开阳磷矿10种木本植物叶片重金属富集特征

植物对重金属具有一定的吸附能力,植物修复是生态修复不可或缺的一部分,利用植物减缓和治理重金属污染具有重要意义.选取开阳磷矿马路坪矿区生命周期较长的木本植物及其土壤作为研究对象,探究木本植物受Cu、Zn、Pb、Cd、As等5种重金属污染土壤的效应,对植物重金属含量及其富集特性进行研究分析,筛选出累积重金属的植物,作为矿区...     

Distribution of heavy metals in soil and accumulation in plants at an agricultural area of Umudike,Nigeria

This study assessed the distribution of heavy metals in soil and their subsequent accumulation in plants at a site at Umudike, Nigeria, that had been contaminated by agrochemicals. Soil and plant samples were analysed for zinc (Zn), chromium (Cr) and cadmium (Cd). The highest concentrations of Zn (251.50 mg/kg) and Cd (61.33 mg/kg) were obtained at a soil depth of 0–10 cm. The highest concentrations of Zn (16.52 mg/kg), Cd (27.12 mg/kg) and Cr (164.07 mg/kg) were accumulated by Baphia nitida. The levels of Cd, Cr and Zn in soil were 27.97–61.33, 24.97–45.43 and 148.57–251.50 mg/kg, and their concentrations in B. nitida were 16.18–27.13, 97.99–164.07 and 0.10–16.52 mg/kg, respectively. There were significant correlations between Cd and Cr and Cd and Zn in soil, as well as between Cd and Cr in plants. The concentration of Cd in soil reflected a state of pollution relative to Dutch criteria for soil and the FAO/WHO Codex Alimentarius Commission.     

稀土尾矿区土壤重金属污染与优势植物累积特征

矿山废弃地不仅占用大量土地,而且还是严重的污染源,因此,矿山废弃地的生态恢复己成为一项紧迫而重要的研究课题。对广东省河源市和平县下车镇内的稀土矿区土壤的重金属污染情况进行调查,并对该区优势植物对重金属的富集特征进行分析,以期对稀土尾矿区的生态系统的恢复和重建提供理论依据。主要研究的3种植物分别是：马唐草（Digitaria sanguinalis）,香根草（Vetiveria zizanioides）,望江南（Cassia occidentalis）。采用原子吸收分光光度法测定稀土矿区废弃地土壤和植被中Mn、Pb、Zn的含量,并计算优势植物对重金属的生物富集系数BAC（Biological Accumulating Coefficient）和生物转移系数BTC（Biological Transfer Coefficient）。结果表明：研究区域的土壤中重金属含量Mn、Pb、Zn的平均含量均超出广东省土壤背景值和中国土壤背景值,土壤受Mn污染最严重,其次是Pb、Zn的污染。3种草本植物对于Pb的BAC和BTC均小于1,说明这3种植物对Pb的富集和运输能力都很弱。香根草对于Mn和Zn的BAC分别为0.9和0.4,小于1,BTC分别为3.7和1.1,大于1,说明香根草对Mn和Zn的富集能力不强,但吸收后的运输能力很强。马唐草和望江南2种植物对于Mn和Zn的BAC和BTC均大于1,说明它们对重金属Mn和Zn具有较强的吸收和转移能力,是Mn和Zn的超富集植物。马唐草覆盖率高,抗病虫能力强,可作为该矿区生态恢复的先锋植物,望江南可以间作种植。     

大气沉降对土壤重金属累积的影响

选择大气污染严重的太原市为研究区,通过定点监测,分析了不同类型区大气TSP和降尘的污染状况及周年内的月变化趋势,测定了大气干湿沉降中Hg、Cd、Pb三种重金属元素的含量,并计算出大气干湿沉降对土壤系统重金属的年输入量分别为Hg4.48g/(hm2×a),Cd6.34g/(hm2×a),Pb349.4g/(hm2×a);不同类型区大气污染状况与大气沉降输入土壤中重金属累积顺序一致均为工矿区＞城区和近郊区＞风景区＞远郊区。     

