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1.
砖红壤及其矿物表面对重金属离子的专性吸附研究   总被引:21,自引:0,他引:21       下载免费PDF全文
本文对Cu^2+、Zn^2+、Co^2+、Ni^2+和Cd^2+在砖红壤、针铁矿、无定形氧化铝和高岭石表面上的专性吸附进行的研究结果表明:PH是影响重金属离子吸附过程的最重要因素,而表面带电性质对吸附过程的影响不大。砖红壤表面的吸附顺序是Cu^2+〉Zn^2+〉Co^2+〉Ni^2+≥Cd^2+;针铁矿表面的吸附顺序是Cu^2+〉Zn^2+〉Cd^2+〉Ni^2+〉Co^2+;而无定形氧化铝和高岭  相似文献   

2.
土壤溶液中重金属离子的浓度   总被引:1,自引:0,他引:1       下载免费PDF全文
徐莉英  邢光熹 《土壤》1995,27(5):245-246,280
测定了正常土壤和污染土壤溶液中Mn,Cu,Zn,Co,Ni,Cr和Pb的浓度,分别计算了土壤溶液中这些重金属离子的浓度占该元素全量浓度的比率,并讨论了土壤PH与土壤溶液离子浓度与土壤全量Cu,Zu,Co,Ni,Mn,Cr和Pb的比率的关系。  相似文献   

3.
红壤粘粒对Co、Cu、Pb和Zn吸附亲和力的研究   总被引:25,自引:5,他引:25       下载免费PDF全文
王维君  邵宗臣  何群 《土壤学报》1995,32(2):167-178
本文研究了高度风化的酸性红壤对Co,Cu,Pb,Zn离子的吸附特性。用吸附曲线形状,吸附方程,分配系数,pH50值等讨论了吸附亲和力特征及其影响因素和吸附反应的机理。结果表明,红壤粘粒吸附重金属离子主要由Fe,Al氧化物所控制。金属离子对红壤粘粒的吸附亲和力(以pH50表示)主要决定于离子本化学性质,亲和力以Cu≥Pb>Zn>Co顺序减少,易水解的离子吸附亲和力较大,亲和力也受土壤组分及其表面性质  相似文献   

4.
土壤离子吸附:2.主要阴阳离子的吸附特性   总被引:5,自引:0,他引:5  
综述了土壤与环境中主要阴离子HPO^2-4,MoO^2-4,SO^2-4,F^-,Cl^-和NO^-3以及主要阳离子K^+,Na^+,Ca^2+,Mg^2+和重金属离子Cu^2+,Zn^2+,Ni^2+,Co^2+,Pb^2+等的吸附特性和研究进展。  相似文献   

5.
以砂培玉米幼苗为材料,研究了酚-Ni复合污染对根,叶细胞膜相对透性的影响,根、叶组织中Ni、Cu、Zn、Mn、Fe、K、Ca、Mg、P等九种元素的含量以及线粒体、细胞核中Ni含量的变化;根、叶细胞线粒体细胞色素氧化酶活性等变化等。结果表明,在显影响细胞膜透性浓度值的酚-Ni联合作用下,幼苗根、叶细胞膜相对透性较酚、Ni单独作用时明显增大,根、叶组织及线粒体,细胞核中的Ni含量较Ni单独存在时显  相似文献   

6.
本文对广西武鸣县黑荆树营养元素的组成特征以及营养元素与单宁相对含量、总量的关系进行了研究。结果表明:黑荆树强烈积聚微量元素Cu和Zn,N含量达到高量级水平,在化学组成上属于N>Ca>K(Zn,Cu)型树种。树皮单宁含量受N,P,Mg三元素的综合作用极为显著,而单宁总量受K,Mg元素的综合作用极显著。在黑荆树成熟期,P,K对树皮单宁含量和总量有显著的促进作用,而N和Mg则发生抑制作用。  相似文献   

