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1.
生物壳体的Sr/Ca、Mg/Ca比值能反映其沉积水体的Sr/Ca、Mg/Ca比值 ,在一定条件下反映水体的盐度、温度 ,并分别与宿生水体的盐度、温度呈正比关系。生物壳体的87Sr/ 86Sr比值是恢复盆地古水文条件的一种重要手段。本文以著名的泥河湾盆地小渡口剖面的第 2 8层为实例 ,力图通过对有孔虫、介形虫、腹足类生物壳体Sr/Ca、Mg/Ca比值与87Sr/ 86Sr比值的对比研究 ,并结合前人所作的中更新世古地理特征研究 ,来恢复生物壳体沉积时泥河湾古湖水的温度、盐度 ,进而进行古气候、古环境的恢复。研究结果表明 :在 0 .97~ 0 .94Ma间 ,古泥河湾湖为一陆相湖泊 ,湖水的温度、盐度变化趋势相吻合 ,均呈低—高—低的演化特征 ,可能对应着盆地水体的扩展—退缩—扩展变化。其中 ,在 0 .96~ 0 .95Ma间 ,古泥河湾湖具有较高的温度、盐度特征。  相似文献   

2.
为了划分岩浆岩的岩石化学组,提出了利用多维空间的问题。其空间坐标是:石英标准度[S=(Si-(2Ca″+3Na+3K—Na′))/M],碱度[NKS=(Na+K)/Si]、碱度类型(K/Na)、浅色度[AF=(Al+Al′)/M]、铁度(Fe/Mg)、钙-铝度[CAF=(Ca′+Al′)/(Fe+Mg)。式中Ca′、Al′、Na′对长石矿子来说是过剩的钙、铝和碱,Ca″为长石和似长石中的钙,M=Fe+Mn+Mg+Ca′+Al′+Ti。岩浆岩样品所占据的多维空间区的特征是岩石化学参数具有平均的和标准的偏差。确定所研究的样品属于哪一种标准属性,要通过关于多维平均偏差平衡的假设检验的方法或者利用A.提出的均一性标准来完成。  相似文献   

3.
李勇  徐炜 《地球与环境》2019,47(2):218-226
为了研究水泥工业区内污染土壤中金属元素含量变化特征,对安徽省凤阳县水泥工业区内一条土壤剖面中金属元素(Al、Fe、Ca、Mg、K、Na、Cr、Ba、Mn、Zn)含量进行了测量。结果显示,土壤剖面分2层,第一层(0~20 cm)为污染层,该层Al、Fe、Mg、Na、Ba、Mn、Cr元素主要来源于自然土壤,没有富集,Ca、K、Zn元素主要来源于水泥粉尘的输入,存在富集,其中0~2 cm土壤的富集因子最大,Ca和Zn含量最高,指示0~2 cm土壤被污染的程度最深。第二层(20 cm以下)为土壤母质层,该层各金属元素含量相对比较稳定。由于0~2 cm土壤中Ca、Zn元素还没有大量向下淋溶,导致第一层土壤中Ca、Zn含量随采样深度的增加而减少。土壤剖面中Ca和Zn的含量能指示水泥粉尘对工业区土壤环境的污染,土壤母质层的Ca、Zn含量可以作为参考的警戒值。  相似文献   

4.
对中国铝业贵州分公司电解铝厂进行样品采集,根据厂区内部环境特征,分为8个样地,共采集纤枝短月藓(Brachymenium exile)样品24份。利用Optima 5300 V电感耦合等离子发射光谱仪,对该厂区内纤枝短月藓植株及其基质8种金属元素(Al、Ca、Fe、K、Mg、Na、Pb、Ti)含量进行测定分析。金属含量测定结果表明,该厂区Al元素含量明显高于其他金属元素含量(基质中其平均含量达到154011.28 mg/kg,植物体内平均含量为28 998.63 mg/kg)。纤枝短月藓可以很好地反映Al、Mg、Na、Ti这4种元素变化,在一般环境下可以较好的指示Ca元素含量,对于Fe、K、Pb这3个元素含量变化不能很好的反映;因此纤枝短月藓对铝厂部分金属元素具有监测意义。  相似文献   