Heavy metal pollution in soil and plants at bone char site

This study determined the heavy metal concentration in soil and plants at a bone char site in Umuahia, Nigeria. Soil and plant samples collected in a randomized complete block design (RCBD) were analyzed for zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), and arsenic (As). The concentration of metals in soil and plants in the vicinity of the bone char site are as follows: Zn (172?mg?kg^?1) and Ni (0.62?mg?kg^?1) in soil were highest at site P₃, Pb (2.37?mg?kg^?1) and As (0.08?mg?kg^?1) at site P₁, and Cd (18.30?mg?kg^?1) at site P₂. In plants, the concentrations of Zn (41.17?mg?kg^?1) and Cd (3?mg?kg^?1) were highest in Albizia ferruginea, Ni in Dialium guineense (0.09?mg?kg^?1), while Pb was in D. guineense (0.08?mg?kg^?1) and Spathodea companulata (0.06?mg?kg^?1). The levels of Zn, Cd, Pb, Ni, and As in soil ranged from 11.2 to 172, 2.68 to 18.2, 0.026 to 2.37, 0.33 to 0.62, and 0.02 to 0.08?mg?kg^?1, respectively. In plants, the concentration of Zn, Cd, Pb, and Ni ranged from 2.01 to 41.17, 0.12 to 3, 0.02 to 0.08, and 0.03 to 0.09?mg?kg^?1, respectively. There were significant correlations between Zn and Cd, and Pb and As in soil. The high concentration of Cd in soil might affect soil productivity.     

烟气脱硫石膏对滩涂围垦土壤重金属解吸及残留形态的影响

滩涂围垦土壤是重金属等难降解污染物的主要最终归宿场所之一,其重金属的解吸将影响重金属的迁移性、生物有效性和潜在毒性,研究重金属的解吸对土壤污染评价、修复及环境容量预测至关重要.研究了烟气脱硫石膏对广州市南沙滩涂围垦土壤重金属的解吸效果,并分析了烟气脱硫石膏对重金属形态的影响.在离心管中称取20.0 g过0.25mm筛土样,加入20 mL水和不同量的烟气脱硫石膏,在室温下于恒温振荡器振荡,风干研碎后用原子吸收分光光度法测定重金属全量,并用Tessier连续提取法研究了处理前后重金属形态变化.研究结果表明,随着脱硫石膏施用量的增加,经过振荡离心后的滩涂围垦土壤中重金属质量分数先急剧下降,之后变化趋于平缓.与原土相比各重金属最大解吸率分别为:Cd 30.38%,Cu17.73%,Ni 15.00%,Zn 14.19%,Pb 9.46%,Cr 8.89%.比较处理前后重金属的形态变化,发现各重金属的可交换态解吸率均达50%以上,并且重金属碳酸盐结合态质量分数也有减少.说明烟气脱硫石膏能降低土壤对重金属的吸附,经振荡离心后能降低土壤中重金属的毒性和生物可利用性.     

农田土壤重金属污染状况及修复技术研究

重金属污染因具有毒性、易通过食物链在植物,动物和人体内累积,对生态环境和人体健康构成严重威胁。随着工业快速发展、农药及化肥的广泛使用,农田土壤重金属污染越来越严重,研究农田土壤重金属污染现状及修复技术对农产品安全具有重要意义。综合国内外农田土壤重金属污染状况,农田土壤重金属污染主要来源于固体废弃物堆放及处置、工业废物大气沉降、污水农灌和农用物质的不合理施用。该文综述了国内外有关农田重金属污染土壤修复技术（物理修复、化学修复、生物修复、农业生态和联合修复）的研究进展,并针对各种修复方法,阐述了其原理、修复条件、应用实例及其优缺点,重点论述了植物修复的机理和应用,提出了草本与木本联合修复可有效提高农田土壤重金属复合污染的修复效率,为农田土壤土壤重金属复合污染修复提出了新的途径。最后在对已有研究分析的基础上,提出了联合修复技术（如生物联合技术、物理化学联合技术和物理化学-生物联合技术）可以在一定程度上克服使用单一修复手段存在的缺点,可提高复合污染的修复效率、降低修复成本,未来应深入探索联合修复技术间的相互作用机理,以期为农田土壤重金属综合治理与污染修复提供科学依据。     

