Gehalte an Haupt- und Nebenelementen in Konkretionen aus Oberböden von Marschen – Untersuchungen mit einer Mikrosonde

Contents of major and trace elements in concretions of surface samples from marsh soils – Electron microprobe analysis The amounts of 14 elements (Ti, Fe, Mn, Si, Al, Ca, and P, S, Co, Ni, Cu, Zn, Cd, Pb) in concretions of four A horizons of marsh soils were determined by electron microprobe analysis on thin sections. According to the major element compositions the following types of concretions can be distinguished: Ti-Fe(-Mn) concretions (31–39% Ti; 18–29% Fe; 0,3–5,5% Mn); Fe(-Mn) concretions (31–58% Fe; ≤ 1,8% Mn); Fe-Si(-Mn) concretions (6–28% Fe; 8–42% Si; ≤ 5% Mn); Mn-Fe and Mn-Fe-Si concretions (16–40% Mn; 2–9% Fe; 2–15% Si). The formation of Ti-Fe(-Mn) concretions can be explained by adsorption of Fe²⁺ ions under reducing conditions on surfaces of Ti minerals followed by oxidation to Fe(III) oxide. In this way pseudorutile may be formed. Concretions with high Fe and/or Mn content often contain occlusions of carbonates, silicates and/or SiO₂ (bioopal) which may act as nuclei for their growth. Redox processes in marsh soils result in the formation of concretions with dominating Fe or Mn accumulation. Among the group of trace elements, P and S (like Ti and Si) reach their highest concentrations in Fe rich concretions (up to 54.000 mg P/kg and 4.200 mg S/kg). The accumulation of these elements is obviously influenced by anion competition, especially of P and Si, and probably also Ti. Likewise, high amounts of Pb were found in Fe(-Mn) concretions (up to 12.000 mg/kg). Co, Ni, Zn, and Cd show the highest amounts in Mn rich concretions (Co up to 3.400; Ni 1.800; Zn 13.200; Cd 1.000 mg/kg). Cu is also accumulated in some concretions (up to 1140 mg/kg) but no clear affinity to one of the different types of concretions was found.     

Metal Pools, Fluxes, and Budgets in an Acidified Forested Catchment on the Precambrian Shield, Central Ontario, Canada

Atmospheric emissions of metals have decreased in North America; yet, metals remain an environmental concern due to their environmental persistence and toxicity to biota. In this study, pools and mass budgets were calculated for 15 metals in an acidified forested catchment in Central Ontario. Metals that were enriched in bulk deposition over background average values (As, Cd, Pb, Zn) were generally enriched in the forest floor and upper lake sediment. While the metal pool in vegetation is small compared with the soil pool, internal cycling of metals via litterfall is comparable to atmospheric deposition, soil water, and stream fluxes. Partitioning coefficients calculated from metal concentrations in soil water and bulk soil suggest that Cd, Mn, Ni, and Zn are the most mobile. The mineral soil and lake sediments were sinks for most metals, while the wetland was a source of metals during the study year, which was a drought year. Overall, lithogenic metals (Al, Ba, Co, Fe, Mn, Rb, Sr, Zn) primarily from a weathering source generally exhibited net export from the catchment, while metals contained in atmospheric pollution (As, Cd, Cr, Cu, Ni, Pb, V) exhibited net retention. Despite the acidified nature of the catchment, it functions to retain many pollutant metals.     

Composition and mineralogy of iron-manganese concretions from some soils of the Indo-Gangetic plain in Northwest India

Iron-manganese concretions from three reference soil series of the Indo-Gangetic plain of Punjab have been investigated for their composition, micromorphology and mineralogy. The data show that amounts of Fe, Mn, Co, Ni, Cu and Zn in the concretions are higher than in the surrounding soil matrix. The contents of Mn, Co and Ni increase and that of Fe decreases with the increasing size of concretions. Cu or Zn contents do not show any systematic differences with concretion size. A major portion of these elements is oxalate- and dithionite-extractable. A minor fraction is present in the silicate structure as well as in the pyrophosphate-extractable forms. The Fe and Mn compounds present in the concretions are x-ray amorphous. The concretions appear to have developed in situ.     

