Environmental risk evaluation of the use of mine spoils and treated sewage sludge in the ecological restoration of limestone quarries

The ecologic restoration criteria in areas degraded from extraction activities require making use of their mine spoils. These materials do not meet fertility conditions to guarantee restoration success and therefore, need the incorporation of organic amendments to obtain efficient substratum. Reducing the deficiencies in the organic material and restoration material nutrients with the contribution of treated sewage sludge is proposed in this work. This experiment was based on a controlled study using columns. The work was conducted with two mine spoils, both very rich in calcium carbonate. The first mineral, of poor quality, came from the formation of aggregates of crushed limestone (Z). The other residual material examined originated in limestone extraction, formed by the levels of interspersed non-limestone materials and the remains of stripped soils (D). Two treatments were undertaken (30,000 and 90,000 kg/ha of sewage sludge), in addition to a control treatment. The water contribution was carried out with a device that simulated either short-duration rain or a flooding irrigation system in order to cover the surface and then percolate through the soil. The collection of leached water took place 24 h after the applications. Different parameters of the leached water were determined, including pH, electrical conductivity, nitrate anions, ammonium, phosphates, sulphates and chlorides. The values obtained for each irrigation application are discussed, and the nitrate values obtained were very elevated.     

Macroseismic practice in Slovenia

In 1986, a project was started concerning the improvement of macroseismic data management in Slovenia. It was decided to establish a network of collaborators all over Slovenia (20 251 km², approx. 2 million inhabitants), dense enough to allow the use of the MSK scale. Since the uniform spatial distribution with desired density of collaborators is hard to achieve, several methods are being used to obtain new collaborators. At present we have approximately 4100 collaborators in our computer supported database.When an earthquake is felt in Slovenia, the seismologist decides to what areas the questionnaires are to be sent. The prospective observers can be chosen by two criteria: density and quality marks. The density mark allows us to choose a number of observers in the same town or village, based mostly on the quality of answers and demographic conditions. The quality mark is computed, combined with the previous marks, and updated every time a completed questionnaire is returned.The average number of shocks for which the questionnaires are being sent is about 25 per year during the normal seismic activity. The average number of questionnaires is approximately 300 per event. The percentage of the returned questionnaires is above 66%. A user-friendly, interactive program has been developed to manage the database with information about collaborators, to select an area, density and quality threshold of inquiry, and to print addresses onto questionnaires.     

基于主成分分析的青藏高原多年冻土区高寒草地土壤质量评价

土壤质量评价是提高对土壤质量理解的关键环节。为了了解青藏高原多年冻土区高寒草地土壤质量的基本情况,在青藏高原腹地西大滩至安多地区,根据不同海拔梯度和植被盖度共采集了154个土壤样品。通过主成分分析（PCA）法确定了影响青藏高原多年冻土区高寒草地土壤质量的最小数据集（MDS）：全氮、全磷、全钾。根据影响土壤质量的最小数据集对青藏高原多年冻土区高寒草地土壤质量进行评价,得出了不同海拔、不同植被盖度下的土壤质量指数（SQI）。通过对不同海拔、不同植被盖度的土壤质量指数进行对比研究表明：随着海拔的升高,SQI呈增加的趋势,即海拔4 300～4 600 m（0.270±0.043） < 海拔4 600～4 900 m（0.326±0.061） < 海拔4 900～5 200 m（0.410±0.075）;随着植被盖度的增加,SQI也呈现增加的变化趋势,即植被盖度小于50%（0.262～0.265） < 植被盖度大于50%（0.336～0.344）。在分别考虑了有机质、盐分、土壤水分对土壤质量的影响下得出的土壤质量指数值与基于最小数据集得到的土壤质量指数相一致,说明基于主成分分析的最小数据集可以对青藏高原多年冻土区高寒草地土壤质量做出较准确的评价。     

石漠化地区土地利用方式对土壤团聚体稳定性及有机碳的影响

以典型高原山地喀斯特石漠化6种土地利用方式土壤为研究对象,探讨不同生态恢复条件下,坡耕地转变为林地、草地及林草套种地后对表层土壤结构稳定性及其有机碳含量的影响.结果表明:在坡耕地实施石漠化治理措施,造林种草后,>0.25 mm团聚体含量显著增加,以人工林、次生林居多,坡耕地较少.在干湿筛处理下,采用平均质量直径(MWD...     

