Biomedical subjects

I H Suffet

Publications and source records attributed to I H Suffet.

At least 19 recordsLinked to original sources

PubMed2004

Effects of chlorine and chloramines on earthy and musty odors in drinking water.

Water treatment plants in the US may operate under the assumption that chlorine masks earthy and musty odors from geosmin and 2-methylisoborneol (MIB) in drinking water. To test this hypothesis, we evaluated the effects of chlorine and chloramines on geosmin and MIB by two sensory analysis approaches--a statistical Pairwise Comparison Test, and Flavor Profile Analysis (FPA). All Pairwise Ranking test statistics were significant (p<0.05); we conclude that panelists can differentiate minor differences in geosmin and MIB concentrations in a Pairwise Comparison Test even in the presence of chlorine. FPA appeared to be more challenging in discerning subtle differences in concentrations of geosmin or MIB than did the Pairwise Comparison Test, and the presence of chlorine (0.5-20 mg/L) and chloramines (3-24 mg/L) confused the panelists (i.e showed a larger error in the intensity of response reported by the panel), but did not necessarily mask geosmin or MIB.

Camphanes↗

PubMed2004

Compost odor control using high carbon wood ash.

A pilot study on the feasibility of using high carbon wood ash to control composting odor emissions was conducted at a green material composting facility. The study's treatments consisted of adding 0%, 12.5%, and 25% high carbon wood ash by volume to green-material compost feedstock in three separate windrows. The wood ash has properties similar to activated carbon with an active surface area of 105 square metres per gram on a dry weight basis. The odorant emission data suggest that the higher percentage wood ash treatment results in the most effective control of most compost odors and that wood ash provides effective treatment of volatile fatty acids and some aldehydes and ketones. The 25% wood ash treatment resulted in more effective treatment of odors for a longer time period than the 12.5% treatment. Acetaldehyde had the highest concentration in the control (14,000 times its odor threshold concentration), was reduced by high carbon ash by over 97% but remained 386 times its reported odor threshold concentration after 14 days. Ethyl mecaptan and ammonia were produced in the process and were also over their reported human detection limits.

Adsorption↗

PubMed2004

Understanding odorants associated with compost, biomass facilities, and the land application of biosolids.

Odorous water and air can result from compost, biomass facilities and land application of biosolids. Common odorous compounds from these biodegradation systems include alcohols, aldehydes, fatty acids, solvents and various sulfur and nitrogen compounds. Each odorant possesses a unique individual odor signature i.e. odor character or quality, odor threshold concentration and chemical concentration. This paper develops an initial understanding of how the volatile odorous chemicals and their relative concentrations produced are related to the total odor quality from the process by their odor threshold concentrations. The compost process is used as an example. It was estimated, that on day 1 and 7, the primary fatty acids controlling the fermented and rotten odors were butyric acid and valeric acids, individually, unpleasant and rancid odors, respectively, although acetic acid had the highest fatty acid concentration on both days. In the same way, aldehydes and ketones controlled the disappearance of the sweet odor from day 1 to 7.

Acids↗

PubMed2004

Development of an odor wheel classification scheme for wastewater.

Overall, in the air pollution control field, odor concentration and intensity as well as hedonic rating have been well studied to the point where some level of standardization is being developed or is already in place. However, there has been no standardization with respect to odor quality characterization. There is now sufficient understanding of the types of odorous compounds that can arise from wastewater treatment processes to develop an odor classification scheme. This article presents the first wastewater odor wheel or classification scheme that should form the foundation for the evolution of odor quality data reporting with links to chemical causes.

Environmental Monitoring↗

PubMed2004

The effect of applying a pipe-joint lubricant to connect ductile iron pipe on off-flavors in drinking water distribution systems.

This study was used to help define the contribution to taste and odor problems caused by the application of a pipe-joint lubricant to connect ductile iron pipe in drinking water distribution systems. Tyton Joint Lubricant (TJL) was studied. The lubricant produced odors that are continually oxidized by chlorine or oxygen. The mechanism of oxidative rancidity, one of the major causes of food spoilage is the apparent mechanism of oxidation. The odors produced by the lubricant were characterized by a Flavor Profile Analysis (FPA) panel as well as GC/MS and Sensory GC analysis. The most common odors perceived in the TJL water samples for the first six days were waxy/oily and soapy odors with a rancid oil, odor note. The waxy/oily and soapy odors decreased with time in the chlorine medium as the rancid oily odor note increased. Numerous aldehydes, ketones, alcohols and borneol compounds, produced from the lubricants, were tentatively identified and linked to the odors perceived by the FPA panel.

