The formation of duplex soils on hillslopes in the Sydney Basin,Australia

Field studies of Duplex soils (Red and Yellow Podzolics or Ultisols) on hillslopes in the Sydney Basin show that their primary morphological feature (the texture contrast between A and B horizons) is explicable in terms of differential bedrock alteration combined with downslope movement of the coarser grained materials as a discrete surface layer. The more usually invoked processes of clay illuviation and/or clay destruction are of no more than minor importance in the genesis of Duplex soils in this area.     

重金属污染矿区复垦土壤微生物生物量及酶活性的研究

对铜矿废弃地复垦土壤微生物生物量及酶活性研究结果表明 ,与对照土壤相比 ,矿区复垦土壤微生物生物量C、N和P均有所降低 ,微生物商Cmic Corg可作为矿区重金属污染土壤微生物学敏感指标之一 ;酶活性变化与此相似 ,脲酶、脱氢酶和酸性磷酸酶与对照差异显著 ,其他则与对照差异明显 ,一定程度削弱了矿区土壤中C、N营养元素周转速率和能量循环     

Forms of Cu,Ni, and Zn in soils of sudbury,ontario and the metal concentrations in plants

Forms of Cu, Ni, and Zn in the contaminated soils of the Sudbury mining/smelting district were studied to assess metal mobility and plant availability. Soil, tufted grass (Deschampsia caespitosa (L.) Beauv.), tickle grass (Agrostis scabra Willd.), dwarf birch (Betula pumila L. var. glandulifera Regel) and white birch (Betula paprifera Marsh.) leaf and twig samples were taken from 20 locations around three Cu-Ni smelters. The sampling sites were collected to cover a wide range of soil pH and soil Cu and Ni concentrations. The water-soluble, exchangeable, sodium acetate-soluble, and total concentrations of the metals in the soils were analyzed. The soils were contaminated with Cu and Ni up to 2000 µg g^?1. Zinc concentrations were also elevated in some samples above the normal soil level of 100 µg g^?1. The mobility of Cu and Zn, expressed as the proportion of metals in Fl and F2 forms, increased with soil pH decrease. A strong positive correlation was found between the soil exchangeable (F2) Ni and the soil pH. Concentrations of Cu and Ni in birch twigs showed a good linear relationship with exchangeable forms of the metals in soils. A highly significant correlation was also found between total Ni in soils and the metal content of the twigs. No significant correlation was found between Zn concentrations in the soils and plants. Birch twigs are a good indicator (better than leaves) of Cu and Ni contamination of the Sudbury soils. The mobile forms of Cu and Ni and low pH seem to be the main factors that will control the success of revegetation. Strong variability of the soil metal mobility requires any reclamation effort be site-specific.     

微生物改良基质对新围垦海涂盐土改良的初步研究

海涂围垦区是陆海过渡带,围垦区土壤的传统洗盐和培肥技术易威胁近海生态环境,因此,探索新型、生态的盐土改良技术十分重要。该研究初步研究了新型微生物改良基质的盐土改良功能,结果表明微生物改良基质效果显著。相较于对照处理,微生物改良基质处理水稻产量增加了83.2%(P<0.05);土壤饱和含水率、田间持水量、总孔隙度、有机质、全氮、速效钾分别增加了13.80%、20.00%、6.80%、2.30倍、53.00%、31.00%(P<0.05);土壤容重降低了6.90%;土壤细菌、真菌和放线菌数量分别增加了10.30、11.20和3.18倍;水稻生育期累积灌溉水量减少了35.20%;0~10和>10~20cm土层可溶性盐质量分数分别降低了61.10%和54.40%。微生物改良基质能够在短期内加速盐分洗脱,提升土壤质量,是海涂新围垦区盐土改良的生态高效措施。     

Iron oxide and clay minerals and their relation to colours of red and yellow podzolic soils near Sydney,Australia

The iron oxide and clay minerals in some typical red and yellow podzolic soils from New South Wales have been investigated by X-ray diffraction and infra-red spectroscopy. The dominant iron oxide mineral is goethite containing about 13–14 mol % AlOOH, this being the mineral which gives the yellow soils their characteristic colour. The red soils also contain finely divided hematite which masks the colour of the goethite. Lepidocrocite was not detected in any of the soils examined. The dominant clay minerals are kaolinite and dioctahedral interstratified illite-smectite, the latter being more concentrated in the finer clay fractions, especially in soils developed on calcareous greywacke. In the red podzolic soil developed on Ashfield shale, illite-smectite is strongly interlayered with well-ordered aluminous material. Dickite occurs in this soil.     

