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1.
To elucidate the mechanism of transfer of heavy metals into the food chain, an experiment was carried out with a calcareous soil, to which two different doses of a sewage sludge compost contaminated with either Cd or Zn, Cd, Cu, and Ni were applied. A crop of lettuce was then grown in the amended soils. The application of sewage sludge composts to a calcareous soil lowered the soil's pH, although the value was always around 8 at the end of the experiment. Electric conductivity rose with organic amendment. As anticipated, such an amendment improved the nutritional level of the soils, particularly Nand P, both total and available. Plant yields were negatively affected by organic amendments contaminated with heavy metals, the most dangerous in our experiment being Cd and Zn since this metals easily taken up by plants. As Ni and Cu form insoluble complexes with the organic matter of the sewage sludge composts they are not readily absorbed. Of the metals studied, Cd and Zn showed the highest bioavailability index.  相似文献   

2.
Abstract

Fifty soil samples (0–20 cm) with corresponding numbers of grain, potatoes, cabbage, and cauliflower crops were collected from soils developed on alum shale materials in Southeastern Norway to investigate the availability of [cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), and manganese (Mn)] in the soil and the uptake of the metals by these crops. Both total (aqua regia soluble) and extractable [ammonium nitrate (NH4NO3) and DTPA] concentrations of metals in the soils were studied. The total concentration of all the heavy metals in the soils were higher compared to other soils found in this region. Forty‐four percent of the soil samples had higher Cd concentration than the limit for application of sewage sludge, whereas the corresponding values for Ni, Cu, and Zn were 60%, 38%, and 16%, respectively. About 70% the soil samples had a too high concentration of one or more of the heavy metals in relation to the limit for application of sewage sludge. Cadmium was the most soluble of the heavy metals, implying that it is more bioavailable than the other non‐essential metals, Pb and Ni. The total (aqua regia soluble) concentrations of Cd, Cu, Zn, and Ni and the concentrations of DTPA‐extractable Cd and Ni were significantly higher in the loam soils than in the sandy loam soils. The amount of NH4NCyextractable metals did not differ between the texture classes. The concentrations of DTPA‐extractable metals were positively and significantly correlated with the total concentrations of the same metals. Ammonium nitrate‐extractable metals, on the other hand, were not related to their total concentrations, but they were negatively and significantly correlated to soil pH. The average concentration of Cd (0.1 mg kg‐1 d.w.) in the plants was relatively high compared to the concentration previously found in plants grown on the other soils. The concentrations of the other heavy metals Cu, Zn, Mn, Ni, and Pb in the plants were considered to be within the normal range, except for some samples with relatively high concentrations of Ni and Mn (0–11.1 and 3.5 to 167 mg kg‘1 d.w., respectively). The concentrations of Cd, Cu, Zn, Ni, and Mn in grain were positively correlated to the concentrations of these respective metals in the soil extracted by NH4NO3. The plant concentrations were negatively correlated to pH. The DTPA‐extractable levels were not correlated with plant concentration and hence DTPA would not be a good extractant for determining plant availability in these soils.  相似文献   

3.
In a small‐plot trial different doses of sewage sludge (equivalent 82‐330 tons of dry matter per hectare) were incorporated in 0—25 cm depth (1982—1985). The aim of the investigations was to study the fate of the heavy metals Zn, Cd, Cu, Ni, Pb, and Cr, to determine their concentration in different soil fractions using a sequential extraction method and to ascertain their uptake by Zea mays L. plants. Eleven years after the last application the metals supplied with the sludge had moved as far as 50 cm in depth. The concentrations of Zn, Cd, Cu, Ni, and Cr in the saturation extract of the sampled soil layers were closely correlated with the concentrations of dissolved organic carbon (DOC). This result suggests that the heavy metal displacement was partly connected with the DOC movement in the soil. Considerable amounts of Zn and Cd coming from sewage sludge were found in the mobile fractions of the soil. Cu, Ni, and Pb were located especially in organic particles, and Cr was obviously bound by Fe‐oxides. Nine years after the last application the binding species of heavy metals were still different compared with those in the untreated soil. The whole withdrawal of heavy metals by plants yielded <1 % of the applied amounts. In the case of Zn the uptake from the sludge amended soil decreased during the experimental period. No similar tendency was observed for the other elements. In any case their annual variations of uptake exceeded the effect of sludge application.  相似文献   

