芦苇定居后铜尾矿细菌群落结构的变化

Soil samples were collected from both bare and vegetated mine tailings to study the changes in bacterial communities and soil chemical properties of copper mine tailings due to reed (Phragmites communis) colonization. The structures of bacterial communities were investigated using culture-independent 16S rRNA gene sequencing method. The bacterial diversity in the bare mine tailing was lower than that of the vegetated mine tailing. The former was dominated by sulfur metabolizing bacteria, whereas the latter was by nitrogen fixing bacteria. The bare mine tailing was acidic (pH = 3.78), whereas the vegetated mine tailing was near neutral (pH = 7.28). The contents of organic matter, total nitrogen, and ammonium acetate-extractable potassium in vegetated mine tailings were significantly higher than those in the bare mine tailings (P < 0.01), whereas available phosphorus and electrical conductivity were significantly lower than those in the bare mine tailings (P < 0.01). The results demonstrated that 16S rRNA gene sequencing could be successfully used to study the bacterial diversity in mine tailings. The colonization of the mine tailings by reed significantly changed the bacterial community and the chemical properties of tailings. The complex interactions between bacteria and plants deserve further investigation.     

Changes of Bacterial Community Structure in Copper Mine Tailings After Colonization of Reed (Phragmites communis)

Soil samples were collected from both bare and vegetated mine tailings to study the changes in bacterial communities and soil chemical properties of copper mine tailings due to reed (Phragmites communis) colonization. The structures of bacterial communities were investigated using culture-independent 16S rRNA gene sequencing method. The bacterial diversity in the bare mine tailing was lower than that of the vegetated mine tailing. The former was dominated by sulfur metabolizing bacteria, whereas the latter was by nitrogen fixing bacteria. The bare mine tailing was acidic (pH = 3.78), whereas the vegetated mine tailing was near neutral (pH = 7.28). The contents of organic matter, total nitrogen, and ammonium acetate-extractable potassium in vegetated mine tailings were significantly higher than those in the bare mine tailings (P< 0.01), whereas available phosphorus and electrical conductivity were significantly lower than those in the bare mine tailings (P< 0.01). The results demonstrated that 16S rRNA gene sequencing could be successfully used to study the bacterial diversity in mine tailings. The colonization of the mine tailings by reed significantly changed the bacterial community and the chemical properties of tailings. The complex interactions between bacteria and plants deserve further investigation.     

天然蒙脱石和沸石改良对黑麦草在铜尾矿砂上生长的影响

通过温室盆栽试验,开展了天然蒙脱石和沸石处理对黑麦草在铜矿尾矿砂上生长影响的研究。结果表明:蒙脱石和沸石改良对黑麦草的地上部生物量没有显著影响,但改变了黑麦草的根重;而施用肥料促进了黑麦草生长。蒙脱石的加入使尾矿砂的有效态锌含量显著降低,但对有效态铜的含量影响不明显;而沸石的加入均显著降低了尾矿砂的有效态铜和锌的含量;另外,矿物的加入降低了尾矿砂的pH值,但其变化与尾矿砂重金属有效态含量变化之间无相关性。矿物的加入降低了黑麦草根中的铜锌吸收,但蒙脱石增加了第一茬黑麦草地上部铜锌吸收,对第二茬黑麦草地上部铜锌吸收无影响;而沸石对两茬黑麦草地上部铜锌含量均无显著影响。不同生长期黑麦草对铜锌吸收量有差异,第二茬黑麦草的地上部锌含量明显高于第一茬,而铜含量则变化不大。     

铜尾矿对水溶液中磷的吸附与解吸

为研究铜尾矿作为吸附剂对水溶液中磷的吸附与解吸,从铜陵尾矿库采取尾矿样本,以其作为吸附材料对KH2PO4配制的水溶液进行吸附,用比色法测定磷的平衡浓度,然后计算平衡吸附量和解吸量。结果表明,Langmuir和Freundlich等温吸附方程能够较好地描述铜尾矿对水溶液中磷的吸附过程;尾矿废弃物对水溶液中磷酸根的吸附量与尾矿样本中游离氧化铁、晶质氧化铁、有机络合铁含量以及烧失量呈极显著正相关,而与pH呈极显著负相关;各种植物群落下A层尾矿对磷的吸附量低于C层,尾矿对水溶液中磷的平均最大吸附量超过0.85 mg.g-1,铜官山老尾矿库白茅群落下硬盘层对水溶液中磷的平均最大吸附量达到8.66 mg.g-1,被铜尾矿吸附的磷的平均解吸率低于5%。     