Evaluation of Strength Characteristics of Tropical Black Clay Treated with Locust Bean Waste Ash

An expansive tropical black clay (also known as black cotton soil because the cotton plant thrives well on it) was treated with up to 15 % locust bean waste ash (LBWA) to assess its soil improvement potential. Samples were subjected to index, compaction using three energy levels (British Standard light, BSL, West African Standard, WAS or ‘Intermediate’ and British Standard heavy, BSH), shear strength (unconfined compressive strength, UCS), California bearing ratio, CBR and durability tests. Results obtained show that the natural soil is not suitable for road construction. The maximum dry density (MDD) and optimum moisture content (OMC) decreased and increased, respectively. Regardless of the compactive effort and curing period, strength and durability properties increased with higher LBWA content with the BSL effort recording the best improvement. However, based on durability results, the optimal 12.5 % LBWA treatment of black cotton soil did not satisfy criteria for its use in road construction as a stand alone additive. Also, significant improvement in soil properties was obtained using the BSL compactive effort, which is easily achieved in the field. The benefits of the application include reduction in the cost of soil improvement and the adverse environmental impact of locust bean waste.     

湖泊湿地生态地球化学评价的标准体系

湖泊湿地生态地球化学评价的研究重点为湖泊湿地生态系统中的重金属、植物营养元素及一些有机污染物,评价标准体系相应地包括水质基准、营养物基准、水体沉积物质量基准、饮用水卫生标准、土壤环境质量标准、食品卫生标准、湖泊水库富营养化标准等。     

Economic Sampling and Extraction of Undisturbed,High Quality Samples in Normally Consolidated Lacustrine Clays Using a Large Diameter Tube

This paper describes the development, design and use of a large diameter sampling tube. High quality test specimens are essential for the investigation of mechanical properties of a soil for high risk projects and when complex and expensive testing methods are to be used. Block sampling is recommended to give the highest sample quality for clayey soils, however, extracting blocks of normally consolidated lacustrine silty clay without excessive disturbance was challenging due to the inherent structure of the soft varved silty clay and difficulty in maintaining K_o conditions, as well as no vertical strain, in the sample. A new sample tube, with an inner diameter of 196 mm, an area ratio of 4% and an outer cutting-edge angle of 11° was designed to offer a larger cross sectional area than conventional thin walled sampling tubes, to provide the necessary side support and to prevent water ingress at the sides of the sample. The length-diameter aspect ratio was 1.275 to optimise the amount of clay sampled for subsequent testing and in an attempt to minimize the pressure in front of the tube. Samples were taken in initially newly excavated trenches at a depth of c. 1 m with this new sampler and with conventionally sampled soil specimens, prior to the main testing programme with samples from 6 m depth. A comparative study was then performed including preliminary unconsolidated unconfined compression tests followed by anisotropically consolidated undrained triaxial compression tests. It was important to establish whether this approach had led to an improvement in sample quality prior to embarking on an extensive triaxial stress path testing programme on this varved soil (Messerklinger, Non-linearity and small strain behaviour in lacustrine clay, 2006; Messerklinger and Springman, Geotech Test J 30(6), 2007; Messerklinger and Springman, Geotech Geol J, 2008). The results showed that the undrained shear strength of the specimens from the new sampler was consistently around 20% higher than that of specimens extruded from conventional thin walled tube samplers. This confirmed that samples with a significantly higher quality could be extracted from normally consolidated, fine grained, varved lacustrine deposits with this large diameter ‘block’ sampling tube.     

