Turbulence Effects on Volatilization Rates of Liquids and Solutes

Abstract

Volatilization rates of neat liquids (benzene, toluene, fluorobenzene, bromobenzene, ethylbenzene, m-xylene, o-xylene, o-dichlorobenzene, and 1-methylnaphthalene) and of solutes (phenol, m-cresol, benzene, toluene, ethylbenzene, o-xylene, and ethylene dibromide) from dilute water solutions have been measured in the laboratory over a wide range of air speeds and water-stirring rates. The overall transfer coefficients (K(L)) for individual solutes are independent of whether they are in single- or multi-solute solutions. The gas-film transfer coefficients (kG) for solutes in the two-film model, which have hitherto been estimated by extrapolation from reference coefficients, can now be determined directly from the volatilization rates of neat liquids through a new algorithm. The associated liquid-film transfer coefficients (kL) can then be obtained from measured K(L) and kG values and solute Henry law constants (H). This approach provides a novel means for checking the precision of any kL and kG estimation methods for ultimate prediction of K(L). The improved kG estimation enables accurate K(L) predictions for low-volatility (i.e., low-H) solutes where K(L) and kGH are essentially equal. In addition, the prediction of K(L) values for high-volatility (i.e., high-H) solutes, where K(L) approximately equal to kL, is also improved by using appropriate reference kL values.

Emissions of Organic Compounds in Surfactant Solutions under Air Turbulence

“…If α is also a constant under a specific environmental condition, Eq. (3) may be deduced as (Lee et al, 2004a) OL…”

“…Moreover, the α value increases with the increasing liquid mixing intensity, and decreases with the increasing wind speed. The more detailed description has been presented in the literature (Lee et al, 2004a).…”

“…The data is illustrated in Table 2. The experimental process was described in the other report (Lee et al, 2004a;Chao, 2009a). The α values are obtained when the accurate H values are determined.…”

“…According to the traditional two-film model, the relationship between K OL and H for the high H solutes is defined difficultly (Chao et al, 2005a). A new model, that is, the surface-depletion rate-limiting (SDRL) model, was developed to describe the effects of H values on the volatilization rates of organic solutes (Lee et al, 2004a). In traditional two-film model, the decreases in the thickness of gas-film and liquid film were used to interpret the increases in volatilization rates of the organic compounds under the wind and liquid-mixing conditions.…”

Seasonal Variability in Benzene Removal by Vertical-Flow Constructed Wetland Filters

“…Processes such as adsorption, biodegradation and volatilisation contributed to benzene removal (Corley et al 1996;Lee et al 2004;Li et al 2006). Concerning adsorption removal, no obvious temperature dependencies were observed and negligible differences in benzene removal efficiency at 4°C, 10°C and 20°C were detected in industrial wastewater adsorption studies (Adachi et al 2001).…”