Evaluation and source identification of trace element contamination of soils in the Qixia lead-zinc mining area,Jiangsu, China

Purpose

The Qixia mine is one of the largest lead-zinc mines in Eastern China and has been operational for approximately 60 years. Source identification for trace element contamination of soils in the Qixia mining area has been lacking. This report details the evaluation and source identification of trace element contamination (including Cu, Zn, Pb, Cd, Hg, Cr, As, and Ni) of soils in this area.

Materials and methods

Thirty-three soil samples from roadsides and fields in the study area were collected and analyzed. The index of geo-accumulation (I _geo) was employed to evaluate contamination. Methods of multivariate statistical analysis were used to determine the probable sources of the pollutants.

Results and discussion

The analysis showed that the levels of contamination ranked in the following order: Cd > Pb/Zn> > As/Cu> > Hg > Cr/Ni. In the sampling area nearest the mine, soil samples collected from roadsides showed much higher levels of contamination than those collected from fields away from the roadways. Trace element contamination decreased as the distance from the mine increased. Contamination extended to a distance of approximately 700 m from mineral transportation routes, with the area of greatest impact at 200 m or less. Multivariate statistical analysis and ore composition data suggest that the Cu, Zn, Pb, Cd, and As found in the soil samples originate from anthropogenic sources. Ni and Cr are considered to be at natural background concentrations.

Conclusions

This study distinguished between natural and anthropogenic sources of trace element contamination in the soils of the Qixia mining area. The contamination of Cu, Zn, Pb, Cd, and As is linked to the mining activities and is likely due to the transportation of ore concentrates and tailings.     

Patterns of trace metal concentration and acidity in montane forest soils of the northeastern United States

Forest floor and mineral soil samples were collected from subalpine spruce-fir forests at 1000 m above mean sea level on 19 mountains in the northeastern United States to assess patterns in trace metal concentrations, acidity, and organic matter content. The regional average concentrations of Pb, Cu, and Zn in the forest floor were 72.3 (2.9 s.e.) μg g^?1, 8.5 (0.7) μg g^?1, and 46.9 (2.0) μg g^?1, respectively. The regional average concentrations of Pb, Cu, and Zn in the mineral soil were 13.4 (0.8) μg g^?1, and 18.2 (1.2) μg g^?1, respectively. The regional average pH values of the forest floor and mineral soil were 3.99 (0.03), and 4.35 (0.03), respectively. The Green Mountains had the highest concentrations of Pb (105.7 μg g^?1), and Cu (22.7 μg g^?1), in the forest floor. They also had the highest concentrations of Cu (18.0 μg g^?1), in the mineral soil. Site aspect did not significantly influence any of the values. Concentrations of Pb were lower than concentrations reported earlier in this decade at similar sites while concentrations of Cu and Zn remained the same. We believe that these lower Pb concentrations reflect real changes in forest Pb levels that have occurred in recent years.     

The Nature and Distribution of Metals in Soils of the Sydney Estuary Catchment, Australia

Total topsoil 50th percentile Cu, Pb and Zn concentrations (n?=?491) in the Sydney estuary catchment were 23 ??g?g^?1, 60 ??g?g^?1 and 108 ??g?g^?1, respectively. Nine percent, 6% and 25% of samples were above soil quality guidelines, respectively and mean enrichment was 14, 35 and 29 times above background, respectively. Soils in the south-eastern region of the catchment exhibited highest metal concentrations. The close relationship between soil metal and road network distributions and outcomes of vehicular emissions modelling, strongly suggested vehicular traffic was the primary source of metals to catchment soils. Catchment soil and road dust probably make an important contribution to contamination of the adjacent estuary. The concentration of soil metals followed the land use trend: industrial?>?urban?>?undeveloped areas. A high proportion (mean 45%, 62% and 42%, for Cu, Pb and Zn, respectively) of metals in the soils may be bioavailable.     

Use of factor analysis to differentiate pollutants from other trace metals in surface soils of the mineralized area of Madison County,Missouri, U.S.A.

