study in the greenhouse. Shoot yields and shoot Se concentration in each of ten grasses common to the region were determined from plants harvested three weeks after germination and from shoot regrowth harvested four weeks after the first harvest. Shoot weights were reduced for 5 of the 10 species growing in soils with medium and high Se status. Total shoot weights of Cynodon dactylon and Panicum coloratum from two harvests were consistently highest in all soil materials and are highly recommended for use as a stabilizing cover crop for lands disturbed from uranium mining. Generally, no correlation was observed between shoot weight and plant Se concentration or uptake in the 10 species. However, plant tissue Se concentrations in all species for at least one of the two harvest dates were above the 5 mg kg^‐1 concentration considered potentially harmful to grazing livestock. Therefore, none of these species would be a suitable forage for livestock grazing on reclaimed Se‐enriched uranium mining overburden.     

Influence of soil physicochemical properties, particle size fractions and mineralogy on the leaching potentials of arsenic and antimony in abandoned mine soils

At abandoned mine sites, arsenic (As)- and antimony (Sb)-enriched soils are often disposed of through onsite burial or capping. In highly weathered mine sites, the mobility of As and Sb is typically controlled by iron (Fe)(Ⅲ)/Fe(Ⅱ) phases; thus, the suitability of such disposal methods and appropriate testing techniques are questionable. In the present study, leaching potentials of As and Sb were examined using the toxicity characteristic leaching procedure (TCLP), waste extraction test (WET), and WET-extended procedure (WET-EXT) at three abandoned mine site soils in Australia. The leached concentration of As regularly exceeded USEPA criteria (5 mg L^-1). The highest leached concentrations of As and Sb were observed in the finest particle size fraction (< 0.053 mm) by WET-EXT (1 040 mg L^-1 for As and 21.10 mg L^-1 for Sb) followed by WET (800 mg L^-1 for As and 20.90 mg L^-1 for Sb). The TCLP method resulted in the lowest concentrations of leached As (0.000 9 mg L^-1) and Sb (0.000 3 mg L^-1). Crystalline and amorphous As-bearing Fe oxides were the main phases in the soils studied. However, the best correlations of leached As determined by TCLP (0.832), WET (0.944), and WET-EXT (0.961) were found with the non-specifically sorbed (NS1) As fraction. The mineralogical and sequential extraction data clearly indicate the dominant role of Fe geochemistry in controlling leachability of As and Sb. The TCLP method was unlikely to be suitable for assessing leachability, as it exhibited no relationship with leachable Fe and substantially lower leached As and Sb than the other two methods. Given the high to extremely high leachable As and Sb concentrations, most of the soil samples would not be recommended for placement in capping works, old shafts, or reduction systems (e.g., collection in drainage basins).     

Mobility and phytoavailability of arsenic in an abandoned mining area

The mobility and phytoavailability of arsenic in an area affected by the abandoned exploitation of an arsenical tungsten-tin deposit was studied to establish the current and eventual environmental risks and to propose possible remediation practices. Soil and plant samples were collected at different distances from the polluting sources and analyzed for their As content and distribution. Critical soil total concentrations of As were found, with values in the range 175-2300 mg kg^− 1. The readily labile As contents represent < 0.2% of the total concentrations, whereas the As contents more prone to be mobilized could rise up to 25%. Different phytostabilizing plants were identified, namely, Agrostis castellana (Boiss. & Reut.), Centaurea jacea L., Eryngium campestre L. and Scirpus holoschoenus L.. Such plants show important root bioaccumulation factor values in relation to the labile As contents (up to 197, 58, 201 and 88, respectively) and low translocation factor values (down to 0.170, 0.032, 0.173 and 0.036, respectively). Additionally to promote the revegetation with these plants, the species Rumex acetosella L. should be eliminated as this behaves as an index plant, reaching above-ground As concentrations up to 218 mg kg^− 1.     

