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1.
利用自制的Cu、Zn、Pb和Cd污染的灰潮土和黄泥土,通过室内培养实验研究了不同绿化植物废弃物添加量和不同培养时间对这两种污染土壤中这4种重金属形态的影响。结果表明,绿化植物废弃物的加入抑制了Cu的活化,且添加60%绿化植物废弃物时有机结合态Cu的含量最高;绿化植物废弃物与污染土培养2~3个月时,残余态Zn的含量最高,对植物的毒害最小;绿化植物废弃物添加量为60%时灰潮土中有效态Pb含量较低,而添加量为30%时黄泥土中有效态Pb含量最低;绿化植物废弃物添加量的多少对灰潮土Cd形态的影响较小,但黄泥土中的Cd则随绿化植物废弃物量的增加活性逐渐减弱,且两种土壤均在培养2~3个月时可交换态Cd的含量最低。  相似文献   

2.
不同pH值混合螯合剂对土壤重金属淋洗及植物提取的影响   总被引:6,自引:1,他引:5  
为了得出混合螯合剂(MC)淋洗去除重金属的最佳pH值以及对后续植物提取重金属的影响,用Ca(OH)2将pH值为2.75的MC提高至pH值5、7和9,对重金属污染土壤进行了盆栽淋洗试验,而后种植东南景天(Sedum Alfredii),测定淋出液及植物重金属含量。另外,通过浸提试验研究了含有不同阳离子的MC对重金属淋洗效果的影响。结果表明,pH值为5和7的MC显著提高了Cd、Pb和Cu的淋出率。与Na+、K+离子相比,Ca2+的存在能够提高MC对重金属的淋洗去除。pH值7和9的MC淋洗土壤后提高了东南景天的生物量,但是降低东南景天中Cd和Zn的浓度,导致其植物提取率低于无淋洗剂对照。在化学淋洗+植物提取联合技术中,Cd和Zn主要靠植物提取去除,植物提取率分别可达土壤Cd的30%~40%和土壤Zn的6.5%~6.9%;而Pb和Cu主要靠混合螯合剂淋洗去除,去除率分别为2.3%~2.6%和1.6%~2.0%。综合来说,如果需要同时去除Cd、Zn、Pb和Cu,降低土壤重金属有效态含量,用pH值9的MC淋洗土壤联合植物提取较为合适。  相似文献   

3.
大庆龙凤湿地土壤重金属空间分布特征   总被引:2,自引:0,他引:2  
对大庆龙凤湿地土壤Cu,Cr,Cd,Zn,Pb和As六种重金属元素的空间分布特征进行了研究.结果表明:湿地土壤表土层(0-10 cm)Cu,Cr,Cd,Zn,Pb和As在水平分布上的变化较大,除Cr和Zn外,Cu,Cd,Pb和As含量均低于松嫩平原土壤重金属含量平均值;在土壤剖面中,Cu,Cr,Cd和As都随着土层深度的增加逐渐减少,而Pb和Zn则是先增加后减少,这与区域内土壤的理化性质、成母土质、岩石风化及淋溶作用有极大的关系.Cu,Cd,Zn,Pb,As五种重金属元素之间,除Cu和As间相关关系不显著外,其余各重金属元素之间均呈极显著的正相关关系,而Cr只与Cu呈显著正相关,与其他各重金属元素之间均未表现出显著的相关性,由此推测Cu,Cd,Zn,Pb,As元素的来源可能相同,且具有一定的共生组合性,而Cr则受湿地周边复杂环境及人为随机因素的影响较大.  相似文献   

4.
为探明不同耕作方式下稻-油轮作系统中土壤重金属有效性的变化规律,测定了21年长期定位试验稻-油轮作系统中土壤及其剖面的主要理化性质和重金属有效含量,分析了二者间的关系。结果表明,与翻耕相比,垄作免耕使各土层土壤有机质含量和阳离子交换量显著提高,并具有明显的表层聚集现象,土壤pH值明显降低。耕层土壤Cd、Cu和Zn有效量以垄作免耕处理最高,土壤Pb的有效量则以常规平作处理最高,不同耕作方式下,土壤有效Cd和Pb出现表聚现象,但有效Zn和Cu随土壤深度的变化无明显规律。相关分析表明,土壤有机质含量与土壤Cd、Zn有效量呈极显著正相关关系,与土壤Pb、Cu有效量呈显著正相关,土壤pH值与土壤Pb有效量呈显著正相关,而土壤阳离子交换量与4种重金属有效量间的相关性不显著。由此推测,耕作方式主要是通过影响土壤有机质含量而影响重金属元素的有效性,垄作免耕较翻耕在改良土壤理化性质上有较大优势,却使0-20cm和20-40cm土层重金属有效量显著增加,表现出明显的表层富集趋势。  相似文献   

