硫酸盐对锌和镉在可变电荷土壤上吸附的影响

SO4^2- and Zn^2 or Cd^2 were added to three variable charge soils in different sequences.In one sequence sulfate was added first ,and in the other,Zn^2 or Cd^2 first.The addition of sulfate to the system invariably caused an increase in adsorption of the heavy metal added,with the effect more remarkable whn the soil reacted with the sulfate prior to the metal.the shift in pH50 for both Zn and Cd adsorption was aslo comparatively larger in the first sequence of reactions .It was suggested that the increase in negative charge density and the resultant negative potential of the soil were the primary cause of the pronounced effect of sulfate on adsorption of Zn or Cd,and the formaiton of the ternary surface complex-S-SO4-M might also play a role in the effect.     

土壤重金属元素测定方法比较

采用3种方法:M3-双硫腙、DTPA-AAS、EDTA-AAS测定了土壤中有效态锌的含量,并且进行比较,研究了M3-双硫腙方法的精密度、重现性,并分别进行了M3浸提剂及双硫腙萃取剂重现性的重现性实验。结果表明:M3-双硫腙法与标准参比法呈显著相关,M3浸提剂及双硫腙萃取剂的重现性好。M3-双硫腙法精密度高、工效快,可用于土壤重金属的联合速测。     

不同水分状况下施锌对玉米生长和锌吸收的影响

选择潮土(砂壤)和土(粘壤)两种质地不同的土壤,进行盆栽试验,研究不同土壤水分条件下施锌对玉米生长和锌吸收的影响。结果表明,施锌显著增加了玉米植株根、茎、叶以及整株干物质重;缺锌条件下玉米植株根冠比、根叶比和根茎比趋向增大。施锌显著提高了玉米植株各器官中锌的浓度和吸收量,并明显促进锌向地上部运移。干旱胁迫抑制了玉米植株生长,根冠比、根茎比、根叶比增大;随着土壤水分供应增加,植株生长加快,各器官生物量以茎和叶增加大于根。水分胁迫下,在潮土上玉米叶片中锌浓度上升;在土上叶片中锌浓度下降。但增施锌后,根和茎锌浓度增加幅度较大,叶片增加幅度较小;施锌和水分胁迫对根和茎锌浓度的交互作用极显著。水分胁迫下,玉米植株对锌的吸收总量减少。水分胁迫和锌肥施用对玉米叶片、茎锌吸收量的交互作用十分显著,但对根锌吸收量的交互影响不显著。     

菜园土壤高磷条件对油菜磷、锌含量的影响

采用盆钵试验研究了菜园土高磷条件下对油菜磷、锌颉颃作用的影响。结果表明,随着土壤有效磷含量的升高,油菜植株体内的含磷量也在不断升高,但上升的趋势逐渐减缓,其中,茎叶的含磷量始终大于根中的含磷量。而植株的含锌量则有很大的不同,随着土壤有效磷含量的增加,植株根中的含锌量也在不断的增加,直到趋于平稳,而茎叶中锌的含量随土壤有效磷含量的升高而增加到一定程度后表现出下降的变化趋势。这说明油菜的磷、锌颉颃作用是发生在植株体内的一种生理机制。     

两种矿山生态型香薷对铜的吸收、分布和积累特性研究

Two ecotypes of Elsholtzia, Elsholtzia splendens and E. argyi, are dominant plants growing on Cu and Pb-Zn smelters, respectively. Samples of the two ecotypes and the corresponding soils from fields of a copper mining area and a Pb-Zn mining area of Zhejiang Province, China, were analyzed to investigate Cu or Zn tolerance of these two ecotypes. Effects of nine Cu levels (0, 5, 10, 20, 40, 80, 160, 240 and 320 mg Cu L^-1 as CuSO₄·5H₂O) on growth and uptake, translocation and accumulation of Cu in these two ecotypes were examined in a solution culture experiment. The experimental results showed that dry weights (DW) of shoots and roots were depressed, and growth of E. splendens was less depressed than that of E. argyi when treated with ≥ 5 mg Cu L^-1. Concentrations of Cu in shoots of E. splendens and E. argyi exceeded 1 000 mg kg^-1 DW at ≥ 40 mg Cu L^-1. The maximum Cu accumulated in the shoots of Cu-treated E. splendens and E. argyi reached 101 and 142 μg plant^-1. Furthermore, analysis of plant samples from the fields showed that these two ecotypes can tolerant excess heavy metals and produced high dry matter, and E. splendens can accumulate 11.7 mg Cu plant^-1 grown on the Cu smelter. Therefore, E. splendens and E. argyi could be good plants for phytoremediation.     