黄土丘陵沟壑区煤矿沉陷耕地复垦

探索开发适宜黄土地貌和气候特点以及黄土丘陵采煤沉陷损伤规律的土地复垦模式,对于实现该区数量质量并重管理的耕地保护目标具有重要的现实意义。该文基于开采设计、沉降观测参数和MSAS软件,预测山西兴县斜沟煤矿一采区沉陷损毁土地面积为16.54 km2,损毁土地类型以耕地和草地为主,其中轻度破坏耕地面积3.70 km2,中度破坏耕地面积2.41 km2,重度破坏耕地面积0.17 km2。结合黄土丘陵沟壑低潜水位区土地损毁特征和区域生态保育和国土整治目标,拟对轻度破坏的1.65 km2耕地采用裂缝充填和土地平整复垦措施,按照集中连片的原则对轻度、中度和重度破坏的4.63 km2耕地采用坡改梯的土地复垦工程措施进行复垦,实现增加耕地面积0.40 km2,每年减少水土流失4.94万t,提高了耕地质量等级。研究认为,结合企业复垦资金和社会资金投入,按照集中连片的原则对采煤沉陷破坏的耕地采取坡改梯复垦是该区域损毁耕地复垦的有效模式。     

Properties of Urbic Anthrosols from an abandoned shunting yard in the Ruhr area, Germany

The soil conditions of an abandoned shunting yard in the Ruhr area were studied to find the most important factors influencing plant growth and nutrient cycling. The chemical and physical conditions of five Urbic Anthrosols with different development histories were compared with those of a nearby Calcic Cambisol under agricultural use. In the second half of the 19th century, the ground level of the shunting yard site was raised about 2 m. The soils are now mainly Regosols, mostly well drained in the topsoil. The coarse material contents (>2 mm), which are up to 100% in base layers of railway tracks, and the quality of the man-made substrates (crushed rock, slags, ashes, coke) are the most important factors influencing plant growth. Poor physical structure and low contents of fine fraction (<2 mm) lead to low water storage. Together with a low available nutrient stock, these properties lead to poor establishment of vegetation. The burning of coal by steam engines produced highly polluted ashes that fill pore spaces in the railway ballast layers. All the investigated fine substrata of the shunting yard layers exhibit a higher magnetic susceptibility than the rural soil. The ashes still contain unburned coal so that, although the total organic C content of the man-made soils reaches 37%, the wide C:N ratio does not indicate the actual quality of humic substances. The acid neutralization potential of the topsoil layers of the shunting yard will be consumed by acidic atmospheric deposition within a few decades, whereas in the surrounding Calcic Cambisols, it will take more than a thousand years. This may cause further problems of groundwater quality, as the heavy metals will become more soluble. The low soil quality makes such sites suitable for vegetation species that cannot compete in the surrounding very eutrophic agricultural landscape.     

草原区露天煤矿植被覆盖度时空演变与驱动因素分析

采用多时相Landsat TM遥感数据,借助于植被指数与植被覆盖度,基于不同时序植被覆盖度格点回归斜率、标准差和基末年等级转换矩阵等,分析了研究区植被覆盖度空间异质性及其驱动机制,剖析了采复联动下研究区、开采区和复垦区植被覆盖度变化趋势和波动程度,进而揭示随着时间变化采复活动与植被覆盖度间的响应。研究结果表明：不同年份研究区植被覆盖度及其等级空间分布整体上具有一定相似性,矿山采复活动在一定程度上打破了区域植被覆盖度时空演变格局;研究区植被覆盖度以中（Ⅳ等）、中低（Ⅲ等）为主,按多年均值计算,两者之和占研究区总面积的80%以上;植被覆被度呈增加和减少的区域面积比为2∶3,相关系数在?0.9266～0.4805之间,斜率正值范围内相关性并不显著,而负值范围的?0.9266～?0.895呈现不同程度显著性相关;露天采区、排土场及其周边1.5 km范围内的植被覆盖度呈显著下降趋势,且趋于一致。矿区植被恢复经历了一个“高—低—高”的周期循环,半干旱草原区复垦管护期限尽量保证在6 a以上。70%以上区域在研究时段内植被覆盖度发生转换,转换较为频繁,Ⅰ等植被覆盖度中的90%是由采矿活动转入的。露天煤矿区植被覆盖的提升有赖于矿区社会压力减少和生态恢复力提高两方面。研究成果将为露天煤矿及其所在区域生态环境科学保护与决策、恢复和治理提供信息支撑。     

