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1.
Coastal floodplains are highly vulnerable to inundation with saline water and the likelihood of inundation will increase with sea level rise. Sediment samples from floodplains containing coastal lowland acid sulfate soils (CLASS) in eastern Australia were subjected to increasing seawater concentration to examine the probable effects of sea level rise on acidity and metal desorption. Ten soils were mixed with synthetic seawater concentrations varying from 0% to 100% at a solid:solution ratio of 1:10 for 4 h. There was a slight decrease in pH (≈ 0.5 units) with increasing seawater concentration following treatment, yet, calculated acidity increased significantly. In most soil treatments, Al was the dominant component of the calculated acidity pool. Al dominated the exchange complex in the CLASS and, correspondingly, was the major metal ion desorbed. In general, concentrations of soluble and exchangeable Al, Fe2+, Ni, Mn and Zn in all soil extracts increased with increasing salinity. Increasing trace metal concentrations with increasing seawater concentration is attributed to the combined effects of exchange processes and acidity. The increasing ionic strength of the seawater treatments displaces trace metals and protons adsorbed on sediments, causing an initial decrease in pH. Hydrolysis of desorbed acidic metal cations can further contribute to acidity and increase mobilisation of trace metals. These findings imply that saline inundation of CLASS environments, even by relatively brackish water may cause rapid, shorter-term water quality changes and a pulse release of acidity due to desorption of acidic metal cations. 相似文献
2.
赫章土法炼锌区水-沉积物重金属污染的时空变化特征 总被引：1，自引：0，他引：1
对赫章土法炼锌区河流水体和沉积物重金属污染状况及时空变化特征进行了研究。结果表明,水体和沉积物受到多种重金属污染：地表水体中Pb、Zn、Cd的均值分别为137.19×10-3、1 919.38×10-3、14.21×10-3 mg.L-1,分别是地表水环境质量标准Ⅲ类水质标准的2.74、1.91、2.84倍;沉积物中Cu、Pb、Zn和Cd的均值分别为702.79、3 242.8、5 427.6、32.19 mg.kg-1,分别是土壤环境质量标准三级标准的1.76、6.49、10.86、32倍。水体和沉积物中Cu、Pb、Zn和Cd沿河流总体呈无规律性的变化,受炼锌废渣堆和铅锌选矿厂影响的地点,水体和沉积物重金属含量均较高,污染严重。近10年来,炼锌区河流水体和沉积物重金属污染仍然很严重,水体重金属污染呈加重特征,沉积物中Pb、Zn污染呈减轻趋势,Cd和Cu污染则加重。 相似文献
3.
[目的]探讨盐渍化对土壤酸度的可能影响,为了解设施栽培土壤的酸化过程提供依据。[方法]采集了不同酸化特征的设施栽培土壤、露天栽培土壤和自然酸性土壤等3类表层土壤和剖面分层土壤样品,通过化学分析和室内添加肥料盐及土壤洗盐模拟试验,比较研究设施栽培土壤、露天栽培土壤与自然酸性土壤中活性酸、潜性酸、盐基饱和度之间关系差异及其受土壤盐分积累的影响。[结果]与自然酸性土壤相比,设施栽培土壤的酸是人为输入式,其酸化主要发生在表层,土壤剖面呈自上而下下降。在相同交换性酸水平的条件下,设施栽培土壤的pH值最低,其次为露天栽培土壤,而自然酸性土壤的pH值相对较高。在相同土壤pH值的情况下,自然酸性土壤的盐基饱和度明显低于设施栽培土壤和露天栽培土壤,而设施栽培土壤的盐基饱和度高于露天栽培土壤;设施栽培土壤的交换性酸中活性酸组成比例高于自然酸性土壤。增加中盐的积累可显著降低设施栽培土壤pH值;设施栽培土壤的盐分淋洗过程在降低土壤盐分的同时也降低了土壤的活性酸(提高了土壤的pH值)。[结论]盐分的积累增强了设施栽培土壤中潜性酸向活性酸的转化,高量施用化肥不仅可直接通过酸性物质的输入促进土壤pH值的下降,同时由此引起的盐分也可在一定程度上进一步降低土壤的pH值。 相似文献
4.