江苏蔬菜产地土壤重金属污染现状调查与评价

江苏苏南、苏中、苏北蔬菜产地土壤Cd、Hg、As、Pb、Cr含量的检测结果表明,该省蔬菜地土壤5种重金属平均含量除Cd略高于20世纪80年代背景值外,其他4种均未超出,总体质量较好,然而各检测点间差异较大,特别是苏南部分地区污染较重,且部分点Cd、Hg、As远超过国家无公害蔬菜产地环境标准值(GB/T18407.1—2001),表明苏南部分产地已不适宜生产无公害蔬菜。以GB/T18407.1—2001为评价标准,采用Nemerow指数法进行评价,全省土壤重金属平均综合污染指数为0.54,属1级安全。苏北、苏中、苏南分别为0.30、0.29、1.20,即苏南为3级土,属轻污染,苏北、苏中为1级土,属安全。苏中、苏北明显好于苏南。全省有15%蔬菜地土壤已受不同程度重金属污染,主要分布在苏南,且Cd、Hg分担率较高。     

土壤胶体对重金属运移行为的影响

累积在表层土壤中的重金属,在一定条件下可以向地下迁移,进而影响地下水水质.由于现有污染物运移预测模型对重金属等污染物在土壤中运移的预测与实际监测结果偏差巨大,土壤胶体对土壤重金属运移的影响越来越受到人们的重视.土壤胶体组成丰富,在土壤环境中广泛存在.土壤胶体能够与重金属等污染物质相结合,对重金属等污染物质的运移产生重要影响.土壤胶体运移和土壤胶体与重金属的相互作用受到水动力、pH、离子强度、胶体粒径、土壤含水率等多种物理化学条件的影响.本文综述了土壤胶体对土壤重金属运移影响的诸多因素,介绍了胶体作用下重金属等污染物在多孔介质中的运移模型,提出了当前研究中存在的问题,并对今后需要展开的工作提出了建议.     

钢铁工业遗留场地土壤重金属洗脱剂筛选研究

土壤重金属污染限制了工业遗留场地再利用,通过振荡试验考察了HCl、HNO3和EDTA对工业遗留场地土壤中超标重金属Pb、Zn、Cd和As的洗脱效果。结果表明：土壤Pb、Zn、Cd、As的脱除效果均随洗脱剂浓度增加而增加;HCl、HNO3和EDTA等3种洗脱剂浓度分别为0.5、0.5和0.1 mol.L-1时,土壤Pb、Cd质量分数可降低至场地安全再利用的控制标准以内（分别为140 mg.kg-1、1mg.kg-1）;洗脱剂浓度分别增至2、2和0.2 mol.L-1时,土壤Pb、Cd质量分数继续降低,Zn、As质量分数有大幅降低但没有达到其相应的场地安全控制标准（分别为200、20 mg.kg-1）;与EDTA相比,HCl在低浓度时的重金属脱除效果较差,但HCl浓度增加对重金属脱除率的提高效果更为明显;洗脱液pH值（7.88~0.15）与重金属脱除率均呈显著负相关且与As的负相关系数最小,说明洗脱液pH值变化对As去除的影响相对较小;与HCl和HNO3相比,EDTA洗脱液pH值与Pb脱除率之间的负相关系数较大,与Zn、Cd、As脱除率之间的负相关系数较较小,说明EDTA洗脱液pH值变化更易对Pb的去除产生影响。     

The effects of application of agricultural wastes to firing range soil on metal accumulation in Ipomoea aquatica and soil metal bioavailability

The immobilisation of heavy metals in the soil of a 25-year-old active firing range using durian (Durio zibethinus L.) tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) was investigated. The immobilisation effects were evaluated in terms of metal accumulation in water spinach (Ipomoea aquatica) and soil metal bioavailability. A pot experiment was conducted by amending the firing range soil with DTS, CC and EFB at application rates of 0%, 1% and 3% (w/w), respectively. All amendments increased the biomass yield and reduced the uptake of heavy metals in the plant tissue. Zn had the highest values of Bioconcentration Factor (BCF: 0.301–0.865) and Translocation Factor (TF: 1.056–1.883). Pb was the least-accumulated and transported metal in the plant tissues, with the BCF and TF values of 0.019–0.048 and 0.038–0.116, respectively. The bioavailable fraction of heavy metals in the firing range soil decreased following the application of the three agricultural wastes studied. DTS, CC and EFB did not cause toxicity symptoms in the water spinach over the pot experiment. Therefore, DTS, CC and EFB are considered promising immobilising agents for the remediation of metal-contaminated land.     