Barium, Be, Co, Cr, Cu, Li, Mn, Ni, Pb, Sr, and V concentrations were determined in 97 surface soil samples collected 1000 m apart on a regular grid in Madison county, Missouri, U.S.A. The data were normalized by a log₁₀ transformation and a matrix of correlation coefficients computed. Strong correlations were observed between several metals and statistically significant correlations were found between others. The data were then analyzed by R-mode factor analysis. Three factors satisfactorily explained the data variance and were interpreted as follows. Factor 1 (55% variance) comprised a group of elements which contaminated local soils as a consequence of operations connected with non-ferrous metal mining. Factor 2 (33 % variance) contained elements which accumulate in soils during weathering. The remaining elements were grouped together in factor 3 (12% variance) and here soil contents appeared to be controlled by rock composition.     

Local background concentrations of trace elements in soils: a case study in the Grand Duchy of Luxembourg

Background concentration values of trace elements were determined for soils in the southern part of the Grand Duchy of Luxembourg, which are developed on the Bituminous shale (BS), the so-called “Bifrons” shale, and the “Minette” (M) Fe-oolitic sandstone substrates. Sampling sites with minimal anthropogenic influence were selected, and soil profile samples were analysed for major and trace element contents. A clear distinction is seen between the trace element content of the soils developed on the Minette sandstone on the one hand and those developed on shales on the other hand. For the Minette soil samples, most elements are present in concentrations exceeding those reported in literature for soils developed upon sandstones, with, for example, values of up to 278 mg kg⁻¹ As (median value 123 mg kg⁻¹), 287 mg kg⁻¹ Cr (median value 126 mg kg⁻¹), and 95 mg kg⁻¹ Co (median value 33 mg kg⁻¹). In the shale soil samples, concentrations are generally lower except for Cu and Mo. These elements reach maxima of up to 66 mg kg⁻¹ Cu (median value 41 mg kg⁻¹) and 59 mg kg⁻¹ Mo (median value 26 mg kg⁻¹). The results confirm the importance of determining background concentrations locally.Bivariate analysis shows a linear relationship between Fe content and elements such as As, Co, and Ni for the Minette soils. No relationship is found between trace element concentrations and clay or organic carbon (OC) content, but this could be due to the limited variation of these factors among the studied soils. A reconnaissance study with regard to the availability of the trace elements in the Minette soil samples shows that these elements are quite immobile and hence of minimal threat to the ecosystem.     

Heavy metal concentrations and correlations in rain‐fed farm soils of Sifangwu village,central Gansu Province,China

Concentrations of copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr), mercury (Hg), arsenic (As), organic carbon (abbreviated to OC) content and pH were measured in rain‐fed farm soils collected in Sifangwu Village which is located central Gansu Province, Northwest China. Concentrations of Cu, Pb, Cd, Hg and As are higher than the background values in grey calcareous soil. Cd concentration exceeds the Threshold of Secondary Environmental Quality Standard for Soil in China by 261 per cent. By bivariate analysis, it was found that OC does not correlate with heavy metal in the village. This is due to the semiarid conditions and agricultural activities. Principal component analysis (PCA) was used to assess the soil data, applying varimax rotation with Kaiser Normalization. The result shows that the data set is defined for three latent components. 1) PC1, which consists of Cu and Cr, and what is characterized as a component subject to strong lithological influence. 2) PC2, dominantly loaded by OC, Pb and Cd, is linked to agricultural influence, i.e. fertilization and cultivation. 3) PC3, the heavy metals Hg and As, in this component are from aerial deposition, thus this PC is named the atmospheric factor. Because PC1 explains 45·026 per cent of total variance, the source of the heavy metal in topsoil in the study area is assumed to be mainly derived from the lithology. Copyright © 2006 John Wiley & Sons, Ltd.     