Organic Matter Dynamics,Aggregation, and Carbon Sequestration in Mine Tailings Amended with Humic Substances

Mechanisms of macroaggregation, carbon dynamics, and carbon sequestration were investigated in degraded mine tailings. Humic substances (HSs), wheat straw, lime, and their various combinations were added to the mine tailings and then incubated at 20 °C for 24 weeks. A significant increase (up to 79%) of water‐stable macroaggregates was observed in the HS‐amended tailings after the incubation. During the macroaggregation, 20–33% sand of the mine tailings was bound by HS‐derived active carbon pool. The organic carbon concentration of the macroaggregates significantly increased in the HS‐amended mine tailings compared to the control. Mineral‐associated organic matter carbon derived from the HSs was mainly responsible for the increased concentration of macroaggregate carbon and the increased amount of macroaggregates as well. This active pool of added organic matter was sequestered in aggregates during the process of macroaggregation and thus improved the structure of the mine tailings.     

Revegetation of copper mine tailings with ryegrass and willow

To restore vegetation on metal mine tailings is very difficult because they often contain high concentrations of heavy metals, low nutrient content and low water retention capacity. This study involved 3 experiments that evaluated the effects of 4 treatment amendments: montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass (Loliurn perenne L.) and willow (Salix virninalis L.) with Cu and Zn mine tailings from two mining areas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also when organic manure, which contained high concentrations of inorganic salts, was added to the mine tailings, it significantly hindered ryegrass growth (P=0.05).Meanwhile, with ryegrass organic manure significantly increased (P=0.05) the extractable Cu concentration in both mine tallings. When montmorillonite was used as a mine tailings amendment with willow, the height and tress number at the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. However there was no significant difference for height, tress number, dry weight or root dry weight at the 2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention in mine tailings were essential during revegetation of mine tailings.     

金属尾矿砂的改良和植被重建研究进展

针对金属尾矿砂的理化性状以及所带来的环境影响进行了简要介绍和评述,着重从改良的角度论述了我国治理修复金属矿区尾矿砂的研究进展、存在的问题和将来的发展方向。     

不同改良剂对黑麦草在铜矿尾矿砂上生长的影响

Montmorillonite, rice straw, organic manure and chemical fertilizer were used as amendment materials for copper mine tailings, and their effects on mine tailing pH, nutrients and metal availability to ryegrass were investigated. Chemical fertilization was the most effective one in improving ryegrass growth in mine tailings among the amendment materials examined. It was found that montmorillonite raised biomass of ryegrass at the 1st and 2nd cuts, but it did not give further positive effects at the 3rd and 4th cuts. The effect of organic materials on ryegrass growth was not so good as expected, mainly due to their slow decomposition in mine tailings with less soil microorganisms. Available Cu and Zn contents in mine tailings decreased in the presence of montmorillonite but increased when rice straw and organic manure were used as amendments. Cu and Zn contents in ryegrass decreased with increasing the rate of montmorillonite application but increased with the rate of rice straw. Zn showed much stronger mobility from soil to ryegrass than Cu, and almost all the available N and P in mine tailings, except for the treatments with organic manure, were completely consumed after ryegrass had grown in mine tailings for more than four months and been harvested for four times. Owing to its large biomass and high metal uptake, ryegrass is a potential plant for remediation of metal contaminated soils in practice.     

Determination of Acid Volatile Sulfides and Chromium Reducible Sulfides in Cu-Zn and Au Mine Tailings

The present study investigated the use of chemical extractions for the determination of acid volatile sulfides (AVS) and chromium reducible sulfides (CRS) in sulfidic mine tailings from Au and Cu-Zn mines. The main objectives of the study were to understand the factors affecting AVS and CRS extraction in mine tailings and to use the AVS and CRS data as indicator of biotic reactions, including microbial sulfate-reduction. Tailings from one Cu-Zn mine and two Au mines located in the Timmins area, Ontario, Canada, were extracted for AVS and CRS, along with pure metal sulfides. Tailings were also characterized by XRD and the relative abundance of pyrite and pyrrhotite in the samples was determined. Our results showed that AVS in mine tailings were generally not extractable at cold temperature, but they could be extracted from most tailings samples at ～ 80 °C. AVS extraction of pure metal sulfides showed that pure pyrrhotite was partially soluble during cold and hot extractions and that it significantly contributed to the overall AVS fraction of the tailings. Such findings complicate the use of AVS as bio-indicators of microbial activity because a large fraction of the pyrrhotite present in the tailings originated from the ore deposit. The CRS fractions were found to be unaffected by the presence of pyrrhotite and truly represented the pyrite content of the tailings. The use of AVS and CRS data from mine tailings can be helpful in assessing the distribution of metal sulfides but attention must be paid to their true significance.     

