Radium system

Moore DG, Edmond (1984) Radium and barium in the Amazon River system. J Geophys Res 89 2061-... 

Sanchez F, Rodriguez-Alavarez MJ (1999) Effect of pH, conductivity and sediment size on thorium and radium activities along Jucar River (Spain). J Radioanal Nucl Chem 242 671-681 Sarin MM, Krishnaswami S, Somayajulu BLK, Moore WS (1990) Chemistry of U, Th, and Ra isotopes in the Ganga-Brahmaputra river system Weathering processes and fluxes to the bay of Bengal. Geochim Cosmochim Acta 54 1387-1396... 

The air circulation must continue at least three hours. It is not only necessary to distribute the radon accumulated in the radium solution bottle into the entire system (for this purpose a shorter time would be sufficient) but it takes three hours to establish the equilibrium between radon and its short-lived daughters in the medium. 

Whether Wells s novel affected Soddy as much as Soddy s Interpretation of Radium influenced Wells is impossible to determine, but Soddy s move into monetary theory in the postwar period was, in some ways, already implicit in his alchemical vision of the new science.8 Modem alchemy—the atomic science of transmutation, with all its alchemical connections to spiritual systems, gold, and even greed—that Soddy had been exploring in his pre-War writings may have helped turn this Nobel Prize-winning chemist into what was commonly called a money crank. ... 

Most water systems are required to monitor for radioactivity and certain radionuclides, and to meet maximum contaminant levels (MCLs) for these contaminants, to comply with the Safe Drinking Water Act (SDWA). Currently, USEPA requires drinking water to meet MCLs for beta/photon emitters (includes gamma radiation), alpha particles, combined radium 226/228, and uranium. However, this monitoring is required only at entry points into the system. In addition, after the initial sampling requirements, only one sample is required every three to nine years, depending on the contaminant type and the initial concentrations. 

EPA. 1988c. Maximum contaminant levels for radium-226, radium-228, and gross alpha-particle radioactivity in community water systems. 40 CFR 141.15 Federal Register, 533. 

The Advanced Recovery Systems, Inc. (ARS) developed the patented, ex situ DeCaF hydrometallurgical technology to decontaminate fluoride by-products and to recover recyclable metals. The technology uses a proprietary acid mixture to digest the fluoride matrix, freeing radioactive contaminants (e.g., uranium, thorium, or radium) and hazardous contaminants (e.g., lead, arsenic, or chromium). Radioactive elements are recycled or disposed. Metals are also recycled, and fluoride is recovered as a high-value salt for aluminum smelting. 

In 1898 there was discovered an element, radium, which con tinually and spontaneously emits light, heat, and other radiations. Investigation of these astonishing phenomena by the Curies and others revealed more than forty interrelated radioactive elements which, like radium, are unstable. They do not, however, occupy forty places in the periodic system, but are crowded into twelve places. The explanation for the existence of these numerous so-called radioactive isotopes and their genealogical descent from uranium and thorium were discovered independently by K. Fajans, F. Soddy, A. S. Russell, and A. Fleck. Since the original literature on the radioactive elements embraces such a vast field of research, the following account of their discovery is necessarily far from complete. 

Before we study the behaviors of U-series disequilibria during partial melting, we try to understand a simple case of U-decay series in an isolated system in the absence of melting. For this undisturbed closed system, the uranium-thorium-radium (U-Th-Ra) series disequilibria (Fig. 

Note Table includes systems currently exceeding 10 pCi/L. a Values are reported as thousands of dollars per year. b Values are reported as millions of dollars per year. c Interim maximum contaminant level for radium. 

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