铜锌镍锰赋存形态的土体变化特征研究

本文用逐步连续分级法研究了砂姜黑土中铜锌镍锰的化学形态在土壤剖面中的变化特征以及耕作措施等对其的影响力，结果表明，砂姜黑土中换态，有机态和无定形铁结合态铜锌镍锰的相对含量随剖面深度增加而降低，氧化锰态和残留态则随剖面加深而提高；碳酸盐结合态因元素种类的耕种方式而异，抑或增加抑或降低；晶形氧化铁态可以分类两类，铜镍变化不很明显，锌锰随剖面深度增加而增加，旱耕熟化尤其是水旱轮作后，土壤中铜锌镍锰由植物     

旱改水对砂姜黑土中锌含量的影响研究

本文用连续分级浸提法,研究了旱改水对砂姜黑土中锌的含量、赋存形态和有效性的影响。砂姜黑土中的锌绝大部分以残留态存在,晶态铁结合态约占１０％,其余形态锌一般小于＃％。这些形态锌可以分为三类;一类为土壤锌的强度因子,即代换态锌,另一类是土壤锌的容量因子,即有机态、无定形铁结合态的晶形铁结合态锌;第三类为残留态 有效态锌主要来自代换态。旱改水后,晶形铁结合态锌向有机态和无定形铁结合态锌转化,使得土壤中锌     

旱改水对土壤铜含量及其有效性的影响研

旱改水对土壤Cu含量及其有效性的影响研究结果表明 ,代换态铜是土壤中Cu的强度因子 ,而晶形铁结合态铜和残留态铜为植物无效态铜且需经形态转化才有效 ,其他形态铜既是容量因子也是强度因子 ,其有效程度大致为无定形铁结合态铜 >有机结合态铜 >氧化锰结合态铜 >碳酸盐结合态铜。旱改水促进碳酸盐结合态铜、氧化锰结合态铜尤其是残留态铜向代换态铜、无定形铁结合态铜和有机态铜转化 ,提高土壤铜有效性和可移动性 ,并使Cu淋溶损失 ,导致水旱轮作土壤耕层全Cu贫化     

耕作改制对砂姜黑土微量元素的影响研究

研究旱作改水旱轮作对砂姜黑土中微量元素含量、有效性和赋存形态等的影响结果表明,砂姜黑土旱作改水旱轮作后,微量元素的总含量除Mo外,均呈贫化趋势且达显著水平;Cu、Fe、Mn和Mo的有效性明显提高,Zn的有效性降低,严重缺Zn可能限制作物产量提高;残留态、晶形铁态和碳酸盐态微量元素含量随旱作改水旱轮作时间的延续而降低,有机态和无定形铁态微量元素的含量则不断增加,代换态微量元素含量变化与有效态微量元素相似,呈两极分化,Cu和Ni增加,而Zn和Mn降低.     

耕作改制对砂姜黑土微量元素的影响

研究旱作改水旱轮作对砂姜黑土中微量元素含量、有效性和赋存形态等的影响结果表明,砂姜黑土旱作改水旱轮作后,微量元素的总含量除Ｍｏ外,均呈贫化趋且达显著水平;Ｃｕ、Ｆｅ、Ｍｎ和Ｍｏ的有效性明显提高,Ｚｎ的有效性降低,严重缺Ｚｎ可能限制作物产量提高,残留态、晶形铁态和碳酸盐态微量元素含量随旱作改水旱轮时间的延续而降低,有机态和无定形铁态微量元素的含量则不断增加,代换态微量元素含量变化与有效态微量元素相似     

耕作改制对砂姜黑土中锰的影响

研究砂姜黑土旱改水对土壤中Mn含量、赋存形态和有效性的影响结果表明,砂姜黑土中Mn存在于粘土矿物、晶形氧化铁、无定性氧化铁、氧化锰态、有机物和碳酸盐中比例分别为27.19%~46.26%、10.48%~21.65%、2.76%~12.28%、17.39%~26.53%、10.61%~24.57%和0.16%~8.35%。旱改水实施水旱轮作后砂姜黑土中全Mn含量极显著降低,平均降幅为8.77%,但伴随土壤pH值的趋中性,土壤中Mn由植物有效性较低的晶形铁结合态逐渐向植物有效性较高的氧化锰态、无定形铁态和有机态转化,活化了土壤中的Mn,提高了Mn的有效性和可移动性。     

