Unification of The Oxygen Transfer Standards

Abstract

Johnny Lee

Current application of clean water aeration test standards for wastewater treatment systems is based on the most commonly and internationally used standards for the clean water test, such as the ASCE(USA), CEN(EU/EFTA), and DWA(Germany). All the standards are mostly unified in respect to the methodology employed to calculate the oxygen mass transfer coefficient KLa, in the use of a non-steady state method or a variation of such; in the use of sulfite deoxygenation or a variation of such to give a zero starting point; in the use of probes or a variation of such to measure step change of dissolved oxygen concentration; and, in the use of the non-linear regression method of analysis or a variation of such to estimate the transfer parameters. But there are differences between the various standards, and therefore, there is a need to reconcile all the standards for the benefit of mankind. In particular, this paper addresses a problem common to all the standards, which is the application of clean water test result to in-process oxygen transfer rates, as a first step in the attempt of unifying the standards. In particular, this paper mainly applies to a diffused system but the proposed concept of gas-side oxygen depletion should be applicable to all kinds of aeration systems even for non-submerged aeration equipment.

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