山西矿区土地复垦科学研究与试验示范十八年回顾

山西农业大学矿区土地复垦与生态重建课题组创建于1986年。18年来,课题组采用多学科交叉融合、多专家联手攻关、课题研究与矿区生产紧密结合的方式,先后跨院、跨校、跨省、跨国,同国内外15家科研院所、100多名科研人员,承担国家级课题5项、省级课题7项,并将研究的阶段性成果应用于25项有关工矿企业土地复垦标准的制定和科技开发中。获山西省科技进步一等奖1项、二等奖2项、鉴定成果4项。出版专著4部,发表论文150余篇,编制规划设计报告书25部,积累矿区土地复垦与生态重建图片3580余张、图书800余册。培养研究生30名。相关研究内容也新增到4部面向21世纪课程教材或全国"十五"规划教材中。研制的采矿废弃地未来空间生态景观安全格局的规划设计、地形重塑、土壤重构、植被重建、环境灾害控制、生产力快速提高等综合集成技术体系,为整体推进山西省及黄土高原采矿废弃地的生态经济系统重建和可持续利用作了较充足的技术储备。     

矿区生态破坏阶段的土地利用/覆被变化研究——以平朔安家岭矿为例

以平朔安家岭矿为例,在对矿区地貌、植被、土壤等景观要素调查分析的基础上,研究了生态破坏阶段的土地利用/覆被变化扰动因子,土地挖损、土地压占及土地占用的时空顺序、数量、类型及程度,为矿区的生态重建和可持续发展提供依据。     

保山昌宁烟区土壤和烟叶中矿质元素分析研究

[目的]为了协调烟叶化学成分,提高烟叶品质.[方法]对保山昌宁主烟区植烟土壤和烟叶中微量元素进行分析.[结果]烟叶中锌、锰、铜含量与土壤中对应元素显著正相关,昌宁县三烟区土壤铜、铁含量丰富,锌、锰缺失,其中11.14％土壤缺锰,2.05％的土壤严重缺锌;烟叶中铜含量偏高,铁含量偏低,锌含量适中.[结论]在烤烟生产上要注意增施锌肥,控制铜肥,喷施锰肥.     

潼关县废弃金矿周围土壤重金属研究

[目的]确定吸收各种重金属的植物种类,建立人工湿地生态系统。[方法]以潼关县废弃金矿周围土壤为研究对象,测定土壤受重金属污染的种类、程度。[结果]不同距离不同深度的土壤样品中As、Hg、Cd等3种重金属含量均超过国家土壤重金属含量的最高限值;重金属Pb在土壤表层中的含量较高,而在深层土壤中含量较低;金属元素Zn和Cr的含量均在国家土壤重金属含量的允许范围内;在不同距离不同深度的土壤样品中均检测到放射性元素Rb,其含量在78～88 mg/kg波动。[结论]在进行矿区的植物修复时,As、Hg、Cd是需要重点考虑的重金属元素,主要考虑土壤表层Pb的吸收,不需要重点考虑Zn、Cr。     