5.
以沈阳农业大学长期定位试验为基础,选取(0~20cm)不同年限土壤样品,分析了无肥对照(CK)、单施化肥(N4P2)、中量有机肥(M2)、高量有机肥(M4)和高量有机肥+化肥(M4+N2P1)5个处理下土壤重金属元素Cu、Zn、Pb和Cd全量及其有效态含量的变化。结果表明,20多年的定位施肥增加了土壤中重金属元素Cu、Zn、Pb和Cd全量,虽然有所波动但总的趋势明显,其中以M4+N2P1处理对Cu和Zn增加最为明显,而Pb和Cd在M4处理增长量最大,单施N4P2处理对4种重金属元素全量影响不明显。施有机肥能显著提高Cu、Zn和Cd有效态含量,与对照相比分别平均提高61.28%、169.3%和123.7%,不同施肥处理土壤中Cd含量已超标,属污染水平。有效态Pb在N4P2处理要显著高于其他各处理,而各年份M4处理有效态Pb的含量要低于CK处理。20年来有效态Pb含量相对于CK平均降低了4%。土壤中4种重金属全量与其有效态含量相关性表明:Cu、Zn和Cd全量与其有效态含量呈极显著正相关关系,全量Pb与有效态Pb呈显著负相关而与有效态Cu和Zn不显著相关。  相似文献   

6.
深圳市主要公园及道路绿地土壤重金属含量状况比较研究   总被引:4,自引:1,他引:4  
史正军  吴冲  卢瑛 《土壤通报》2007,38(1):133-136
对深圳城市主要公园和道路绿地土壤Cu、Zn、Pb、Cd含量状况进行取样调查分析。研究结果表明,绿地土壤重金属含量与土地利用类型有关,表现为道路绿地土壤Cu、Zn、Pb平均含量高于公园绿地土壤,而Cd平均含量则相反。采用不同土壤重金属污染评价方法对深圳城市绿地土壤进行的环境质量评价均表明深圳城市绿地土壤Cd污染现象显著。在考察的四种重金属元素中,Zn含量与土壤有机质、pH有关,其中pH对Zn含量的影响相对较大;土壤Cu与Pb、Zn呈直线相关,表现出相互依存的关系。  相似文献   

7.
不同施肥雷竹林土壤重金属含量的动态分析   总被引:11,自引:1,他引:11  
姜培坤  徐秋芳 《水土保持学报》2005,19(1):168-170,180
为了解早产高效雷竹林施肥与土壤重金属有效态含量关系,在浙江省雷竹主产区布置了肥料试验,动态采集了各处理土壤样品,用ICP法分析了土壤重金属有效态含量。结果表明:Pb、Cd、Zn、Cr和Cu5种重金属有效态含量,无论是在有机肥化肥混合处理区还是纯化肥处理区随时间变化均有较大波动,5种重金属有效态含量均表现为8月份含量较高,以后则明显下降,到次年4月份又明显升高。比较不同施肥处理土壤重金属有效态含量发现,有效Zn和有效Cr含量在3个不同用量的纯化肥间有显著差异,而不同用量有机肥化肥混施处理间所有重金属有效态含量均无显著差异,有效Pb、Cd、Cu在不同用量纯化肥处理间差异性也不显著。土壤有效Pb、Cr和Zn含量覆盖区显著高于不覆盖区,3种重金属有效态含量覆盖区分别是不覆盖区的1.59倍、1.30倍和1.26倍。  相似文献   

