Groundwater conditions

The sorption of plutonium on a variety of the common minerals of igneous rocks under groundwater conditions is illustrated in Figure 3 (57, 58, 59). For comparison the sorption of other acti-... 

Hexachloroethane is also relatively resistant to degradation in the aquatic environment. No hydrolysis of hexachloroethane in water was observed after 11 days at 85 C at 3 pH levels (3, 7, and 11) (Ellington et al. 1987). However, hexachloroethane may be reduced in aquatic systems in the presence of sulfide and ferrous ions (Kriegman-King and Reinhard 1991). The transformation rate of hexachloroethane to tetrachloroethylene under simulated groundwater conditions at 50 C was evaluated without ferrous or sulfide ions, with minerals (biotite and vermiculite) providing ferrous ions, and with minerals and sulfide ions. Reported half-lives for hexachloroethane were 365 days for hexachloroethane alone, 57-190 days with minerals present, and 0.45-0.65 days in the presence of both minerals and sulfide. 

FIGURE 3.24 Groundwater conditions near the ground surface. Saturated and saturated zones (a), profile of moisture content vs. depth (b), pressure head and hydraulic head relationships insets = water retention under pressure heads less than (top) and greater than (bottom) atmospheric (c), profile of pressure head vs. depth (d), and profile of hydraulic head vs. depth (e). (After Freeze and Cherry, 1979.)... 

Near-shore facilities are typically characterized by shallow groundwater conditions. The occurrence of LNAPL product on the water table presents the need for immediate containment and continued recovery of the product to abate degradation of ground-water quality, hydrocarbon vapor migration, and discharge of hydrocarbon product to surface waters. A pneumatically operated, double-diaphragm, suction-lift pump has been frequently used in such circumstances to contain and recover LNAPL. 

Salama RB, Otto CJ, Fitzpatrick RW (1999) Contributions of groundwater conditions to soil and water salinization. Hydrogeol J 7 46-64... 

Region/country Population exposed Arsenic concentration ranges (ng L 1) Aquifer type Groundwater conditions Year(s) of discovery... 

The coupons were contacted with tracer-free groundwater solutions, which were assayed after 28 d to determine the amount of activity that is reversibly bound to the granite under normal groundwater conditions. 

The EPA s strategy includes a national registration of pesticides and state-directed management by monitoring and pesticide use restrictions based on local groundwater conditions. 

J. Whyte, Surface Appearances Can Deceive Groundwater Conditions a Major Factor in Responsible Mine Closure, Hazardous Mater. Manag. 15(2), 17-18, Apr./May (2003). 

Hakanf.n, M., and A. Lindberg. 1991. Sorption of neptunium under oxidizing and reducing groundwater conditions. Radiochim. Acta 52/53 147-51. 

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