The Detection of Taste and Odor in Osaka's Drinking Water

1988 ◽  
Vol 20 (8-9) ◽  
pp. 37-42 ◽  
Author(s):  
H. Sano
Keyword(s):  
Drinking Water ◽  
Tap Water ◽  
Odor Concentration ◽  
Consumer Panel ◽  
Taste And Odor ◽  
Musty Odor ◽  
Taste Assessment

Laboratory and consumer panels were used to determine the threshold odor concentration(TOO of 2-methylisoborneol (MIB) and geosmin in water. The consumer panel was also used to assess the taste of tap water. The results showed that laboratory panel TOCs of MIB and geosmin were 4 and 94 ng/l respectively, while those of consumer panels were 12 and 360 ng/l respectively. In taste assessment, 8% of consumers assessed drinking water as offensive or bad even when the tap water wasn't contaminated by musty odor substances. However if it was contaminated by MIB at its TOC level, 17% of consumers assessed the water as offensive and bad.

The Relationship between Concentration and Sensory Properties of 2-Methylisoborneol and Geosmin in Drinking Water

1988 ◽  
Vol 20 (8-9) ◽  
pp. 11-17 ◽  
Author(s):  
T. Ito ◽  
T. Okumura ◽  
M. Yamamoto
Keyword(s):  
Drinking Water ◽  
Water Temperature ◽  
Forced Choice ◽  
Residual Chlorine ◽  
Mixing Ratio ◽  
Consumer Panel ◽  
Triangle Method ◽  
Musty Odor ◽  
The Relationship ◽  
Mixed Samples

The study of the relations between the senses of smell and taste and odorant concentration is important for the solution of odor problems. The threshold concentrations of odor and taste (TOC, TTC) of 2-methylisoborneol (MIB) and geosmin were measured by the non-forced choice triangle method using 12-20 panelists. Both TOC and TTC were found to be functions of water temperature and the concentration of residual chlorine. The TOC and TTC of mixed samples were rather lower than the concentrations calculated from the mixing ratio. The sensitivities of the consumer panel and the number of musty odor complaints from consumers are related to MIB or geosmin concentration. The ratio of the number of complaints to MIB (or geosmin) concentration decreased after maximum complaint, but the sensitivity of the consumer panel remained the same.

scholarly journals Evaluation of Drinking Water Quality in Schools in a District Area in Hanoi, Vietnam

2020 ◽  
Vol 14 ◽  
pp. 117863022095967
Author(s):  
Dang The Hung ◽  
Vu Thi Cuc ◽  
Vu Thi Bich Phuong ◽  
Dao Thi Thanh Diu ◽  
Nguyen Thi Huyen Trang ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Samples ◽  
Primary Schools ◽  
Tap Water ◽  
Total Iron ◽  
Drinking Water Quality ◽  
National Standard ◽  
Taste And Odor

Background: Drinking water quality affects directly human health. Assessment and prevention of water-borne diseases are crucial for primary prevention, especially for children. Objective: The main aim of this study was to investigate the quality of drinking water from tap water in preschools and primary schools in a district area in Hanoi City, Vietnam. Methods: A cross-sectional study was performed from August to October 2019. Water samples from tap water of 154 schools in a district area of Hanoi were collected to determine the quality of drinking water. From each school, at least 2 bottles of water samples were collected on the basis of a standard operating procedure (SOP). Each water sample was analyzed for microbial and physicochemical parameters, including Color, Taste and Odor, Turbidity, pH, Nitrite, Nitrate, Ammonium, Total Iron, Permanganate, Chloride, Hardness, Total Manganese, Sulfate, Arsenic, Coliform, and E.coli, by analytical methods. The obtained values of each parameter were compared with the standard values set by WHO and National Technical Regulation on Domestic Water Quality of Vietnam. Results: All of the schools employed community water system as a main source for drinking water. The results showed that all tested samples were found to be within the standards for some physicochemical properties, including Color, Taste and Odor, Hardness, Chloride, Total Iron (Fe2+ và Fe3+), Total Manganese (Mn), Nitrate (NO3–), Sulfate (SO42–), and Total Arsenic (As). On the other hand, some samples did not meet the allowable limits of the national standard, due to pH (3.9%), Turbidity (0.6%), Nitrite (3.2%), Permanganate (6.5%), and Ammonium (5.8%). Furthermore, the microbial data revealed that the substandard water samples from municipal water systems were contaminated by Coliform (9.7%) and/or E.coli (7.8%). Conclusions and recommendations: Contaminants such as bacterial and chemical agents in to drinking water could be occurred during transport, storage and handling before using by the consumer without regular surveillance. A periodic treatment procedure and monitoring system to keep the level of microbial and chemical contamination of drinking water in schools under control should be performed.