Heavy metals in surface soils of the Warta river valley in an urban area In the urban area of the city of Poznan the contamination with heavy metals was investigated. From the top soil layers of five cross-sections of the valley of the Warta river 87 samples were collected. Beside common soil characteristics the contents of arsenic, barium, cadmium, chromium, copper, iron, lead, manganese, phosphorus and zinc were analyzed. Predominantly the level of contamination with heavy metals is low in the valley soils. A higher level was found in the area of the old city centre. Especially the contents of lead, copper and zinc were raised. Downstream of the sewage plant discharge into the river Warta increased contents of lead and cadmium were found. The distribution of heavy metals in the river Warta sediments indicates that the reason of the local increase of heavy metal contents is the sewage water discharge, Correlations between the content of different heavy metals and other soil properties (pH, clay and P-content, C/N-ratio) were calculated. 相似文献
5.
Heavy metal enrichment and mobility in the infiltration zone of stemflow from beech (Fagus sylvatica) in the Vienna woods Filtering action of beech crowns in a polluted atmosphere produces acidic stemflow enriched with heavy metals. Series of soil profiles through the infiltration zone of stemflow waters were analyzed in three old growth beech stands on pseudogley (aqualf) soils of the northeastern Vienna Woods to study soil acidification and heavy metal accumulation and mobility: + In the infiltration zone of stemflow soil pH can be less than pH 3 and thus more than 2 pH units lower than in profiles more distant from the stem base. + Heavy metal contents of the soil peaked near the stembase. Maximum values for lead were 500 to 1.200 mg·kg?1 soil, for copper 70 to 150 mg·kg?1 soil and for zinc 250 to 500 mg·kg?1 soil. + Manganese was not enriched but leached out from the soil profile. + The proportion of AED-complexable lead and copper to total lead and copper decreased under stemflow influence in the topsoil but increased in the subsoil. These results indicate that significant amounts of heavy metals are deposited with stemflow in beech stands of the Vienna Woods. Strong soil acidification enhances heavy metal solubility and thus promotes leaching into deeper soil strata. 相似文献
6.
中国土壤酸化呈现出全国普遍发生的趋势,对作物产量、农产品品质和生物多样性造成不利影响。自20世纪50年代以来,我国在酸性土壤方面开展了大量工作,取得显著成效,但因我国酸性土壤分布详情不明、土壤酸化机制存在争议、耐逆作物品种缺乏、作物酸害阈值不清、改良产品及技术落地性差等问题,酸性土壤利用仍受到极大限制。针对上述问题,绘制了新的中国土壤酸碱度图,明确了我国酸性土壤的分布详情,讨论了土壤酸化机制特别是氮肥与土壤酸化之间的关系,论述了土壤酸化的危害,解析了植物和微生物对酸性土壤的响应和适应机制,提出了分区分级分类改良、酸度改良和肥力提高并重、有机无机肥配施、发展特色农业等酸性土壤改良和利用策略,建议进一步加强酸性土壤新型改良剂、作物酸害阈值、氮肥高效利用、中微量元素、耐逆作物育种和土壤酸化模型等方面研究,以期为酸性土壤可持续利用提供支撑。 相似文献
7.
《Communications in Soil Science and Plant Analysis》2012,43(11-12):1467-1478
Abstract The accumulation of heavy metals in tea leaves is of concern because of its impact on tea quality. This study characterized long‐term changes of soil properties and heavy‐metal fractions in tea gardens and their effect on the uptake of metals from soils by the plants. Soil and tea leaf samples were collected from five plantations with a history of 2–70 years in Jinghua, Zhejiang Province, southeast China. The six chemical fractions (water‐soluble, exchangeable, carbonate‐bound, organic‐matterbound, oxide‐bound, and residual forms) of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), manganese (Mn), lead (Pb), and zinc (Zn) in the soils were characterized. Dissolved organic‐matter accumulation in the soils and effects of low‐molecular‐weight organic acids on solubility of soil heavy metals were also tested. Long‐term tea plantation use resulted in accumulation of dissolved organic matter, decrease of soil pH, and elevation of water‐soluble and exchangeable metal fractions, thereby increasing metal contents in leaves. The influence was more significant when soil pH was less than 4.4. The results indicated that both acidification and accumulation of dissolved organic matter induced by tea plantations were also important causes of increased accumulation of the metals in the tea leaves. This was particularly true for the soils polluted with low concentration of heavy metals, because availability of the metals in these soils was mainly controlled by pH and dissolved organic matter. 相似文献
8.
