Authors:Caroline A. Pinto, J. Dweck, J. J. Sansalone, F. K. Cartledge, M. E. Tittlebaum, and P. M. Büchler
Summary This paper presents a study of a cement-based solidification/stabilization process of storm water runoff solid residuals by non-conventional differential thermal analysis (NCDTA). The study was used to investigate the early hydration stages of a type I Portland cement containing the raw residual, two fractions of the residuals (coarse and fine), and two additives (quicklime and sodium bentonite). During these stages the fine fraction of the residuals retards the hydration reactions more than the coarse one, and both fractions have components that are reactive during the hydration process. When sodium bentonite is present in the pastes, the higher the initial cement content of the pastes, the lesser is the reactivity of the residuals. The presence of quicklime, which undergoes simultaneous highly exothermal hydration, accelerates the cement hydration reactions as well as those due to the presence of the residual solids. In these quicklime-containing compositions, the effect of sodium bentonite is similar to that when no quicklime is added, except when the whole residuals are used.
Authors:D. Beals, K. Hofstetter, V. Johnson, G. Patton, and D. Seely
A portable, field rugged, sampling and analysis system has been developed for the rapid screening of aqueous samples during scoping and remediation studies. Using field portable equipment, water is pumped through ion selective solid phase extraction (SPE) disks, at a flow rate of 150-250 ml/min, and counted for the radionuclide of interest in the field using portable detectors. SPE disks are currently available to selectively concentrate 99Tc, 90Sr, radiocesium (134Cs and 137Cs) and radium isotopes. In the field the radiocesium concentration is determined by gamma-spectrometry, 90Sr and 99Tc are determined by beta-counting. A one-liter sample can be processed and ready for counting within ten minutes. Using a 5-minute counting time, a detection limit of <50 pCi/l for 99Tc or 90Sr and ~50 pCi/l for 137Cs has been achieved. Up to 10 liters of water have been processed for the analysis of 99Tc and 137Cs when lower limits of detection were required. The sampling and analysis system has been field tested at the Savannah River Site (SRS), Aiken SC, and the Hanford Site, Richland WA. The SRS H-area tank farm storm water runoff system was analyzed for 90Sr and 137Cs. Groundwater from the SX tank farm at the Hanford Site was analyzed for 137Cs and 99Tc. Groundwater from seeps below the 100-H area at Hanford was analyzed for 90Sr and 99Tc.
Authors:Dušan Rusnák, Štefan Stanko, and Ivona Škultetyová
, Reddy A. S.
Conceptualizing a decentralized storm-water treatment system for an urbanized city with improper storm-water drainage facilities , International Journal of Environmental Science and Technology , Vol. 12 , No. 9 , 2015 , pp