Ch5_3aeration theory and practice

Ch5_3aeration theory and practice - Liquid Phase (Bulk...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Theory and Practice of Aeration Gas Phase (Bulk) Liquid Phase (Bulk liquid) C w < C s Cs: saturated DO in water Cw: actual DO in water
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Theory The rate of oxygen transfer can be expressed by: dC w /dt = ka ( C s - C w ) where C s and C w are the saturation and actual concentration of dissolved oxygen, respectively; ka is a constant (volumatric mass transfer coefficient), which depends upon temperature, interfacial area, and the resistance of movement from air phase to water phase .
Background image of page 2
Oxygen transfer resistance The step which offers the most resistance to the movement of oxygen molecules is called the rate- limiting step. In most cases in water and wastewater treatment, sufficient agitation is provided to minimize the thickness of the films that are the limiting factor.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
In summary, the major factors of the O2 transfer process include: Surface area; Temperature; Degree of under- or super-saturation; Type of gas; Mixing; Impurities in Water; Time. : controllable
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 18

Ch5_3aeration theory and practice - Liquid Phase (Bulk...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online