نتایج جستجو برای: pb and zn
تعداد نتایج: 16841450 فیلتر نتایج به سال:
metals concentrations in lumbricus terrestris and soil samples from the dumpsites located in zaria metropolis, nigeria were measured spectrophotometrically. mean metal content in dumpsite soils were: 25.95 - 75.17, 8.33 - 382.94, 124.84 - 206.96, 34.24 - 666.67 and 111.11 - 488.10mg/kg for cd, cu, mn, pb and zn respectively. while the concentration ranges recorded in l. terrestris samples were;...
This study was designed to investigate heavy metal (Cu, Zn, Pb, and Cd) contamination levels of soils, vegetables, and rice grown in the vicinity of the Dabaoshan mine, south China. The concentration of Cu, Zn, Pb, and Cd in paddy soil exceeded the maximum allowable concentrations for Chinese agricultural soil. The heavy metal concentrations (mg kg(-1), dry weight basis) in vegetables ranged fr...
An integrated analysis has been carried out on two cores dated by combination of (210)Pb and (137)Cs in order to characterize the extent of heavy metal accumulation in the Liaodong Bay, Northern China. The concentrations and burial fluxes of Zn, Pb, Cd, and Hg increased abruptly after late 1970s. The enrichment factors of Cd, Hg, Zn and Pb are more than 30, 10, 7, and 3.5, respectively, in the ...
It is well established through field observations, experiments, and chemical models that oxidation (redox) state and pH exert a strong influence on the speciation of dissolved components and the solubility of minerals in hydrothermal fluids. log fO2–pH diagrams were used to depict the influence of oxygen fugacity and pH on monocarboxylateand dicarboxylate-transport of Pb and Zn in low-temperatu...
In the present investigation flocculation of dissolved Cu, Zn, Pb, Ni and Mn in a series of mixtures with salinities ranging from 1.5 to 9.5% during mixing of Talar river water with the Caspian Sea water was studied. The flocculation trend of Zn (87.22%) >Mn (45.31%) >Pb (39.09%) >Cu (36.58%)>Ni (12.70%) indicates that Cu, Zn, Pb and Mn have non-conservative behavior and Ni has relatively conse...
One of the significant factors affecting biochar properties is the pyrolysis temperature. This study aimed to investigate the effect of pyrolysis temperature on the properties and fractionation of Zn and Pb in biochars produced by sewage sludge. Biochars were prepared at temperatures of 300 to 700 °C and the physicochemical properties, availability, and fractionation of Zn and Pb were investiga...
This study examined trace metal contamination of sediments in Guiyu, China where primitive e-waste processing activities have been carried out. It was found that some river sediments in Guiyu were contaminated with Cd (n.d.-10.3mg/kg), Cu (17.0-4540mg/kg), Ni (12.4-543mg/kg), Pb (28.6-590mg/kg), and Zn (51.3-324mg/kg). The (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of the Pb-contaminated sedime...
Recent ice core measurements show lead concentrations increasing since 1970, suggesting new nonautomobile-related sources of Pb are becoming important worldwide (1). Developing a full understanding of the major sources of Pb and other metals is critical to controlling these emissions. During the March, 2006 MILAGRO campaign, single particle measurements in Mexico City revealed the frequent appe...
In this study, inductive coupled plasma-optical emission spectroscopy (ICP-OES) is employed for the evaluation of soil pollution for selected metals in the Vanderbijlpark area of South Africa. Soil samples investigated were collected from five different sites in the city based on their proximity to the industrial areas of Vanderbijlpark. Soil samples were collected from close to traffic robots,...
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