Equipment Design↗

PubMed2004

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

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.

Bromine↗

PubMed2004

Chlorinous flavor perception in drinking water.

Chlorinous flavors at the tap are the leading cause of customers' complaints and dissatisfaction with drinking water. To characterize consumer perception and acceptance to chlorinous tastes, extensive taste testing was performed with both trained panelists and average consumers. Taste testing with trained panelists showed that chlorine perception is underestimated by disinfectant flavor thresholds reported in the literature. However, trained panelists significantly overestimate the average consumer's ability to perceive chlorine. In addition, consumer perception seems to be influenced by the chlorination practices of the country they live in. Among water quality characteristics that may influence chlorine perception, temperature was not found to induce any significant change. The influence of total dissolved solids (TDS) on chlorine perception remains unclear and, as reported elsewhere, background tastes such as musty, may significantly impact chlorine threshold.

Chlorine Compounds↗

PubMed2004

Public thresholds for chlorinous flavors in U.S. tap water.

Considering this rapid growth in the purchasing of bottled water and home filtration devices, utilities are increasingly concerned about consumer dissatisfaction with tap water quality. This project aimed to characterize public perceptions of chlorinous flavors in drinking water, and how these impact customers' choices with respect to consumption of tap water alternatives. On-site taste tests at seven water utilities with 30 to 40 panelists at each site, were conducted using a forced-choice triangle test method (ASTM method E679-91) to measure public sensitivity to chlorine and chloramine in drinking water. The chlor(am)ine concentration increased from set to set. The best-estimate sensitivity limit for each panelist was the geometric mean of that concentration at which the last miss occurred and the next (adjacent) higher concentration. The measured sensitivity limit of average American populations to free chlorine (159 persons tested) and chloramine (93 persons tested) in tap water were 0.8 and 3.7 mg/L Cl2, respectively. These thresholds are much higher than those previously reported in the literature using trained FPA panels. No significant differences were observed between tap water users and users of tap water alternatives or between the various markets tested with respect to average sensitivity, though individual sensitivity varied widely.

Community Participation↗

PubMed2003

Xenobiotic organic compounds in runoff from fields irrigated with treated wastewater.

Investigations of agricultural nonpoint source pollution typically focus on a relatively narrow range of targeted toxic and biostimulatory compounds (e.g., specific pesticides, nutrients). Regular application of numerous other organic compounds to agricultural fields in pesticide formulations, irrigation water, soil amendments, and fertilizers may result in their transport into surface waters via runoff. We examined whether potentially toxic dissolved and particle-associated "nontarget" organic compounds were present in surface runoff from agricultural fields irrigated with disinfected tertiary recycled water or wastewater effluent-dominated streamwater. Gas chromatographic-mass spectrometric analyses of filtered runoff samples revealed the presence of numerous nontarget compounds of potential toxicological significance including pesticide transformation products, pesticide adjuvant chemicals, plasticizers, flame retardants, pharmaceuticals, and personal care product ingredients. Although the toxicity of many of these compounds is poorly characterized, some may elicit subtle but profound toxicological effects. Agricultural runoff also represented a source of allochthonous natural organic matter to the stream system.

Agriculture↗

PubMed2002

Electrochemical removal of bromide and reduction of THM formation potential in drinking water.

Trihalomethanes (THMs), a by-product of the chlorination of natural waters containing dissolved organic carbon and bromide, are the focus of considerable public health concern and regulation due to their potential as a carcinogen by ingestion. This paper presents a promising new water treatment process that lowers the concentration of bromide in drinking water and thus, lowers the THM formation potential. Bromide is oxidized by electrolysis to bromine and then the bromine apparently volatilized. The electrolyzed water, when chlorinated, produces measurably lower amounts of THMs and proportionately fewer brominated THMs, which are of greater public health concern than the chlorinated THMs. Removing bromide should also reduce the formation of other disinfection by-products such as bromate and haloacetic acids.

