00000nam 2200000zi 4500 9.877257 CaOODSP 20241203113651 m o d f cr bn||||||||| 190731s1994 onca ob f000 0 eng d CaOODSP eng rda CaOODSP n-cn-on En13-5/94-27E-PDF Azcue, José M., 1957- author. Arsenic forms in the mine-polluted sediments of Moira Lake, Ontario / by Jose M. Azcue and Jerome O. Nriagu. Arsenic in sediments of Moira Lake, Ontario [Ottawa] : Environment Canada, Water Science and Technology Directorate = Environnement Canada, Direction générale des sciences et de la technologie, eau, [1994] 1 online resource (pages 405-415) : illustrations. text txt rdacontent computer c rdamedia online resource cr rdacarrier [NWRI contribution] ; 94-27 Cover title. Originally published in: Environment international, v. 19, no. 4, 1993. Digitized edition from print [produced by Environment and Climate Change Canada]. Includes bibliographical references. "The sediments of Moira Lake, Ontario, have accumulated large quantities of arsenic and toxic metals since the 1830's when mining began in its drainage basin. Despite the fact that the mine activities ceased in 1961, leachates from the abandoned mine wastes still deliver large quantities (about 3.5 Mg.y⁻¹) of arsenic to the lake. The As concentrations at the top of the sediments average about 545 µg.g⁻¹, with maximal concentrations of about 1000 µg.g⁻¹ occurring at depths of 23-27 cm. Approximately 56% of the As in the sediments is bound to the iron and manganese oxides. Observed changes in the profiles of As bound to the different chemical fractions suggest that some of the oxide-bound As is being converted to the residual phases. In view of the dominant form of As in the sediments, changes in the Eh or pH may trigger the release of large quantities of As to the overlying water"--Page 405. gccst Mining industry gccst Lakes gccst Sediments gccst Water pollution gccst Pollutants Nriagu, Jerome O., 1942- author. Canada. Environment Canada. Canada. Water Science and Technology Directorate. National Water Research Institute (Canada) NWRI contribution ; 94-27. (CaOODSP)9.844121 PDF 1.45 MB https://publications.gc.ca/collections/collection_2019/eccc/en13-5/En13-5-94-27-eng.pdf