洞庭湖地区红土微量与稀土元素地球化学特征及其环境意义

Trace element (TE) and rare earth element (REE) contents in red soils from the Dongting Lake area of China were determined to understanding the provenance and weathering characteristics of the red soils. The results showed similar REE distribution patterns among red soils from the Dongting Lake area, Xiashu loess from Zhenjiang, loess and the Pliocene red soil from the Loess Plateau. These patterns implied a similar provenance from dust-storms, except for red soil R5 which formed by bedrock weathering and had significant light REE (LREE) enrichment and heavy REE (HREE) depletion due to longer weathering periods and higher intensity of weathering. Trace element, especially the Rb/Sr and Li/Ba ratios, and REE, especially the LREE/HREE ratio and δEu could trace weathering intensity. Higher Rb/Sr, Li/Ba, and LREE/ HREE ratios and negative Eu anomalies were present in the red soil from the Dongting Lake area. The weathering intensity was in the decreasing order of R5 in the Dongting Lake area > red soil from the Dongting Lake area (including reticulate red soil, weak reticulate red soil, and homogeneous red soil formed by dust storms) > Xiashu loess from Zhenjiang > Loess-paleosol and Pliocene red soil from the Loess Plateau. Variations in the TE and REE contents of soil could be effectively used to study the provenance and the weathering intensity.     

国际碳中和背景下我国开征碳税的策略选择

基于Citespace工具,对碳中和背景下的我国矿山生态修复的文献进行知识图谱可视化分析。在中国知网和Web of science网站中检索2000 ~ 2022年国内相关文献,应用Citespace 5.8 R3软件对作者、机构、关键词绘制知识图谱并进行分析。结果中英文文献分别纳入844篇和75篇,以寿立永等为代表的研究学者765位;研究机构以中国科学院为代表;生态修复为关键词频次最高的关键词。突现关键词显示,废弃矿山是人们关注的重点对象,“碳中和”是矿山生态修复的重要背景,绿色矿山是未来矿山修复的目标之一。关键词时间图谱发现矿山的生态修复是一项因地制宜、政府企业合作的实现循环共赢的一项持久战。矿山生态修复的法律政策的改善、政府企业的加入、科技技术的创新和人民意识的强化是未来的研究趋势。     

Properties and development of soils on reclaimed alluvial sediments of the Humber estuary,eastern England

Sunk Island, an area of reclaimed estuarine alluvial sediments in the lower Humber estuary, provides a series of recent surfaces ranging from around 100 to 260 years old, upon which soil properties associated with soil ripening can be examined free from the disturbance of subsequent flooding and sedimentation. Within the first 100 years of pedogenesis, overall bulk density of the sediment has increased, and profile differentiation has resulted from structural development, organic matter accumulation and tillage. The original sedimentary structures of the soil have gradually become obscured and overprinted by ped and pore patterns related to wetting and drying, burrowing and root development. Aeration has accelerated organic matter decay and accentuated the difference between topsoil and subsoil contents. Variations in aeration and moisture content have resulted in mottling, which has become less prevalent as the soils develop. Properties such as available water content, organic C and cation exchange capacity (CEC) depend upon the grain size characteristics, in particular clay content. Exchangeable bases have been progressively removed, reaching a state of quasi-equilibrium within 150 years of reclamation. Crystallisation of goethite has extended progressively deeper into the profile through time, accompanied by a decrease in amorphous iron compounds.     

Litter dams and microterraces formed on hillslopes subject to rainwash in the Sydney Basin,Australia

Observations of the results of erosion on hillslopes destabilized by fire were made over various periods up to 4.5 years in the Sydney Basin, Australia. On many sites a microrelief form of litter dams and microterraces were noted and the conditions favouring their formation identified. Litter dams formed during the first runoff event after the fire. In normal conditions they stabilized rapidly then slowly deteriorated over 3 or 4 years. A general model of litter dam and microterrace morphology and sedimentology is presented and their significance in the genesis of hillslope soils is discussed.     

南宁河洲生态农业规划区土壤重金属污染评价

对南宁河洲生态农业规划区土壤中Cd、As、Pb、Hg、Cu、Zn等重金属含量进行了调查和分析测定．应用模糊评判法进行评价。结果表明．其土壤主要受Cd和As的污染；12个试点中4个点为尚清洁，8个点为轻污染。     

