镉铅的固化对苎麻生长和重金属吸收的效应

为探明镉、铅重金属污染土壤固化处理对苎麻生长和重金属吸收的影响,通过盆栽试验研究了镉、铅复合污染黄褐土中施加硅藻土、膨润土、石灰石粉和沸石粉对土壤中镉、铅各形态含量的影响以及对苎麻生物量、叶片丙二醛含量及重金属镉、铅积累特性的影响。结果表明:添加沸石粉和高浓度(9~12 g·kg~(-1))硅藻土、膨润土可以显著减少土壤中镉的酸可提取态含量;添加硅藻土、膨润土和沸石粉对降低土壤中酸可提取态铅有很好的效果,降低量可达43.1%。固化剂的施加使得苎麻各部位吸收镉、铅减少,全株镉、铅累积量分别降低9.9%~62.7%和5.8%~28.4%,且固化剂施加量达到9 g·kg~(-1),对苎麻吸收镉、铅影响增大。除石灰石粉外,其他三种固化剂均使得苎麻生长受到的不良影响降低。     

新乡小冀工业区周边土壤重金属污染评价与形态分析

通过实地调查和实验分析,对小冀工业区周边土壤中六种重金属(Cd、Cr、Cu、Ni、Pb和Zn)进行了总量测定。参照GB15618-1995二级标准,采用单因子指数法和内梅罗综合污染指数法对土壤质量进行了现状评价,并采用Tessier五步连续萃取法对超标重金属Cd、Ni和Zn进行了形态分析及生物活性分析。结果表明:1)Cr、Cu和Pb含量均未超过国标二级标准,Cd、Ni和Zn三种重金属含量均超标,工业区综合污染非常严重,主要污染元素是Cd;2)Cd、Ni和Zn在土壤中的形态分布差异性较大,Cd主要以铁锰氧化物结合态存在,Ni和Zn主要以残渣态和铁锰氧化物结合态存在;3)金属生物活性系数大小顺序为Cd>Zn>Ni,迁移系数的大小顺序是Cd>Zn>Ni,其中Cd的生态风险很大。     

干旱区绿洲土壤中Cd、Pb、Zn、Ni复合污染对芹菜的影响及其富集迁移规律

通过盆栽试验和室内分析初步研究了干旱区绿洲土壤中Cd、Pb、Zn、Ni复合污染对芹菜生长的影响及重金属在芹菜体内的富集迁移规律。结果表明:随着外源重金属添加量的增加,芹菜的生长受到明显抑制。根据多元回归分析和偏相关分析,芹菜地上部和根部吸收Pb量分别与外源添加Pb、Zn、Ni量和Cd、Pb、Zn、Ni量达到极显著相关,其中土壤Zn含量的增加极显著的降低了芹菜地上部和根部对Pb的吸收。芹菜地上部及根部对Cd、Pb、Zn、Ni四种元素的富集系数大小顺序均为:Cd>Zn>Ni>Pb,且根部对四种重金属元素的富集能力显著大于地上部。Cd在芹菜中的平均迁移能力最强,Zn、Ni次之,Pb的迁移能力最弱。     

Heavy metal contamination of urban topsoil in a petrochemical industrial city in Xinjiang,China

Heavy metal pollution is a widespread phenomenon in many countries of the world.In this study,we conducted a field investigation to assess the status of heavy metal pollution in urban soils of Dushanzi,a district of Karamay city in Xinjiang,China.A total of 56 soil samples in the topsoil layer of 0–15 cm were collected within the urban area and seven elements(Cu,Zn,Cd,Pb,Cr,As and Ni) were analyzed.The mean concentrations of these metals were all higher than their corresponding background values of soils in Xinjiang.We used the pollution index and ecological risk index to assess the degree of heavy metal pollution and the potential ecological risk of urban soils.The pollution index values of Cu,Zn,Cd,Pb,Cr,As and Ni were 1.81,1.35,4.64,1.27,1.80,1.39 and 1.22,respectively;and the potential ecological risk index values for them were 12.03,1.79,185.05,8.39,4.78,18.44 and 1.79,respectively.These results indicated that urban soils in Dushanzi were polluted by heavy metals to some extent and demonstrated a high ecological risk,as influenced by industrial activities.Cd was the key element for the metal pollution of urban soils in the study area.Correlation analyses,principal component analysis coupled with the spatial distribution maps of element concentrations further revealed that heavy metal pollution of urban soils can be mainly attributed to petrochemical industry,coal chemical industry,traffic and commercial activities.     

