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51.
生物修复技术在重金属污染治理中的应用 总被引:10,自引:0,他引:10
随着工业的发展,重金属对环境的污染越来越引起人们的关注。生物修复技术以其投资少、效率高、可以原位修复低浓度有害污染物的特性而在环境污染治理中发挥了巨大的作用,自上世纪80年代产生以来,得到了越来越广泛的应用。本文简要介绍了几种生物修复技术在污染治理中的应用,以期进一步推动重金属污染的治理和修复工作。 相似文献
52.
一种新型吡嗪铱(Ⅲ)配合物的合成及其磷光性质 总被引:2,自引:0,他引:2
利用5-甲基-2,3-二苯基吡嗪(MDPP)和水合三氯化铱(IrCl3•H2O),合成了一种新型吡嗪铱配合物Ir (MDPP)2 (acac).通过1H NMR、元素分析和质谱方法对配合物结构进行了表征,并研究了配合物的吸收光谱和光致发光光谱.结果表明,配合物Ir (MDPP)2(acac)在393和528 nm处存在单重态1MLCT(金属到配体的电荷跃迁)和三重态3MLCT的吸收;在588 nm 处有较强的金属配合物三重态的磷光发射,是一种绿色磷光材料. 相似文献
53.
S. M. Dal Bosco R. S. Jimenez C. Vignado J. Fontana B. Geraldo F. C. A. Figueiredo D. Mandelli W. A. Carvalho 《Adsorption》2006,12(2):133-146
The adsorption capacities of commercial and Brazilian natural clays were evaluated to test their applications in wastewater
control. We investigated the process of sorption of manganese(II) and cadmium(II) present in synthetic aqueous effluents,
by calculating the adsorption isotherms at 298 K using batch experiments. The influence of temperature and pH on the adsorption
process was also studied. Adsorption of metals was best described by a Langmuir isotherm, with values of Q
0 parameter, which is related to the sorption capacity, corresponding to 6.3 mg g− 1 for K-10/Cd(II), 4.8 mg g− 1 for K-10/Mn(II), 11.2 mg g− 1 for NT-25/Cd(II) and 6.0 mg g− 1 for NT-25/Mn(II). We observed two distinct adsorption mechanisms that may influence adsorption. At the first 5 min of interaction,
a cation exchange mechanism that takes place at exchange sites located on (001) basal planes is predominant. This process
is inhibited by low pH values. After this first and fast step, a second sorption mechanism can be related to formation of
inner-sphere surface complexes, which is formed at edges of the clay. The rate constants and the initial sorption rates correlate
positively with temperature in all studied systems, denoting the predominance of a physisorption process. The addition of
complexing agents that are incorporated within the K10 structure, enhance metal uptake by the adsorbent. The results have
shown that both Cd(II) and Mn(II) were totally retained from a 50 mg L− 1 solution when K10 grafted with ammonium pyrrolidinedithiocarbamate (APDC) was used as adsorbent. 相似文献
54.
Alexander Strezov Tzvetana Nonova 《International journal of environmental analytical chemistry》2013,93(12):1045-1054
Heavy metal contents (Fe, Mn, Cu, Pb and Cd) were determined in two brown macroalgal species (Cystoseira crinita and Cystoseira barbata). Samples were collected during six seasons from spring 1996 to summer 2000 from five different sites of the Bulgarian Black Sea coastal zone – Tuzlata, Ravda, Sozopol, Ahtopol and Sinemoretz. The local and seasonal metal distribution and their variations were examined. The data obtained indicate that the two investigated species demonstrate various degrees of metal accumulation and can be used as indicators for the type and quantity of anthropogenic contamination in marine ecosystems. 相似文献
55.
We develop a methodology for the estimation of extreme loss event probability and the value at risk, which takes into account both the magnitudes and the intensity of the extreme losses. Specifically, the extreme loss magnitudes are modeled with a generalized Pareto distribution, whereas their intensity is captured by an autoregressive conditional duration model, a type of self‐exciting point process. This allows for an explicit interaction between the magnitude of the past losses and the intensity of future extreme losses. The intensity is further used in the estimation of extreme loss event probability. The method is illustrated and backtested on 10 assets and compared with the established and baseline methods. The results show that our method outperforms the baseline methods, competes with an established method, and provides additional insight and interpretation into the prediction of extreme loss event probability. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
56.