In addition to strong natural stresses forest ecosystems in the Kola Subarctic, Russia, receive high loads of sulphur and heavy metals from the nickel smelter. To estimate soil response to acid deposition we compared the soil field data along a pollution gradient and simulated time effects. Multivariate technique was applied to investigate spatial distribution of soil field data. Time response of soils to acid deposition was evaluated with the SMART model. According to field observations there is no evidence for strong soil acidification effects close to the smelter. Concentrations of exchangeable Ca and base saturation increase, while acidity decrease in lower soil mineral horizons towards the pollution source. However, some features seem to reflect the early stages of the started acidification. Most soil profiles have low pH values. Despite increasing of exchangeable Ca and Mg towards the smelter in lower mineral horizons due to geological inheritance, they do not reveal the same trends in the upper ones. Concentration of exchangeable K in organic horizons decreases towards the smelter, thus confirming the starting acidification. As result, exchangeable base cations are depleted in the considerable part of shallow soil profiles. According to model simulation the present acid load does not effect considerably on forest soils in background areas, however, dramatic shift in soil chemistry near the smelter is expected within several decades. Due to low pool of exchangeable base cations and low weathering rate continued acid deposition can lead to increased soil acidification and nutrient imbalance. 相似文献
9.
D. Hesterberg 《Land Degradation \u0026amp; Development》1993,4(4):257-267
It is suggested that stopping liming on agricultural land could lead to a potential chemical time bomb (CTB). the sequence of interrelated events leading to the CTB include the end of liming, perhaps caused by a change in land use, a progressive decrease in soil pH and increased solubility of potentially toxic contaminants that accumulate in soils as a result of agricultural practices. Data are presented on rates of long-term soil acidification and modelled changes in the solubility of some trace metals in soil as a result of acidification. Soil acidification rates depend primarily on acid input rates and the soil's acid neutralizing capacity, possibly limited by neutralization kinetics. Experimental data illustrating this point show that the pH decreased rapidly in a field soil receiving ammonium rather than nitrate fertilizer treatment. on a limed agricultural field that was later abandoned and converted to deciduous woodland, The pH of the 0-23 cm soil layers decreased over 100 years from pH 7 to 4.2. Deeper layers acidified at a slower rate. Thermodynamic model calculations simulating the solubilities of metals in a sandy topsoil showed zinc, cadmium and aluminium solubilities increasing exponentially with decreasing pH, resulting in several-fold solubility increases between pH 5 and 4. These results suggest how metal solubility increases after liming stops. the model pH-solubility relationships depended on the type of metal, The solid phase controlling the solubility, and the amount of metal in the soil if adsorption controlled the solubility. Decreasing pH and the resultant increase in metal solubility expected on abandoned farmland might be managed through techniques such as liming or planting forests of selected tree species. 相似文献
10.
J. O. Azeez O. A. Adeleye R. O. Oyinlola 《Communications in Soil Science and Plant Analysis》2016,47(16):1940-1949
The research evaluated the comparative effect of two media of soil acidification on lead (Pb), cadmium (Cd), and zinc (Zn) extractive ability of Tithonia diversifolia in alkaline soil. Application of both amendments increased the solubility of the metals. Sulfur (S) addition was more effective at reducing the soil pH compared with the addition of urea. Lead and cadmium uptake by the plant was significantly higher in the urea treatments compared with sulfur treated soils. Generally, the addition of urea resulted in a higher amount of lead and cadmium in the plant parts. The acidification effect due to S addition was too high for the plant to perform optimally. The addition of S increased the uptake of Zn by the plant compared with the effect of adding urea. The complimentary effect of N addition with the soil acidification enhanced metal uptake. Tithonia diversifolia was classified as a hyper accumulator of metals. 相似文献
11.