Zn and Pb release of sphalerite (ZnS)-bearing mine waste tailings

Background, aim, and scope  Contaminated mine drainage water has become a major hydrogeological and geochemical problem. Release of soluble metal contaminants and acidity from mining sites can pose serious chemical risks to surface and groundwater in the surrounding environment, and it is an important socio-economic factor addressed by working groups like SUITMA Morel and Heinrich (J Soils Sediments 8:206–207, 2008). The release of Zn and Pb from sulfide-bearing flotation residues of a small scale mine in Western Germany is investigated with focus on metal transfer to soil solution. Total contents of the soil material as well as soil water sampled with suction cups were analyzed. The influence of pH on leaching behavior was investigated with pH_stat tests. Isotopic analyses helped assessing seepage water velocity. The aim of this study was the assessment of the environmental behavior of zinc and lead caused by the weathering of sulfide-bearing mine tailings. Especially, we address in this paper the dissolution of sphalerite (ZnS) in contrast to the well-known dissolution processes of pyrite (FeS₂). Materials and methods  Total metal contents of the soil samples were analyzed by energy-dispersive X-ray fluorescence spectroscopy, total C concentration was measured using a CHNS elemental analyzer. X-ray diffraction (XRD) spectra were recorded from powdered soil samples. Soil water was sampled in nylon suction cups. Electrical conductivity (EC), pH, and temperature of the soil water samples were measured in the field immediately after sampling. Major anions (F, Cl, NO₂, NO₃, SO₄) were analyzed by ion chromatography, major cations (Ca, Na, K, Li) were analyzed by flame photometry, heavy metals (Zn, Pb, Fe, Mn, and Mg) by flame atomic absorption spectrometry. Tritium was analyzed by liquid scintillation counting (LSC), ¹⁸O and ²H were analyzed by isotope ratio mass spectrometry (IRMS). pH_stat tests were performed at four different pH values between 2 and 5. Results  Total Zn contents of the soil samples averaged 10 g kg⁻¹, Pb contents averaged 2.5 g kg⁻¹, Fe 22 g kg⁻¹, S 8.0 g kg⁻¹, and total carbon 4.0 g kg⁻¹. Below 2-m depth, soil samples had neutral pH values. Toward the surface, pH decreased down to pH 5.4 in P1 and P3, and to pH 5.9 in core P2, respectively. Dissolved contents of major ions (Mg, Ca, K, SO₄, and HCO₃) in the soil solution increased with depth. Metal concentrations (Fe, Mn, Zn) decreased with depth. The solution pH was neutral to slightly alkaline in samples below 2 m and slightly acidic (pH 6) at 1 m depth. Tritium values are around 7 TU and correspond to modern rain, i.e., after 1975. Stable isotope values plot on the global meteoric water line. The pH_stat tests provide two kinds of information, the acid neutralization capacity after 24 h (ANC24) and the release of metals depending on pH. The ANC24 increases linearly with decreasing pH from about 60 mmol(eq) kg⁻¹ at pH 5 to about 460 mmol(eq) kg⁻¹ at pH 2. Zn and Fe release show a strong increase with decreasing pH to 126 and 142 mmol(eq) kg⁻¹, respectively. Pb release increases at pH <4 and Mn release at pH <5, both to about 10 mmol(eq) kg⁻¹. Discussion  With an average of 10 g kg⁻¹, this field site is highly enriched in Zn. In the oxidized topsoil, Zn concentrations are significantly lower than in the anoxic subsoil. The distribution pattern of total Zn contents and soil pH values indicate that the topsoil, which is prone to oxidation and acidification, is already depleted in Zn. Only in soil core P2, Zn (and Fe) contents in the topsoil were higher than in the subsoil. Oxidation of the sulfidic material leads to redistribution into mobilizable species. High soil water concentrations (10 to 15 mg L⁻¹) can be found at acidic pH. The dominant Zn species in the soil solution is Zn²⁺. At neutral pH, Zn concentrations are below 0.001 mg L⁻¹. During the soil passage, the contaminated seepage water enters the anoxic subsoil with pH buffering carbonates. Results indicate that Zn is immobilized there. However, when the acid neutralization capacity is exhausted, a breakthrough of dissolved Zn to the groundwater has to be expected. Lead averages 2.5 g kg⁻¹ inside the flotation dump. In contrast to Zn, the first centimeters of the oxidized topsoil with high TOC contents show higher Pb contents than the anoxic subsoil. About 80% of the cation exchange capacity in the topsoil is occupied by Pb. In contrast to Zn, Pb is not abundant as aqueous species at slightly acidic pH. Values lower than pH 4 are necessary to mobilize Pb in higher amounts, as pH_stat experiments confirm. Hence, Pb is not expected to be leached out until the buffer capacity of the soil is exhausted. Conclusions  The environmental fate and behavior of Zn and Pb in the flotation dump is strongly depending on pH and redox conditions. Oxidation of sphalerite leads to a transfer of Zn from immobile to easily mobilizable species. Sulfide oxidation leads to an acidification of the topsoil where the buffer capacity is already exhausted due to the leaching of carbonates. At acidic pH, Zn is transferred to the aqueous phase and leached to the subsoil where soil pH is neutral. Electron supply and the buffer capacity of the material are found to be the main factors controlling the mobility of Zn. In contrast, the transfer of comparable amounts of Pb to the aqueous phase requires pH values <4. Since Pb is enriched in the topsoil, not leaching to the groundwater, but direct uptake (e.g., children, animals) and uptake by plants is the highest environmental risk. If the acidification of the soil proceeds with the same rate as in the last 40 years, it will reach the bottom of the tailing in about 200 years and a breakthrough of metals to the groundwater has to be expected. Recommendations and perspectives  The behavior of the different metals and their environmental impact depends on the different metal properties as well as on external conditions, e.g. pH, redox conditions, buffer capacity, and groundwater recharge. To assess the future release of metals from a flotation dump it is crucial to determine the main processes leading to acidification, the buffer capacity, and heavy metal binding forms. The release of heavy metals to the groundwater could be prevented by liming or other buffering techniques de Andrade et al. (J Soils Sediments 8:123–129, 2008). Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Optimization of plant growth-promoting bacteria-assisted phytostabilization of mine tailings