Trace elements in the hydrologic cycle of a tolerant hardwood forest ecosystem

The concentrations and annual fluxes of Fe, Al, Mn, Cu and Pb were measured during 1983 in bulk precipitation, throughfall, stem-flow, forest floor percolate, mineral soil solution below the root zone and streamflow in a maple-birch stand on an acid podzolic soil at the Turkey Lakes Watershed (TLW), Ontario. Inputs of metals to TLW in precipitation were small in comparison with those in the eastern United States and Europe. Considerable loss of Mn and Cu from the vegetation during both the growing and the dormant (leafless) periods was observed and presumed to be due to leaching. The enrichment in soil solution of all metals examined, in relation to throughfall, was greatest for Al (7X) and least for Cu (1.2X). Aluminum was mobilized in both the forest floor and the mineral soil, the latter possibly in association with SO₄ ^2?. Copper was solubilized in the lower forest floor or the mineral soil. Surface soil contents of Al and Cu were reduced by Al and, to a lesser extent, Cu leaching beyond the effective rooting zone. Iron, Mn and Pb were mobilized largely in the F horizon of the forest floor, most likely by organic acids. Leaching of Fe, Mn and Pb was reduced by metal accumulation in vegetation, the lower forest floor, or mineral soil within the effective rooting zone of the vegetation. Most (80 to 99%) of the metals leached from the rooting zone were retained in the watershed and did, not appear in streamwater.     

Correlations between soil ph and metal contents in needles of Norway spruce

The concentrations of 21 elements were determined in 1 yr old needles of Norway spruce (Picea abies) at 39 different sites: The following soil parameters were measured at 3 different depths: pH, loss on ignition, total and EDTA-extractable concentrations of 28 elements. Needle concentrations were tested for correlations with soil parameters. The following significant correlations were found with pH: Al, Co, Cs, Mn, and Rb in needles increased with decreasing soil pH, whereas Ba and Sr decreased. Needle concentrations of As, Ca, Cu, Fe, K, La, Mg, P, Sb, Sc, V, and Zn had no significant correlations with soil pH. AI and Ba in needles correlated also with A1 and Ba extracted from the soil. Needle concentrations of the pairs Co and Mn, Cs and Rb, and Ba and Sr showed significant positive interelement correlations, whereas concentrations of P and K had negative interelement correlations with Mn.     

我国几种土壤中铁锰结核的元素组成和地球化学特点

The objective of this research was to isolate a dichlorvos （2,2-dichlorovinyl dimethyl phosphate）-degrading strain of Ochrobactrum sp., and determine its effectiveness in remediation of a dichlorvos-contaminated soil. A dichlorvos-degrading bacterium （strain DDV-1） was successfully isolated and identified as an Ochrobactrum sp. based on its 16S rDNA sequence analysis. Strain DDV-1 was able to utilize dichlorvos as a sole carbon source, and the optimal pH and temperature for its cell growth and degradation were 7.0 and 30 ℃, respectively. Also, the growth and degradation of strain DDV-1 showed the same response to dissolved oxygen. In addition, the soil degradation test indicated that in soil spiked with 100 mg L^-1 or 500 mg L^-1 dichlorvos and inoculated with 0.5% or 1.0% （v/v） strain DDV-1, complete degradation of dichlorvos could be achieved in 24 h. The present study showed that strain DDV-1 was a fast dichlorvos-degrading bacterium in soil. However, further research will be needed to clarify the degradation pathway and the properties of the key enzymes involved in its biodegradation.     

