Full Description

Oxidation and reduction (redox) reactions are very important in drinking water.Oxidation-reduction potential (ORP) measurements reflect the redox state of water. Redoxmeasurements are not widely made by drinking water utilities in part because they are not wellunderstood. The objective of this study was to determine the effect of oxidant type andconcentration on the ORP of carbonate buffered water as a function of pH. Oxidants that werestudied included: chlorine, monochloramine, potassium permanganate, chlorine dioxide, andoxygen. ORP decreased with increasing pH, regardless of the oxidant type or concentration.ORP increased rapidly with increasing oxidant dosage, particularly at lower concentrations.Differences in the redox potentials of different oxidant systems were also observed. Waters thatcontained chlorine and chlorine dioxide had the highest ORPs. Tests also revealed that therewere inconsistencies with redox electrode measurements. In the standard Zobell referencesolution, two identical redox electrodes had nearly the same reading, but in test waters thereadings sometimes showed a variation as great as 217.7 mV. Includes 11 references, tables, figures.

Product Details

Edition: Vol. - No. Published: 11/15/2004 Number of Pages: 14 File Size: 1 file , 670 KB