7.
城市生活污泥中锌及病原物对作物及土壤环境的影响   总被引:7,自引:0,他引:7  
本通过2年田间试验研究表明,年施用近15(干)t/ha(菜地)或10(干)t/ha(粮田)城市生活污泥未发现对作物可食部分造成Zn,Cu,Pb,Cd及Ni等重金属污染,但Zn在作物体内有一定累积。施用污泥会导致Zn在土壤耕层中明显累积,并使耕层中累积的锌有向下迁移的趋势。未经消化处理的污泥含相当数量大肠菌群及活的虫卵,但施用3个月后致死率达90%-100%。作认为,污泥最好不用于蔬菜地上,而将  相似文献   

8.
Mehlich3通用浸提剂的研究   总被引:24,自引:0,他引:24       下载免费PDF全文
刘肃  李西开 《土壤学报》1995,32(2):132-141
Mehlich3试剂(简称M3)是适用于多类土壤,多种大量和微量养分元素测试的能浸提剂,但对石灰性土壤尚少与生物相关研究的报道。本文以微钵栽培番茄和甜菜的微量元素吸收量及常用法测试值为参比项,对M3-ICP法用于京,冀石灰土壤作了较详细的相关研究。结果表明,M3-B,Cu,Fe,K,Mn,P,Zn值分别与对应的常用法测定值都有极好相关发。M3-B,Cu,Mn,Mo,Zn,Al,Mg,Na值与两种植  相似文献   

9.
研究了我国典型3种可变电荷土壤和4种恒电荷土壤在陪伴阳离子分别为K十、Na十、Ca2+时和1mmolL-1KC1、K2SO4支持电解质中NO3-的吸附。结果表明,NO3-吸附量随pH的增加而减小。在添加相同浓度NO3-时,3种可变电荷土壤对NO3-的吸附量顺序为Ca(NO3)2> KNO3>NaNO3>KNO3十KCI>KNO3+K2SO4;在初始NO3-浓度0.5-5mmolL-1的范围内,吸附量随浓度变化的关系符合Langmuir等温吸附式.由此求出与NO3-吸附结合能有关的常数(K)在不同共存离子存在下数值较小且差异不大,因此认为不同陪伴阳离子和不同伴随阴离子对NO3-吸附的电性机理影响不大,只是改变了土壤表面的正电荷数量从而使吸附量发生变化。4种恒电荷土壤对NO3-的吸附量通常很小,其中在Ca(NO3)2介质中较在其他介质中稍大,最大吸附量仅为1.5~mmol kg-1左右,约为可变电荷土壤的1/10,且在浓度较低时常观察到负吸附。  相似文献   

10.
研究比较了5种氮肥对铅锌矿尾矿污染区土壤中Pb、Zn、Cd和Cu溶出的影响,讨论了它们对重金属溶出的机制,结合盆栽试验中水稻幼苗吸收重金属的相关性分析表明:5种氮肥对土壤中重金属的溶出有不同影响,且与氮肥的浓度有关。其中NH4HCO3,(NH4)2HPO4对Zn和Cu的溶出,NH4Cl和(NH4)2HPO4对Cd的溶出均有较大的促进作用,而10^-2mol/L的(NH4)2HPO4,NH4HCO3  相似文献   

11.
Batch experiments were performed to study metal sorption by pine bark and algae-treated bark. The biosorption of copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), cobalt (Co), and nickel (Ni) in synthetic multimetal aqueous solutions was studied as a function of metal content in solution, and amount and size of bark particles used for sorption. Influence of water hardness (Ca2+ only was tested) on the metal sorption process was also evaluated. Metal uptake from solutions with high heavy metal content (i.e. 10× the limit for leachate from landfills) was found to be independent of Ca2+ concentration. At low metal content in solution (i.e. 1× the limit for leachate from landfills), uptake of Cu, Zn, Ni, and Cd decreased with increasing Ca2+ content in water. Microalgae-treated bark was found to increase the metal sorption efficiency. Air-drying of bark-entrapped algae was shown to be the best method for sorbent drying. In general, the green algae, Chlorella sp. and Pseudokirchneriella subcapitata showed the best results in metal uptake. Sorption of Co, Zn, Ni, and Cd from solution with high levels of both heavy metals and calcium increased by almost 50% with algae treatment of bark was applied. At low levels of metals and calcium content, 100% uptake of Cu and Pb in water was observed. Uptake of other metals from solution with low metal and Ca content was relatively high (50–60%). Low pH (pH 3.0) had no influence on metal sorption from solutions with high metal content. For solutions with low metal content a decrease of metal uptake by 10–15% was observed for all the metals but Pb. Thus, the treatment of bark with microalgae was successful and influenced positively the uptake capacity of the bark.  相似文献   