模拟酸雨对红壤中铝和水溶性有机质溶出及重金属活动性的影响 总被引：29，自引：2，他引：29
在模拟酸雨作用下 ,研究了重金属污染和未污染的酸性红壤和黄红壤中铝和水溶性有机质的溶出以及对重金属活动性的影响。结果表明 ,随模拟酸雨pH值下降 ,土壤pH值和盐基饱和度明显降低 ,而交换性酸度明显增加 ,污染土壤中交换性氢含量比未污染土壤高 ,而交换性铝含量比未污染土壤低。铝溶出量与模拟酸雨pH值密切相关 ,当模拟酸雨pH值在 5 .60～ 3.5 0时 ,供试红壤浸出液中铝浓度几乎在同一水平 ;当pH≥ 4 .5 0时 ,供试黄红壤中溶出铝亦未明显变化 ;当模拟酸雨pH =3.5 0时 ,未污染黄红壤中铝溶出明显增多 ;当pH =3.0 0时 ,供试土壤中铝溶出量急剧增加。随模拟酸雨pH值下降 ,污染土壤中铝溶出比未污染土壤低 ,而有效态重金属活动性明显增加 ;污染土壤中水溶性有机质比未污染土壤溶出明显增加 ,水溶性有机质 -重金属络合体促进了重金属的溶解迁移行为。 相似文献
12.
我国水污染日益严重,Ⅰ类地表水地区较少,目前可供饮用的Ⅲ类水成为研究土壤地表水体系污染状况的热点。选取具有代表性的长江三角洲地区4种母质（河相、湖相、海相沉积物和沟沟堆积物）发育而成的土壤,通过加入不同量的外源铜、锌金属培育污染土样,使其分别达到国家土壤环境质量三级标准的0.25、0.5、1.0、1.5、2.0、2.5倍。在此基础上研究雨水和模拟酸雨条件下,对模拟污染的土样进行解吸,并对解吸曲线进行拟合,在基于地表水Ⅲ类水质标准的铜、锌环境容量的基础上,计算了4种土壤在不同情况下的土壤环境容量,并通过探讨国家土壤标准的吻合性,提出针对不同母质的土壤,对其重金属的土壤污染临界值进行适当的调整,以达到Ⅲ类水标准,保障人类的安全与健康。结果表明,在模拟雨水情况下,基于地表水Ⅲ类标准的4种土壤的环境容量分别为：SEBC-06：铜10002mg·kg^-1,锌848.1mg·kg^-1;SEBC-19：铜1162mg·kg^-1,锌612.9mg·kg^-1;SEBC-20：铜9796mg·kg^-1,锌1047mg·kg^-1;SEBC-25：铜720mg·kg^-1,锌180.2mg·kg^-1。 相似文献
13.
针对南方稻田土壤酸化严重,导致养分流失有毒重金属活化,严重影响稻米质量安全的重大现实问题。以水稻秸秆和谷壳等农业废弃物为原料制备生物炭(分别记为RSC和RHC),研究不同原料生物炭对酸化土壤改良及其对重金属有效性的影响。设置3个生物炭用量(0,20,50 g/kg,分别记为CK、C1、C2),4种土壤酸化水平(pH 4.01,4.25,4.33,4.58,分别记为L1、L2、L3、L4),生物炭与重金属污染土壤共同培养60天后测定土壤pH、全氮、有机质、有效磷、速效钾和有效态Cu、Cd含量。结果表明:RSC对酸化土壤pH的改良效果明显优于RHC,且施炭量越高提高幅度越大,RSC的C2处理使4种酸度水平的土壤pH分别提高了0.68,0.97,1.29,1.71个单位。2种生物炭均能提高土壤的全氮、有效磷、速效钾和有机质含量,其中各施炭处理有机质显著提高,尤以速效钾的增幅最为显著,RSC对4种养分的提高均优于RHC。RHC对土壤有效态Cu含量无显著影响;RSC的C2较C1处理更能降低土壤中有效态Cu含量,使4种酸度水平的土壤分别降低了13.62%,6.57%,4.36%,7.88%。RHC处理的L3、L4土壤中有效态Cd含量显著降低,最大分别降低了13.79%,19.23%。RSC使4种酸度土壤有效态Cd含量最大分别降低了20.00%,25.81%,20.69%,19.23%。相关分析表明,土壤pH与有效态重金属含量呈显著负相关关系。水稻秸秆炭用于改良酸化土壤、降低重金属Cu和Cd有效性的效果更佳,且降低污染土壤中Cd的有效性较Cu好;生物炭对酸化程度越低的土壤pH和有效磷含量的提高以及有效态Cd含量的降低效果较好,而有效态Cu含量的降低效果则在酸化程度越高的土壤中表现更佳;土壤pH是生物炭调控重金属Cu、Cd有效性的主要影响因素。 相似文献
14.
