Distribution-Generated Taste-and-Odor Phenomena

The objectives of this study were to investigate various distribution conditions that directly affect the production of tastes and odors, identify the chemical causes, and develop guidelines to help water utilities solve or prevent these types of problems. This paper presents four case studies of taste-and-odor problems generated in distribution systems. Two types of problems will be presented, (1) problems that occur in association with pipe or reservoir lining material leaching into the water and (2) problems that are caused by a continuation of chemical reactions in the water within the distribution system. The sensory method used was flavor profile analysis (FPA) and the chemical methods were closed loop stripping analysis (CLSA) or liquid-liquid extraction (LLE) coupled with gas chromatography/mass spectrometry (GC/MS). Bromophenols and bromodichloroiodomethanes were found to be the cause of the medicinal odors, while alkyl benzenes and naphthalene were found to be associated with the oil-base paint type of odors.

Download Full-text

The Drinking Water Taste and Odor Wheel for the Millennium: Beyond Geosmin and 2-Methylisoborneol

Water Science & Technology ◽

10.2166/wst.1999.0248 ◽

1999 ◽

Vol 40 (6) ◽

pp. 1-13 ◽

Cited By ~ 59

Author(s):

I. H. (Mel) Suffet ◽

Djanette Khiari ◽

Auguste Bruchet

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Profile Analysis ◽

Gas Chromatography Mass Spectrometry ◽

Taste And Odor ◽

Water Taste ◽

Mouth Feel ◽

New Compounds ◽

Flavor Profile Analysis ◽

Flavor Profile

The “Taste and Odor Wheel” developed over the last 15 years has been updated to include new compounds identified in the eight classes of odorants, four tastes, and one mouth feel/nose feel category. Over the last 10 years, other types of odors have been identified, in addition to chlorinous and ozonous odors of disinfectants, the earthy compound geosmin, and the musty compound 2-methylisoborneol (2-MIB). Sophisticated instrumental analysis, e.g., gas chromatography/mass spectrometry (GC/MS), and sensory analysis, e.g., flavor-profile analysis (FPA), have been successfully combined with sensory GC to identify various odorants.

Download Full-text

Sensory evaluation of the odors produced during bromophenol formation using a multi-level statistical model

Water Science & Technology ◽

10.2166/wst.2004.0581 ◽

2004 ◽

Vol 49 (9) ◽

pp. 241-248

Author(s):

H. Al-Samarrai ◽

J. Matud ◽

K. Wiesenthal ◽

P. Atiyah ◽

A. Bruchet ◽

...

Keyword(s):

Water Quality ◽

Statistical Model ◽

Profile Analysis ◽

Quality Parameters ◽

High Concentration ◽

Worst Case ◽

Taste And Odor ◽

Products Of Reaction ◽

Flavor Profile Analysis ◽

Flavor Profile

In response to reports of medicinal taste and odor problems in suburban Paris, a lab scale study was conducted to investigate the contribution of different water quality parameters - pH, phenol, bromide, chlorine, temperature and dissolved oxygen levels - on bromophenol medicinal odor formation using the Flavor Profile Analysis (FPA) method. A study of six parameters at 2 levels (64 experiments) analyzed by the FPA method suggests that chlorine at high concentration is more important as a controlling agent than phenol under similar conditions and the ratio of HOBr:Phenol and the time for reaction will control subsequent brominated products of reaction. Results from a three-level statistical model indicate that high pH was associated with lower odor intensities, whereas high levels of chlorine, phenol and temperature were associated with high odor intensities. Potential worst case scenarios of water quality conditions were determined for evaluation by chemical identification and kinetics.