铜尾矿污染土壤几种牧草的重金属抗性及微生物群落功能多样性研究

Copper （Cu） mine tailings, because of their high content of heavy metals, are usually hostile to plant colonization. A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China. All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture. However, on pure mine tailings, the growth was minimal, whereas the growth was maximum for the control without mine tailings. The tolerance of grasses to heavy metals followed the sequence： Paspalum notatum 〉 Festuea arundinaeea 〉 Lolium perenne 〉 Cynodon daetylon. The planting of forage grasses enhanced the soil microbial biomass. The Biolog data indicated that the soil microbial metabolic profile values （average well color development, community richness, and Shannon index） of the four forage grasses also followed the sequence： P. notatum 〉 F. arundinaeea 〉 L. perenne 〉 C. daetylon. Thus, P. notatum, under the experimental conditions of this study, may be considered as the preferred plant species for revegetation of Cu mine tailing areas.     

矸石添加对铜尾矿中香根草生长及生理生态的影响

为了探索矸石作为改良剂用于尾矿生态修复,通过盆栽试验,将矸石按一定比例(0,1%,2.5%,5%,10%和15%)添加入铜尾砂,基于铜尾砂理化性质变化,探索矸石对尾砂中香根草生理生态的作用特点。结果表明:矸石添加入铜尾砂后,提高了基质pH、有机质和营养元素含量,降低了有效态重金属浓度(Cd、Cu、Pb和Zn),改善了尾矿贫瘠环境。随矸石添加比例增加,香根草体内重金属浓度呈下降趋势,生物量和光合色素含量呈现低促高抑性变化。同时,可溶性蛋白质和脯氨酸含量随矸石添加比例增加而增加,MDA随添加比例增加而降低,低添加比例的矸石选择性提升了SOD和CAT酶活性,增强了香根草清除体内多余活性氧的能力。矸石加入铜尾砂可稳定铜尾矿中有效态重金属,也能在一定添加比例内,提高香根草抵御铜尾矿胁迫环境的能力。     

铅锌矿废弃地尾矿砂对银合欢幼苗定居的影响

研究了广东省仁化县韶关凡口铅锌矿废弃地尾矿砂对银合欢(Leucaena glauca)幼苗定居的影响。结果表明，尾矿砂中Pb、Zn、Cu、Cd等重金属含量极高，Pb、Zn比对照土壤高100倍左右，Cu、Cd高4～5倍，植物对重金属的吸收、积累量较大，且多集中于根部。尾矿砂中硝态氮(NO^-₃-N)和铵态氮(NH⁺₄-N)含量很低，仅为对照土壤的13%～23%。银合欢幼苗在尾矿砂中能生长，但其叶片光合色素含量较少，株高、复叶数、植株干物质量等生物量显著降低，这主要是由于重金属含量过高导致根系活力降低，限制了植物对水分和营养物质的吸收，其次是土壤贫瘠的影响。     

Growth and Metal Accumulation of Geyer and Mountain Willow Grown in Topsoil versus Amended Mine Tailings

Willows (Salix spp.) are an integral component in the restoration of wetland plant communities that have been impacted by the fluvial deposition of mine tailings. A greenhouse study was conducted to compare growth and metal uptake of Geyer (S. geyeriana) and mountain (S. monticola) willow grown in topsoil versus lime and biosolids amended mine tailings. Biomass, leader length, and tissue metal contents were measured after four months growth. Above and belowground biomass and leader length of Geyer willow were greater for plants grown in topsoil compared to amended mine tailings. However, soil type did not affect mountain willow growth. Analysis for five metals yielded complex results for the two willow species and soil types. As compared to mountain willow, Geyer had greater concentrations of Mn and Pb in aboveground tissues, and Cu in senesced leaves and bark-less leaders when grown in tailings; mountain willow leaves contained greater levels of Cd than Geyer when grown in tailings. Both willow species had foliar Cd levels which were above livestock toxicity tolerance values. Based on growth characteristics, mountain willow appeared better suited for restoration of mine tailings compared to Geyer willow. However, because of the high Cd uptake by both willow species, care should be taken in restoration efforts where wildlife and domestic livestock are likely to browse on the willows.     

