On a new calculation method of sludge mixture aeration and mixing processes in the aeration tanks of the wastewater biological treatment stations

• Published in: Environmental quality management 2018-09, Vol.28 (1), p.57-63
• Main Authors: Andreyev, Sergey Yu, Yakhkind, Michael I.
• Format: Article
• Language: English
• Subjects: absorption coefficient; Aeration; Aeration tanks; air‐distribution device; Biological treatment; depletion coefficient; Design optimization; Dissolved oxygen; distribution coefficient; Environmental management; Environmental quality; Experimental research; gas‐filling coefficient; Liquid phases; liquid velocity; Mass transfer; mass transfer process; Mathematical analysis; mixing process; Mixing processes; saturation concentration; Sludge; Stations; two‐phase liquid‐gas system; Vapor phases; volumetric mass transfer coefficient; Wastewater treatment
• ISSN: 1088-1913; 1520-6483
• DOI: 10.1002/tqem.21572

This paper provides the results of theoretical and experimental research of sludge mixture aeration and the mixing processes in the aeration tanks. For the oxygen mass transfer process in the dynamic two‐phase water–air system formed during aeration, equations were obtained to determine the depletion coefficient of the gas phase in an emerging air bubble, KD, and the change in the dissolved oxygen concentration in the liquid phase, taking this coefficient into account. For the mixing process using an air‐distribution device, the equation was obtained to determine the velocity of the ascending water–air mix stream formed over this device. The proposed equations allow for the optimization of the design and operation of the pneumatic aeration systems used in wastewater biological treatment stations.