Bromides↗

PubMed2002

Comparison of the pollutant loads in dry and wet weather runoff in a southern California urban watershed.

This research compares the relative contributions of potential contaminants discharged in dry weather flow (DWF) and wet weather flow (WWF) from the highly urbanized Ballona Creek watershed (BCW) in southern California using empirical and deterministic models. These models were used to compare the loading of the following pollutants: total suspended solids, biochemical oxygen demand, total nitrogen, total inorganic nitrogen, total Kjeldahl nitrogen, total phosphorus, copper, lead, arsenic, nickel, cadmium, and chromium. The results indicate DWF contributes approximately 10-30% of the total annual flow discharged from Ballona Creek. The annual DWF volume was fairly consistent; the variation in DWF percentage contribution was dependent on the highly variable volume of WWF. The relative contribution to the annual pollutant load varied considerably between each pollutant. In general, the DWF load was found to be significant, especially in years with lower precipitation totals. The results from this investigation have identified the relative relationship between DWF and WWF loads in the BCW and will aid in the decision-making process during the development of an integrated DWF-WWF management plan and allocation of water pollution control funds between DWF and WWF management.

California↗

PubMed2002

Evaluation of urban non-point source runoff of hazardous metals entering Santa Monica Bay, California.

Significant amounts of non-point source runoff enter the Santa Monica Bay from the Ballona Creek Watershed during wet weather flow. The primary objective of this study was to determine the concentrations of hazardous metal pollutants associated with the aqueous and suspended solid phases during wet weather flow. A calculation of the mass of the pollutants for each storm was conducted. Other objectives of this study were to evaluate during a storm event the relationships between (1) soluble and sorbed metals, (2) storm flow and pollutant loading, including a determination if a first flush was present, and (3) total mass loading of pollutants and relative pollution loading from three watershed sub-basins. This study focused on the urbanized watershed of Ballona Creek, which is approximately 330 km2 (127 miles2) in size and developed primarily with residential and light commercial industries. In the 1997-98 rain season, an El Niño year, two storm events were monitored by the collection of hourly grab samples. An initial storm monitored Ballona creek, while a second storm also monitored Ballona Creek along with two smaller sub-watersheds, Centinela Channel and Sepulveda Channel. The results indicated the suspended solids phase primarily transported the mass for five of the six hazardous metals studied: cadmium, chromium, copper, lead, and nickel. Arsenic was found primarily in the aqueous phase.

California↗

PubMed2001

Water quality assessment for indirect potable reuse: a new methodology for controlling trace organic compounds at the West Basin Water Recycling Plant (California, USA).

The West Basin Water Recycling plant (California; USA) was built to increase the region's water resource availability. The plant influent is produced at Los Angeles Hyperion wastewater treatment plant and is treated through two parallel treatment processes depending on the end use: (1) Title 22 water for industrial and urban use, and (2) barrier treatment for groundwater recharge. A new methodology was applied to monitor the fate of base neutral compounds in the water barrier treatment train. The methodology included large sample volumes coupled with integrated chromatographic analysis (ICA). Data indicated a 25% increase in concentration of base neutral compounds after RO pretreatment, followed by a 70% removal efficiency after RO. The increase in concentration after RO pretreatment appears to be linked to the use of lime clarification.

Calcium Compounds↗

PubMed1996

Multi-element, multi-media method for the determination of airborne elemental emissions by inductively coupled plasma atomic emission spectrometry.

The exposure of people to airborne emissions of toxic elements, particularly lead, is well documented. The approach in most studies has been to examine the concentrations of a single element in the air or in the blood of the local population. In urban industrialized settings there can often be many sources of a particular element and the element may not be released alone. In order to establish a full risk assessment and determine the source of emissions, it is important to determine all toxic elements in a variety of media. This paper presents a single analytical procedure for the determination of 16 toxic elements in solids, soils, wipes and glass-fibre filters. The procedure includes adapting an acid digestion method (USEPA SW 846 Method 3050B) and analysis of the digestate by inductively coupled plasma atomic emission spectrometry (USEPA SW 846 Method 6010B). All 16 elements were determined in this medium over several orders of magnitude. Accurate and precise results were obtained to less than 5 ng m-3. The procedure compared well with established procedures for lead.