不同土地管理和利用方式喀斯特坡地养分和碳库管理指数的差异

文章选择环江喀斯特农业生态试验站坡地,设计封育、种植玉米、种植牧草、火烧、刈割和刈割除根6种处理方式,测定了不同处理下坡地土壤养分含量、有机碳、易氧化碳含量和碳库管理指数。结果表明,不同处理下土壤养分含量、有机碳含量和碳库管理指数均存在明显差异。土壤全氮、全磷、碱解氮、速效钾、有机碳和易氧化碳含量随土壤人为干扰的增大而减小,种植玉米、种植牧草和刈割除根处理由于人为干扰较大,上述指标显著低于封育和火烧处理。土壤全钾和速效磷含量均以种植玉米处理最高,而刈割处理最低。土壤缓效钾含量以封育最高,种植玉米和种植牧草处理次之,而刈割处理最低。与封育相比,各处理土壤碳库管理指数均显著降低,其中种植玉米和火烧处理最低,并显著低于其他各处理。此外,土壤全氮、全磷、全钾、碱解氮和有机碳含量随坡位的升高而降低。在喀斯特生态脆弱地区,自然封育有利于土壤养分和碳库管理指数的保持和提高。随着土壤人为干扰的增大,土壤养分含量和碳库管理指数下降。     

GeoPT3. International Proficiency Test for Analytical Geochemistry Laboratories - Report on Round 3

Results from seventy two laboratories participating in GeoPT3, round three of the international proficiency testing programme for analytical geochemistry laboratories, are presented. The report includes analytical results contributed by participating laboratories, together with the z-scores derived from these results using appropriate fitness for purpose criteria. These data are available for use as part of the laboratories' quality control procedures to assess the reliability of analysed results.     

河南信阳板栗生长的土壤地球化学评价

信阳板栗是河南省名特优农产品之一,但是有关信阳板栗生长环境的土壤地球化学方面研究较少,致使目前板栗的种植、规划等缺乏理论依据.本文对河南信阳板栗种植区土壤样品的地球化学元素进行测试分析,研究了土壤地球化学元素与板栗品质之间的相关关系.分析结果显示,板栗品质与土壤有机质、阳离子交换量、pH值、全氮、氨态氮、有效锌、有效铜、有效锰、有效硼呈正相关关系,并且与氨态氮、有效锌、有效铜、有效锰、有效硼的相关性很强,说明耕作土壤增加这些元素的含量有利于提高板栗品质,土壤pH值越接近5～6的最适宜范围,板栗品质越好;板栗品质与土壤容重、速效磷、速效钾呈负相关关系,认为在施用磷肥和钾肥增加速效磷、速效钾,提高板栗产量的同时,应注意板栗品质下降的问题.值得注意的是,研究区土壤中有效硼含量低于土壤临界值,是限制板栗品质的重要因素.本研究为提高信阳板栗品质、规划板栗园的种植、科学管理和合理施肥提供了依据.     

多目标区域地球化学调查与土壤碳储量问题——以江苏、湖南、四川、吉林、内蒙古为例

在全国多目标区域地球化学调查获得土壤高密度和大数据量碳分布数据基础上,提出"单位土壤碳含量"概念和建立土壤碳储量实测计算方法,为精确计算土壤碳储量和估算土壤碳库提供了新的途径。依据"单位土壤碳含量"进行土壤碳储量实测计算,可以按照土壤类型、土地利用分类、生态系统及自然景观等任意划分方式,从不同途径取得市县、省区、流域及至国家土壤碳储量,并在各级次上进行土壤碳库问题研究,解决土地利用、农业种植和环境评估中的实际问题。文章以江苏、湖南、四川、吉林、内蒙古为例进行土壤有机碳储量计算,结果表明,全国土壤碳储量分布不均匀。按照土壤有机碳储量和土壤平均有机碳储量分布,四川省四川盆地西部区土壤有机碳储量为1779887583t,平均有机碳储量最高,为29107.86t/km2;依次为:吉林省平原区有机碳储量2618973357t,平均有机碳储量27427.25t/km2;湖南省洞庭湖区有机碳储量837159672t,平均有机碳储量21977.31t/km2;江苏省有机碳储量1818603526t,平均有机碳储量17117.61t/km2;内蒙古河套地区有机碳储量286247058t,平均有机碳储量9592.73t/km2。     

