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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Physico-chemical studies of metals in the highway environment

Wilson, S. J. January 1984 (has links)
No description available.
2

ADSORPTION OF HEAVY METALS ON SOIL CLAYS (KAOLINITE, CADMIUM, MONTMORILLONITE, ZINC).

PULS, ROBERT WILLIAM. January 1986 (has links)
Metal cation adsorption is the predominant chemical mechanism governing the attenuation of toxic metal movement in soils. Clay minerals are the primary adsorbent surfaces in soils due to their ubiquitous nature and large reactive surface area. This study examined the relative affinity of the metals cadmium, nickel and zinc for the clay minerals kaolinite and montmorillonite. The influence which different mineral adsorbents and different complexing ligands in solution have on the adsorption of metal ions was assessed using the Hard-Soft Acid-Base Principle as a theoretical framework for predicting the maximum extent of adsorption and rate of adsorption. The HSAB principle is that hard bases prefer to complex hard acids and soft bases prefer to complex soft acids. The hypothesis that initiated these investigations was that the hard-soft character of mineral surfaces is due to their surface functional groups and can be measured using metal cation adsorption selectivity experiments where pH and complex ion formation are controlled. When complex ion formation in aqueous solution was minimized (i.e. in Ca(ClO₄)₂), adsorption decreased in the order of decreasing softness, CD > Zn > Ni for both clay minerals. Montmorillonite behaved as a slightly harder Lewis base than kaolinite, sorbing the harder Ni and Zn ions to a greater extent than Cd, although both minerals behaved as soft Lewis bases. In the presence of chloride and sulfate ligands, adsorption sequences changed and reflected results from typical soil solution studies. In some cases the adsorption sequences can be explained using the HSAB principle together with computer speciation data and this approach merits further consideration and research. Adsorption over time and calculated adsorption rate constants were generally consistent with equilibrium selectivity data. Adsorption rates decreased in the order Cd > Zn > Ni in Ca(ClO₄)₂ for both clay minerals. The adsorption curves reflect a two-step adsorption process involving a rapid exchange-type reaction followed by a much slower adsorption involving diffusion into the crystal or alteration of the surface through the formation of a new solid phase involving the adsorbed ions.
3

Vanadium toxicity in the yeast, Saccharomyces cerevisiae

Henderson, G. E. January 1988 (has links)
No description available.
4

Effects of cadmium toxicity on population dynamics of the blowfly Lucilia sericata

Daniels, Susan G. January 1994 (has links)
No description available.
5

Cadmium, zinc and copper regulation involving metallothionein gene expression in the Anuran X. laevis

Woodall, Christopher John January 1988 (has links)
No description available.
6

Proton and metal ion interactions of fulvic acid solution and of alumina and alumina/fulvic acid suspensions

Baker, Alexander Roberts January 1991 (has links)
No description available.
7

Solidification system for metal containing hazardous wastes

Asavapisit, Suwimol January 1998 (has links)
No description available.
8

Toxic waste treatment by slag cements

Ahmed, Yousif Hummaida January 1996 (has links)
No description available.
9

Estimating binding strength and chemical phases of metals adsorbed to sediment components

Whalley, Caroline January 1995 (has links)
No description available.
10

Novel spectroscopic techniques applied to metal cluster compounds

Dallin, Paul Howard January 1991 (has links)
No description available.

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