S. Fiedler C. Siebe A. Herre B. Roth S. Cram K. Stahr 《Water, air, and soil pollution》2009,197(1-4):35-47
In Tabasco the petroleum industry pollutes soil recurrently by oil spills. We analysed Pb, V, Ni and Cr concentrations in water samples, and total metal contents and metal fractions in soil samples of contaminated and non-contaminated soils and in sediments. Besides, we determined Eh, pH, DOC and major ions in water and Eh, pH, Corg in soils and sediments. Sediments contained considerably larger heavy metal (HM) concentrations than soils. Local background concentrations of V, Ni and Cr in soils are larger than global means and oil spillages have not added these metals in quantities that exceed the natural variation. Spillage of formation water increases Pb concentrations in soils, particularly in mobile fractions. The contribution of the oil industry to HM loads is diluted by large fluvial water and sediment discharges and difficult to assess by comparison of total metal contents. Therefore, easily mobile metal fractions are much better indicators. 相似文献
15.
Cyanide and heavy metals were accidentally released from a mine waste lagoon in Romania into tributaries ultimately draining into the Tisza River. Within two months of the cyanide accident two subsequent heavy metal waste spills further contaminated the Tisza River, followed by severe spring flooding, which potentially spread the contamination to soils adjacent to the river. Flood plain soils and shoreline sediments were sampled from two locations on the middle Tisza River and a reference site to conduct a preliminary assessment of metal content and toxicity. Ten-day sediment toxicity tests were conducted with the amphipod,Hyalella azteca and 24 h soil toxicity tests were conducted with the nematode (Caenorhabditis elegans). High concentrations of cadmium, copper, zinc, lead and arsenic were detected in soil and sediment samples. However, no mortality was observed inHyalella exposed to Tisza River sediments and only up to 27% mortality of C.elegans was observed in flood plain soils. Low mortalities are attributed to reduced metal bioavailability caused by high soil cation exchange capacities and possible interactions with sediment organic matter or sulfides. Future studies should focus on factors that alter metal bioavailability and their relationship to potential toxicity of organisms exposed to Tisza River sediments and flood plain soils. 相似文献
16.
The critical loads of acidity and nitrogen has been mapped for Swedish forest soils, using data from the Swedish Forest Inventory. The Swedish critical load map used in negotiations has been based on a number of ecological receptors. For terrestrial ecosystems criteria based on no adverse effect on growth, soil stability and groundwater quality was used. For surface waters, stream and lake biology was used as indicators for setting limits to acidification. A reduction of 75% of the acidity deposition in relation to 1988 is required in order to protect 95% of the forest resource in Sweden from effects of soil acidification. A reduction of 50% of the nitrogen deposition is required to avoid exceedance in more than 5% of the area. The mapping work was carried out by using the PROFILE model. 相似文献
17.
The feasibility of using chelate agents to enhance the electrokinetic remediation of heavy metal contaminated soils has been investigated in this study. Chelate agents were used as washing solutions as well as purging solutions at the electrode compartments. The pH value of the soil significantly affects the removal of heavy metal ions. Due to electrolysis reaction pH increases near the cathode. Without conditioning of the pH value metals precipitate as hydroxides. This problem is solved by the addition of an acid in the cathode compartment. The heavy metals that are dissolved will move to either the cathode or the anode, depending on their charges. This paper presents the results of electrokinetic extraction of cadmium using acetic acid, citric acid and pyridine-2,6-dicarboxylic acid (PDA) as washing and purging solutions, and the removal of zinc using ethylenediamine tetraacetic acid (EDTA) and sodium metabisulfite (Na2S2O5) as washing and purging solutions, respectively. The results showed that the increased experimental time induced a higher removal efficiency of cadmium and zinc. 相似文献
18.
