Occurrence and distribution of organochlorine residues and metals in sediment,water and fish in the catchment area of lake baiyangdian,china

The occurrence and distribution of metals (Al, Cd, Cr, Cu, Pb, Zn), organochlorine residues (HCH, DDT and metabolites, PCBs) and EOC1 (extractable organic bound chlorine) were monitored in 1993 and 1996 in sediment, water and fish in the catchment area of Lake Baiyangdian, China. The levels of the metals, especially Cd and Zn, were significantly higher in the sediment than those in non‐polluted areas. PCBs and chlorinated pesticides constituted only a minor part (< 8.4%) of the extractable organic bound chlorine, indicating the presence of additional, unknown, organochlorine residues. Among the pesticides, DDT was widely distributed and high levels occurred in fish despite a ban of its production and use in 1983. The low quotient of pp‐DDT/pp‐DDE in sediment and fish indicated that the input of DDT to the catchment area was not of recent origin.     

Effect of air-borne heavy metals on the biochemical signature of tree species in an industrial region,with an emphasis on anticipated performance index

The present study demonstrates elevated concentrations of air-borne heavy metals (Fe, 4.791; Cr, 3.142; Pb, 1.718; Cd, 0.069 μg·m^?3) in an industrial region and their subsequent accumulation in tree species grown in that area. Lagerstomia speciosa showed the highest leaf metal concentrations, whereas the lowest metal concentration was observed in Acacia moniliformis. Air accumulation factors (AAF) for heavy metals were in the sequence Cd>Cr>Pb>Fe. Plants exposed to air-borne heavy metals showed a significant (p<0.01, p<0.05) decrease in total chlorophyll and soluble sugars content, with higher synthesis of cellular antioxidants compared with ascorbic acids, proline and thiols (NP-SH). Plants with higher air-borne metal accumulation factors (AAF) generally have a high air pollution tolerance index (APTI) value. Assessment of the anticipated performance index (API) gave Alstonia scholaris as the ‘best variety’ and A. moniliformis and Shorea robusta as ‘very good’ for plantation and greenbelt development in an industrial region.     

In vitro and in vivo inhibition of Ca2+-Mg2+-ATPase activity by cadmium in post larvae of Penaeus monodon

Ca²⁺-Mg²⁺-ATPase is a membrane-bound enzyme and is responsible for regulating cytosolic free calcium. In vitro and in vivo effects of cadmium were studied on Ca²⁺-Mg²⁺-ATPase activity in plasma membrane/mitochondrial fraction of Penaeus monodon post larvae. In vitro studies revealed a concentration-dependent decrease in enzyme activity with an IC₅₀ value of 11.02?µM. In vivo experiments were conducted by exposing the post larvae to 1/10th (0.12?ppm) and 1/5th (0.24?ppm) of LC₅₀ values of cadmium for 30 days. Both ATPase activity and metal accumulation were estimated in post larvae exposed to 0.12 and 0.24?ppm of cadmium at different intervals of 24?h, 48?h, 96?h, 10 days and 30 days. ATPase activity showed a gradual decrease in post larvae on exposure to both the sub-lethal concentrations with respect to their controls and the decrease was significant (p?相似文献   

Efficiency of Zn phytoextraction,biomass yield and formation of low-molecular-weight organic acids in S × rubens – a hydroponic experiment

The aim of the study was to estimate Zn phytoextraction and changes in biomass of S?×?rubens growing in modified Knop's solution with different levels of Zn addition (0.5, 1.0, 2.5 and 5.0?mM). Obtained results were correlated with secretion of selected low-molecular-weight organic acids (LMWOAs) in the rhizosphere, roots and leaves. An increase in Zn concentration in Knop's solution resulted in Zn accumulation in roots, shoots and leaves. The highest accumulation was observed for plants growing in 5?mM Zn, at concentration levels 4741.36?±?98.66, 1227.31?±?16.57 and 2241.65?±?34.90?mg?kg^?1 DW in roots, shoots and leaves, respectively. The bioaccumulation factor and the translocation factor for plants growing in 0.5, 1.0 and 2.5?mM Zn clearly indicate that this Salix taxon is an effective Zn accumulator. The general reduction of Salix biomass with an increase in Zn concentration in the solution was observed. In the rhizosphere, the total LMWOA concentration was almost 0.93?µmol?kg^?1 DM for control (Zn free) plants, while for 5.0?mM of Zn it was 4.9?µmol?kg^?1 DM. Increasing concentrations of acids were observed in roots (1.34 for the control and 5.57?µmol?kg^?1 DM for plants treated with 2.5?mM of Zn).     