Download Full-text

Flavor-Profile Analysis: An Objective Sensory Technique for the Identification and Treatment of Off-Flavors in Drinking Water

Water Science & Technology ◽

10.2166/wst.1988.0221 ◽

1988 ◽

Vol 20 (8-9) ◽

pp. 31-36 ◽

Cited By ~ 11

Author(s):

Stuart W. Krasner

Keyword(s):

Drinking Water ◽

Profile Analysis ◽

Sensory Data ◽

Flavor Intensity ◽

Taste And Odor ◽

Straight Line ◽

Trained Panel ◽

Off Flavors ◽

Flavor Profile Analysis ◽

Flavor Profile

Flavor-profile analysis (FPA) is a sensory method utilizing a trained panel of four to six individuals. Reference materials are used to establish a common vocabulary for different odors found in drinking water. Known quantities of different taste- and odor-causing chemicals are evaluated to calibrate the panel on a consistent intensity scale. Each identifiable descriptor is assigned its own intensity. This method has been successfully applied in the analysis of musty-smelling compounds, e.g., 2-methylisoborneol (MIB). MIB samples and standards from 1 to 80 ng/l have been shown to observe the WeberFechner law (i.e., a plot of flavor intensity versus logarithm of concentration of MIB yielded a straight line). FPA has also been used to handle fishy/swampy odor problems. In many instances, specific causative organic compounds were not identified; however, FPA evaluations of water using different free-chlorine dosages and contact times made possible immediate resolution of these odor problems. FPA has yielded reproducible sensory data that have been useful in better understanding and handling off-flavors in drinking water.

Download Full-text

Flavor Profile Analysis: Taste and Odor Control of the Future

American Water Works Association ◽

10.1002/j.1551-8833.1986.tb05714.x ◽

1986 ◽

Vol 78 (3) ◽

pp. 50-55 ◽

Cited By ~ 16

Author(s):

Jeroen H.M. Bartels ◽

Gary A. Burlingame ◽

I.H. Mel Suffet

Keyword(s):

Profile Analysis ◽

Odor Control ◽

Taste And Odor ◽

The Future ◽

Flavor Profile Analysis ◽

Flavor Profile

Download Full-text

Exposure assessment of taste and odor standards used in the method of flavor profile analysis

Water Science & Technology ◽

10.1016/s0273-1223(99)00559-4 ◽

1999 ◽

Vol 40 (6) ◽

Cited By ~ 3

Keyword(s):

Exposure Assessment ◽

Profile Analysis ◽

Taste And Odor ◽

Flavor Profile Analysis ◽

Flavor Profile

Download Full-text

Exposure Assessment of Taste and Odor Standards Used in the Method of Flavor Profile Analysis

Water Science & Technology ◽

10.2166/wst.1999.0300 ◽

1999 ◽

Vol 40 (6) ◽

pp. 209-215

Author(s):

Linda Schweitzer ◽

I. H. (Mel) Suffet

Keyword(s):

Risk Assessment ◽

Exposure Assessment ◽

Standard Method ◽

Profile Analysis ◽

Occupational Exposures ◽

Limit Values ◽

Threshold Limit Values ◽

Taste And Odor ◽

Flavor Profile Analysis ◽

Flavor Profile

Information on the toxicity of individual chemicals that have been used as known or representative odor standards in the method of Flavor Profile Analysis (FPA) was compiled for an exposure assessment. A full risk assessment was not possible since unit risk values for most of these chemicals do not exist. This study provides a recommendation as to what chemicals can be safely used as known and representative taste and odor standards for the next modification of the Flavor Profile Analysis Standard Method 2170. Excluding any potential odor standard listed as possible or probable carcinogens, there would be no known risk to FPA panelists being exposed to the selected odor reference chemicals at the concentrations used in FPA. Also, the concentrations which panelists are exposed to during an FPA (20 minutes per chemical) are lower than the legal threshold limit values for 8 hour occupational exposures. However, many of the odor reference chemicals have yet to be evaluated for their carcinogenic or noncarcinogenic endpoints. Recommendations are made as to which chemicals should be avoided.