Chemical composition of solutions in macro- and micropores in the upper horizons of soils in the Central Forest State Biosphere Reserve

The average concentrations of Al, Si, Fe, Mn, Pb, Ni, V, Ba, and other elements were 1.5–3.5 times lower (in some cases, up to 60 times) in the macropores than in the micropores. The regularities found agreed with the rules of selective absorption of ions and their capability for the formation of complexes with the components of the soil solids. The behavior of Fe and Mn can be explained by the differences in the redox conditions in the pores of different sizes. The degree of the relationships between the soil solution and the solid phase of the matrix in the macro- and micropores differed by several orders of magnitude (within a pF range up to 4). This fact determined the different mobilization of the elements in the solutions of the macro- and micropores. The reserves of the elements were proportional not only to their concentrations but also to the amount of solution in the appropriate pores.     

Evaluating the degree of weathering in landslide-prone soils in the humid tropics: The case of Limbe,SW Cameroon

This study analyses the behaviour and mobility of major and some trace elements during the physical and chemical development of landslide-prone soil profiles in Limbe, SW Cameroon. The soils result from in situ weathering of Tertiary basaltic and picrobasaltic rocks. Textural and chemical characterisations, together with two mass balance models are applied to understand the mobility and redistribution of elements during the weathering of pyroclastic cones and lava flows. Weathering indices are used to estimate the extent of weathering. The chemical composition of the samples is evaluated by Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP–OES) and their mineralogical composition by X-Ray Diffraction (XRD) analyses. It is observed that intensive weathering results in thick meta-stable soils in which significant loss of Ca, K, Mg, Na and Sr has taken place. There is a noticeable relative enrichment in all analysed trace elements (Ba, Zr, Y, Sc, V, Ni, and Co). Ti, Fe, Al, Mn, P and Ce tend to be leached in some horizons and concentrated in others. Zr, Ti, and Ce concentrations are greater in the soils than in the bedrock but show slight fluctuations in the soil and saprolites hence cannot be used as immobile elements for mass balance evaluations. Y increases progressively with advanced weathering. Major secondary mineral phases developed through weathering are a mixture of expanding (smectites) and non-expanding clays (kaolinite, halloysite and mica). The profiles show the presence of textural heterogeneities that can be exploited as slip surfaces. Data plotted in Si–Al–Fe diagram point out that the most advanced stage of weathering noted in these profiles is the kaolinisation stage.     

Fluxes,residence times,and sources of some elements to Lake Michigan

Fluxes of 28 elements to Lake Michigan are calculated from literature data on sedimentation rates and concentrations in sediments and water. Lake Michigan residence times are roughly 10⁴ lower than oceanic residence times. A mass balance has been formulated for 24 elements, with soil and aerosol as the only sources. These sources provide fourfold excesses of Cu, Hg, Sb, Se, and V, and order of magnitude deficits for Ca, Mg, Na, and Cl, but account (to within 50%) for the observed inputs of Ag, Al, As, Br, Co, Cr, Fe, K, La, Mn, S, Si, Sc, Th, and Zn. Except for Al, Co, La, Si, and Th, deposition from aerosol accounts for at least one-fifth of the total input.     

营养物质及金属离子对DLL-E4菌降解对硝基苯酚的影响

研究了酵母膏、葡萄糖、蛋白胨、土壤浸液及Ca2 、Mg2 、Fe2 、Fe3 、Al3 、Mn2 、Co2 、Zn2 、Li 、Cu 、Cu2 、Ba2 、Ni2 等 13种金属离子对甲基对硫磷降解菌DLL E4降解对硝基苯酚的影响。结果表明 :适量添加酵母膏、葡萄糖和蛋白胨都能有效提高菌株对对硝基苯酚的降解 ,土壤浸液没有影响 ;金属离子中 ,除Li 和 0 1mmolL-1Fe3 外均对DLL E4降解对硝基苯酚的性状有一定的影响 ,其中Ca2 、Mg2 、Mn2 影响不大 ,Fe3 、Fe2 、Al3 、Ba2 、Zn2 高浓度时影响较大 ,Co2 、Cu2 、Cu 、Ni2 对DLL E4降解对硝基苯酚有较大的影响     

Interaction of silicon,iron, and manganese in rice (oryza sativa L.) rhizosphere at low ph in relation to rice growth