苏锡常地区城市公园土壤微量元素分布特征及其环境指示意义

在江苏省国土1/250 000多目标地球化学调查基础上,选择苏州市、吴江市、无锡市、江阴市、常州市、金坛市等45个城市公园土壤作为研究对象,系统研究了当地典型城市公园土壤中Cd、Hg、Pb、Zn、Sb、Sn、B、Se、N、稀土元素(REE)等50个元素含量及土壤pH、总有机碳(TOC)等分布特征。结果表明,城市公园土壤的微量元素分布与城区污染土壤、农田土壤有显著差异,公园土壤的重金属含量总体偏低、N与TOC含量明显低于农田土壤,在公园土壤中S、Se、Cd、Pb、Zn、TOC等元素未出现高强度的人为富集,重金属污染以轻度Hg污染为主,S、Se、Cd、Pb、TOC、pH等指标在200 cm深度内分布相对稳定、未出现元素含量在不同深度的显著变化,指示多数公园土壤的微量元素分布总体上较一般城市土壤更少受人为因素干扰,可为人为活动对城市土壤环境的影响研究提供重要的参比对象。     

Investigation of heavy metal concentrations on urban soils,dust and vegetables nearby a former smelter site in Mortagne du Nord,Northern France

Environmental situations near former industrial sites like Mortagne du Nord (Northern France) in which the soil, dust and homegrown vegetables have been contaminated by heavy metals can represent a sanitary risk to the surrounding population. In order to evaluate the contamination level in different exposition media in this site, 26 urban topsoils, 17 dust and 38 vegetable samples were taken near the former zinc smelter site. All the observed levels on urban soil samples (except one) are over regional agricultural reference values for Cd and Pb. 45 % of the vegetable samples are over the European foodstuff limits and one dust sample taken in the school playground outdoor tarmac area exceeds the French limit in dust set up at 1,000 μg m^?2 for Pb. The Cd and Pb levels fluctuate depending on the use of the ground (kitchen garden, lawn, courtyard) and its location. The lack of simple correlations between the distance from the former smelter site and the Pb concentrations on sampled soils let us think that human activities contributed in the local urban contamination. In this context, who is now responsible for the soil contamination and the human exposure?     

河南省大气重金属沉降高风险区蔬菜重金属含量及健康风险评估

  【目的】  我们研究了大气重金属沉降高风险区菜地重金属的污染状况及污染来源,评价了研究区种植的蔬菜对不同人群(男性、女性、成人和青少年)产生的健康风险,并筛选了低累积重金属的蔬菜类型。  【方法】  在河南省大气重金属沉降风险高的蔬菜产区进行调查。分别采集设施栽培和露地条件下种植的叶类(青油菜、青菜、香菜)、葱蒜类(大蒜)、茄科类(茄子、辣椒、番茄)、瓜果类(苦瓜、黄瓜)、豆类(长角豆、四季豆)和块根类(萝卜)蔬菜样品,分析了蔬菜可食用部位Cd、Pb含量及富集能力,讨论了其主要的污染来源,并利用Monte Carlo模拟,对不同种类蔬菜可食用部位进行概率非致癌健康风险评价。  【结果】  设施栽培和露地条件下,蔬菜可食用部位Cd的富集系数均高于Pb。不同类别的蔬菜对重金属的吸收能力存在明显差异,瓜果类蔬菜为Cd、Pb低累积蔬菜,设施栽培条件下瓜果类蔬菜可食用部位积累的Cd、Pb含量最低,Cd、Pb含量分别为0.020、0.036 (黄瓜)和0.008、0.055 (苦瓜) mg/kg,低于食品重金属污染限值。对比设施栽培和露地条件下种植的蔬菜可食用部位的污染程度发现,露地条件下蔬菜Cd、Pb的污染程度更高,大部分叶类蔬菜和葱蒜类蔬菜为重度污染,其中青油菜Cd内梅罗综合污染指数(P_N)达到10.26,P_N (Pb)达到了10.00。概率风险评价结果表明,不同人群摄入Cd、Pb污染蔬菜产生的复合非致癌健康风险差别不大,其中摄入瓜果类和块根类蔬菜对人体没有明显的负面影响,尤其是瓜果类蔬菜,设施栽培下,成年男性摄入苦瓜产生的总目标危险系数的P₇₅ (第75百分位点)仅为0.120。  【结论】  不同类型蔬菜的Cd、Pb富集能力差异显著,叶类蔬菜对Cd、Pb富集能力最强,瓜果类较弱,尤其是苦瓜。污染区设施栽培的瓜果和豆类蔬菜可安全食用。大气沉降是蔬菜Pb污染的重要来源之一,建议在大气重金属沉降高风险区进行设施栽培,选择低积累Cd、Pb的瓜果类蔬菜,降低重金属对人体健康产生的风险。