12.
Soil/solution partitioning of trace metals (TM: Cd, Co, Cr, Cu, Ni, Sb, Pb and Zn) has been investigated in six French forest sites that have been subjected to TM atmospheric inputs. Soil profiles have been sampled and analysed for major soil properties, and CaCl2‐extractable and total metal content. Metal concentrations (expressed on a molar basis) in soil (total), in CaCl2 extracts and soil solution collected monthly from fresh soil by centrifugation, were in the order: Cr > Zn > Ni > Cu > Pb > Co > Sb > Cd , Zn > Cu > Pb = Ni > Co > Cd > Cr and Zn > Ni > Cu > Pb > Co > Cr > Cd > Sb , respectively. Metal extractability and solubility were predicted by using soil properties. Soil pH was the most significant property in predicting metal partitioning, but TM behaviour differed between acid and non‐acid soils. TM extractability was predicted significantly by soil pH for pH < 6, and by soil pH and Fe content for all soil conditions. Total metal concentration in soil solution was predicted well by soil pH and organic carbon content for Cd, Co, Cr, Ni and Zn, by Fe content for Cu, Cr, Ni, Pb and Sb and total soil metal content for Cu, Cr, Ni, Pb and Sb, with a better prediction for acidic conditions (pH < 6). At more alkaline pH conditions, solute concentrations of Cu, Cr, Sb and Pb were larger than predicted by the pH relationship, as a consequence of association with Fe colloids and complexing with dissolved organic carbon. Metal speciation in soil solutions determined by WHAM‐VI indicated that free metal ion (FMI) concentration was significantly related to soil pH for all pH conditions. The FMI concentrations of Cu and Zn were well predicted by pH alone, Pb by pH and Fe content and Cd, Co and Ni by soil pH and organic carbon content. Differences between soluble total metal and FMI concentrations were particularly large for pH < 6. This should be taken into account for risk and critical load assessment in the case of terrestrial ecosystems.  相似文献   

13.
We studied the properties of the soluble and dispersed compounds of Cu, Mn, Co, Ni, Pb, Zn, and Cd formed by the action of aerobically decomposing plant matter on the respective metal oxides. The metals were mobilized partly in association with colloidal humified organic matter, and partly in true solution as complexes that seemed to be anionic. In the presence of a clay soil there was no net mobilization of colloidally bound Cu, but the dialysable Cu complex was not appreciably sorbed by the mineral colloids and was leached from the reaction mixture. The metals were not precipitated under alkaline conditions from the dialysable complex forms. Material with similar complexing properties was found in the dialysable fractions of a soil organic matter extract, of water squeezed from a raw peat, and of laboratory lysimeter solutions from a podzol under Calluna. Below about pH 6 the exchange of Cu on a soil clay was not affected by the presence of colloidal decomposition products of lucerne. With Co, Ni, and Zn the corresponding pH value was about 4, and the critical value for Cu in the presence of colloidal soil organic matter was also about 4. Below these values the metal and organic matter sorption curves were diametrically opposed so that under these conditions Cu is apparently not strongly bonded to colloidal organic matter.  相似文献   

14.
A batch experiment was conducted to study the effect of pH on the sorption of copper (Cu), cadmium (Cd), zinc (Zn), and nickel (Ni) by cement kiln dust (CKD). The experiment was carried out by adding 25 mL of solutions containing concentrations of 200, 400, 600, 800, and 1000 mg/L of each of these heavy metal cations to 1.00 g of CKD. The pH of these suspensions was adjusted to 2, 5, and 7 as well as non-adjusted. The sorbed amount (Cs) and the sorption percentage of Cu, Cd, Zn, and Ni by CKD increased with increasing the suspension pH. The adsorption data of Cu, Cd, Zn, and Ni were generally well correlated with Langmuir model when the suspension pH was adjusted to 5, 7, non-adjusted and 7, respectively. However, they could be well described by Freundlich model when the suspension pH was adjusted to 5, 2, non-adjusted and 5, respectively.  相似文献   