蔬菜对土壤镉铜锌富集能力的研究

调查了福建部分污染严重地区不同蔬菜对镉、锌、铜的富集能力。结果表明蔬菜对镉的平均富集系数为0.017，锌的平均富集系数为0.116，铜的平均富集系数为0.014。蔬菜对镉的富集系数的品种间差异最大，达315倍，远高于锌和铜的富集系数的品种间差异。茭白、豇豆和莲藕对镉的富集能力较低，可作为镉污染土壤优先选种的蔬菜品种，而青包菜、白包菜、芥菜、空心菜、芋头等对镉的富集系数较高，不宜在镉污染土壤上栽培。     

外源有机酸对两种生态型东南景天吸收和积累锌的影响

通过溶液培养试验,比较研究了外源有机酸对两种生态型东南景天生长和锌吸收与积累的影响。结果表明,外加柠檬酸或草酸能明显增强非超积累生态型东南景天的耐锌毒能力,叶片、茎和根系的生物量均有增加;而对锌超积累生态型东南景天的生长没有显著性影响。外加柠檬酸、草酸或柠檬酸+草酸,锌超积累生态型根系Zn含量显著增加,但叶片和茎组织中Zn含量无明显变化;而非超积累生态型叶片、茎和根系Zn含量均显著增加,尤其是根系Zn含量,与单独Zn处理相比外源有机酸处理增加4～5倍。同样,外加柠檬酸、草酸或柠檬酸+草酸明显提高Zn在非超积累生态型根系和地上部的积累量,且对地上部Zn积累量的促进程度大于根部;柠檬酸的促进作用又比草酸及2种酸混合处理高1倍。然而,有机酸处理对Zn超积累生态型根系Zn积累量有所增加,但对叶片和茎中Zn积累量无影响。叶片和茎中水溶态Zn含量也受外源有机酸的影响,2种生态型叶片、茎中水溶态Zn含量均受有机酸处理而提高。Zn超积累生态型叶片和茎中水溶态Zn含量占总Zn含量比例也受有机酸处理而增大,但非超积累生态型则显著降低。上述结果表明,柠檬酸和草酸可能作为其Zn吸收的配基,促进根系对Zn吸收与积累,叶片和茎中的Zn可能与可溶性有机化合物或无机盐结合。     

干旱条件下氮、磷水平对土壤锌、铜、锰、铁有效性的影响

研究了干旱条件下不同N、P水平对微量元素Zn、Cu、Mn、Fe有效性的影响。结果表明 ,在中壤质土壤含水量 11%～ 14%的情况下 ,不同N、P配比明显增加了土壤剖面中速效P的含量 ,但随着土壤深度的增加 ,土壤速效P呈不断下降的趋势。大田和土壤培养试验表明 ,施P有增加土壤Zn、Cu、Mn有效性的趋势 ,但有效Fe则有下降的趋势。土壤速效P、Zn、Cu、Mn、Fe之间的相关分析表明 ,土壤速效P与有效Zn之间存在显著的正相关关系 (r =0.65) ,而与有效Fe之间则存在显著的负相关关系 (r =- 0.63)。     

重金属迁移与土壤性质的关系

Cu, Zn, Pb and Hg runoff from yellow limestone soil and purple soils and the relationships between the mobility of the heavy metals and the soil characteristics were studied in laboratory using a rainfall simulator. The results showed that the concentrations of soluble Zn in surface runoff were significantly negatively correlated with the contents of < 0.002 mm particles and CEC of the soils, indicating that Zn was mostly adsorbed by clays in the soils. The contents of Cu and Hg in surface runoff were positively related to their contents in the soils. The amounts of Cu, Zn, Pb and Hg removed by surface runoff were influenced by the amounts of soil and water losses and their contents in the soils, and were closely related to the contents of soil particles 1~0.02 mm in size.     

不同pH和供Zn条件下HCO_3~-对冬小麦幼苗生长和锌营养的影响

采用营养液培养法,研究了不同pH和供Zn条件下高浓度HCO3-(10 mmol L-1)对小麦幼苗生长,尤其是对锌营养的影响,结果表明:当营养液起始pH为6时,HCO3-在缺Zn时对小麦根系生长的抑制作用较为明显,而正常供Zn时的影响较小。当营养液起始pH为8时,不论缺Zn还是供Zn,添加HCO3-对根系和地上部均未表现出明显的抑制作用。HCO3-在酸性营养液中能极大促进小麦植株根系和地上部尤其是根系对Zn的吸收,而在碱性条件下则抑制小麦幼苗根系和地上部对Zn的吸收。此外,HCO3-能显著抑制Zn从根系向地上部分的转运,从而造成在根系中的大量积累。HCO3-加入营养液后会生成少量的CO32-,并使营养液pH维持在较高水平上。