苏南经济快速发展区土壤Cu、Ni、Pb、Zn形态及其有效性定量分析——以昆山市为例

研究了江苏省昆山市农田土壤有效态Cu、Ni、Pb、Zn各形态含量及其有效性。结果表明,土壤重金属Cu、Ni、Pb、Zn各形态含量以残渣态有机质结合态铁锰氧化物结合态碳酸盐结合态、可交换态,残渣态含量明显高于其他形态。Cu和Pb有机质结合态所占比例相对也较高,分别达36.09%和28.30%。土壤可交换态含量、碳酸盐结合态含量、Fe-Mn氧化物结合态含量及残渣态含量均以Zn最高;土壤有机质结合态含量以Cu最高;土壤可交换态含量变异系数、土壤碳酸盐结合态含量变异系数及土壤Fe-Mn氧化物结合态含量变异系数以Ni为最大;土壤有机质结合态含量变异系数以Zn最大;土壤残渣态含量变异系数以Pb最大。土壤铁锰氧化物结合态铜和可交换态铜对土壤有效态铜含量影响最大;土壤可交换态镍含量对土壤有效态镍含量最大;土壤铁锰氧化物结合态铅和有机质结合态铅对土壤有效态铅含量影响最大;土壤可交换态锌和碳酸盐结合态锌对土壤有效态锌含量影响最大。     

长期施用有机肥对紫色水稻土铁锰铜锌形态的影响

以长期定位试验为基本材料 ,研究了 9年连续施用有机肥对紫色水稻土铁、锰、铜、锌形态的影响。结果表明 ,有机肥是土壤铁、锰、铜、锌的良好给源。紫色水稻土长期施用有机肥与单施化肥比较 ,土壤中的全铁、全锰变化不大 ,全锌提高了 5.5%～ 30.0% ,交换态铁、碳酸盐结合态铁、有机态铁、无定形结合态铁分别提高了1.5%～12.7%、2.4%～8.9%、11.6%～19.5%、32.5%～72.5%。锰、锌的各形态数量均有不同程度的增加。同时 ,长期施用有机肥增大了土壤铜的消耗 ,全铜含量有下降的趋势。     

耕型红壤和红壤性水稻土铜的化学形态及其有效性

对湖南省 1 0个有代表性红壤样品进行化学分组测定 .结果表明 ,土壤有机态、无定形铁态、晶形铁态和残留态铜分别占全铜量的 1 5 2 %、1 1 7%、1 7 2 %和 5 6 0 % .红壤性水稻土有机态和无定形铁态铜 ,明显高于耕型红壤 ,而晶形态、残留态铜则相反 ,供试土壤有效铜含量与土壤有机态铜和无定形铁态铜含量呈极显著性正相关     

秸秆还田对砂姜黑土理化性质与锰、锌、铜有效性的影响

采用田间试验与实验室培育试验研究作物秸秆还田对砂姜黑土理化性质及Cu、Zn、Mn有效性的影响,结果表明,秸秆还田可降低土壤容重,增大土壤总孔隙度,特别是毛管孔隙度显著增加。土壤中胡敏酸和富里酸含量显著增加,胡敏酸含量的增加对提高土壤有机质活性和改善土壤肥力具有良好效应。与单施化肥比较,秸秆配施化肥土壤中交换态锰、锌、铜含量分别增加11%、21%和41%,有机结合态锰、铜分别增加19%和103%。培育试验表明,加入粉碎的作物秸秆培育90d后,土壤中有效锰、有效铜含量分别增加21%和27%。     