15.
The metal content of bryophytes (Fontinalis antipyretica), invertebrates (Asellus aquaticus, Sialis lutaria, Libellulidae) and fish (Perca fluviatilis, Esux lucius) was measured along an aquatic concentration gradient of Zn, Cu, Cd, Pb, As, Hg, generated by air emissions from the Rönnskär smelters. The separation of pH effects on metal uptake, was facilitated by metal and pH vectors being mostly well separated from each others. The interpretation was facilitated by seasonal small variations in water metal content, which improved the calculation of bioconcentration factors (BCF) as a strict measure of bioavailability. It was found that BCF varied as function of element and taxon. When pH decreased, BCF also did so for Zn, Cd, Ni, Co in bryophytes, while BCF increased for Pb, Cu in in fish. We conclude and agree that one-sided focusing on total concentrations may overlook shifts in speciation due to pH in moderately acidified waters for elements like Cu and Pb.  相似文献   

16.
Heavy metal content of roots and shoots of vines (Vitis vinifera L.) after fertilization with garbage-sewage-sludge-compost The enrichment of Zn, Cu, Pb, Cd, Co, Ni and Cr from garbage-sewage-sludge-compost in vineyard soils, vines and must was studied in field-and pot-experiments. The following results were obtained: 1. In a field experiment, in which garbage-sewage-sludge-compost was applied, a marked soil enrichment of Zn, Cu, Pb, Cd and Cr was found. It was most evident at the 0–20 cm depth but also obvious at the 40–60 cm depth thus indicating downward migration. The soil was not enriched with Co and Ni. The heavy metal content of leaves, berries and must of riesling vines did not increase on the plots treated with garbage-sewage-sludge-compost. 2. In a pot trial, using an acid and an alkaline soil each mixed with garbage-sewage-sludge-compost, it was observed that only the uptake of Zn and Cu increased into the leaves, tendrils and wood of the riesling cuttings. In relation to the content of the substrate, the heavy metals were detected in the roots percentually in the following order: Cu, Cd > Zn > > Pb, Co, Ni, Cr The root contents were mostly substantially higher than those of the shoot. The migration from root to shoot decreased in the following percentual order: Zn > Cu > Cd, Pb 3. The heavy metal content decreased considerably from the roots to the upper plant organs. This was reflected in low concentrations of heavy metals in the vine must.  相似文献   

17.
We conducted batch experiments for ten metals [Mg, Cr(III), Fe(III), Co, Ni, Cu, Zn, Sr, Cd, Pb] and four soil samples of different composition to determine the relation of the soluble fraction (’intensity’︁) to an adsorbed or precipitated metal pool (’quantity’︁) and, thus, to investigate the buffer function of soils. The soil samples were spiked with 6 to 12 exponentially increasing metal doses added as metal nitrates. The native metal pool involved in sorption processes was characterized by an extraction with 0.025 M (NH4)2EDTA (pH 4.6). The quantity-intensity (Q/I) relations of eight metals [except Cr(III) and Fe(III)] were governed by sorption and complexation processes and can be fitted by Freundlich isotherms. Q/I relations for Cr(III) and two soils indicate a sorption maximum, which can be approximated with the Langmuir isotherm. In a calcareous soil high Cr doses induced the precipitation of a Cr oxide. The solution concentrations of Fe are primarily a function of the pH-dependent solubility of ferrihydrite. For all metals pH was the predominant factor controlling the partitioning between the solid and the liquid phase. Drastic losses in the buffer function of soils primarily occurred in the slightly acidic range. Furthermore, adsorption was also metal specific. On the basis of median Freundlich K values, adsorption increased in the order [median KF values and KF range (mg kg—1) in brackets]: Mg (2.9: 0.9—19) < Sr (4.7: 0.6—21) << Co (17.7: 1.1—143) < Zn (26.7: 1.8—301) = Ni (27.6: 2.4—120) < Cd (71: 2.5—405) << Cr(III) (329: 45—746) < Cu (352: 30—1200) < Pb (1730: 76—4110).  相似文献   