4.
肥料重金属含量状况及施肥对土壤和作物重金属富集的影响   总被引:56,自引:5,他引:56  
本文对肥料中重金属的含量状况以及施肥对土壤和农作物重金属累积影响的研究进展进行了系统分析和总结。过磷酸钙中锌(Zn)、 铜(Cu)、 镉(Cd)、 铅(Pb)含量高于氮肥、 钾肥和三元复合肥,有机-无机复混肥料中的Pb含量高于其他化肥。有机肥如畜禽粪便、 污泥及其堆肥中的重金属含量高于化肥,猪粪中的Cu、 Zn、 砷(As)、 Cd含量明显高于其他有机废弃物,鸡粪中铬(Cr)含量高;污泥和垃圾堆肥中Pb或汞(Hg)含量高。商品有机肥Zn、 Pb和镍(Ni)含量高于堆肥,Hg含量高于畜禽粪便。多数研究表明,氮磷钾配施与不施肥相比土壤Cd和Pb含量增加,施用有机肥比不施肥提高土壤Cu、 Zn、 Pb、 Cd含量。施用化肥对农作物重金属富集的影响不明确,而施用有机肥可提高作物可食部位Cu、 Zn、 Cd、 Pb 的含量,影响大小与有机肥种类、 用量、 土壤类型和pH以及作物种类等有很大关系。在今后的研究中应着重以下几个方面, 1)典型种植体系下土壤重金属的投入/产出平衡; 2)不同种植体系下长期不同施肥措施对土壤重金属含量、 有效性影响的动态趋势; 3)典型种植体系和施肥措施下土壤对重金属的最高承载年限; 4)现有施肥措施下肥料中重金属的最高限量标准。  相似文献   

5.
The assessment of heavy metals in spinach (Spinacia oleracea) grown in sewage sludge–amended soil was investigated. The results revealed that sewage sludge significantly (P < 0.01) increased the nutrients and heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), and zinc (Zn) in the soil. The contents of metals were found to be below the maximum levels permitted for soils in India. The most agronomic performance and biochemical components of S. oleracea were found at 50% concentrations of sewage sludge in both seasons. The contents of Cd, Cr, Cu, Mn, and Zn in S. oleracea were increased from 5% to 100% concentrations of sewage sludge in both seasons. The order of contamination factor (Cf) of different heavy metals was Mn > Cd > Cr > Zn > Cu for soil and Cr > Cd > Mn > Zn > Cu for S. oleracea plants after application of sewage sludge. Therefore, use of sewage sludge increased concentrations of heavy metals in soil and S. oleracea.  相似文献   

6.
Plough and subsoil layers of two majoragricultural soil series, Rangsit and Thonburi, foundin Bangkok area of Thailand were studied fordetermining the bioavailability and solubilitybehavior of heavy metals (Cd, Cu, Zn, Mn, and Fe)following application of sewage sludge from awastewater treatment plant and a series of laboratoryexperiments. The soils contained low indigenous heavymetals while the sludge contained higher amounts ofheavy metals but in an acceptable range forapplication as plant nutrient source in agriculturalsoil. Applications of sewage sludge increased pH ofthe acid soil and available plant nutrients to thesoils. The heavy metal concentration levels in thesoils also increased. Most partitioned into easilymobile pools and later into sparingly mobile poolsfollowing 12 weeks of incubation time. Bioavailabilityforms of Cd in soil solution were low but that of Cu,Zn, and Mn remained elevated even at 12 weeks of thereaction time. Applied inorganic Zn depressed Cdsorption capacity of two soils studied but it had noeffect on Cd desorption.  相似文献   

7.
Heavy metals in soil of a sewage sludge experimental field The total amounts of Zn, Cd, Pb, Cu, Cr and Ni were determined in different depths of soils which have obtained sewage sludges in amounts between 180 and 1620 dt dry matter/ha. The elements Zn, Cd. Pb and Cu have been most enriched in the first twenty cm of the soils. The contents of Zn, Cd and Pb in the depth of 40–60 cm also showed a significant increase. The treshold values for Zn and Cd in soils were almost attained respectivly slightly exceeded in the first twenty cm of the soil which has obtained 1440 dt dry matter sewage sludge per ha.  相似文献   