PARTITIONING OF HEAVY METALS IN PODZOL SOILS CONTAMINATED BY MINE DRAINAGE WATERS,DALARNA, SWEDEN

The discharge of acidic mine drainage waters onto a hillslope in Dalarna, central Sweden, has lead to the contamination of the podzol soils with Cu, Fe, Ni, Pb, Zn and sulfate. Samples from contaminated and reference soils have been collected for chemical and mineralogical analyses. Jarosite is identified by x-ray diffraction analysis as a precipitate in the upper horizons (A, E, B) of the contaminated soils, where the soil acidity (pH_KCl～2.6) promotes jarosite stability. The sequential chemical extraction of soil samples indicates that, in the reference A horizon, Cu, Pb, Ni and Zn are bound primarily to cation exchange sites and organic matter. In the A horizon of the contaminated soils closest to the rock dump, metal partitioning is dominated by the Fe oxide fractions, despite the high organic matter content; Pb is almost completely bound to crystalline Fe oxides, possibly adsorbed to Fe oxides or occuring in a jarosite solid solution. In the reference B and C horizons, Cu, Ni and Zn are primarily adsorbed/coprecipitated in the Fe oxide fractions, while Pb remains with a large fraction bound to organic matter. In the Fe-rich B horizon of the contaminated soils, the partitioning of the metals in cation exchange sites and to organic matter has greatly increased relative to the reference soils, resulting from the mobilization of organo-metal complexes down the profile.     

Zinc Transformation in a Calcareous Soil as Affected by Applied Zinc Sulfate,Vermicompost, and Incubation Time

An experiment was conducted to evaluate the effect of zinc (Zn) rates and vermicompost levels on distribution of Zn forms of a calcareous soil. After incubation periods, soil samples were air dried, and a sequential extraction scheme was used to fractionate Zn into soluble and exchangeable, bound to carbonate, organically bound, bound to manganese (Mn) oxide, bound to amorphous iron (Fe) oxide, bound to crystalline Fe oxide, and residual forms. In untreated soil, Zn was mainly in the residual fraction. Increasing rates of applied Zn significantly increased all forms of Zn. Carbonate and residual forms showed the greatest increase. Application of vermicompost significantly increased all fractions except Mn-oxide form. This increase was more pronounced for organically bound, soluble, and exchangeable forms, indicating an increase in bioavailability of soil Zn. Incubation time significantly decreased soluble, exchangeable, and organically bound forms but increased other forms of Zn, meaning a significant reduction in Zn phytoavailability in soil with time.     

Effect of solid-phase speciation on metal mobility and phytoavailability in sludge-amended soil

Sequential extraction was utilized for partitioning Cd, Cr, Ni, and Zn, in soil and sludge samples into five operationally-defined fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. The highest amounts of Cd, Ni, and Zn, expressed as per cent of the total, were found in the Fe-Mn oxide fraction of the sewage sludge. Chromium was significantly associated with the organic fraction of the sludge. The residue was the most abundant fraction for all metals studied in the untreated soil, and for Cd and Ni in the sludge-treated soil. The concentration of exchangeable Cd and Cr was relatively low in the untreated soil and did not change much after sludge application, whereas the concentrations of exchangeable Zn increased about 50 times and the concentrations of exchangeable Ni doubled in the sludge-treated soil. The lysimetric experiment revealed an increase in Zn and Ni uptake by ryegrass and in the percentage of metals leached from the soil profile after massive sludge application. In contrast only negligible changes were observed for Cd and Cr. The assumption that mobility and biological availability are related to metal speciation was confirmed by the agreement between the distribution pattern of Cd, Cr, Ni and Zn in the soils, the uptake of the metals by plants and their capacity for leaching out from the soils.     

Redistribution of cadmium,copper, lead,nickel, and zinc among soil fractions in a contaminated calcareous soil after application of nitrogen fertilizers

This study was conducted to evaluate the redistribution of the heavy metals Cd, Cu, Pb, Ni, and Zn among different soil fractions by N fertilizers. In a lab experiment, soil columns were leached with distilled water, KNO₃, NaNO₃, NH₄NO₃, or Ca(NO₃)₂ · 4H₂O. After leaching, soil samples were sequentially extracted for exchangeable (EXCH), carbonate (CARB), organic‐matter (OM), Mn oxide (MNO), Fe oxide (FEO), and residual (RES) fractions. Distilled water significantly increased the concentrations of Cd and Ni in EXCH fraction, while concentration of Cu and Zn did not change significantly. Application of KNO₃, NaNO₃, NH₄NO₃, or Ca(NO₃)₂ · 4H₂O significantly increased the concentrations of Cd and Zn in EXCH fraction, while concentration of Pb and Ni was decreased. Application of all fertilizers caused an increase of Cu in the OM fraction. Moreover, leaching with these solutions significantly increased Cd [except in Ca(NO₃)₂ · 4H₂O], Cu, and Zn concentrations in the CARB fraction, while Pb and Ni concentrations were decreased. With application of all leaching solutions, Zn in the EXCH, CARB, FEO, and MNO fractions was significantly increased, while Zn in the OM fraction did not change. The mobility index indicated that Ca(NO₃)₂ · 4H₂O increased the mobility of Cd, Cu, and Zn in the soil, whereas NaNO₃ decreased the mobility of Pb and Ni in the soil. The mobility index of Pb decreased by all leaching solutions. Thus, these results suggest that applying N fertilizers may change heavy‐metal fractions in contaminated calcareous soil and possibly enhance metal mobility and that N‐fertilization management therefore may need modification.     