The performance enhancement of 3D-printed electrode comprised of polylactic acid (PLA) and graphite (Gr) doped with graphene oxide (GO) was studied to detect five heavy metal ions in trace level. The pretreatment of PLA/Gr/GO electrode with potential cycling in H2SO4 solution achieved the most sensitive response. The characteristics of the composite electrodes were verified using XPS, FE-SEM, EDXS, Raman, and impedance spectroscopy. The experimental variables affecting the response current were optimized with respect to pH, deposition time, ratio of PLA/Gr/GO, and supporting electrolytes. The pretreated 3D-PLA/Gr/GO electrode showed a wide dynamic range from 0.5 ppb to 1.0 ppm with low detection limits of 0.039–0.13 ppb. The reliability of the PLA/Gr/GO electrode was evaluated by analyzing the reference samples of European Reference Materials. 相似文献
57.
Firstly, poly[phenyl thiadiazole methacrylamide-co-divinylbenzene-co-2-acrylamido-2-methylpropane sulfonic acid] (PTMAAm-co-DVB-co-AMPS), a new polymer resin was synthesized. This polymer resin was characterized by elemental analyzer, X-ray diffractometer, scanning electron microscope (SEM) and IR spectrometer. The glass column packed with the synthesized polymer resin was used for solid phase extraction (SPE). At the same time, the analytes were separated and preconcentrated from various water, dried vegetables samples and standard reference material (CRM) with SPE and determined by flame atomic absorption spectrometer (FAAS). The experimental conditions of this method such as pH, flow rates of sample, flow rates of eluent, type / concentration / volume of eluent, sample volume and matrix ions were examined. The limits of detection (µg L?1) were calculated (3s) 0.9 for Mn(II), 1.4 for Cd(II), Co(II) and Zn(II), 1.5 for Cr(III), 2.2. for Cu(II), 1.9 for Pb(II),1.5 for Ni(II) and 1.9 for Fe(III) (n = 21). The low relative standard deviation, ≤ 2% (n = 11) and preconcentration factor as 75 for analytes were obtained. 相似文献
58.
A. R. Crosland S. P. McGrath P. W. Lane 《International journal of environmental analytical chemistry》2013,93(1-4):153-160
Abstract A standardised EDTA extraction procedure was tested collaboratively by six laboratories using two in-house reference soils identified as soil A and soil B. The extracts were analysed for Zn, Cu, Pb and Mn by Inductively Coupled Plasma Spectrometry. Concentrations of extractable elements in soil A were generally much lower than those found in soil B. All laboratories produced some extreme outlying results, most of these were produced in soil B. Results for Mn were the most variable, with a range of 63.4–100.3 μg g?1 in soil A and 226.4–415.3 μg g?1 in soil B. In both soils, one laboratory reported high values for Zn and Mn and, one laboratory, for soil B, produced values for all four elements which were consistently low. If outlying results are ignored, the results from most laboratories were in reasonable agreement for all elements except Mn. 相似文献
59.
J. Liang J. J. Schoenau 《International journal of environmental analytical chemistry》2013,93(2-4):265-275
Abstract Ion exchange resins in contact with soil can act as a sink for metal cations, thereby simulate the action of plant roots. Ion exchange resins in membrane form offer additional advantages in ease of use and handling. A procedure was developed to assess the bioavailability of four heavy metals Cd, Cr, Ni and Pb via direct in soil burial. A growth chamber experiment with three representative crops (oats, radish and lettuce) was set up to determine the phytotoxic levels of the four heavy metals. The critical levels varied widely from crop to crop, and soil to soil. Lettuce was most sensitive to high concentration of metals. The toxic effects are more pronounced on sandier textured soils. 相似文献
60.
Polymer-Mercury Coated Screen-Printed Sensors for Electrochemical Stripping Analysis of Heavy Metals
Ilaria Palchetti Sanaa Majid Alessandra Kicela Giovanna Marrazza Marco Mascini 《International journal of environmental analytical chemistry》2013,93(7-8):701-711
In the perspective of in-field stripping analysis of heavy metals, the use and disposal of toxic mercury solutions (necessary to plate a mercury film on a carbon electrode surface) presents a problem. The aim of this work was the development of mercury coated screen-printed electrodes previously prepared in the lab and ready to use in-field. Thus some commercially available polymers like Nafion®, Eastman Kodak AQ29®, and Methocel® were investigated as mercury entrapping systems for electrochemical stripping analysis of heavy metals. Screen-printed disposable cells with a silver pseudo-reference electrode, a graphite counter electrode, and a graphite working electrode were used. To modify the sensor, the polymer solution was cast onto the carbon working electrode surface. Detection limits of 0.8 and 1 μg/L were obtained for lead and cadmium respectively. Since Methocel® based electrodes showed the best performance, they were used for the analysis of real samples. The results were compared with those obtained using a classical thin mercury film electrode and ICP spectroscopy. All the experiments reported here were performed in un-deareated solutions as required for in-field analysis. 相似文献