干旱区绿洲土壤Cd、Zn、Ni复合污染对芹菜生长及重金属积累的影响

以干旱区绿洲土为供试土壤,用芹菜(Apium graveolens)做指示植物,通过模拟盆栽试验,研究了土壤Cd、Zn、Ni复合污染对芹菜生长及重金属吸收积累的影响.结果表明:(1)低浓度的Cd、Zn、Ni重金属复合处理在一定程度上可促进芹菜根、茎叶的生长,重金属复合作用增强时,即Cd、Zn、Ni浓度增大时,毒害作用逐...     

绿洲区土壤镍的吸附解吸特性

土壤重金属的移动性和生物有效性与重金属的吸附解吸及形态分布密切相关.通过序批试验、单步提取和连续提取的方法,研究绿洲区土壤镍(Ni)的吸附解吸特性.结果发现:①所研究的土壤呈现碱性,具低有机质含量和高碳酸盐含量特征,土壤未被镍所污染;②Freundlich可以用来模拟绿洲区土壤对镍的吸附行为.吸附能力与土壤粉粒、黏粒、全磷、有机质、CEC成显著正相关,而与砂粒成显著负相关,土壤pH并不是影响绿洲区土壤吸附镍的重要因子,绿洲区土壤对镍的吸附不是哪一个土壤理化参数所控制,而可能是土壤理化参数的联合控制;③绿洲区土壤镍的解吸量随土壤中镍吸附量的增加而增加,土壤镍解吸量与解吸前吸附量的关系可以用幂函数进行模拟;④在添加50 mg/L镍的条件下,绿洲区土壤吸附的镍主要以铁-锰结合态、碳酸盐结合态和可交换态为主.     

Interaction between Cd and Pb in the soil-plant system: a case study of an arid oasis soil-cole system

The Hexi Corridor,our study area,is located in Northwest China and is also the most developed area of oasis farming in arid regions of Northwestern China.However,the rapid development of metallurgy and chemical industries in this region poses a great threat to the accumulation of heavy metals in crops.The objectives of this study are(1)to determine the influence of heavy metals on plant growth;(2)to assess the translocation capability of heavy metals in soil-plant system;and(3)to investigate the interaction between heavy metals.Pot experiments were conducted on cole(Brassica campestris L.)grown in the arid oasis soils singly and jointly treated with cadmium(Cd)and lead(Pb).Nine treatments were applied into the pots.Under the same planting conditions,three scenarios of Cd,Pb and Cd–Pb were designed to compare the interaction between Cd and Pb.The results showed that the response of cole weights to Cd,Pb and Cd–Pb treatments was slight,while Cd and Pb uptakes in cole were more sensitive to the single effects of Cd and Pb concentration in soils from the lower treatment levels.Under the influence of the single Cd,Pb and joint Cd–Pb treatments,Cd concentrations were lower in the cole roots than in the shoots,while for Pb,the results were opposite.Comparison studies revealed that the interaction of Cd and Pb could weaken the cole’s ability to uptake,concentrate and translocate heavy metals in arid oasis soils.     