8.
重金属Cd、Zn、Cu、Pb复合污染对土壤微生物和酶活性的影响   总被引:16,自引:4,他引:16  
通过野外土样采集及室内测定,研究了云南东川铜矿区土壤酶和微生物特征,并采用盆栽试验研究了重金属Cd、Zn、Cu、Pb复合污染对土壤微生物和酶活性的影响。结果表明,距离矿口越近,土壤有机质、有效N、P、K的含量、土壤pH值亦越低,土壤酶活性和土壤微生物数量、微生物生物量C和N受到的抑制程度也增强,其中土壤酶中的酸性磷酸酶和过氧化氢酶,土壤微生物中的细菌对重金属污染较为敏感。盆栽试验中,Cd、Zn、Cu、Pb复合污染使白菜(Brassica rapapekinensis)生物量明显下降,且随复合污染程度的增加,白菜生物量下降幅度增加。Cd与Zn、Cu、Pb,Zn与Cd、Cu、Pb,Cu与Cd、Zn、Pb的复合效应机制为协同效应,而Pb与Cd、Zn、Cu的复合效应机制为拮抗效应。重金属Cu、Zn、Pb、Cd复合污染使土壤酶活性显著降低,但低量的Cd、Zn、Cu、Pb复合污染刺激了细菌、真菌、放线菌、微生物生物量C和N。重金属Cd、Zn、Cu、Pb对土壤酶活性和土壤微生物数量及微生物生物量C和N的复合效应机制表现出协同和拮抗效应。  相似文献   

9.
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   

10.
以典型工业城陕西省铜川市土壤为研究对象,采用BCR(欧共体标准物质局)连续形态分级法和Hakanson潜在风险指数法分别研究了人类活动性元素Pb,Cu,Cr,Zn的形态分布特征、环境迁移与生态风险;利用振荡浸提动力学试验(25℃平衡振荡24h)探讨了人工合成低氨基多羧酸(APCAs)乙二胺四乙酸(EDTA)、二乙烯三胺五乙酸(DTPA)和低分子有机酸(LMWOAs)抗坏血酸(Vc)对重金属Pb,Cu,Cr,Zn的淋溶解吸特征与动力学机制。结果表明,铜川市工业区土壤重金属污染程度严重,总体潜在生态风险程度较强;重金属Zn和Cu的环境迁移趋势较大。淋溶动力学试验表明,不同类型有机酸对土壤Pb,Cr,Cu和Zn的淋溶解吸具有相似的动力学过程,但淋溶速率和解吸量随有机酸的不同各异。重金属Pb,Cr,Cu和Zn各形态量之和与有机酸EDTA和DTPA淋溶解吸量呈指数关系,而与低分子有机酸Vc淋溶解吸量成线性关系。从而进一步表明低分子有机酸Vc与氨基多羧酸类有机酸EDTA和DTPA对土壤重金属Pb,Cr,Cu,Zn淋溶解吸机制不同。  相似文献   

11.
对天水果园表层(0~20 cm)219件土壤样品进行研究,测定5种重金属(Zn、Cu、Pb、Cr和Cd)及有机质含量,以天水小陇山土壤为对照,运用相关分析和主成分分析方法区分土壤中重金属的来源。结果表明,①Zn、Cu、Pb、Cr和Cd含量分别为77.39、23.03、23.62、61.49 mg.kg-1和0.07 mg.kg-1,其中Cd极显著(P〈0.01)高于小陇山土壤,其余4种重金属虽高于小陇山土壤但无显著差异性(P〉0.05);②研究区土壤Cu、Pb、Cr三者间在0.01或0.001水平上具有显著正相关性,且这3种重金属与土壤有机质具有显著正相关性,其余重金属间不存在显著相关性;③主成分分析显示Cu、Pb和Cr来源相似,主要来自于成土母质,Cd来源于人为施肥因素,Zn的富集受多种因素影响。研究评价结果显示,天水地区果园土壤Cd受人为施肥影响较大,具有一定程度的富集。  相似文献   

12.
通过在重金属污染土壤中分别施加沸石、石灰石、硅藻土、羟基磷灰石、膨润土和海泡石6种固化剂,研究了这6种固化剂对土壤中Pb、Cd、Cu、Zn的固化效果,筛选出几种效果较好的固化剂。实验结果表明:沸石、石灰石和羟基磷灰石均能够有效地降低土壤中交换态Pb、Cd的含量,并且明显减少了土壤中Pb、Cd的毒性浸出量,其中沸石最多降低土壤中交换态Pb、Cd含量分别达到48.7%和56.2%,减少土壤中Pb、Cd的毒性浸出量达到37.1%和30.1%;沸石、石灰石均能够有效降低土壤中交换态Cu的含量,降低量分别高达68.1%和85.2%,膨润土能有效减少土壤中Cu的毒性浸出量,减少量最高达到66.51%;石灰石对土壤中Zn有着良好的固化效果。  相似文献   