18.
Retention of Cd, Cu, Pb and Zn by Wood Ash, Lime and Fume Dust   总被引:2,自引:0,他引:2  
Heavy metals are of interest due to their deleterious impacts on both human and ecosystem health. This study investigated the effectiveness of wood ash in immobilizing the heavy metals Pb, Cd, Cu and Zn from aqueous solutions. The effects of initial metal concentrations, solution pH, ash dose and reaction time on metal sorption, as well as the metal sorption mechanisms were studied. To investigate the effect of initial metal concentrations, solutions containing Cd, Zn (25, 50, 75, 100 or 125 mg L?1), Cu (25, 50, 75, 100, 125, 150 or 175 mg L?1) or Pb (250, 500, 750, 1000, 1250, or 1500 mg L?1) were reacted with 10 g L?1 ash for two hours. For the effect of pH, solutions containing 100 mg L?1 of Cd, Cu or Zn or 1500 mg L?1 of Pb were reacted with 15 g L?1 ash over a pH range of 4 to 7. The wood ash was effective in immobilizing the four metals with a sorption range of 41–100 %. The amounts of metals retained by the ash followed the order of Pb > Cu > Cd > Zn. As expected, absolute metal retention increased with increasing initial metal concentrations, solution pH and ash dose. Metal retention by the ash exhibited a two-phase step: an initial rapid uptake of the metal followed by a period of relatively slow removal of metal from solution. Metal retention by the ash could be described by the Langmuir and Freundlich isotherms, with the latter providing a better fit for the data. Dissolution of calcite /gypsum minerals and precipitation of metal carbonate/sulfate like minerals were probably responsible for metal immobilization by the ash in addition to adsorption.  相似文献   

19.
Fifteen Finnish Lapland lakes have been investigated to study pollution levels and possible acidification effects on nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), cadmium (Cd), lead (Pb), manganese (Mn), iron (Fe), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg) and aluminium (Al) concentrations in sediments. Four lakes have average water pH lower than 6.0 and alkalinity lower than 0.050 meq/1. Contamination factor (Cf, ratio of metal concentrations in the uppermost to the deepest layers for a given lake sediment core) of Pb is high, particularly for acidic and acidifying lakes (Cf=5.2–10.4). Ni, Cu, Co, Zn and Cd concentrations increase insignificantly towards sediment surface of some lakes (with a neutral pH) with the rare exception. The influence of passible lake acidification consists of decreasing Cu, Cd, Al, Zn concentrations and organic material contents (loss on ignition) towards the sediment surface. The buffer capacity index (BCI), determined as the ratio of the sum of alkaline and alkaline-earth metals (K, Na, Ca, Mg) to Al, is lower for acidic lakes (from 0.12 to 0.36), whereas for the other lakes the BCI values are higher (from 0.42 to 1.34). Thus, BCI-values, decreased contents of Al, Cd, Zn and Cu, as well as organic matter contents (OMC in the upper lake sediment suggest acidification of freshwater environments.  相似文献   

20.
A 20-month column experiment investigated leaching of Al, Cu, Mn, Ni, Zn, Cd and Pb during sulphide oxidation in mine tailings with and without sewage sludge (SS) amendment. Leachate pH decreased gradually in all columns during the experiment, irrespective of treatment, due to sulphide oxidation. As the degree of sulphide oxidation, and thus the pH trajectory, differed between replicates (n?=?3), running data for each column used are reported separately and the relationships between sulphide oxidation, metal leaching and treatment in each column compared. Mean pH in the columns correlated negatively with total amounts of leached SO4 2-. In the beginning of the experiment the leachate concentrations of Al, Cu, Zn, Ni and Pb were higher in SS-treated columns due to high initial concentrations of dissolved organic carbon. As leaching proceeded, however, the amounts of Al, Cu, Mn and Ni leached from the columns were closely related to the degree of sulphide oxidation in each column, i.e. to its mean pH. There were no statistically significant differences between treatments regarding the total amounts of metals leached and thus addition of sewage sludge to the tailings appeared to play a minor role for metal leaching patterns. Peak concentrations of Al and Cu in the leachate from untreated tailings and of Zn in the leachate from both untreated and SS-treated tailings at pH 4 exceeded national background values for groundwater.  相似文献   

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