5.
于采暖季收集石家庄市4种类型铺装道路的降尘,分析其中的Na、K、Cr、Cu、Al、Zn、As、Cd、Pb、Mg、Ca、Fe、Si等13种元素的质量浓度,结果表明样品主要组成元素为Al、Ca、Mg、Fe、Si、Na、K,各元素含量差异较大且分布不均匀。各元素在不同道路类型和不同高度的分布存在差异:大小顺序为主干道次干道快速路支路,且1.5米处2.5米处。利用富集因子法和聚类分析探究降尘中元素的来源发现:采暖季道路降尘的主要来源由地壳、道路交通和煤炭和生物质燃烧构成。  相似文献   

6.
对钱塘江杭州段沿岸土壤11个采样点中的铁锰及相关指标进行了系统研究.结果表明,土壤中Fe,Mn的平均质量分数分别为1.97%(425 mg/kg),变异系数分别为13%,37%.土壤pH值范围在4.64~7.56,处于酸性-弱碱性.变化幅度较大.矿质元素Al的平均质量分数5.68%,变异系数11%.K,Na,Mg的平均质量分数分别为1.76%,1.21%,0.76%:3个指标的变异系数均不超过25%.Ca的质量分数范围为0.55%~1.85%,变异系数较大,为33%.土样矿质元素聚类分析结果表明,钱塘江沿岸土样分为3类:第1类Fe,Mn,Al最低,Ca,Na,Mg较高,主要位于萧山;第2类Fe,Mn,Al次之,Ca,Mg最低,主要位于桐庐以及富阳东郊;第3类Fe,Mn,Al相对较高,主要位于富阳.相关性分析结果表明.Fe与Mn,Al呈极显著相关,Mn与Al呈显著相关,Ca与Na,Mg呈极显著相关,矿质元素与粉砂粒(2~20μ m)的相关性较好,而与粘粒不具相关性.  相似文献   

7.
为了掌握雾霾期大气PM 2.5和PM 10中无机元素污染特征,于2013年10月20~31日期间采集了东北某市发生严重雾霾时大气PM 2.5和PM 10样品,分析了颗粒物样品中21种无机元素(K、Ca、Na、Mg、Mn、Pb、Cd等)的浓度。结果表明:大气PM 2.5和PM 10浓度普遍超标,超标率分别达88.89%、66.67%;大气PM 2.5和PM 10中元素质量浓度主要是由Na、S、Ca、K、Fe、Al、Si、As、Mg 9种元素贡献;元素的富集状况分析表明,Na、Zn、Ca、Cr、Ni、Cu、Mn、Cd、Pb和As在非雾霾期和雾霾期期富集程度较高,污染较严重,受人为污染源影响较大;以不同元素做参比,所得各元素富集系数不同。  相似文献   

8.
川东北地区元素大气沉降通量及其季节变化   总被引:1,自引:1,他引:0  
从2011年8月~2012年7月在川东北地区共收集12个月的大气沉降样品.采用电感耦合等离子体质谱仪(ICP-MS)分析了样品在弱酸性环境下(pH值在2左右)溶解态组分中Na、Mg、Ca、K、Si、Sr、Ba、Zn等元素的含量,计算了这些元素的沉降通量.结果表明:①各元素的沉降通量存在显著的季节变化.Na的沉降通量随着降水增加而显著增加,显示它主要以大气湿沉降为主;Ca、Si、Ba、Sr、Mg的沉降通量在冬季或春季显著上升,显示这些元素的沉降可能主要与大气粉尘活动有关.②不同的元素之间年沉降通量存在显著差异,Na的沉降通量最大,达到30 497μg·(102cm2·a)-1,比最小的Ba沉降通量[27.4μg·(102cm2·a)-1]高出3个数量级.  相似文献   