13.
典型设施栽培土壤重金属含量变化及其风险评价   总被引:9,自引:1,他引:8  
采用野外调查采样和室内分析相结合的方法,对典型设施栽培地山东寿光的部分土壤重金属含量进行测定,并根据温室蔬菜产地环境质量评价标准,选取单项污染指数法和尼梅罗综合指数法对土壤的重金属污染状况进行了环境质量评价。结果表明,重金属Cu、C r、Pb在设施栽培土壤耕层(0—20 cm)的含量达最大值,显著高于露地土壤;而设施栽培土壤中Zn和Cd的含量分别在20—40 cm和40—60 cm的土层达到最大值,其中Zn含量在0—20 cm和60—80 cm的土层显著高于露地土壤,Cd含量在0—20 cm,40—60 cm,60—80 cm和80—100 cm的土层显著高于露地土壤。从不同使用年限设施栽培土壤中重金属含量变化看出,重金属在设施栽培24~年的土壤中含量最高。对研究区设施栽培土壤重金属含量进行风险评估及分级发现,山东寿光设施土壤耕层主要受到重金属Cd的污染。  相似文献   

14.
This study evaluated cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) sorption characteristics of three tropical soils. Data obtained conformed to Freundlich sorption model and the S-shaped isotherm curve. Sorption efficiency of Zn and Pb were highest in alkaline soil while slightly acid soil had the highest Cd and Cu sorption efficiency for monometal sorption. In competitive sorption, metals were more sorbed in slightly acid soil while the least efficiency was recorded in acid soil. Distribution coefficient; Kd (average across soil types) in monometal sorption followed the order: Pb > Zn > Cd > Cu. For competitive sorption, the order was Zn > Pb > Cu > Cd. When in competition, Cd was preferentially sorbed in slightly acid and alkaline soils and Zn for acid soil. Conclusively, lead is more in equilibrium solution when in competition with Cd, Zn and Cu making it potential agent of soil and groundwater pollution.  相似文献   

15.
smelters in Northern France were studied by analysing the chemical forms of these metals and evaluating their phytoavailability. These metals were determined using flame or electrothermal absorption atomic spectrometry (FAAS or ETAAS), depending on their concentration levels. After optimisation of the ETAAS method, characteristic mass of In in water and aqua regia were 9.9 and 18 pg, respectively, showing the high sensitivity of the analytical Soil contamination by metals from anthropogenic activities (e.g., mining and smelting) is a major concern for the environment and human health. Environmental availability of cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), and indium (In) in 27 urban soils located around two former Pb and Zn smelters in Northern France were studied by analysing the chemical forms of these metals and evaluating their phytoavailability. These metals were determined using flame or electrothermal absorption atomic spectrometry (FAAS or ETAAS), depending on their concentration levels. After optimisation of the ETAAS method, characteristic mass of In in water and aqua regia were 9.9 and 18 pg, respectively, showing the high sensitivity of the analytical procedure. Metal partitioning was conducted using a four-step sequential extraction procedure. The results showed that Cd and Zn were mainly in the acid-extractable and reducible forms in the urban soils studied. In contrast, Pb and In were largely in the reducible fraction. However, in some samples, the amount of In extracted in the residual or exchangeable fraction was higher than that in the reducible fraction. Copper was mainly found in the reducible and residual fractions. A pot experiment was conducted in a glasshouse with seven soils (six contaminated and one uncontaminated) and two plant species, ryegrass and lettuce. The results showed transfer of metals from the contaminated soils to the shoots of ryegrass and the edible part of lettuce. The metal bioconcentration factor was in the order of Cd Cu > In > Zn Pb for lettuce leaves, whereas for ryegrass shoots, three orders were found, Cd > Zn > Cu In > Pb, Cd ≥ In > Zn > Cu Pb, and Zn > Cd > Cu > In > Pb, depending on the physico-chemical properties of the soils, such as pH, cation exchange capacity, carbonates, and organic matter. It was established that the metal toxicity was related to the contamination levels and the physico-chemical properties, including pH, organic matter, and in a lesser extent, Ca, Mg, and phosphorus contents, of the soils. However, it was shown that lettuce could grow on soils having high Cd and CaCO3 contents. Cadmium was one of the most available metals while Pb was always the least available in the soils studied.  相似文献   