Recent studies have indicated that plant growth-promoting bacteria (PGPB) can improve revegetation of arid mine tailings as measured by increased biomass production. The goals of the present study were first to evaluate how mode of application of known PGPB affects plant growth, and second to evaluate the effect of this inoculation on rhizosphere microbial community structure. PGPB application strategies investigated include preliminary surface sterilization of seeds (a common practice in phytoremediation trials) followed by a comparison of two application methods; immersion and alginate encapsulation. Results with two native desert plant species, Atriplex lentiformis and Buchloe dactyloides, suggest that seed surface sterilization prior to inoculation is not necessary to achieve beneficial effects of introduced PGPB. Both PGPB application techniques generally enhanced plant growth although results were both plant and PGPB specific. These results demonstrate that alginate encapsulation, which allows for long-term storage and easier application to seeds, is an effective way to inoculate PGPB. In addition, the influence of PGPB application on B. dactyloides rhizosphere community structure was evaluated using PCR-DGGE (denaturing gradient gel electrophoresis) analysis of bacterial DNA extracted from rhizosphere samples collected 75 d following planting. A comparative analysis of DGGE profiles was performed using canonical correspondence analysis (CCA). DGGE-CCA showed that rhizosphere community profiles from PGPB-inoculated treatments are significantly different from both uninoculated tailings rhizosphere profiles and profiles from the compost used to amend the tailings. Further, community profiles from B. dactyloides inoculated with the best performing PGPB (Arthro Mix) were significantly different from two other PGPB tested. These results suggest that introduced PGPB have the potential to influence the development of the rhizosphere community structure found in plants grown in mine tailings.     

矿区土壤重金属元素的形态分布及生物活性

[目的]研究矿区土壤铜、铅和锌的形态分布及生物活性。[方法]选取广东某金属硫化物矿区外围2个代表性的农田深层土壤样品,运用Tessier连续提取法分析其铜、铅和锌的总量和5种化学形态。[结果]结果表明,土壤中铜、铅和锌主要以残渣态形式存在,铁锰氧化物结合态和有机物结合态次之,碳酸盐结合态很少,可交换态最低。不同元素在不同土壤类型和不同土壤层位的形态分布有很大差别。以生物活性系数来评价重金属的危害性,这3种元素的生物活性均偏低,其中铅〉锌〉铜,生物可利用性不高,对生态环境的潜在危害性不大。[结论]该研究结果对土壤铜、铅和锌的环境生物效应及其迁移转化规律具有重要意义。     