为理解石灰岩地区农田土壤重金属积累特点及污染风险,以浙西石灰岩地区为例,随机选择了153块重金属污染农田,点对点采集了土壤和水稻样品,分析了土壤和糙米中镉的含量及土壤性状,探讨了石灰岩地区污染农田土壤与稻米镉积累特点及其与土壤性状的关系。结果表明,土壤全镉随粘粒含量的增加而增加,随土壤pH的下降而下降;土壤有效镉占全镉的比例与土壤pH呈负相关,糙米中镉含量与土壤有效镉、水溶性镉呈显著正相关;糙米中镉含量与土壤pH、有机质含量及粘粒含量均呈现显著负相关,土壤pH是影响石灰岩地区农田糙米镉积累最为重要的因素。《土壤环境质量－农用地土壤污染风险管控标准（试行）》（GB 15618—2018）的污染风险筛选值并不适用于石灰岩地区高pH的土壤。当6.5 < pH ≤ 7.5时,土壤重金属镉含量与农产品中重金属镉超标结果并不一致,其风险筛选值（0.60 mg kg?1）偏低,实际的风险筛选值可能在0.80 mg kg?1以上。土壤水溶性镉较土壤全镉和有效镉能更好地评估石灰岩地区农作物重金属镉的污染风险。 相似文献
19.
Holm P.E. Christensen T.H. Lorenz S.E. Hamon R.E. Domingues H.C. Sequeira E.M. McGrath S.P. 《Water, air, and soil pollution》1998,102(1-2):105-115
Soil water concentrations of cadmium and zinc were measured in plant pots with 15 contaminated soils which differed in origin, texture, pH (5.1 – 7.8) and concentrations of cadmium (0.2 – 17 mg Cd kg-1) and zinc (36 – 1300 mg Zn kg-1). The soil waters contained total concentrations of 0.5 to 17 µg Cd L-1 and 9 to 3600 µg Zn L-1, which were dominated by free metal ions as measured by an ion exchange-resin method. Annual leaching outflows were estimated from soil water concentrations to be 0.5 – 17 g Cd ha-1 y-1 and 9 – 3600 g Zn ha-1 y-1 per 100 mm of net percolation, corresponding to 0.1% per year of the total soil content of cadmium and zinc. The measured soil water concentrations of cadmium and zinc did not correlate linearly with the corresponding soil concentrations but correlated fairly well with concentrations measured in Ca(NO3)2 extracts of the soils and with soil water concentrations estimated from soil concentrations and pH. Such concentration estimates may be useful for estimating amounts of cadmium and zinc being leached from soils. 相似文献
20.
Antti-Jussi Lindroos John Derome Hannu Raitio Pasi Rautio 《Water, air, and soil pollution》2007,180(1-4):155-170
The effects of soil processes, related to the oxidation of sulphide sediments, on heavy metal concentrations in the soil and soil solution were investigated in a Norway spruce stand on a fine-textured, acidic soil rich in sulphates located on the isostatic land-uplift western coast of Finland. The age of the soil is ca. 300–400 years, and the soil texture is silt and till. The chemical properties of the soil and soil solution clearly reflected the formation of acid sulphate (AS) soil. Compared to background reference values for podzolic coniferous forest soil, the pH of the soil solution in the mineral soil (20–40 cm depth) was very low, and the Al, Fe and S concentrations extremely high. The Zn and Ni concentrations in the soil solution were also strongly elevated, and similar to the concentrations reported close to anthropogenic heavy-metal emission sources. The concentrations of Cd and Cu were also frequently elevated. In contrast, the acidity and metal concentrations of the soil solution sampled in the organic layer were not elevated. Similarly, exchangeable Zn and Ni concentrations were also elevated in the mineral soil, but not in the organic layer. Because Norway spruce has a very superficial rooting system and the zone with exceptionally high metal concentrations did not extend up to the topmost soil layers, sulphide-oxidation derived soil acidification is not likely to pose a serious threat to forest ecosystems growing on this type of site. Despite the elevated concentrations of protons and many metals in the mineral soil and soil solution (20–40 cm), the nutrient status of the spruce stand was satisfactory and the general health of the stand has been reported to be relatively good. 相似文献