16.
广东大宝山矿区土壤重金属污染   总被引:28,自引:0,他引:28  
Soil contamination in the vicinity of the Dabaoshan Mine, Guangdong Province, China, was studied through determi- nation of total concentrations and chemical speciation of the toxic metals, Cu, Zn, Cd, and Pb, using inductively coupled plasma mass spectrometry. The results showed that over the past decades, the environmental pollution was caused by a combination of Cu, Zn, Cd, and Pb, with tailings and acid mine drainage being the main pollution sources affecting soils. Significantly higher levels (P ≤ 0.05) of Cu, Zn, Cd, and Pb were found in the tailings as compared with paddy, garden, and control soils, with averages of 1486, 2516, 6.42, and 429 mg kg^-1, respectively. These metals were continuously dispersed downstream from the tallings and waste waters, and therefore their concentrations in the paddy soils were as high as 567, 1 140, 2.48, and 191 mg kg^-1, respectively, being significantly higher (P ≤ 0.05) as compared with those in the garden soils. The results of sequential extraction of the above metals from all the soil types showed that the residual fraction was the dominant form. However, the amounts of metals that were bound to Fe-Mn oxides and organic matter were relatively higher than those bound to carbonates or those that existed in exchangeable forms. As metals could be transformed from an inert state to an active state, the potential environmental risk due to these metals would increase with time.  相似文献   

17.
中国太原市农业土壤的重金属污染状况   总被引:5,自引:0,他引:5  
To evaluate the current state of the environmental quality of agricultural soils in Taiyuan City, a hotspot for China’s industrial development, the concentrations of 8 heavy metals in soils were investigated by means of extensive sampling in farmlands, forestlands, and grasslands in the city. Statistical analyses and spatial distribution maps were used to identify the most significant heavy metal pollutants. The mean concentrations of As, Cd, Cu, Hg, Pb, Zn, Ni, and Cr were slightly higher than their background values in Taiyuan’s topsoil, but were lower than the maximum permissible concentrations in the Chinese Environmental Quality Standard for agricultural soils. Farmland soils in Taiyuan had the highest average Cd, Cu, Hg, Pb, Zn, and Cr concentrations, but the As and Ni concentrations did not differ significantly among the farmland, forestland, and grasslands. Soil contamination by Cd, Cu, Hg, Pb, Zn, and Cr was mainly derived from farming practices, especially the use of sewage water for irrigation. In contrast, As and Ni might derive mainly from the soil parent material. The identification of heavy metal sources in agricultural soils may provide a basis for taking appropriate action to protect soil quality.  相似文献   

18.
The goal of this study was to measure the As, Cu, Fe, Pb and Zn contents of soils amended with municipal solid waste (MSW) and MSW-biosolids compost and to determine the long-term transport of these metals to lower soil horizons. Lead, Cu, Cd and Zn contents in the composts were 3–20 times more concentrated in the compost compared to the soil at the Calverton, NY, U.S.A. farm. As a result, Pb, Cd, Cu and Zn were elevated in the upper 5 cm soil layer following compost application and the metal enrichment was proportional to the amount of compost applied (21–62 Mg ha-1). In addition, Pb, As and Cu contents of the non-compost amended Calverton soils were enriched above the tillage depth (20–25 cm). Cu, Pb and As enrichment was attributed to the historical use of sodium arsenite, lead arsenate and copper sulfate insecticides and fungicides. Results of the metal analyses of soil cores collected 16 and 52 months following compost application showed that Cu, Zn and Pb remained confined to the upper 5 cm soil layer. The low water extractable fraction of these metals in MSW and MSW-biosolids compost was a major factor limiting the transport of these metals to lower soil horizons. In contrast, Cd leaching from the upper 0–5 and 5–10 cm soil layers was continuous over the 52 month study period and was attributed primarily to the presence of soluble Cd in phosphate fertilizer initially applied to the Calverton farm soil.  相似文献   

19.
用地积累指数法和单因子内梅罗综合指数法研究了沈阳地区蒲河、浑河、细河以及沈抚灌渠周边农田表层土壤中7种重金属的污染状况。结果表明,表层土壤中As、Hg、Cd、Pb和Cr的最大值出现在细河周边,Zn和Cu的最大值出现在沈抚灌渠周边,Hg、Cd、Pb、Zn、Cu、Cr6种重金属的平均含量在各个区域中差别明显。Cd与Hg之间的相关系数高,表明Cd、Hg来源相同;Pb、Zn、As、Cu相关性好,判定可能来自同一来源。地积累指数和单因子内梅罗综合指数计算结果表明,Cd、Hg、Zn污染在这些河流地区较普遍,Pb、Cu、Cr和As在部分地区受到污染,部分细河沿岸农田土壤受到严重污染。  相似文献   

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