湖北黄石国家矿山公园种子植物区系研究

在野外调查和资料整理的基础上,对黄石国家矿山公园自然植物区系组成和分布区类型进行了研究。该地区共有种子植物129种,隶属于51科、96属;科的分布类型以世界分布和泛热带分布为主;属的分布以泛热带和北温带分布属为主,温带成分和热带成分比例相当,反映出该区是亚热带和温带植物区系的交汇地区。该区植物种类较为贫乏,草本植物类型占明显优势,充分体现出该区植被的次生性特点。     

晋陕蒙矿区排土场不同改良模式下土壤养分效应研究

探究晋陕蒙矿区排土场不同改良模式下土壤养分效应及差异。在内蒙古准格尔旗永利煤矿排土场,选取砒砂岩沙黄土混掺(FS)、风化煤沙黄土混掺(WC)、沙黄土(SL)三种人工熟化的新构土体,与周边以长芒草为主的原地貌土壤(OL)以及新建排土场(CK)作对比,分析3种改良模式下0～20 cm表层土壤中有机碳、全氮、硝态氮、铵态氮、有效磷的含量变化及改良效果差异,并采用加权综合法对几种土壤类型的养分质量进行综合评价。结果表明:(1)不同改良模式排土场相比新建排土场,土壤各养分含量均有显著提高,原地貌土壤在0～10 cm和10～20 cm两个土层中,有效磷含量较对照分别降低了0.36 mg·kg-1和0.9 mg·kg-1。(2)重构小区中不同改良模式下土壤有机碳、有效磷、硝态氮均已超过原地貌土壤养分含量,土壤铵态氮基本达到原地貌水平,土壤全氮尚未恢复至原地貌水平。(3)由5种土壤养分指标计算出的土壤质量指数在0～10 cm土层中的变化范围是0.16～0.79,在10～20 cm土层中的变化范围是0.16～0.55,几种土壤类型的土壤质量指数排序为WCFSSLOLCK。总体而言,不同改良模式土壤养分质量以风化煤掺混土体最高,其次是砒砂岩掺混土体,沙黄土高于原地貌土壤,对照质量最差。     

龙游硫铁矿区农田土壤重金属污染的空间 变异及在水稻中的积累

为了解浙江龙游硫铁矿区农田重金属污染状况,采集矿区265件农田土壤样品,分析8种重金属Cu、As、Hg、Zn、Cd、Ni、Pb、Cr元素全量,利用地统计学软件GS+9.0对研究区土壤各元素指标进行半变异函数拟合,并利用普通克里格法进行插值并绘制空间分布图。采集30件水稻籽粒样品,分析重金属在研究区中水稻籽粒的累积特征,并进行了健康风险评价。结果表明:矿区土壤中8种重金属元素的变异系数从0.72到1.76,离散程度较高。8种重金属的土壤空间半变异函数Cu、As、Hg元素符合指数模型,Zn、Cd、Ni、Pb符合球状模型,Cr符合高斯模型。元素Cu、Pb、Zn、Cr、Ni的块金值与基台值的比值C0/C0+C都小于0.25,说明空间变化主要受地质背景等因素影响;元素Cd、Hg和As的块金值与基台值的比值C0/C0+C在0.25~0.75之间,说明除了地质背景因素,人为活动等随机因素也有影响。矿区水稻籽粒中重金属Ni和Cd的变异系数最高,分别为0.95和0.87,说明Ni和Cd元素可能存在异常积累。矿区水稻籽粒对重金属的富集能力由大到小依次为Cd、Zn、Cu、Ni、As、Hg、Cr、Pb。健康风险评价结果表明矿区农田水稻籽粒中元素As、Cd的风险商大于1,存在潜在健康风险;而其他6种重金属Cu、Hg、Zn、Ni、Pb和Cr基本属于安全范围。