Download Full-text

A Comparison of 1988-1990 Flavor Profile Analysis Results with Water Conditions in Two Northern California Reservoirs

Water Science & Technology ◽

10.2166/wst.1992.0030 ◽

1992 ◽

Vol 25 (2) ◽

pp. 19-25 ◽

Cited By ~ 7

Author(s):

K. Seligman ◽

A. K. Enos ◽

H. H. Lai

Keyword(s):

Chlorophyll A ◽

Profile Analysis ◽

Quality Data ◽

Water Quality Data ◽

Taste And Odor ◽

Storage Reservoirs ◽

Anabaena Sp ◽

Diatom Blooms ◽

Flavor Profile Analysis ◽

Flavor Profile

Flavor Profile Analysis (FPA) results were compared with water quality data for two storage reservoirs of the East Bay Municipal Utility District in Oakland, California to determine what conditions exist at the time of an earthy or musty taste and odor episode. Strong musty and earthy aromas coincided most frequently with fall Anabaena sp. blooms and summer Anacystis sp. blooms. Occasional Aphanizomenon sp. blooms were concurrent with Anabaena sp. blooms, so odor problems associated with Aphanizomenon sp. could not be distinguished. Geosmin concentrations of 30-140 ng/L were found in water containing 100,000-300,000 Anabaena sp. cells/100 mL, but 2-methylisoborneol concentrations never exceeded 25 ng/L. Both reservoirs experienced relatively odorless large spring diatom blooms resulting in high chlorophyll a concentrations, so chlorophyll a alone did not serve as a helpful indicator of imminent odor problems. Fall cyanobacteria blooms closely followed the onset of reservoir destratification, so weekly temperature and dissolved oxygen depth profiles successfully predicted the start of a cyanobacteria bloom. Musty and earthy odors in the filter plant effluent were lower than those in the influent, but effluent FPA numbers reached 4 during two large taste and odor episodes, suggesting that granular activated carbon installed 1-2 years earlier may not remove all odor-causing compounds of a large taste and odor episode.

Download Full-text

Flavor Profile Analysis and GC/MS Detection of Phenolic Iodinated Disenfection Byproducts in Drinking Water for the USA Space Program

Water Science & Technology ◽

10.2166/wst.1999.0258 ◽

1999 ◽

Vol 40 (6) ◽

pp. 45-51 ◽

Cited By ~ 3

Author(s):

Andrea M. Dietrich ◽

Susan Mirlohi ◽

Willian F. DaCosta ◽

Jennifer Peters Dodd ◽

Richard Sauer ◽

...

Keyword(s):

Drinking Water ◽

Potable Water ◽

Profile Analysis ◽

Major Product ◽

Space Program ◽

Odor Threshold ◽

Odor Evaluation ◽

The Usa ◽

Flavor Profile Analysis ◽

Flavor Profile

Reactions of iodine and phenol were investigated to determine which iodophenols were produced and their odor properties. The research was performed in support of the USA space program that applies iodine to disinfect potable water for spacecraft use. Higher concentrations (50 mg/l) and higher iodine:phenol (e.g. 10:1) ratios resulted in the formation of greater iodophenol concentrations and higher substituted iodophenols. The reactions were fast and nearly complete within 1 hour. For pH 5.5 and 8 and all iodine:phenol ratios, formation of monosubstituted compounds indicated that 2-iodophenol was favored over 4-iodophenol. At the intermediate iodine:phenol ratios of 1:1 and 2:1, substantial amounts of the diiophenols formed and persisted for up to 32 days. The diiodophenols were not detected at iodine:phenol ratios of 0.2:1 and 10:1. The compound 2,4,6-triiodophenol was the major product formed at a 10:1 iodine:phenol ratio and the formation of this trisubstituted phenol appeared nearly complete. Odor evaluation indicated that the iodophenols have much lower odor threshold concentrations (OTC) than phenol. The 2- and 4- iodophenol had OTC values of ≅ 1 and 500 μg/l, respectively, with odors described as “medicinal, phenol, chemical”.

Download Full-text