Rice (Oryza Sativa L.) nutrition is influenced by the interactions of (Iron) Fe, (Manganese) Mn, and (Silicon) Si in the rhizosphere. A greenhouse experiment was carried out with rice grown in four low‐pH soils (a granitic lateritic red earth, a paddy soil from the red earth, a basaltic latosol, and a paddy soil from the latosol). Rice was grown in pots with the roots confined in rhizobags and the rhizosphere soil and nonrhizosphere soil were analyzed separately for active Si, Fe, and Mn by Tamm's solution. Silicon and Mn concentrations were lower in the rhizosphere soil indicating a depletion which was higher for the basaltic soils and for the paddy soils. Iron concentrations were higher in the rhizosphere soil indicating an accumulation that was higher for granitic soils and for the upland soils. Plant growth response was due mostly to Mn with the basaltic soils supplying toxic amounts and the granitic soils being deficient. Iron accumulation in the rhizosphere caused lower plant uptake of Si, phosphorus (P), and calcium (Ca) and higher Fe and aluminum (Al) absorption leading to the conclusion that Fe deposition on plant roots and in rhizosphere may block the uptake of other nutrients.     

On some general regularities of the formation and changes in properties of mn‐fe concretions in soils of humid landscapes

An attempt is made to formulate general regularities of changes in the amount and composition of Mn‐Fe conoretions in soils of humid landscapes, confined to various soil‐forming rocks within the Russian platform. It is concluded, that the intensive formation of concretions is highly conditioned by waterlogging degree of soils and their hydrological regime. The content of concretions is always maximum in gley‐like soils (seldom in gley ones), independing on genesis of parent rocks; the fraction distribution of Mn‐Fe concretions proves to be stable in time; Mn amount is declined with increasing the waterloggiing degree of soils, while the content of Fe becomes increased; the highest accumulation of such microelements as Co, Pb, Cd is observed in concretions, which are rich in Mn. The concretions are characterized by a high amount of X‐ray‐amorphous Fe as well as by a low magnetic susceptibility. The chemical composition of concretions is shown to be preferable for quantitative diagnosis of the water‐logging degree in soils.     

Evaluation of Nitric Acid Extraction of Elements from Soils and Sediments in Two watersheds in East Tennessee

Determining the total elemental concentrations of soils requires a total dissolution method, in which hydrofluoric acid (HF) is commonly used. However, this method is tedious and risky due to the dangerous reagent HF. This study compared a single acid extraction technique using a nitric acid (HNO₃) extraction method to total dissolution (HF + microwave assisted aqua regia) for evaluating the total elemental concentrations in soils and sediments. The two methods were used to analyze the elemental content of soils and sediments from the Oostanaula Creek and Pond Creek watersheds in East Tennessee. Twenty-one elements (Al, Ba, Ca, Co, Cr, Cu, Fe, K, La, Li, Mg, Mn, Nd, P, S, Si, Sr, Ti, V, Zn, and Zr) were subsequently measured using inductively coupled plasma optical emission spectrometry (ICP-OES). The extraction efficiency for HNO₃ relative to the total was compared and discussed. In general, HNO₃ can extract the elements in absorbed phases and those residing in non-silicate minerals. Six elements (Ba, Co, Fe, Ca, Mn, and P) generated significant correlations between total and HNO₃ in both OC and PC watersheds. Finally, the elements were grouped according to the interrelationships of their total elemental concentrations based on the dendrogram plots, suggesting their geochemical association in soils and sediment forming minerals.     

Microbial DNA extraction and analyses of soil iron–manganese nodules

Iron–manganese (Fe–Mn) nodules and concretions are soil new growth, reflecting soil environmental conditions during their formation. Bacteria play a dominant role in the oxidation of dissolved Mn(II) in aqueous systems and the formation of marine and freshwater Fe–Mn nodules. However, the role and significance of bacteria in soil Fe–Mn nodule formation have not been well recognized. In this paper, microbial DNA was directly extracted from two Fe–Mn nodule samples collected from Wuhan and Guiyang in central China. The extracted DNA was amplified by polymerase chain reaction (PCR) and cloned. The clones were then screened by amplified ribosomal DNA restriction analysis (ARDRA). Twenty patterns were obtained for Wuhan sample and Guiyang sample, respectively. DNA sequencing and phylogenetic analyses revealed that the bacterial compositions of the Fe–Mn nodules were mainly belonged to Firmicutes, β-proteobacteria, γ-proteobacteria branches of the domain bacteria. These divisions had close relativeness with Mn(II)-oxidizing bacteria identified from marine Fe–Mn nodules, implying the possible contributions of these bacteria to soil Fe–Mn nodule formation.     