Chemical extractability and availability of heavy metals after seven years application of organic wastes to a citrus soil

Abstract. The chemical extractability of heavy metals introduced into the soil during 7 years application of sewage sludge, composted municipal solid waste and sheep manure, and their availability to citrus plants were studied. The total content of metals in the soil (0-20 cm)was increased by the use of sludges and compost, but only the Ni content in the saturation extracts of soil was significantly increased. Total Cd, Cr, Cu, Ni, Pb, and Zn were sequentially fractionated into water-soluble plus exchangeable, organically bound, carbonate-associated, and residual fractions. Most of the heavy metals were present in carbonate and residual fractions, although substantial amounts of water-soluble plus exchangeable Cd, and organically bound Cu and Ni were found. No significant increases in the metal contents in leaves and orange fruits were observed, with the exception of Pb in leaves. Several statistically significant correlations between metal content in plants, metal content in soil fractions, and chemical characteristics of soil were also found.     

Long‐term transformations of cadmium,cobalt, copper,nickel, zinc,vanadium, manganese,and iron in arid‐zone soils under saturated condition

Abstract

The bioavailability and toxicity of metals in soils to plants, hence to animals and human beings through the food chain, and their mobility in the ecosystems highly depends upon their forms, pathways and kinetic rates of transformation in soil. Long‐term transformation pathways, kinetics and lability of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), zinc (Zn), manganese (Mn), and iron (Fe) in two arid‐zone soils were studied under saturated water regime (simulating the moisture regime in the soil during the raining season and shortly after irrigation) by using operationally selective sequential dissolution techniques. Iron, Mn, Co, vanadium (V), Ni, Zn, and Cu were transformed from the non‐available form (reducible oxide fraction) and potential available form (easily reducible oxide fraction) into the available and readily available form (exchangeable and carbonate fractions), thereby increasing their mobility, availability or toxicity. However, Cd was transformed from the readily available form into the potentially available form, thus decreasing its lability. The fast transformations of all metals occurred in the first month, followed by a much slower process.     

Redistribution and Availability of Iron,Manganese, Zinc,and Copper in Four Malian Agricultural Soils Amended with Solid Municipal Waste Compost

Abstract

Municipal waste compost can improve the fertility status of tropical soils. The redistribution of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in tropical soils after amendment with solid municipal waste compost was investigated. Four tropical agricultural soils from Mali characterized by poor trace‐element status were amended with compost and incubated for 32 weeks at 35°C. The soil were analyzed at the beginning and the end of the incubation experiment for readily available fractions, organic fractions, and residual fractions as operationally defined by sequential extraction. Readily available Fe increased significantly with compost application in most soils. Readily available Mn was mostly unaffected by compost application. After 32 weeks, readily available Zn had increased, and readily available Cu had decreased. Readily available levels of the elements remained greater than deficiency levels in the compost‐amended soils. Organic fractions of the elements increased after compost addition. The organic fractions and residual forms, depending on the element and the soil, remained constant or increased within the duration of the experiment.     

Effect of Organic Materials on Partitioning,Extractability and Plant Uptake of Metals in an Alum Shale Soil

