[The formation of trihalomethanes precursor in anionic surfactant biodegradation].
Trihalomethanes (THMs) formed by chlorination of precursor substances in raw water, are found in drinking water. They are found at concentration levels higher than those of other organic contaminants. In the present study, the relationship between the formation of THM precursors and anionic surfectants biodegradation was investigated. Three anionic surfectants (LAS, AS and soap), dissolved in river
National organic reconnaissance survey for halogenated organics
A contribution submitted to the JOURNAL by James M. Symons (Active Member, AWWA), ch., Stds. Attainment Br., WSRL; Thomas A. Bellar, res. chem., MDQAL: J. Keith Carswell (Active Member, AWWA), res. san. engr., WSRL; Jack DeMarco (Active Member, AWWA), tech. asst., WSRL; Kenneth L. Kropp, engrg. tech., WSRL; Gordon G. Robeck (Honorary Member, AWWA), dir., WSRL; Dennis R. Seeger, res. chem., WSRL; Clois J. Slocum, res. chem., WSRL; Bradford L. Smith, physical sci. tech., WSRL; and Alan A. Stevens (Active Member, AWWA), res. chem., WSRL, all of the EPA, Cincinnati,
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.