Distribution of elements in some Fe-Mn nodules and an iron-pan in some gley soils of New Zealand

Three soil nodules and an iron-pan have been analysed for the elements Al, Si, Ti, V, Mn, Fe, Co, Ni, Cu and Zn using an electron microprobe. From the surface analysis it appears that the nodules consist of two major concentration zones of enrichment, viz. Mn-rich, Fe-rich zones and a third zone low in Mn and Fe. The elements Co, Ni, Cu and Zn are enriched in the first zone, whereas vanadium is enriched in the second zone. Four concentration zones are distinguishable in the iron-pan, Ti-rich, Fe-rich, Ti and Fe-rich and a zone low in Ti and Fe. The metals Mn, Co, Ni, Cu and Zn are mainly enriched in the Ti/Fe-rich zone. The associations of the trace elements with the major components of the nodules and iron pan are discussed in terms of physico-chemical factors.     

Dynamics of mineral components in the forest floor of an acidic beech (Fagus sylvatica L.) forest

Seasonal changes of the mineral components Na, K, Mg, Ca, Mn, Fe, Al, Si and ash were investigated in the L1 horizon of an acidic beech (Fagus sylvatica L.) forest using litterbags (1 mm and 45 μm mesh-size) buried for up to 467 days in the forest floor. The element dynamics in this surface horizon were compared with the concentration and the total amount stored in a complete sequence of horizons (L1, L2, F1, F2 and H) taken from a moder profile in the Solling area. In the 1 mm litterbags with free access of the mesofauna, the concentrations of all cations were increased in comparison to the 45 μm treatment. This increase was highly significant, especially with regard to Fe and Al. The concentrations of these two cations were closely related to Si during the decomposition of fresh leaf litter in the L1 horizon. Si is the dominant element of ash in the litterbags and down the profile. The total amounts stored in the forest floor revealed that the Fe and Al input considerably exceeded the input by litter fall, and dry and wet deposition due to incorporation of mineral soil material. The input of soil material was also indicated by a decrease in the molar Si/Al ratio from 17 to 6 and in the relation of nutrient cations to ash from 30% to 2.5%.     

Depth Profile Of Trace Elements In a Sediment Core Of a High-Altitude Lake Deposit At The Pyrenees, Spain

Depth concentration profiles of 26 elements, i.e. trace elements (As, Ba, Cd, Co, Cr, Cu, Hg, Ni, Pb, Rb, Sr, V and Zn), lithophiles (Si, Al, Fe, Mn, Na, K, Mg, Ca and Ti) and nutrients (C, P, N, S) have been established in a sediment core collected at the Respomuso Lake (Pyrenees, Spain). This high altitude lake of glacier origin was transformed into reservoir in the fifties of last century. Correlations among the depth profiles of the above elements were established. HCl-extractable elements, which are better related to bioavailability, followed the profiles of total contents. Principal component analysis was applied to establish the binding behaviour of trace elements in the sediment matrix and, in turn, to search for their anthropogenic or natural sources. It was seen that Cu, Ni, Pb, Sr and Zn clustered together, and with exception of Sr, they were not clearly associated with any major component of the sediment. Their depth profiles correlate well with each other, hence indicating their presence as a result of atmospheric pollution. Redox-sensitive elements such as Fe and Mn follow a similar trend along the vertical profile. Depth profiles of As an Co correlate well with those of Fe and Mn. Principal component analysis showed that As, Co, Fe and Mn clustered together, which confirms the close association of As and Co with Fe-Mn oxyhydroxides. As concentrations in many strata exceed the ERM value, and therefore, significant biological effects are expected. Dissolution of minerals such as pyrite, chalcopyrite and galena taking part in the mineralogy of this area accounts for the As concentration found. Ba, Cr, Rb and V were associated with the sediment matrix (aluminosilicates), hence showing low mobility.     

