These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Gas transfer from air diffusers.
    Author: Schierholz EL, Gulliver JS, Wilhelms SC, Henneman HE.
    Journal: Water Res; 2006 Mar; 40(5):1018-26. PubMed ID: 16490229.
    Abstract:
    The bubble and surface volumetric mass transfer coefficients for oxygen, k(L)a(b) and k(L)a(s), are separately determined for 179 aeration tests, with diffuser depths ranging from 2.25 to 32 m, using the DeMoyer et al. 12003. Impact of bubble and free surface oxygen transfer on diffused aeration systems. Water Res 37, 1890-1904] mass transfer model. Two empirical characterization equations are developed for k(L)a(b) and k(L)a(s), correlating the coefficients to air flow, Qa, diffuser depth, hd, cross-sectional area, Acs, and volume, V. The characterization equations indicate that the bubble transfer coefficient, k(L)a(b), increases with increasing gas flow rate and depth, and decreases with increasing water volume. For fine bubble diffusers, k(L)a(b) is approximately six times greater than k(L)a(b) for coarse bubble diffusers. The surface transfer coefficient, k(L)A(s), increases with increasing gas flow rate and diffuser depth. The characterization equations make it possible to predict the gas transfer that will occur across bubble interfaces and across the free surface with a bubble plume at depths up to 32 m and with variable air discharge in deep tanks and reservoirs.
    [Abstract] [Full Text] [Related] [New Search]