生物炭：一种新型改良剂能修复矿物、工业以及污水废弃物污染的土壤

Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality and watercourses due to the erosion of contaminated soils for absence of vegetative cover.High concentrations of toxic elements, organic contaminants, acidic soils, and harsh climatic conditions have made it difficult to re-establish vegetation and produce crops there. Recently, a significant body of work has focussed on the suitability and potentiality of biochar as a soil remediation tool that increases seed emergence, soil and crop productivity, above ground biomass, and vegetation cover on mine tailings, waste rock piles, and industrial and sewage waste-contaminated soils by increasing soil nutrients and water-holding capacity, amelioration of soil acidity, and stimulation of microbial diversity and functions. This review addresses: i) the functional properties of biochar, and microbial cycling of nutrients in soil; ii) bioremediation, especially phytoremediation of mine tailings, industrial waste, sewage sludge, and contaminated soil using biochar; iii) impact of biochar on reduction of acid production, acid mine drainage treatment, and geochemical dynamics in mine tailings; and iv) treatment of metal and organic contaminants in soils using biochar, and restoration of degraded land.     

鸡粪改良对铜尾矿基质中无机氮组分及3种豆科植物生长发育的影响

基质改良和耐性物种选择是重金属矿业废弃地生态修复的关键。本文通过室内盆栽试验,以4kg尾矿为植物盆栽基质,分别加入腐熟鸡粪0、8、16、32g混匀,记作MA0（CK）、MA8、MA16、MA32处理方式,研究不同比例腐熟鸡粪改良对铜尾矿基质中无机氮组分及3种豆科植物决明（Cassia tora）、田菁（Sesbania cannabina）、菽麻（Crotalaria juncea）生长发育的影响。结果表明,添加鸡粪改良处理后,3种豆科植物生长的尾矿基质中均以硝态氮为有效氮的主要形态,总无机氮含量为17.96～44.82mg·kg-1。其中菽麻MA32处理组尾矿基质中铵态氮含量（5.31mg·kg-1）最高,菽麻MA16处理组尾矿基质中硝态氮含量（43.06mg·kg-1）和总无机氮含量（44.82mg·kg-1）最高。MA16处理时,田菁和菽麻叶绿素a、叶绿素b、叶绿素a＋b值均表现最大。3种豆科植物叶绿素a/b为0.92～1.08。在同一鸡粪比例处理中,菽麻叶绿素a、叶绿素b、叶绿素a＋b值均显著高于决明和田菁（P〈0.05）。鸡粪改良铜尾矿基质能够促进3种豆科植物生长,植物株高、冠幅、根长均增加,并且随着生长期延长,增加明显。其中MA32处理菽麻70d株高（94.40cm）最大,阻止尾矿风蚀水蚀的效果最好。综合分析表明,MA16处理方式可作为鸡粪改良铜尾矿基质理想的比例模式,菽麻可作为铜尾矿生态修复优选植物种。     

Stabilization of Mine Tailings Using Fly Ash and Sewage Sludge Planted with Phalaris arundinacea L.

The impact of plants (Phalaris arundinacea L.) on the leakage of ammonium, cadmium, copper, nitrate, phosphate, and zinc from sulfidic mine tailings covered with wood fly ash and sewage sludge was investigated. Either ash or sludge was placed in contact with the tailings, and ash layers of either low or high compactness were used. It was revealed that an ash/sludge cover effectively decreased the metal leaching from the tailings regardless of the order in which the materials were applied. Plants decreased the amount of leachate and the concentrations of ammonium and phosphate. The presence of ash below the sludge decreased the plant uptake of copper and zinc and nitrate leakage. However, when the ash was added as a thin (1.5 cm) porous layer, roots and air reached the tailings and caused high metal leakage. The results support the use of a vegetated ash/sludge cover in the treatment of mine tailings, provided that the sealing layer is firm enough to prevent root penetration.     

Limiting factors for reforestation of mine spoils from Galicia (Spain)

Mined areas are a continuing source of heavy metals and acidity that move off site in response to erosion. Revegetation of the mine tailings could limit the spread of these heavy metals and acidity. This study was conducted to evaluate, at four tailings on opencast mines of Galicia (Touro: copper mine; and Meirama: lignite mine, NW Spain), the chemical and physical soil quality indicators and limiting edaphic factors concerning forest production. Selected zones were: (1) The tailings formed by the waste materials from the depleted Touro mine; (2) the decantation site of deposited sludge coming from the copper extraction in the flotation stage; (3) and (4) tailings of 3 and 10 years old of the Meirama lignite mine. The main physical limitations of the mine soils are the low effective depth (<50 cm), high stoniness (>30 per cent) and high porosity (>60 per cent); which make them vulnerable to soil erosion and seriously interferes with the forest production. Soils coming from the decantation site of copper mine do not have physical limitations. The main chemical limitations of mine soils are their acidity (pH from 3·62 to 5·71), and aluminium saturation (>60 per cent in copper mine soils, and >20 per cent in lignite mine soils), low CECe (from 5·34 to 9·47 cmol₍₊₎ kg⁻¹), organic carbon (from 0·47 to 7·52 mg kg⁻¹) and Ca²⁺ and Mg²⁺ contents, and imbalance between exchange bases. Mine soils coming from the decantation site of copper mine soils are strongly limited by the high Cu content (1218 mg kg⁻¹). Lime and organic amendments are the most important factors in providing a suitable medium for plant growth. Copyright © 2004 John Wiley & Sons, Ltd.     

