No abstract

Akgerman (1) based on significant liquid structure and absolute rate theory works better than all the other expressions. The Wilke-Chang Equation, although as accurate for many systems, is inaccurate when the solute is a small molecule like hydrogen or helium or when solvent is a viscous liquid. The Stokes-Einstein and the Eyring equations are inaccurate, perhaps due to the questionable assumptions in their derivations leading to the final expressions. The Othmer and Thakar expression, on the other hand, cannot predict the temperature dependency of diffusion coefficients and is inaccurate for nonaqueous solvents. LITERATURE CITED

Inclined cascade aeration (ICA) was effective in removing 10 chlorinated volatile organic chemicals (VOCs) from drinking water at liquid loadings of 5 gpm/ft (1.04 L s–1/m) to 15 gpm/ft (3.1 L s–1/m). Overall mass transfer (or desorption) coefficients (KLav) were an order of magnitude larger (0.08–0.54 s–1) than those reported for packed‐tower aeration. A curve fit of the experimental data for all 10 VOCs with the equation KLav = 0.019 + 0.091 (Hp)$f14(sin θ)$, in which Hp is the Henry's law constant (atm) and θ is the angle of inclination, yielded desorption coefficients within ± 18 percent of experimental values. A cascade angle of 60° was found most efftcacious for compounds with Hp values >300 atm; compounds with Hp values <300 atm were most effectively stripped at yet steeper angles.