Soils developed on sulphide-bearing shale (alum shale) in Norway contain naturally high amount of heavy metals. We conducted a greenhouse pot experiment to study the effect of four rates (0, 2, 4, and 8%) and three sources (cow manure, pig manure and peat soil) of organic matter in partitioning and distribution, extractability and plant uptake of Cd, Cu, Ni and Zn in an alum shale soil. Sequential extraction scheme was used to determine the distribution patterns of metals in the soil. DTPA was used for extracting the metals from the soil. Wheat (Triticum aestivum) was used as a test crop to study the plant uptake of metals. The highest amount of Cd was present in the exchangeable fraction, irrespective of the rate and source of organic matter applied. Copper, Ni, and Zn, on the other hand, were present only in small quantities in this fraction. The largest fraction of Cu was associated with organic matter and the amounts present in the oxide, carbonate and exchangeable fractions were very small. Nickel and Zn were found mainly in the residual fraction. Increasing rates of cow and pig manure decreased the amounts of Cd and Ni associated with the exchangeable fraction whereas, the addition of peat soil at the same rate increased the amounts of these metals associated with this fraction. This effect of organic matter was primarily associated with the change in soil pH caused by different organic matter sources. The DTPA-extractable metals were decreased with increasing rates of organic matter application, irrespective of its source. Grain and straw yields of wheat were decreased with increasing rates of organic matter. The application of organic matter increased the Cu and Zn concentrations in both grain and straw. The concentration of all metals was lower in plants grown in the cow manure amended soil as compared to those grown in the soil amended with either pig manure or peat soil. These results sugggest that the source of organic matter was a determining factor for metal distribution in the soil and for metal uptake by plants. In this study cow manure slightly increased the soil pH and thus was more effective than either pig manure or peat soil in reducing the plant uptake of metals but in general the efficiency of the organic material in reducing heavy metal uptake was small.     

Mycorrhizal (Rhizophagus Intraradices) Symbiosis and Fe and Zn Availability in Calcareous Soil

Greenhouse experiment was conducted to assess the iron (Fe) and zinc (Zn) fractionation patterns in soils of arbuscular mycorrhizal (AM) fungus-inoculated and uninoculated maize plants fertilized with varying levels of Fe and Zn. Soil samples were collected for Fe and Zn fractions and available Fe, Zn and phosphorus (P) contents besides organic and biomass carbon (BMC), soil enzymes and glomalin. Major portion of Fe and Zn fractionations was found to occur in the residual form. Mycorrhizal symbiosis increased the organically bound forms of Fe and Zn while reducing the crystalline oxide, residual Fe and Zn fractions, indicating the transformation of unavailable forms into available forms. Soil enzymes, viz. dehydrogenase and acid phosphatase activities in M+ soils, were significantly higher than M? soil consistently. Overall, the data suggest that mycorrhizal symbiosis enhanced the availability of Fe and Zn as a result of preferential fractionation and biochemical changes that may alleviate micronutrient deficiencies in calcareous soil.

Abbreviations: AM: arbuscular mycorrhiza; Fe: Iron; Zn: Zinc; P: Phosphorous; Amox-Zn: amorphous oxide bound zinc; Cryox-Zn: crystalline oxide bound zinc; DAS: days after sowing; DTPA: diethylene Triamine Penta Acetic Acid; MnO₂-Zn: manganese oxide bound zinc; OC-Zn: organically bound zinc; WSEX: water soluble plus exchangeable zinc; MnO₂ Fe: manganese oxide bound iron; OC-Fe: Organically bound iron; WSEX Fe: water soluble plus exchangeable iron.     

Kinetics of speciation of copper,lead, and zinc loaded to soils that differ in cation exchanger composition at low moisture content

Abstract

A better understanding of the fates of heavy metals in wide range of soils is important in improving efficiency of remediation technologies of heavy metals polluted soils. To contribute to this field we studied the kinetics of speciation of copper (Cu), leaf (Pb), and zinc (Zn) in six soils differed in major cation exchanger composition. Soluble salts of Cu, Pb, and Zn were loaded to the soils, incubated at field moisture contents, and the change in chemical forms of the metals was traced by sequential extraction. In Inceptisols predominated by 2:1 layer silicates and poorly crystalline iron oxides, the added Cu and Pb were found mostly in exchangeable and oxide bound fractions, with decreasing and increasing proportion of the former and the latter during 50 days after addition, respectively. In allophanic and humic Andisols, about 50 to 70% of the total Cu and Pb was found in oxide bound fraction with a significant amount in organically complexed fraction in the latter. The amounts of Cu and Pb in each fraction varied only slightly with time in these soils. The proportion of oxide bound Cu arid Pb was relatively low in a kaolinitic Ultisol irrespective of its higher iron oxide content. Zinc was found mostly in exchangeable and soluble fractions except in Andisols. Low crystallinity of oxide minerals as well as their amount is important factors determining heavy metal retaining capacity of soils. The exchangeable and oxide bound heavy metals should be treated separately in models simulating removal of heavy metal cations by washing and electrokinetic methods.