煤炭开采对矿区土地利用景观格局变化的影响

为揭示煤炭资源开采对矿区土地利用景观格局变化的影响,以徐州沛北矿区为例,应用GIS、景观生态学和数理统计方法,分析了该区土地利用结构和景观格局变化,并从生命周期的角度探讨了煤炭开采对景观格局演变过程的影响。结果表明:1994—2014年间沛北矿区土地利用结构和景观格局变化显著,耕地、林地和未利用地减少,工矿建设用地和塌陷水体持续增加;景观呈破碎化和均匀化趋势,景观分形特征趋于简单化和规则化。进一步对景观指数突变检验分析可知,耕地最大斑块指数和集聚度指数分别在1999年和2001年出现突变点;塌陷水体的最大斑块指数自1995年起持续上升,而集聚度指数呈显著上升—变化不显著—显著上升的趋势。煤炭持续大规模开采导致地面塌陷、积水,耕地损毁以及快速城镇化是景观格局变化的主要原因,但随着矿区土地复垦,耕地、水体面积增大,景观破碎化程度减小,对塌陷地的治理取得了一定成效。研究结果对矿区土地复垦和受损生态景观修复具有重要的指导作用。     

Soil bacterial community responses to cadmium and lead stabilization during ecological restoration of an abandoned mine

Ecological restoration refers to the gradual recovery of damaged ecosystems by utilizing their self-recovery capacity and artificial measures. It is considered as an effective technique to alleviate heavy metal pollution in open-pit mining soils. However, little is known about the stability of heavy metals and soil bacterial responses in artificially restored soil-plant systems. In this study, different vegetation restoration strategies were established in the Dabaoshan mining area, China, and the accumulation and transfer of Cd/Pb in the soil-plant system and the responses of the soil bacterial community were investigated. Results showed that ecological restoration with a combination of trees, shrubs and grasses/herbs could increase soil cation-exchange capacity and organic matter content, but not soil pH. The mixture of trees, shrubs and grasses/herbs was most effective for reducing the available Pb content to 33.7% of the content in the control, and the mixture of trees and grasses/herbs was beneficial in reducing Cd to 60.4% of the content in the control. Data showed that ecological restoration could change the quantity, composition and community structure of soil microorganisms. The soils in which a mixture of trees, shrubs and grasses/herbs were grown had the greatest abundance and diversity of bacteria; the abundances of Proteobacteria increased by 12% and Actinobacteria by 5% from those of the control. Plant coverage, soil available Cd content, and organic matter emerged as major determinants of bacterial community composition. This study demonstrates a promising remediation strategy for limiting Cd/Pb mobility in mining areas.     

Characterization of arsenic serious-contaminated soils from Shimen realgar mine area,the Asian largest realgar deposit in China

Purpose

Serious arsenic (As)-contaminated soils have the potential to cause contamination of ground water and surface water, being toxic to plant, animals, and human. The aim of study was to characterize As contamination in the soils from Shimen realgar mine area, the largest realgar deposit in Asia.

Materials and methods

Total As concentrations, As chemical fractionation, and As potential solubility both at various land use types (smelting and processing plants (SPP), mining site (MS), and agriculture land (AL)) and soil depths (0–100 cm) were investigated. As speciation in soil was examined using X-ray absorption fine structure (XAFS) analysis, and risk assessment was also carried out to evaluate potential ecological risk of As contamination.

Results and discussion

As concentrations in the studied area were extremely high, and the total As concentration reached up to 5240.8 mg kg^?1. Moreover, total As and NaHCO₃-extractable As concentrations in all soil layers for various land use were far beyond the range of the non-contaminated soil. The potential ecological risk level of As posed higher to serious risk to the environment based on ecological risk index values. Sequential extraction confirmed that As is mostly bonded with amorphous and poorly crystalline hydrous iron and aluminum oxides (65?～?70 %), and only a small proportion (about 11 %) is partitioned in residual fraction, suggesting high risk of As mobilization. According to XAFS analysis, As was predominantly present in the form of arsenate, and arsenite was also found in the samples from SPP, MS, and AL.