8.
Abstract

Phytoremediation is increasingly used to remediate metal contaminated soils. However, in order to provide technically efficient phytoremediation of contaminated sites the plant yield and metal uptake have to be enhanced dramatically. The aim of the study was to find appropriate combination of plant species and fertilizers capable of improving yields of the plants and stimulate a transfer of metals to more available to the plants forms. Wheat Triticum vulgare was used for the phytoremediation research. To increase yield of crops and enhance mobility of metals in the rhizosphere the soils were amended with three fertilizers (urea, horse manure, and “ispolin”). Short-term (36 d) vegetation test showed that concentrations of heavy metals in the plants grown in contaminated soil (from site 2) were significantly higher than those in the plants grown in clean soil (from site 1). Growth of wheat resulted in a decrease of Cd content in the soil. Amendment of the contaminated soil with urea enhanced the effect and the decrease of Cd concentration in the soil was more significant. The best effect was demonstrated after application of ispolin: concentrations of Cd, Cu, Pb, and Zn in the rhizosphere decreased 1.2–1.4 times as compared with those in the initial contaminated soil (the decrease was statistically significant).  相似文献   

9.
Abstract

City sewage sludge was applied to the surface layer (0–10 cm) of two sandy soils, slightly calcareous with 8.9% CaCO3 and moderately calcareous with 26.7% CaCO3, at the rates of 0, 25, 50, 75, and 100 Mg ha‐1. The effects of sewage sludge and its rates on total soluble salts, pH of soils and concentration and movement of some heavy metals within soils were investigated. Soil samples were packed at bulk density of 1.5 g cm‐3 in PVC columns and incubated for 19 weeks. The results indicated that total soluble salts (EC) of the treated layer increased with increasing sewage sludge rates. Soluble salts also increased with an increase in soil depth for both soils. The pH values of treated layers in two soils decreased with increasing sewage sludge rates. With increasing sewage sludge rates, concentrations of heavy metals [cobalt (Co), nickel (Ni), cadmium (Cd), and leaf (Pb)] increased in the treated layers compared to the untreated layers and their mobility was restricted mostly to the upper 30‐cm depth. Movement of Co and Pb in both the soils was predominately limited up to a depth of 40 cm for Co and 5 cm for Pb below the treated soil layer. Nickel and Cd movement was mostly limited to a depth of 10 cm in slightly calcareous soil and 5 cm in moderately calcareous soil. Metal movement in the respective soils is ranked as Co>Ni=Cd>Pb and Co>Ni=Cd>Pb. The low concentrations of heavy metals and the restricted mobility with soil depth, suggest that this material may be used for agricultural crop production without any toxic effect on plants.  相似文献   

10.
太原市污灌区土壤重金属污染现状评价   总被引:1,自引:0,他引:1  
对太原市污灌区土壤重金属分布特征进行了分析评价,结果表明重金属Pb、Zn、Cu、Ni、Mn、Cr、As、Hg、Cd含量均值均未超过土壤环境质量标准(GB15618—1995),但其平均值均显著高于太原市土壤背景值。各重金属间的相关分析表明,Pb、Zn、Cu、Ni、Mn、Cr、As、Cd之间呈极显著相关,说明这8种元素污染源可能相同。Hg是本区表层土壤重金属污染的主要因子,重金属元素的污染程度依次为Hg〉Cd〉Pb〉As〉Cu〉Zn〉Cr〉Mn〉Ni。土壤重金属单项污染指数均值均大于1,综合污染指数为2.81,总体上,污染水平为中度及其以上。各种重金属单因子污染指数和综合指数在研究区有相似的空间分布格局,总体分布趋势为东南部小店地区和中南部晋源区相对较高,南部清徐县相对较小;通过因子分析并结合污灌区污染源调查,表明Hg除受污水灌溉的影响外,燃煤释放的Hg可能是重要来源之一,Cd、Zn、Pb和Cu可能来自污水灌溉和大气沉降,以污水灌溉的贡献为主,Ni、Mn、As、Cr来自污水灌溉。Hg、Cd是太原市污灌区土壤中需要优先控制的重金属。  相似文献   