环青海湖地区表层土壤重金属富集含量及其生态风险评价

为评估环青海湖地区表层土壤中重金属富集含量与生态风险状况,按网格法采集87组土壤样品,采用电感耦合等离子体原子发射光谱法(Inductively Coupled Plasma-Atomic Emission Spectrometry,ICP-AES)测定土壤重金属Cd、Cr、Pb、As、Cu、Zn和Ni,并利用内梅罗综合污染指数法、污染负荷指数法、相关性分析和因子分析等方法,探析了研究区土壤重金属含量、污染程度、生态风险及污染来源。结果表明:环青海湖地区表层土壤中重金属Cd、Pb污染在所研究的元素中最为严重,Cr、As、Cu、Zn和Ni次之,且草地的表层土壤重金属污染情况相比农田和沙地较严重。从污染负荷指数法来看,研究区土壤重金属整体上未达到污染水平,但部分采样点污染严重。内梅罗综合指数法分析显示,研究区整体上为重度污染,且单项污染指数存在不同程度超标,其污染程度依次为Cd>Pb>As>Cu>Zn>Ni>Cr。潜在生态风险指数法表明,整个研究区的综合潜在生态风险为中等程度,其中Cd、As的贡献率接近80%,部分区域潜在生态风险较高。相关性和因子分析可以发现,Cr、Pb、As、Cu、Zn和Ni之间的相关性显著,污染程度基本一致,很可能具有同源性。综上可知,环青海湖地区已出现土壤重金属污染,且存在潜在生态风险,需要采取适当的监测和相应治理措施。     

河西灌区马铃薯茎基腐病的发生规律与防治技术研究

本文首次报道马铃薯茎基腐病在田间表现为立枯型、萎蔫型、根腐型、黄化型4种症状类型,一般在苗期至现蕾期、开花期至结薯期为发病高峰期;明确了河西灌区种植的大多数品种对茎基腐病无明显抗性;发病程度与多种因素有关,灰钙土发病较重,其次为壤土,沙土发病较轻;土壤pH与含水量较高发病重;植株密度较高发病重;连作年限越长发病越重;与油菜、茄科蔬菜连作发病较重;高温有利于该病发生;经药剂种薯、土壤、灌根处理表明：以代森锰锌、菌核净和敌磺钠种薯和土壤处理,代森锰锌、井•1亿活枯草芽孢菌、菌核净灌根处理,防效达50.3%～65.9%。     

干旱区耕作土壤中重金属镉铅镍剖面分布及行为研究--以白银市区灰钙土为例

通过对干旱区长期污灌农田土壤中重金属的剖面分布及行为进行研究,结果表明:在长期灌溉与降水下渗水流作用下,重金属物质可发生不同程度的淋溶迁移;迁移程度依次为Cd>Ni>Pb;元素Cd具有显著的负指数迁移规律,而元素Pb、Ni规律性不明显.     

Risikoabschätzung von Schadelementen (Schwermetallen) im System Boden/Pflanze

In rural areas, representing about 97% of the agricultural and horticultural area, the content of heavy metals in harvested products does not create a significant risk to consumers. In urban areas with about 3% of the horticultural area and on agricultural production fields with corresponding history, local contaminations may exceed the precautionary values for soils. For these areas, an estimation of possible risks is advisable and necessary. On the base of investigations of transfer of heavy metals (As, Cd, Cr, Co, Cu, Hg, Ni, Pb as well as Zn) via the path soil to plant “bio concentration factors” (BCF) have been determined for various horticultural crops (leaf-vegetable, shoot-vegetable, fruit-vegetable, root-vegetable, kitchen herbs and fruit). By use of these BCFs in combination with human toxicological values of the heavy metals (TDI), guiding values can be derived for tolerable soil contamination with the respective metals. These guiding values allow a simple risk assessment of the respective contaminated soils for cultivation and consumption of crops or crop products.     

金昌市城区绿化带土壤重金属含量特征及污染评价

通过对金昌城区主要交通干道周围绿化带土壤的取样调查,分析了Cu、Zn、Ni、Pb和Cd五种重金属元素含量分布的总体特征,并利用地积累指数法对绿化带土壤重金属进行污染评价。结果表明:五种重金属平均含量均超过了该地区的背景值,其中Cu和Ni含量最高,且具有明显的高度富集的特征。绿化带土壤中五种重金属变异系数均较大,其中Cu和Ni变异系数达到了125.06%和86.64%,属强变异性。地积累污染指数法的污染评价结果显示,Cu和Ni已分别构成4级和3级污染,且污染范围较广;而Zn和Pb均未构成污染,Cd构成了1级污染,但大部分样点中其含量均已超过了该地区的土壤背景值,表现出了明显的积累。     