龙湖主湖区开挖及防渗方案优化研究

郑州市郑东新区龙湖这样大规模的城市人工湖建设在我国尚属首次。在平均湖深4.5 m的前提下以及已有研究成果的基础上,采用现场调研、室内外试验、水质分析及数值分析计算相结合的综合研究方法,结合实际工程经验对龙湖开挖及防渗方案进行研究,结果表明,龙湖主湖区开挖宜采用干法和湿法相结合的“综合开挖”方案;防渗宜采用水中抛土和碾压铺盖相结合的方案,这样既能保证成湖,又不会对周边地区地下水系统和地质环境造成大的影响,还能满足水质要求,从施工设备和工程投资角度来讲也是合理可行的。另外,在龙湖正式开挖之前,应先在现场进行试挖工程,对开挖、防渗设计进行优化。     

全国土地质量地球化学调查二十年

土地质量地球化学调查计划是我国继区域化探全国扫面计划之后一个新的国家地球化学填图计划,该计划实施20年来,在支撑土壤环境污染防控、土地资源管理、国家重大立法、精准扶贫等方面做出了重大贡献,显著拓展了地质工作服务链。本文从计划的提出背景、项目的组织实施、主要进展、调查技术的进步和分析测试技术的提高与质量控制方案的完善等方面回顾了该计划的发展历程。从全国耕地地球化学状况、全国省会城市土壤环境质量状况、中国主要淡水湖泊沉积物环境质量状况、中国主要农耕区20年来土壤碳库变化4个方面对调查成果做了全面总结。全方位介绍了调查应用成果在土地管理、土壤污染防治、农业种植结构调整、脱贫攻坚、地方病防治、油气勘查、固体矿产勘查等7个领域中的应用。并在调查技术革新、评价方法创新和调查与研究融合三个方面对土地质量地球化学调查工作的未来发展趋势做了展望。     

地下水污染调查中水样有机组分分析质量控制

根据《地质矿产实验室测试质量管理规范》的要求,为保证地下水污染调查中样品的准确测定,需采取质量控制方法。文章阐述了地下水样品的前处理和测定过程的质量控制措施,建立了地下水有机组分分析过程的质量控制流程,确保其检测数据达到规范所允许的范围。     

基于碎石屏障的土壤盐渍化改良技术及机理研究

利用碎石屏障阻断非饱和带毛细上升为土壤盐渍化改良提供了新思路.为了研究碎石屏障对盐渍化土壤改良的可行性以及碎石层结构和埋深对改良效果的影响,在河套灌区西部杭锦后旗典型盐渍化分布区建立试验地,设置了7组不同碎石屏障处理工艺开展土壤盐渍化改良试验,对试验地40 cm深度的土壤盐分、pH、阳离子交换量、交换性钠百分率等参数进行了为期一年的监测和分析.结果表明,7组不同处理中,埋设深度为60~80 cm,利用颗粒直径为1 cm和3 cm的碎石按上细下粗的结构分两层铺设的处理方法改良效果最佳;从表层到40 cm深,土壤EC值平均下降55.9%.较大的碎石屏障埋深,上细下粗的铺设方式,可提高下层碎石孔隙度,并在非饱和带深处切断毛细管,从而有效降低土壤毛细上升高度,抑制深层土壤中的盐分上移"返盐",改良效果较好.      

北盘江流域水土流失及石漠化调控

以1989- 2001年通过盘江桥、高车断面的输沙量资料,分析北盘江流域的水土流失状况。结果表明,喀斯特地区的水土流失特征具有非线性的复杂关系。为了改善北盘江流域的生态环境质量,有必要对石漠化过程和人类活动方式采取适当的调控措施。通过对不同尺度范围可行性的探讨,认为按尺度层次划分的坡地改良方式,可能是北盘江喀斯特地区石漠化治理较为有效的途径。      