9.
在开封市周边地区采集96个地表灰尘样品,按照土壤背景值研究方法,探讨了灰尘K、Na、Ca、Mg、Fe、Mn、Al和Ti等主要金属元素的背景值,并与研究区表土元素背景值及开封市区灰尘元素平均含量进行了比较。结果表明:地表灰尘Al、Ti、K、Na、Ca、Mg、Fe和Mn的背景值分别是70.67、4.85、19.56、16.42、23.37、9.21、20.83和0.74 g/kg;与研究区表土元素背景值相比,灰尘K、Mn背景值分别低3.69%和6.33%,而Mg、Na、Fe、Al、Ca和Ti则分别高14.98%、10.42%、10.10%、9.36%、8.40%和4.30%;开封市区灰尘Mn、Ti、Fe、Na、Al和Mg含量分别比其背景值低69.11%、16.67%、14.92%、9.09%、6.63%和0.84%,而Ca和K分别比其背景值高8.94%和4.92%;灰尘粒径大小、矿物组成和人类活动是影响主要金属元素背景值的重要因素。  相似文献   

10.
本文通过对伊犁河谷西部塔克尔莫乎尔沙漠内的可克达拉(TKP)剖面典型层位样品 的不同粒级组分地球化学元素分析,探究西风环流控制的沙漠沉积区元素特征和化学风化指标 在不同粒级组分中的分布特征。研究结果表明TKP 剖面Na 和Sr 元素趋向于在粗粒级中富集; Fe、Mg、Al、Rb 元素趋向于细粒级中富集,K 元素含量随粒径增大先升高再降低,16 ~ 32 μm 粒 级处出现谷值;Ti 元素含量与粒度关系不明确。CIA、Rb/Sr 随粒级增大逐渐降低,Na2O/Al2O3、 Na2O/K2O、K2O/Al2O3 随粒级增大逐渐升高。TKP 剖面地球化学元素和比值在<2 μm、2~16 μm、 16 ~32 μm 细粒级组分不同粒级间变化较为剧烈,32~ 63 μm、63~125 μm、>125 μm 粗粒级组分 变化则不明显,而且粗粒级组分在剖面中的变化也比较稳定。剖面整体风化程度较弱,因此这 种现象可能是物源不统一造成的,为塔克尔莫乎尔沙漠具有物源多样性特点的观点提供了地球 化学元素方面的证据。  相似文献   

11.
Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis (DGGE) and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity (both in gene richness and diversity index values) and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor (50 mg/kg) recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos (150 mg/kg) caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos (250 mg/kg) produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes (bands) responded differently to the impact of agrochemicals: four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.  相似文献   

12.
Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.  相似文献   

13.
Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury (HgT), combinative mercury (Hgc) and gaseous mercury (HgG), and content of total organic carbon (TOC), but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of (HgG,/HgT)1992〉(HgG/HgT)1996〉〉(HgG/HgT)2000. A simple outline of Hg release in landfill could be drawn: with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants (e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum) are capable of enriching more Hg than herbaceous plants.  相似文献   

14.
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.  相似文献   

15.
The influence of the nonionic surfactant Tween 80 on pentachlorophenol (PCP) oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration (CMC). Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.  相似文献   

16.
Decomposition of alachlor by ozonation and its mechanism   总被引:1,自引:0,他引:1  
Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.  相似文献   

17.
以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.  相似文献   

18.
In this study an effort has been made to use plant polyphenol oxidases; potato (Solanum tuberosum) and brinjal (Solanum melongena), for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.  相似文献   

19.
Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.  相似文献   

20.
RemovalofheavymetalsfromsewagesludgebylowcostingchemicalmethodandrecyclinginagricultureWuQitang,NyirandegePascasie,MoCehuiF...  相似文献   

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