Conclusions

The results indicate that the extra high concentrations of As were caused by both natural geochemical enrichment and long-lasting ore mining, smelting, and processing, and land use can greatly influence As contents in surface soil. These findings can be important for risk assessment and for the development and implementation of suitable management and remediation strategies.

     

Phosphorus fractions in soils from an area with high density of livestock population

The concentrations of total phosphorus and its distribution in fractions of different solubility have been investigated in 6 different organic manures and in 69 soil samples from two counties with high concentrations of livestock population (Cloppenburg and Vechta, Lower Saxony). In the manures, large proportions of total P (means: 24% and 44%) were extracted by H₂O and anion exchange resin so that increases in labile soil P fractions can be expected if these manures are applied. The high total P-concentrations of the soils up to 8173 mg kg^?1 were related to pedogenesis and soil use. Data such as soil P test (H₂O-P, DL-P) values above the P-fertilizer recommendations and considerably larger proportions of soluble and labile P-fractions (7%-47% of total soil P) than in other regions strongly suggested that significant P-losses from the soils are likely. Therefore, reductions of P inputs to soils and measures to reduce the P-solubility and mobility are necessary for water conservation in this region.     

Assessment of mercury dispersal in an abandoned mining area by soil and lichen analysis

The total Hg content in soil and in the epiphytic lichen Parmelia sulcata was determined in a former cinnabar mining area on Mt. Amiata. Metal concentrations in soil and in lichen are significantly related and decrease at increasing distances from the zone most affected by minespoil and by air which is still vented from mine shafts. On the basis of these results and of Al analysis, it seems likely that anomalous Hg content in Mt. Amiata lichens is mainly due to the out-gassing of volatile Hg from soil, from vegetation and, in the most heavily polluted zone, to the air from mine shafts.     

Spatial distributions of metal(loid)s and their transport in agricultural soils around abandoned metal mine sites in South Korea

Journal of Soils and Sediments - To develop efficient strategies and methods to remediate soils contaminated by metal(loid)s, it is vital to monitor the metal(loid)s in the soil by conducting field...     

Lipid biomarkers and their environmental significance in mine soils from Eastern Europe

The present study describes signature lipid biomarkers in reclaimed mine soils (RMSs), an unreclaimed spoil and a natural soil (Vertisol) for a major coal mine basin in Eastern Europe. Alkanes, fatty acids and fatty alcohols, as well as coal biomarkers were abundant in the mine soils and the unreclaimed spoil. The alkanes distribution in the RMSs was bimodal with maxima at C₁₈ and C₂₉/C₃₁ and points at two origins for the alkanes, terrigenous plants, including soil borne and from the coal source. Fatty acid carbon preference indices (CPI_even/odd = 10.4 and 8.1 for the mine soils under pine and grass vegetation) reflect the increasing role of terrestrial vegetation in the formation of organic matter. The higher concentrations of the long-chain alkanes, fatty acids and alcohols are speculated as the reason for the severe and extreme water repellency observed with the Vertisol and the unreclaimed spoil. The presence of terrigenous steroid and triterpenoid markers in the RMSs is an indication of the ongoing soil formation processes. The analysis of lipid extracts allowed for the assessment of sensitive molecular indicators of biogenic terrigenous and coal origin and the degree of soil recovery following >20 years of spoils reclamation.     

Risk assessment of Arbutus unedo L. fruits from plants growing on contaminated soils in the Panasqueira mine area,Portugal

Purpose

In the Panasqueira mine area, Arbutus unedo L. (arbutus tree) grows on soils developed on waste materials and on soils impacted by mining activity. The arbutus berry brandy is considered a product with economic value. The aims of this study were to evaluate the biogeochemical impact of the mining activity on soils and arbutus trees, to assess the possible risks associated with human consumption of the fruits and the derived brandy, and to evaluate the potential of the arbutus tree in phytostabilization.