不同生育期类型水稻对镉积累的研究

以江苏省有代表性的早熟中粳、中熟中粳、迟熟中粳、早熟晚粳和中熟晚粳5种生育期类型的56个粳稻品种为材料,在Cd污染农田中研究不同生育期类型粳稻品种Cd积累特性.结果表明,56个供试水稻品种籽粒Cd含量变化范围为0.014～0.054 mg·kg-1,水稻籽粒Cd含量在品种间差异显著(P＜0.05),其中籽粒Cd含量最高的品种是ELTO,扬粳687、泗阳1382、广陵香粳和武香粳9号水稻籽粒Cd含量较低.不同生育期类型水稻籽粒Cd含量以早熟中粳较高,中熟中粳较低,分别为0.024和0.020 mg·kg-1.不同生育期类型水稻籽粒Cd富集系数差异不显著,而不同生育期类型间转运系数存在差异.     

High cadmium pollution risk on vegetable amaranth and a selection for pollution-safe cultivars to lower the risk

A pot experiment was carried out by growing 29 different genotypes (Amaranthus spp.) of vegetable amaranth under low- (0.12 mg·kg^-1) and middle- (0.40 mg·kg^-1) cadmium (Cd) exposure. The result showed that amaranth was vulnerable to cadmium (Cd) contamination in soil. Variations of Cd concentrations in both roots and edible parts among genotypes were significant (P<0.001) in both treatments. Cd concentrations in edible parts of the tested genotypes grown under low- and middle-Cd levels were significantly correlated (p<0.01), implying that Cd-accumulating property of amaranth is genotype-dependent. Differences in Cd chemical forms between cv. Nanxingdayemashixian (cv. Nan), a selected typical pollution-safe cultivar (Cd-PSC), and cv. Pennongjianyexian (cv. Pen), a selected typical non-Cd-PSC, under different Cd exposure conditions were compared. It was found that the alternation of Cd in F_NaCl (Cd form extracted by 1 mol·L^-1 NaCl) may be a key factor in regulating Cd accumulation of different amaranth genotypes and that the protein-binding Cd is considered to be associated with Cd translocation. The results indicated that amaranth is capable of enduring high level of Cd pollution when grown as vegetable crop, and accordingly, consuming vegetable amaranth would bring high health risk. Therefore, adopting Cd-PSC strategy would help reducing the risk of Cd pollution in amaranth. In this study, cv. Nan was identified as a Cd-PSC and recommended to be applied production practice.     

