A new technique, called modulated thermogravimetry, is introduced as a tool for obtaining continuous kinetic information for decomposition and volatilization reactions. The approach makes use of an oscillatory temperature program to obtain kinetic parameters during a mass loss. MTGA may be used under quasi-isothermal conditions to observe a single mass loss or may be combined with linear heati...

BACKGROUND Sealants and other building materials sold in the U.S. from 1958 - 1971 were commonly manufactured with polychlorinated biphenyls (PCBs) at percent quantities by weight. Volatilization of PCBs from construction materials has been reported to produce PCB levels in indoor air that exceed health protective guideline values. The discovery of PCBs in indoor air of schools can produce nume...

Assistant Professor of Botany, Duke University, Durham, N.C. 27706; and Research Assistant, Department of Biological Sciences, University of California, Santa Barbara, CA 93106 Abstract: Precipitation and dry fallout were collected over a 2-year period at a remote site in the Santa Ynez Mountains, Santa Barbara County, California, USA and analyzed for nutrient content. Mean annual depositions o...

The effect of controlled drainage (CD) on ammonia volatilization (AV) losses from paddy fields under controlled irrigation (CI) was investigated by managing water table control levels using a lysimeter. Three drainage treatments were implemented, namely, controlled water table depth 1 (CWT1), controlled water table depth 2 (CWT2), and controlled water table depth 3 (CWT3). As the water table co...

N-nitrosodimethylamine (NDMA) is a potential carcinogen frequently found in treated wastewater as a byproduct of chlorination. The potential for NDMA to contaminate the groundwater is a significant concern. A solute fate and transport model, Hydrus-1D, was used to evaluate the leaching potential of NDMA under different irrigation practices and soil properties. The results indicate that the risk...

Experiments were conducted to investigate the fate of ethylbenzoate and soil microorganisms in shallow aquifers. Biodegradation and volatilization have been identified to be the major mechanisms in attenuating ethylbenzoate in contaminated soils. The parameters of an available model have been obtained by fitting it to the experimental data. Various facets of biodegradation, including the effect...

Several bacterial strains carrying genes determining mercury resistance on naturally occurring plasmids will convert 10(-5)m Hg(2+) (chloride) to a form of mercury which is volatile and soluble in organic solvents. The volatilization activity is induced by exposure to HgCl(2).