Release Kinetics of Si,Al, Fe,and Mn from Acid Soils in the Presence of EGCG

Plant polyphenols can affect soil processes. In the present study, batch experiments were conducted to study the effects of epigallocatechin gallate on the release kinetics of silicon (Si), aluminum (Al), iron (Fe), and manganese (Mn) from acid Anthrosol and Luvisol. The results indicated that the optimal model describing the release kinetics of these elements was a double constant, simple Elovich, or parabolic diffusion equation, and a first-order equation was not suitable. These elements went through an initial rapid-release phase, followed by a slower-release phase. The order of release amounts and rates for Anthrosol was Si > Al > Fe > Mn, but they were different at different phases. However, the order for Luvisol was always Al > Mn > Si > Fe. Meanwhile, the release amount and rate of every element was in the order Luvisol > Anthrosol. The results of this study could help to resolve Al and Mn toxicity in acid soils.     

喀斯特峰丛洼地原生林区土壤矿质元素空间异质性研究

运用经典统计学和地统计学方法研究了喀斯特峰丛洼地原生林保护区土壤矿质元素钙、镁、硅、铁、铝、锰的空间变异和相关关系,结果表明,在喀斯特峰丛洼地原生林区土壤矿质元素存在空间上的异质性。从半变异函数的模型拟合来看,块金值与基台值的比均小于25%的标准,表明变量具有强烈的空间相关性,且由结构性因素引起的空间变异占主导因素。Kriging等值线图显示,在不同的坡位出现了高值区和低值区,硅、铁和铝在中上坡出现高值区,而钙、镁和锰在中下坡出现低值区,这6个指标在研究区域均出现围绕1~3个中心点聚集分布出现高值或低值区,说明气候、母质、地形和微地貌对喀斯特原生林区土壤矿质元素空间变异起主导作用。     

浓度与pH互作下表没食子儿茶素没食子酸脂（EGCG）对黄壤Al、Fe、Mn迁移的影响

对淋溶环境下黄壤的Al、Fe、Mn浓度进行分析,探讨浓度与pH互作下表没食子儿茶素没食子酸脂(EGCG)对黄壤Al、Fe、Mn迁移的影响。采用二因素四水平完全随机试验,用48个不同浓度和pH组合的EGCG溶液对黄壤进行间歇淋溶,测定淋出液中Al、Fe、Mn浓度,分析黄壤Al、Fe、Mn迁移总量和迁移过程。结果表明,黄壤Al、Fe、Mn迁移总量在浓度与pH互作下均有显著差异;高浓度(5.00mmol/L)高pH(5.5)EGCG溶液有利于Al和Fe的迁移,迁移总量分别为180.24mg/L和41.15mg/L;而EGCG溶液在高浓度(5.00mmol/L)低pH(3.5)时有利于Mn的迁移,其迁移总量为4.50mg/L;Al、Fe、Mn迁移总量在浓度与pH互作下主要表现为AlFeMn。随着淋溶的进行,淋出液中Al和Mn浓度在中后期(大致在第8次取样后)均逐渐降低;但随着中、高浓度(1.00,5.00mmol/L)高pH(5.5)、高浓度(5.00mmol/L)中pH(4.5)的EGCG溶液淋溶的进行,淋出液Fe浓度先增加后降低;当EGCG浓度与低pH(3.5)互作时,淋出液Fe浓度随淋溶的进行整体呈现明显的升高趋势。EGCG溶液的淋溶对土壤Al/Mn毒的治理有一定效果,且淋溶前期的效果更明显,但EGCG溶液不具备同时经济高效治理土壤Al/Mn毒的优势。