复合改良剂对稻田Cd、As活性与累积的协同调控

为同时降低水稻糙米中Cd、As含量,以达到国家标准食品污染物限量标准,选取湘南某矿区Cd-As复合污染稻田土壤,以盆栽实验研究复合改良剂QFJ(羟基磷灰石+沸石+酸改性炭化秸秆)对土壤中Cd、As生物有效性及对水稻各部位累积Cd、As的影响,探讨QFJ对土壤Cd、As生物活性与稻米Cd、As累积的协同调控.结果表明:施用QFJ降低了水稻糙米中的Cd、As含量,施加量2g/kg时,糙米中Cd、As含量分别为0.19mg/kg和0.14mg/kg,均低于对照组的0.49mg/kg和0.27mg/kg,且同时低于0.2mg/kg,达到了国家标准食品污染物限量标准.施用QFJ提高了土壤pH值0.02~0.68单位,增加了土壤CEC、OM含量,同时土壤中Cd 的酸可提取态、交换态及TCLP提取态含量分别降低了7.3%~32.5%、12.6%~39.8%和40.7%~60.1%,对As的交换态和TCLP提取态含量的影响趋势是先降低后增大.糙米中Cd含量与土壤中Cd的3种提取态含量存在极显著正相关关系,As含量与其土壤中TCLP提取态含量存在极显著正相关关系.当QFJ施加量在2g/kg水平时,土壤中Cd、As的生物活性可协同控制在较低水平,从而同时降低了糙米中Cd、As含量.施用QFJ使得Cd在水稻根表铁膜中的含量呈增大趋势,在水稻其他部位含量呈减小趋势;As在谷壳中含量呈减少趋势,在其他各部位呈先减小后增大的趋势.水稻吸收的Cd和As大部分累积在根部和茎叶部,各部位Cd累积率大小是白根 > 茎叶 > 糙米 > 谷壳,As是茎叶 > 白根 > 糙米 > 谷壳.根据Cd-As污染程度不同,可考虑施用2~4g/kg QFJ以达到水稻的安全生产.     

矿区植物假繁缕对铅、锌积累特性的研究

采用温室砂培盆栽试验研究了假繁缕(Pseudostellaria maximowicziana)对铅、锌积累的影响.结果表明,在所设定的重金属浓度范围内,假繁缕根干质量、地上部分干质量、根冠比及植株铅、锌含量均随所施铅、锌浓度的增加呈增大的趋势.根和地上部分铅含量最大值分别为1386.08,1197.93mg/kg;锌含量最大值分别为9250.50,8243.15mg/kg.植株铅和锌转运系数均1.偏相关分析表明,假繁缕根和地上部分铅、锌的吸收间可能产生协同或加和作用.     

樟树对14CO2的吸收和积累

为了探明14CO2在环境中的行为,采用同位素示踪技术研究了樟树对14CO2的吸收和积累动态,并探讨了樟树作为监测大气14CO2污染指示植物的可能性和优越性.结果表明,通过叶片光合作用从空气中吸收的14CO2会在樟树叶片中积累,检测到的14C比活度数值较大,表明空气中的14CO2易于通过叶片的光合作用而进入樟树叶片组织中;在污染前期14CO2主要被新叶组织中吸收,后期主要积累在老叶中,反映出新叶对空气14CO2污染比较敏感,而老叶积累效应明显.樟树叶片的这一特性可用于监测大气14CO2污染.     

三明铅锌矿区植物对重金属的富集特征

采用野外调查与室内分析相结合的方法,对福建三明典型矿区尤溪铅锌矿、大田铅锌矿以及尤溪铅锌矿冶炼厂等进行了调查,研究这些矿区重金属含量较高的区域如采矿区、尾砂库、洗矿排水沟以及铅锌矿冶炼厂厂区和排水沟冲积扇区域土壤中的Pb、Zn和Cd的含量,在此基础上,对在这些区域自然定居的16种优势植物体内的三种重金属元素的耐性、富集特性进行了分析。结果表明：该矿区的主要优势物种为禾本科和菊科植物,其中笔管草（Equisetum ramosissimum）、一年蓬（Erigeron annuus）和五节芒（Miscanthus floridulus）的地上部重金属富集量较大,对矿区周边污染土壤修复有潜在应用价值;乌蕨（Stenolomachusana）、千金子（Bochloe dactyloides）、二歧飘拂草（Fimbristylis dichotoma）、柔枝莠竹（Microctegium Vimineum）、短叶水蜈蚣（Kyllingabrevifolta）、狗娃花（Heteropappushispidus）适用于污染程度较高且植物萃取技术难以实施的重金属污染矿业废弃地。矿区植物地上部zn含量平均值最高,为1225．74mg·kg-1,植物地上部Pb含量范围在52．78-2137．11mg·kg-1,平均为521．39mg·kg-1;一年蓬地上部cd含量达到了119．51mg·kg-1,超过了超富集植物的临界值100mg·kg-1,转运系数为1．3,是潜在的Cd超富集植物。