Abstract
During the past four decades many investigators have considered the use of Oxidation-Reduction Potential (ORP) measurements for the management and control of operations in activated sludge process, anaerobic digestion process and toxic substance treatment process. These reports indicated available and interesting results in the exemplification and utility of the value of ORP measurement. But what kind of factors influenced the value of ORP was not indicated.
This paper aims to evaluate the relationship between temperature, DO, H2S, pH and the value of ORP in the Nernst Electrode Potential Equation and attempts to discuss on the degree of influence for ORP value on the following items.
(1) The temperature of the solution.
(2) Relationship between DO and ORP in case of gradual DO increasing and decreasing.
(3) Relationship between artificial H2S solution and ORP.
(4) The hydrogen-ion concentration (ΔEh/ΔpH and ΔrH/ΔpH).
