Fe(III)-As(III) bearing precipitates have been successfully used for arsenic immobilization in copper smelter weak acid effluents. However, knowledge on their precise characteristics is very limited compared to ferric arsenate precipitates which are the preferred disposal option. As(III) is the dominant arsenic species in the weak acid effluents, and high costs are incurred in oxidizing As(III) to As(V) prior to ferric arsenate precipitation. Detailed characterization of Fe(III)-As(III) bearing residues is fundamental for accurate prediction of their long term stability. Synchrotron-based analysis of the Fe(III)-As(III) bearing precipitates from the effluent treatment plant (ETP) at Xstrata’s Horne Copper Smelter in Quebec identified ferric arsenate and gypsum as the major phases, and other minor phases including zinc hydroxide and franklinite. The predominant As species was As(V) which accounted for 49 to 84% of the total As in the Horne ETP sample. The high As(V) levels detected in the Horne ETP co-precipitates may be due to the partial oxidation of As(III) during prolonged storage, prior to synchrotron analysis. Tooeleite was investigated as an alternative potential disposal option for As(III) immobilization from copper smelter weak acid effluents. Lime neutralization of an equimolar Fe(III)-As(III) bearing weak acid solution resulted in about 85% As being removed at pH 2.7 and the formation of gypsum-bearing tooeleite at pH 2 to 3.5. At >pH 4, the rapid transformation of tooeleite occurred to form a poorly crystalline equimolar ferric arsenite which was stable at pH 6 to 10. Co-precipitation tests also showed that equimolar ferric arsenite was precipitated at pH>4. US EPA Toxicity Characteristic Leaching Procedure (TCLP) analysis indicated that both tooeleite and ferric arsenite have relatively high As solubilities. Calcination of tooeleite was explored as a method for improving the stability of tooeleite, and calcination of tooeleite in air at 600˚C produced a ferric arsenate calcine with a TCLP solubility of <5 mg/L As. The calcine iii produced from the lime-precipitated tooeleite at 600 ˚C was found to contain an iron arsenate (Fe7As6O24) which had a slightly higher TCLP As solubility of 13.1 mg/L. The precipitation of tooeleite from an As(III)-bearing weak acid and calcination of the resultant precipitate may offer a new process for As(III) fixation from copper smelter weak acid effluents. / Thesis (Ph.D, Mining Engineering) -- Queen's University, 2013-01-31 23:47:37.942

Thesis (Ph. D.).--Catholic University of America, 1942. / Summary : p. 26. Includes bibliographical references (p. 27).

The spectra of arsenic have been photographed from the infra-red to the vacuum ultraviolet with a 21 foot grating, a 2 metre vacuum grating, a Littrow prism spectrograph, and a constant deviation spectrograph using an elect-rodeless discharge source. The wave lengths of 1500 lines in the region 550 to 9300 A have been measured relative to Iron standards. Some 300 of these were previously classified, chiefly in As I and As II. Another 500 have now been assigned to the various spark spectra, leaving less than 10% of the observed intensity unaccounted for. The chief extension has been made in As II with more than 50 new energy levels being established. The resulting analyses have been critically examined in terms of the intermediate coupling relations proposed by M.H. Johnson* and the atomic energy relations due to Bacher and Goudsmit+. These relations permit the evaluation of important radial integrals of Slater, and the study for the first time of how these integrals changes both in the various spark spectra of an element and with the successive series members within a given spectrum For unperturbed configurations these theories are found to be satisfactory. *M.H. Johnson, Jr. Phys. Rev. 38, l628, 1931; 39, 197, 1932 + R.F. Bacher and S.A. Goudsmit, Phys. Rev. 46 948; 1934 / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Th. Etat--Pharmacie--Lille II, 1988. / Bibliogr., 12 p.

Thesis (Ph.D.)--Aberdeen University, 2009. / With: Monitoring the arsenic and iodine exposure of seaweed-eating North Ronaldsay sheep from the gestational and sucking periods to adulthood by using horns as a dietary archive / Guilhem Caumette ... et al. Environmental Science and technology 2007: 41, 8, 2673-2679. Includes bibliographical references.

Theses (M.S.)--Marshall University, 2007. / Title from document title page. Includes abstract. Document formatted into pages: contains 80 pages. Bibliography: p.67-71.

"Part of thesis submitted for the degree of doctor of philosophy, University of Wisconsin, 1918." / At head of title: A century of the United States pharmacopoeia. 1820-1920. "Reprinted from Vol. XX of the Transactions of the Wisconsin Academy of Sciences, Arts and Letters." Includes bibliographical references.

"Part of thesis submitted for the degree of doctor of philosophy, University of Wisconsin, 1918." / At head of title: A century of the United States pharmacopoeia. 1820-1920. "Reprinted from Vol. XX of the Transactions of the Wisconsin Academy of Sciences, Arts and Letters." Includes bibliographical references.

No description available.

Thèse de doctorat : Géosciences : Nancy 1 : 2008. / Titre provenant de l'écran-titre.