Materials and methods

Soil samples (10–15 cm deep) developed on waste materials, on schists affected by seepage water or treatment plant effluents and on colluvium-alluvium materials were characterized (fraction <2 mm) for pH, particle size distribution, organic carbon (C_org), cation exchange capacity (CEC) and NPK by classical methodologies. Plant (A. unedo) samples (roots, leaves and twigs, and fruits) were collected at the same sites as the sampled soils, washed with tap and distilled water and dried at 40 °C. The elements’ concentrations in soils (total fraction—four-acid digestion and available fraction—diethylenetriaminepentaacetic acid extraction), plants (ashing followed by acid digestion) and brandy samples produced with fruits collected on contaminated and non-contaminated sites were determined by inductively coupled plasma atomic emission spectroscopy.

Results and discussion

The soils are mainly acid, silty loam, with variable values for C_org, CEC and NPK. They are contaminated with As (158–7,790 mg/kg), Cd (0.6–79 mg/kg), Cu (51–4,080 mg/kg), W (19–1,450 mg/kg) and Zn (142–12,300 mg/kg). The available fraction of the soils is quite variable between <0.04 and 76 % of the total, depending on the element. Trace elements’ concentrations, in leaves and twigs, are within the normal range for plants, except for Cd and Zn that, in some samples, are above the normal values, but without phytotoxic symptoms. Trace elements’ concentrations in fruits are low. The calculated hazard quotient for all trace elements in arbutus berry was <0.1. In the brandy, elemental concentrations are within the legal standards, except for Pb, whose higher concentrations may result from distillery equipment.

Conclusions

According to the EC 466/2001 legislation and with a hazard quotient of <1, the arbutus berry consumption does not constitute health risks for humans. The fruits can be used to produce local brandy. The concentration of copper in brandy is within the range established by the Portuguese legislation. Arbutus unedo can be used in the phytostabilization programs in the Panasqueira area, for it is a pioneer species and a non-accumulator of trace elements.     

矿山复垦保证金测算方法综述及改进

为分析中国矿山复垦保证金测算方法存在的问题,提出科学合理的方法,以促进保证金制度的健康发展。该文对国内外的测算方法进行了总结及对比分析,结果表明:国际上的成功实践及理论界的研究均证实应依据复垦成本测算保证金,但实践中,中国各地测算方法不一,且测算出的数额往往低于复垦成本,影响了保证金制度的公平性和有效性;理论界测算复垦成本的方法可分为两类,即通过对"标准费用"的修正测算复垦成本及将复垦过程中发生的各种费用加总测算复垦成本,这2种方法均不能兼顾客观性、科学合理性及可操作性。应将各地保证金的测算依据统一为复垦成本;针对已有测算方法的不足,该文进而从导致矿山复垦成本发生差异的根本原因入手,提出了基于土地破坏主导因子的测算方法并构建了测算模型,为以复垦成本为依据统一全国的测算方法提供了理论支持。     

矿山废弃地土地复垦与生态恢复研究进展

矿山开采破坏环境、挤占耕地,诱发严重的社会问题.近几十年来,矿山废弃地土地复垦和生态恢复已成为跨学科研究热点,然而,和欧美发达国家相比,我国矿山废弃地工作存在土地复垦比率低与复垦质量差的特点.矿山废弃地土地复垦和生态恢复主要包括3方面:土壤重构、生物恢复和废水控制与处理.土壤重构技术主要包括物理、化学和工程措施,目标是重构适宜的土壤剖面和理化性质,重金属污染去除技术也是土壤重构的重要内容.生物修复可以划分为植物修复、土壤动物修复、土壤微生物修复以及菌根生物修复技术.就生态恢复和土地复垦的内涵、目标、基础理论和技术体系展开评述,并指出建立健全管理机构、明确资金来源对矿山废弃地复垦的重要性.同时认为应当加强矿山废弃地生态环境影响机制机制研究,采用3S技术和信息系统技术监测、评估和监管复垦工作,努力实现矿山废弃地环境损害减缓技术突破,建立矿山废弃地土地复垦和生态恢复的理论体系与技术规范.     

Effect of peach root residues,lime and supplemental nitrogen on survival and yield of peach trees in a decline area

Abstract

Supplemental N fertilization significantly increased survival and yield of Elberta peach trees growing in a severe decline area. There was a trend for supplemental N plus dolomitic lime to give further increases in tree survival and individual tree yields but did not significantly influence nutrient content of leaves. Trees did not respond to peach root residue applications.