Chemical Identification and Organoleptic Evaluation of Iodine and Iodinated Disinfection By-Products Associated with Treated Spacecraft Drinking Water

Type of Document Master's Thesis
Author Dodd, Jennifer Peters
URN etd-34521672975650
Title Chemical Identification and Organoleptic Evaluation of Iodine and Iodinated Disinfection By-Products Associated with Treated Spacecraft Drinking Water
Degree Master of Science
Department Civil Engineering
Advisory Committee
Advisor Name Title
Andrea Dietrich Committee Chair
Daniel Gallagher none
Robert Hoehn none
Keywords

* disinfection by-product
* iodine
* iodoform
* flavor profile analysis

Date of Defense 1997-02-11
Availability unrestricted
Abstract

Aboard the International Space Station,

potable water will likely be produced from

recycled wastewater. The National

Aeronautic and Space Administration

(NASA) plans to use iodine as a disinfectant,

and, consequently, the formation of iodinated

disinfection by-products (IDBPs) requires

investigation. Objectives of this research were

to determine possible precursors of IDBPs,

identify IDBPs formed, and apply flavor

profile analysis (FPA) as a tool to evaluate

water qaulity. Experiments were performed by

separately reacting iodine with each of the

following organic compounds: methanol,

ethanol, 1-propanol, 2-propanol,

1-methoxy-2-propanol, acetone, and

formaldehyde. NASA previously identified all

of these compounds in wastewater sources

under consideration for recycling into potable

water. Experiments were performed at pH 5.5

and 8, iodine concentrations of 10 and 50

mg/L, and organic concentrations of 5 and 50

mg/L. Gas chromatography/mass

spectrometry was used to identify and monitor

the concentrations of organic species.

Spectrophotometry was used to monitor the

iodine concentration. Acetone was the only

compound identified as an IDBP precursor

and it reacted to produce iodoacetone and

iodoform. Concentrations of iodoform from

0.34 mg/L to 8.637 mg/L were produced at

conditions that included each pH level, iodine

concentration, and acetone concentration. The

greatest iodoform concentration was

produced at pH 8 from 50 mg/L of iodine and

acetone. FPA indicated that the odor

threshold concentration (OTC) of iodoform

was 1.5 ug/L, and the OTC of iodine was 500

ug/L. Both iodine and iodoform have

medicinal odors, making it difficult to

distinguish each compound when present in a

mixture.

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