Air Pollutants↗

PubMed1990

Comparison of quarter-hourly on-line dynamic headspace analysis to purge-and-trap analysis of varying volatile organic compounds in drinking water sources.

On-line dynamic headspace analysis was refined for the quarter-hourly monitoring of select volatile organic compounds (VOCs) in ground and surface waters, for extended periods of time. Hourly comparisons were made to on-line purge-and-trap analysis, and to purge-and-trap analysis after sample preservation and storage. Variations in VOC concentrations of 6047% biweekly, 222% daily, 97% hourly, and 35% quarter-hourly were observable, with the 15-min cycle of the dynamic headspace analysis. The headspace analyzer had superior retention time stability, required less maintenance, and had 1/4 the analysis time as a typical purge-and-trap-gas chromatograph system used for hourly comparisons.

Calibration↗

PubMed1987

The effect of cyclohexene, a preservative in dichloromethane on the liquid-liquid extraction and analysis of chlorinated drinking water.

Liquid-liquid extraction with dichloromethane is the Environmental Protection Agency's (EPA) method of choice for the analysis of acid or base neutral organic chemicals in water. Free radical chlorination and oxidation products of cyclohexene (the solvent preservative) in dichloromethane have been observed in extracts of chlorinated drinking water (after 10(5) fold concentration) by gas chromatography and gas chromatography-mass spectrometry. The chlorinated cyclohexene derivatives limit the quantitative and qualitative analysis of compounds eluting at Kovát's index less than 700-1000 and the use of these extracts for organoleptic and mutagenic studies. The effect of residual free chlorine in water on the cyclohexene present in the solvent was studied. Over ten cyclohexene derivatives were produced in every case when any residual free chlorine was present in the water. When chlorine is reduced to chloramine, the cyclohexene derivatives were greatly reduced in number and amount.

Chloramines↗

PubMed1987

Analysis of acetone-hexane artifacts produced in the Soxhlet extraction of solid environmental samples.

A study was performed to examine the artifact formation during the acetone-hexane Soxhlet extraction of suspended materials collected on glass fiber filters. Capillary gas chromatographic analysis showed a great number of artifacts of significant concentration in the Soxhlet extractions of the filters after cleaning, the acetone solvent blank and the acetone-hexane Soxhlet blank. Gas chromatographic-mass spectrometric analysis indicated that the compounds are primarily condensation products of acetone produced during the Soxhlet extraction process and solvent impurities. Acetone and hexane washes of the glass fiber filters showed a large variety of compounds to be present on the filters as received from the manufacturer. A reaction scheme is proposed to explain the formation of some of the acetone condensation products identified in this study. A comparison study using methylene chloride to clean and extract the filters showed considerably less artifact formation and solvent impurities. The development of an appropriate quality assured extraction method, which minimizes artifact formation, is needed for the broad spectrum analysis of non-polar trace organics associated with suspended materials in aquatic samples.

Acetone↗

PubMed1986

Predominant bacterial genera in granular activated carbon water treatment systems.

Granular activated carbon (GAC) beds may be used for removal of dissolved organic matter during the treatment of drinking water. However, they might also change the microbiological quality of the water entering the distribution system either by changing the predominant bacteria or the bacterial density of the treated water. A 3-year pilot plant study of water treatment using GAC beds was conducted at the Baxter Water Treatment Plant in Philadelphia. During the study, bacteria were isolated from the raw water and from the effluents of the GAC treatment units. At the end of the study, bacteria were also isolated from the GAC units and from sand beds operated in parallel with the GAC units. Bacterial genera in the GAC effluents and in the GAC units themselves were similar to those found in the raw water and in the sand beds. Prechlorination and (or) preozonation of the water before GAC treatment had no noticeable effect on the bacterial genera found as compared with GAC unit having no predisinfection. The bacterial genera found in this study were similar to those found in seven other studies of GAC water treatment that used a variety of treatment schemes and a variety of heterotrophic plate count techniques to evaluate bacterial populations. From these several studies it appears that GAC treatment does not change the nature of the bacterial populations associated with drinking water.

Adsorption↗