Detection of the root lesion nematode Pratylenchus penetrans in potato tubers

The root lesion nematode Pratylenchus penetrans parasitizes a wide range of economically important crops, including potato (Solanum tuberosum). Damage by P. penetrans impacts not only the potato yield but can also reduce the tuber quality. Detailed information on tuber infection by P. penetrans is scarce for most cultivars and molecular detection of nematodes from infected tubers is needed. The objective of this study was to assess tuber symptomatology due to P. penetrans infection in 10 potato cultivars and to provide an accurate molecular methodology for nematode detection using tuber peels. Sprouts of certified potato seed from cultivars Agata, Agria, Camel, Désirée, Dirosso, Kennebec, Laura, Picasso, Royata, and Stemster were planted in 2 L pots, and soil was inoculated with 4 P. penetrans/g of soil. Sixty days after inoculation, tubers were harvested, inspected for lesions, and the number of nematodes/g of potato peel assessed. Observations of tubers with symptoms showed the presence of P. penetrans in superficial layers of peels around the lenticels and injured necrotic tissue. Different nematode stages were detected in tubers of all inoculated cultivars, varying from 4 to 46 nematodes/g of potato peel. Species-specific primers showed suitable sensitivity and reproducibility for the detection of P. penetrans in tuber potato peel samples. The molecular detection of P. penetrans directly from tuber peels can facilitate routine nematode inspections of potato seed tubers or cull potatoes for nematode detection, and prevent further dissemination of this species.     

Contents and spatial distribution patterns of heavy metals in the hinterland of the Tengger Desert,China

The desert in northern China is one of important sources of loess and one significant source of material for sandstorms in Asia. The sand/dust that is transported from desert when sandstorms occur can destroy the growth of crops, cause serious losses and great harm to the economic construction and life safety, and cause natural environment pollution. Hence, it is very important to deepen the research into heavy metals in surface deposits at vulnerable ecological region of arid land of northern China to guide local industrial and agricultural development and improve environmental protection. In this research, 10 heavy metal elements (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, and Th) were tested and analyzed in 33 soil sample sites collected from the hinterland of the Tengger Desert, northern China. The results showed that the average abundance of Th exceeded its background soil value of China by more than 5.2 times, which suggests that the Tengger Desert is polluted by Th. In addition, based on principal component analysis, spatial differentiation, and correlation analysis, we identified the source of element with a coefficient of variation in abundance of greater than 0.5 or exceeding the background soil value of China. Principal component analysis and correlation analysis showed that the sources of heavy metals of Cr, Mn, Fe, Co, Ni, Cu, and Cd were similar, while those of Th and Zn were different. Moreover, based on the contents and spatial distribution characteristics of those heavy metal elements, we found that the formation of heavy metal elements enrichment areas is caused by industrial pollution, development of irrigated agricultural, geological, and geomorphic conditions, and the sedimentary environment in the study area. Our result can provide information on the environmental background values of soils in the hinterland of the Tengger Desert. Background value of China^a(mg/kg)     

省道路边菜地土壤重金属含量分布及污染评价

采集西安市S107省道路边菜地土壤样品,利用XRF法测定土壤样品中重金属的含量,研究路边土壤中重金属的含量变化特征及污染水平。研究结果显示,路边菜地土壤中存在着Cu、Pb、Zn、Cr、Mn、Ni和V的累积现象。土壤重金属含量空间变化分析表明,防护林能够有效限制扩散能力强的Pb和Cr的传播范围,可阻挡通过大颗粒污染物扩散的Cu、Zn、Mn、Ni、V和As进入菜地土壤。单项污染指数评价结果显示,菜地土壤中Cu、Pb、Zn、Cr、Mn、Ni、V单因子污染指数均在1.0～1.7范围内,都达到了轻度污染,其中Pb、Cr污染指数能达到1.6和1.7,污染相对较重。路边菜地土壤重金属的综合污染指数分别为1.9和1.8,污染水平为轻度。     