11.
大宝山矿区农田土壤重金属污染及其植物累积特征   总被引:7,自引:0,他引:7  
张晗  靳青文  黄仁龙  林宁  贾珍珍  舒月红 《土壤》2017,49(1):141-149
对金属矿山选冶活动影响的农田土壤,不同灌溉水源会影响重金属的分布累积特征。根据实际情况将大宝山矿区农田土壤分为污水灌溉区、清水灌溉区、自然修复区和对照区,并进行土壤和植物样品采集,调查研究了土壤的基本理化性质,Cd、Pb、Cu、Zn、Mn 5种重金属的含量和化学形态分布,以及不同区域植物中重金属的含量。结果表明:污灌区Cd、Pb、Cu、Zn的含量最高,是自然修复区和清水灌溉区的1.75倍~10.51倍,对照区最低;Mn在各采样点的含量无显著差别。土壤Cd、Cu、Zn、Pb含量两两之间显著正相关,Mn与Cu、Zn、Cd、Pb呈负相关关系;土壤pH与重金属环境有效态关系密切。残渣态是5种重金属的主要存在形态,有机态含量也较高;Cd的环境有效态含量占总量的比例是其他4种重金属的2倍左右。稻米中5种重金属在清水灌溉区的含量均比污水灌溉区低,其中Cu和Zn的含量在两区域均未超标(NY861-2004),而Pb和Cd的含量严重超标。重金属在自然修复区和清水灌溉区呈现较低的土壤污染和人体健康风险,该研究数据可为金属矿区土壤污染控制提供科学的依据。  相似文献   

12.
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.  相似文献   

13.
Silvopastoral systems are ancient farming systems in the world, consisting of the combination of a woody component (trees or shrubs) and crops and/or animals within the same land‐management unit. In various European Union (EU) countries, the possibility of using sewage sludge as a fertilizer is under consideration as a viable method of disposal, considering the increase in sewage‐sludge production in recent years and the restrictions imposed by European policy on the usual methods of disposal. The concern is the concentration of heavy metals, which can reach humans through the food chain. In Spain, R.D. 1310/1990, as well as European Directive 86/278, limit the total in‐soil heavy‐metal concentration, but not the solubility changes, which directly affect plant absorption and leaching of heavy metals throughout the soil profile. The objective of this experiment was to compare, in a silvopastoral system over a period of 3 years, the effect of applying three doses of sewage sludge combined with and without liming, on total and available soil Zn and Cu and their concentration in plants. Liming did not affectct Zn and Cu availability; however, sewage sludge increased Zn and Cu availability, though total in‐soil Zn was increased only in November 2000. In‐plant Zn concentration was increased by sewage sludge in the last 2 years of the study. In all cases, the quality of forage obtained and measured with regard to the concentrations of Zn and Cu was adequate for animal consumption. With respect to sewage‐sludge application as a fertilizer, the management of heavy‐metal availability must be included in the policy, because environmental risk could then be adequately evaluated.  相似文献   

14.
The accumulation of heavy metals in soils and crops by practical sewage sludge application An accumulation of cadmium, lead, zinc and copper was found in some soils and crops after sewage sludge application as compared with same soils and plants not fertilized with sewage sludge. In the soils the heavy metals mainly were accumulated in the Ap-horizons. The displacement into subsoils was small, in spite of the good permeability of the sandy soils investigated. Relatively the mobility of zinc and cadmium in soils was most distinct. Within the plants the accumulation of the heavy metals was strongest in the roots, however also evident in the shoots of rye, barley and oats. Zinc and copper was concentrated in the grains, too. On the meadow-land an accumulation of the elements investigated was found in the blades of rye grass (Lolium perenne L.).  相似文献   

15.
Stability and resilience of a variety of soil properties and processes are emerging as key components of soil quality. We applied recently developed measures of biological and physical resilience to soils from an experimental site treated with metal‐contaminated sewage sludge. Soils treated with cadmium‐, copper‐ or zinc‐contaminated, digested or undigested sewage sludge were studied. Biological stability and resilience indices were: (i) the time‐dependent effects of either a transient stress (heating to 40°C for 18 hours) or a persistent stress (amendment with CuSO4) on decomposition, and (ii) the mineralization of dissolved organic carbon (DOC) released by drying–rewetting cycles. Physical stability and resilience measures were: (i) compression and expansion indices of the soils, and (ii) resistance to prolonged wetting and structural regeneration through drying–rewetting cycles. Soil total carbon and DOC levels were greater in the sludge‐amended soils, but there were no differential effects due to metal contamination of the sewage sludge. Effects of metals on physical resilience were greater than effects on soil C, there being marked reductions in the expansion indices with Cd‐ and Cu‐contaminated sludge, and pointed to changes in soil aggregation. The rate of mineralization of DOC released by drying and wetting was reduced by Zn contamination, while biological resilience was increased in the Zn‐contaminated soil and reduced by Cd contamination. We argue that physical and biological resilience are potentially coupled through the microbial community. This needs to be tested in a wider range of soils, but demonstrates the benefits from a combined approach to the biological and physical resilience of soils.  相似文献   