Heavy metals from soil and domestic sewage sludge and their transfer to Sorghum plants

We studied the mobility and transport of heavy metals such as Cu, Zn, As, Cd, Cr, Ni, and Pb, from soil and soil amended with sewage sludge to sorghum plants. The total and ethylenediaminetetraacetic acid (EDTA) extractable heavy metals in agricultural soil and untreated domestic sewage sludge (DWS) samples were determined. The correlation between the total and extractable metals in soil and sewage sludge was investigated. The total and extractable heavy metals in soil, sewage sludge and sorghum grain were analysed by flame and electro thermal atomic absorption spectrometer (FAAS/ETAAS), after digestion in microwave oven. Statistically good correlations were obtained between the total contents of all heavy metals and their respective extractable fractions in soil and domestic wastewater sludge. Transfer factors of all heavy metals from domestic sewage sludge to sorghum grains were determined.     

西安污灌区土壤重金属含量及对西红柿影响研究

通过对西安污灌土和西红柿Cu,Pb,Cd,Cr,As,Hg元素分布的研究,结果表明这些元素在污灌土中发生了明显累积,但不同元素的累积强度不同。重金属从土壤向西红柿的迁移转化中,迁移累积率在灌土中Cd＞As＞Cu＞Cr＞Hg＞Pb,而正常土中Cd＞As＞Hg＞Cu＞Cr＞Pb。西红柿不同生长阶段对土壤中重金属吸收程度不同,西红柿Cu、Cd、Hg含量与土壤中该元素含量呈明显的正相关关系。     

不同大气污染区林木根区土壤重金属和酶活性研究

黄埔区是广州市污染较严重的地区,其中林木也受到了大气等污染物的危害。林木根区的土壤重金属和酶活性是探讨污染对林木影响机制和反映污染程度的重要指标。作者分别在该区的石化厂、硫酸厂附近林地和非污染的华南农业大学校园(对照)共3个区选择了台湾相思、马尾松、尾叶桉和荔枝4个树种、11个采样点,共采集了33个供试土壤样品,分析了林木根区土壤重金属(Cu、Zn、Pb、Cd)全量、有效量和土壤酶(脲酶、过氧化氢酶、酸性磷酸酶和蛋白酶)活性。结果表明,(1)石化厂重金属含量总体上与对照区差异不大,而硫酸厂区重金属含量则显著地高于对照区,污染严重。(2)不同调查区根区土壤酶活性存在显著差异,各调查区平均土壤酶活性大小顺序基本上表现为:对照区>石化厂区>硫酸厂区,尤其是硫酸厂区显著地低于对照区;而同一调查区不同树种之间的酶活性也存在差异,台湾相思根区土壤脲酶的活性均比其它树种高;从酶活性看,在硫酸厂严重污染胁迫下,台湾相思比尾叶桉更耐污染。(3)对土壤重金属含量和酶活性进行典型相关分析得出:根区土壤有效Zn含量对过氧化氢酶和酸性磷酸酶活性有明显的刺激作用,但抑制了蛋白酶活性;有效Cd则抑制了过氧化氢酶和酸性磷酸酶活性,但刺激了蛋白酶活性。     

土壤重金属X射线荧光光谱非标样测试方法研究

采用粉末压片制样,用X射线荧光光谱非标样测试方法测定土壤中Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、Ga、As、Cd、Sn、Sb、Pb、Hg等15种重金属元素。研究了样品制备方法和元素测量条件等影响测试准确度的因素。结果表明此方法不需对固体样品进行消化处理,无需制备标准样片,快速、简便、效率高,是一种非破坏性的分析方法,方法的检出限、准确度和精密度基本能够满足土壤中有毒有害重金属的快速筛查要求。     