西安市污灌区土壤中重金属潜在生态危害评价

为摸清西安市污灌区土壤环境质量现状及变化趋势,本研究采用西安市污水灌区农业环境质量状况调查的部分数据资料,以Lars Hakanson的潜在生态危害指数对4种重金属的危害程度进行了评价。结果表明,西安污灌区Pb、Cd、Hg、As潜在生态危害系数差异不大,其中Pb、Cd、As的潜在生态危害系数都小于40,生态危害程度为轻度,Hg则大于40,生态危害程度为中等;从潜在生态危害指数看,1982和1998年两次调查结果都小于150,重金属潜在生态危害为轻度。1998年在污灌区各元素的实测结果表明Cd和As为非污染,Pb为轻微污染,Hg污染程度比较严重,且有加重趋势。     

干旱区绿洲土壤Cd-Zn复合污染下重金属形态及其生物有效性的研究

通过模拟基于Cd-Zn复合污染下干旱区绿洲土壤的胡萝卜盆栽试验,用Tessier连续提取法对胡萝卜土壤中Cd、Zn的形态分布进行分析,同时就生物利用性形态的变化研究了Cd、Zn的生物有效性。结果表明:1)原状土壤中Cd和Zn主要以残渣态存在,随着复合胁迫浓度的增加,Cd的主要赋存形态逐步转变为碳酸盐结合态和可交换态,Zn主要赋存形态逐步转变为以铁锰氧化态和残渣态,但有效态和潜在有效态的比例大大增加。2)胡萝卜对Cd、Zn的富集作用均为地上部分大于地下部分,对Cd的富集能力远远大于Zn。3)胡萝卜吸收的Cd和Zn不仅包括可交换态和碳酸盐结合态,还包括了在一定条件下释放出来的铁锰氧化态和有机结合态。     

沣河沿岸土壤重金属分布特征及来源分析

在野外调查的基础上,以陕西省沣河沿岸土壤为研究对象,结合数据统计与GIS制图,对Co、Cr、Cu、Mn、Pb、Zn、Ni和V 8种重金属元素富集特征、空间分布、生态风险及来源进行分析。结果表明：研究区各重金属元素含量在人群、工厂密集地显著富集,并均有着随水流方向呈总体升高的趋势。土壤中Co、Cr、Mn、Pb和V的几何均值分别为21.5、92.1、611.1、32.9 mg•kg^-1和75.4 mg•kg^-1,均高于陕西省土壤背景值。其中,Co、Cr、Mn和Pb含量的超标率达100%、75%、63%和25%,表现为以Co为主的多种重金属复合污染。污染评价结果表明：研究区存在不同程度的重金属污染,其中,Co、Cr、Pb和Ni污染主要集中在沣河中下游河段,Cu污染主要集中在沣河中上游河段。沣河沿岸土壤重金属污染与人类活动关系密切,应引起重视。     

蓝田冶炼厂周边农田土壤重金属复合污染分析评价

为了解粗铅冶炼活动对周边土壤的污染情况,防止重金属再污染和修复改良已污染土壤,对蓝田冶炼厂周边农田土壤中重金属含量的空间分布规律进行初步分析,并运用单项污染指数法和内梅罗综合污染指数法对该区重金属污染水平进行评价.结果表明:水平方向上,距冶炼厂100 m处的表层土壤中Pb、Zn、Cu、Cd四种重金属的含量最高,分别达1 341.693、188.877、251.015、21.810 mg/kg,依次为国家土壤环境质量二级标准的3.833、0.630、2.510、36.349倍.随着距离的增大,重金属含量大体都呈现出先上升、后下降最后趋于稳定的分布状况;剖面土壤中,重金属含量从表层到深层递减,0～35 cm范围各层含量变化幅度较大,35 cm以下基本上趋于稳定.从综合污染指数来看,表层土壤和剖面土壤各样点的综合污染指数均远大于3,说明该区农田土壤已处于重度复合污染状态.