16.
Soil application of sewage sludge as an amendment in crop plants has became a popular method of municipal sewage-sludge disposal in many countries. However, the presence of heavy metals in untreated sewage sludge has raised concerns of adverse effects on crop growth, quality of product, and environmental health. Gamma irradiation is one of the treatments for hygienization of sewage sludge before use as fertilizer. To evaluate the potential of gamma-irradiated sewage sludge as fertilizer in vegetable crops, the field investigation was conducted in a root crop, radish (Raphanus sativus L.), during the 2005–06 and 2006–07 growing seasons in a sandy loam soil. Treatments consisted of three source of fertilizers [farmyard manure (FYM), gamma-irradiated sewage sludge (GISS), and nonirradiated sewage sludge (NISS)]; each were compared at six application levels (1, 3, 6, 7, 9, and 11 t ha?1). The physicochemical properties of all the three fertilizers used in this study were compared. Growth parameters and yields of radish were not significantly influenced by source of fertilizers or their application levels, except plant stand, which was influenced by type of fertilizers used. There was no significant difference observed between source of fertilizer treatments with respect to any of the measured soil properties, including major nutrients [nitrogen (N), phosphorus (P), and potassium (K)], metallic micronutrients [copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn)], and heavy metals [nickel (Ni), lead (Pb), cadmium (Cd), and cobalt (Co)]. Soil P and Zn were influenced by the various level of fertilizers. However, the interaction effect of source and level of fertilizer was absent for all the measured parameters. The maximum pollutant limits in sewage sludge and soil for agricultural use in different countries were compared. The concentration of metallic micronutrients and heavy metals in soil were less than the prescribed limit of the United States Environmental Protection Agency (USEPA), and no significant accumulation was noted after 2 years of application of GISS and NISS even at higher application rates.  相似文献   

17.
污泥农用对土壤和作物重金属累积及作物产量的影响   总被引:20,自引:2,他引:20  
以3 a定位试验为基础,比较3种不同处理的污泥肥料(消化污泥、污泥堆肥及污泥复混肥)农田施用下土壤养分、土壤和作物籽粒中Mn、Cu、Zn、Pb、Cd 5种重金属的积累以及作物产量的变化情况,以阐明污泥农用对土壤及作物的影响。研究表明,3种污泥肥料提高了土壤中氮素和有机质的含量;与空白和普通化肥处理相比,3种污泥肥料增加了土壤中Mn和Cu的含量,而对土壤交换态重金属含量没有显著影响;3种污泥处理均增加了小麦籽粒中Zn的含量;相对普通化肥处理,3种污泥肥料处理对小麦和玉米产量均无显著影响。合理施用污泥肥料可以有效地提高作物产量;污泥肥料施用对土壤重金属有一定累积效应,但短期施用对土壤比较安全。  相似文献   

18.
Abstract

Two composts were tested in eleven different Malus domestica orchards: one was a sewage sludge and bark compost with a low heavy metal content, the other was a municipal solid waste compost with a higher concentration of metals. For six years the zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), cadmium (Cd), and chromium (Cr) content were monitored in the soil, both in ‘total’ and EDTA extractable form, and in leaves and fruits. The resulting data demonstrate clearly that the sewage sludge and bark compost did not cause any significant increase of heavy metal levels in soil and plants; this compost can thus be used to fertilize the soil with no danger either to the environment or to crops. In contrast, the municipal solid waste compost led to a notable accumulation of all the metals examined in the soil and, above all in the case of Pb and Cd, also in the vegetation and the fruits.  相似文献   

19.
北京城乡交错带土壤重金属的空间变异特征   总被引:22,自引:0,他引:22  
  相似文献   

20.

Purpose  

Acidic soils exhibit high trace element availability compared to neutral pH soils, and thus, when trace metals are added (e.g. due to sewage sludge application), measures should be taken to reduce their mobility. In this experiment, we tested two such methods, liming and zeolite addition. The aim was to measure the availability, in ryegrass (Lolium perenne L.), of heavy metals (Cu and Zn) added to soil with sewage sludge in both acidic and limed soil.  相似文献   

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