杨树、落叶松对土壤重金属的吸收及修复研究

在沈阳生态实验站开展了木本植物对土壤重金属的吸收积累及修复效应的研究,实验结果表明,重金属污染物已影响了杨树(Populus canadensis)的正常生长,Cd、Cu、Zn复合污染处理杨树总生物量比对照下降了26%。Cd、Cu、Zn处理杨树和落叶松重金属吸收量多于对照,杨树叶Cd、根Cu重金属吸收量分别比对照增加了2.09倍、2.2倍。落叶松(Larix koreana)根Cd、Cu、Zn的吸收量比对照分别增加了2.17、1.95和1.42倍。树木体内重金属元素迁移能力的大小分别为Cd>Zn>Cu,重金属吸收系数大小依次为杨树>落叶松,重金属在杨树体内的迁移能力及地上部吸收能力要大于落叶松。土壤一旦遭受重金属污染(Cd、Cu、Zn),通过木本植物杨树、落叶松修复净化的时间相当漫长。     

中国土壤重金属污染修复技术的专利文献计量分析

综述了国内外主要土壤修复技术,进行了技术经济比较分析。利用国家知识产权局专利检索系统,采用主题词检索,从重金属污染物种类、技术类型两个方面分析了中国土壤重金属污染修复技术的专利申请与授权状态。结果表明：土壤重金属污染修复技术以植物修复与微生物技术为主,其次为固定修复技术;土壤镉、铅、铜、砷的修复技术专利申请量明显高于其余重金属的;农田土壤重金属污染修复技术专利申请量明显高于场地重金属修复技术的;农田土壤重金属污染修复除降低土壤中重金属含量外,还可以从植物营养调控与土壤调理剂的角度降低农产品中重金属含量。最后,进行了土壤污染修复产业政策分析。     

三种木本植物对酸雨的敏感性和抗性

酸雨污染对生态系统和人类生存环境造成严重影响,研究植物抗性及其对环境的适应能力是大气污染胁迫退化生态系统恢复中植物种类选择的基础和前提。作者选择陶瓷工业污染区南海西樵山和相对清洁区肇庆鼎湖山自然生长的木本植物鸭脚木(Schefflera octophylla)、荷木(Schima superba)当年生叶和一年生叶以及马尾松(Pinus massoniana)一年生针叶进行生理指标的测定和分析。结果表明:在酸雨污染环境下,3 种植物叶片的细胞膜透性受到损害,光合色素降解,PSII 最大光化学效率下降;对酸雨污染的敏感性次序为:马尾松>鸭脚木≥荷木,马尾松为酸雨敏感种。初步讨论了树木对酸雨污染的部分抗性生理机制,为酸雨污染地区退化生态系统恢复之植被选择提供理论依据。     

Heavy metals in soils and crops in Southeast Asia

In a reconnaissance soil geochemical and plant survey undertaken to study the heavy metal uptake by major food crops in Malaysia, 241 soils were analysed for cation exchange capacity (CEC), organic carbon (C), pH, electrical conductivity (EC) and available phosphorus (P) using appropriate procedures. These soils were also analysed for arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn) using aqua regia digestion, together with 180 plant samples using nitric acid digestion. Regression analysis between the edible plant part and aqua regia soluble soil As, Cd, Cr, Cu, Hg, Ni, Pb and Zn concentrations sampled throughout Peninsular Malaysia, indicated a positive relationship for Pb in all the plants sampled in the survey (R ² = 0.195, p < 0.001), for Ni in corn (R ² = 0.649, p < 0.005), for Cu in chilli (R ² = 0.344, p < 0.010) and for Zn in chilli (R ² = 0.501, p < 0.001). Principal component analysis of the soil data suggested that concentrations of Co, Ni, Pb and Zn were strongly correlated with concentrations of Al and Fe, which is suggestive of evidence of background variations due to changes in soil mineralogy. Thus the evidence for widespread contamination of soils by these elements through agricultural activities is not strong. Chromium was correlated with soil pH and EC, Na, S, and Ca while Hg was not correlated with any of these components, suggesting diffuse pollution by aerial deposition. However As, Cd, Cu were strongly associated with organic matter and available and aqua regia soluble soil P, which we attribute to inputs in agricultural fertilisers and soil organic amendments (e.g. manures, composts).     

马鞍山市盆山农场土壤和植物中的重金属含量

论述了马鞍山市盆山农场的土壤和植物中几种重金属元素的含量、分布和特点,以及它们之间的相关性,并探讨其中几种重金属元素在土壤和茶叶（嫩叶）中含量的相关关系。