土壤碳蓄积量变化的影响因素研究现状

土壤碳库的动态平衡影响作物产量和土壤肥力的高低，是土壤肥力保持和提高的重要研究内容。简要评述了土壤理化特性、温度和降水变化、大气CO₂浓度上升、人类的农业活动对土壤有机碳蓄积量的影响，介绍了当前对土壤碳蓄积量动态变化的研究进展，认为应加强气候变化和土地利用/土地覆被变化与土壤碳循环研究的结合，提高对陆地生态系统碳循环变化的认识，并需要从生态环境保护的利益和可持续发展的理论出发，进一步加强土地管理方式的改变，促进土壤有机质的积累，提高土壤对碳的固定。     

Changes in water extractable organic matter during incubation of forest floor material in the presence of quartz, goethite and gibbsite surfaces

The release of dissolved organic matter (DOM) from forest floor material constitutes a significant flux of C to the mineral soil in temperate forest ecosystems, with estimates on the order of 120-500 kg C ha⁻¹ year⁻¹. Interaction of DOM with minerals and metals results in sorptive fractionation and stabilization of OM within the soil profile. Iron and aluminum oxides, in particular, have a significant effect on the quantity and quality of DOM transported through forest soils due to their high surface area and the toxic effects of dissolved aluminum on microbial communities. We directly examined these interactions by incubating forest floor material, including native microbiota, for 154 days in the presence of (1) goethite (α-FeOOH), (2) gibbsite (γ-Al(OH)₃), and (3) quartz (α-SiO₂) sand (as a control). Changes in molecular and thermal properties of water extractable organic matter (WEOM, as a proxy for DOM) were evaluated. WEOM was harvested on days 5, 10, 20, 30, 60, 90, and 154, and examined by thermogravimetry/differential thermal analysis (TG/DTA) and diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy. Results indicated significant differences in WEOM quality among treatments, though the way in which oxide surfaces influenced WEOM properties did not seem to change significantly with increasing incubation time. Dissolved organic C concentrations were significantly lower in WEOM from the oxide treatments in comparison to the control treatment. Incubation with goethite produced WEOM with mid-to-high-range thermal lability that was depleted in both protein and fatty acids relative to the control. The average enthalpy of WEOM from the goethite treatment was significantly higher than either the gibbsite or control treatment, suggesting that interaction with goethite surfaces increases the energy content of WEOM. Incubation with gibbsite produced WEOM rich in thermally recalcitrant and carboxyl-rich compounds in comparison to the control treatment. These data indicate that interaction of WEOM with oxide surfaces significantly influences the composition of WEOM and that oxides play an important role in determining the biogeochemistry of forest soil DOM.     

Geochemical Evaluation of Soil Quality in Menyuan County of Qinghai Province北大核心CSCD

青海省门源县内林草地面积大于44万公顷,耕地仅不到4.2万公顷,林草地资源丰富。2016年在门源县地区开展了1：25万土地质量地球化学评价工作,是青海省首次在大面积林草地区开展1：25万土地质量地球化学调查工作,具有较好的示范作用。通过评价土壤养分、土壤环境等级划分了土壤质量地球化学综合等级,结果表明：门源县土壤质量一等优质土壤占比92.4%,二等良好土壤占0.8%,三等中等土壤占5.6%,四等差等土壤占0.9%,五等劣等土壤占0.3%。通过项目实施可服务门源县土地资源管理,为门源县土地规划利用、农业种植结构调整及生态环境治理等提供依据,助力门源县绿色有机农畜产品输出地建设。     

内蒙古鄂伦春旗东部主要农耕区土壤有机碳含量及主要影响因素分析

利用鄂伦春自治旗东部主要耕地区1：25万土地质量地球化学调查数据,查明了研究区内表层和深层土壤有机碳储量和有机碳密度分布特征,分析了研究区内土壤有机碳储量、有机碳密度与土壤类型、土地利用方式之间的关系,探讨了土壤类型和土地利用方式对土壤有机碳的作用机理.结果表明研究区内土壤有机碳含量分布不均,土壤类型和土地利用方式是土壤有机碳储量和有机碳密度的主要影响因素.