impact of high aluminium loading on a small catchment area (thuringia slate mining area) – geochemical transformations and hydrological transport

A field study was performed on the effects of acid mine leachate from slate mine tailings seeping into a small river passing through the tailings. Before entering the tailings the river water has high alkalinity which neutralizes acidity upon mixing with leachate within the tailings. Donwstreams of the tailings the pH of the river water ranges about pH = 8, the water contains high concentrations of sulfate (≈1500 μmol/1 and particulate bound aluminium (≈80 μmol/I), but low concentrations of dissolved aluminium (≈3 μmol/1). It is therefore assumed that AI(OH)₃ colloids are precipitated during the neutralisation process and transported out of the tailings. The concentration of particulate bound aluminium along the river shows a strong correlation with the concentration of sulfate, which indicates that particulate bound aluminium is conservative. It therefore seems that under dry weather conditions (under most of the sampling was performed) no chemical retention mechanism exists which confines the distribution of aluminium to a restricted part of the catchment area. In contrast, the white river sediment is rich in both aluminium and sulfate, which suggests the temporary formation of aluminium hydroxosulfate minerals. Favorable (i.e. acidic) conditions may prevail at high discharges where the acidity accumulated in the tailings is flushed into the river with its subsequent acidification.     

The Potential for Waste‐Derived Materials to Form Soil Covers for the Restoration of Mine Tailings in Ireland

Revegetation of mine tailings sites can require significant amounts of topsoil, the sourcing of which can be costly and have detrimental impacts. To address this problem at an Irish mine tailings site, engineered soils were created by mixing varying rates of glacial till with stockpiled peat and compost. Soil status was assessed using a range of soil parameters and vegetation growth characteristics and compared with locally sourced topsoil. Hordeum vulgare (Barley) germination and growth trials were assessed on engineered soils: compost with glacial till, peat with glacial till, compost/ peat with glacial till and topsoil. A range of soil quality parameters were examined including: nutrient status, dehydrogenase activity, metals availability and physical characteristics (bulk/particle density and porosity). Results demonstrate that compost derived soils yielded superior plant biomass and nutrient content, whilst peat derived treatments exhibited nutrient deficiency. Whilst the engineered soils offer potential as an alternative to sourcing topsoil for covering mine tailings, the phosphorus and metal content of composts should be assessed prior to inclusion. Copyright © 2015 John Wiley & Sons, Ltd.     

Uptake and Distribution of Lead (Pb) and Cadmium (Cd) in the Freshwater Crab,Potamonautes Perlatus (Crustacea) in the Eerste River,South Africa

This paper evaluates the effects of organic amendments and ironprecipitation on pore size distribution and mechanical resistancein sulphide mine tailings, as related to plant habitat requirements. Unaltered tailings, oxidised tailings collected from untreated, fertilized and sludge-amended plots in the field,and mixtures of unaltered tailings and organic amendments prepared in the laboratory, were analysed for pore size distribution. The organic amendments (sewage sludge, peat mossand paper mill sludge) were each applied at the rates of 0, 16 and 33% by volume. A difference in pore-size distribution between untreated and treated samples was shown in both field and laboratory samples. Both inorganic and organic amendments caused a decrease in pores holding water at soil water potentials–10 to –60 kPa, but increased the pores holding water at tensions below –60 kPa. This resulted in a decreased or unchanged content of plant available water (W_a) in all laboratory samples and in the fertilized field samples. Penetration studies in the field showed that additions of fertilizer, without any organic matter, had resulted in hardpans in the oxidised tailings that significantly increased themechanical resistance in the surface horizon. Thus, this studyindicates that the physical influence of the oxidation processestaking place in sulphide mine tailings can be magnified by additions of soil amendments. The aggregation of iron oxides and negatively charged particles such as organic substances orphosphate anions may cement the tailings, which can result inimpeded root growth.