Events linked to Geosmin and 2-methylisoborneol (2-MIB) in a Water Supply in the State of Rio de Janeiro, Brazil: a case study

2021 ◽  
Vol 5 (5) ◽  
pp. 214-220
Author(s):  
Adriana Sotero - Martins ◽  
Elvira Carvajal ◽  
José Augusto Albuquerque dos Santos ◽  
Priscila Gonçalves Moura ◽  
Natasha Berendonk Handam ◽  
...  
Keyword(s):  
Drinking Water ◽  
Rio De Janeiro ◽  
Tap Water ◽  
Total Concentration ◽  
Cyanobacterial Blooms ◽  
Metropolitan Region ◽  
Metagenomic Data ◽  
Taste Intensity ◽  
Raw Water ◽  
Taste And Odor

Tastes and odors in tap water are problems faced by water companies worldwide, with consumers complaints mainly during summer, when cyanobacterial blooms occur and produce compounds such as geosmin and 2-methylisoborneol (2-MIB). We analyzed the data on taste and odor intensity and total concentration of geosmin and 2-MIB compounds in drinking water and raw water collected by the sanitation company supplying of the metropolitan region of Rio de Janeiro (Brazil) during the 2020 and 2021 water crises. Statistical and metagenomic analyses of the raw water samples of the year 2020, were performed. Organoleptic data allowed to signal the presence of these taste and odor (T&O) compounds in the drinking water, and the mean values of taste intensity were above the maximum allowed value of the Brazilian legislation, on average 37.5 times in 2020 and 5 times in 2021, indicating that the measures did not eliminate the problem. There was a linear correlation of 0.97 between the standard organoleptic taste and the total concentration of T&O in 2020. Metagenomic data, from raw water in the year 2020, for the mtf, mic and glys genes indicated 2-MIB as responsible for T&O. Modifications in the surveillance system of catchment and drinking water quality need to be adopted to circumvent the problems of cyanobacterial blooms in the Guandu basin, as conditions favorable to blooms will occur as long as the sanitation problems in this watershed are not solved.

Application of Chlorine Dioxide in Drinking Water Disinfection

2012 ◽  
Vol 461 ◽  
pp. 497-500
Author(s):  
Deng Ling Jiang ◽  
Bo Wen Chen ◽  
Guo Wei Ni
Keyword(s):  
Drinking Water ◽  
Chlorine Dioxide ◽  
Production Cost ◽  
Tap Water ◽  
Water Disinfection ◽  
High Quality ◽  
Taste And Odor ◽  
Water Plant ◽  
Drinking Water Disinfection ◽  
By Products

Chlorine dioxide was applied to drinking water for reducing the quantity of organic pollutants such as chloroform and the taste and odor problems. A modified mode for operation in tap water plant was proposed following an investigation of the reaction mechanism by which ClO2 reacts with aquatic organic materials. By using such techniques, by-products such as chlorite and chlorate were effectively minimized and high quality drinking water was produced with reduced production cost of water treatment.

scholarly journals Evaluating the efficiency of chlorine removal from potable tap water using off-gassing, boiling, and filtration treatment methods

2018 ◽  
Author(s):  
Katrina Wong ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Helen Heacock ◽  
Frederick Shaw
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Tap Water ◽  
Water Sources ◽  
Free Chlorine ◽  
Chlorine Concentration ◽  
Taste And Odor ◽  
Untreated Water ◽  
Alternative Water ◽  
Alternative Water Sources

  Background: One of the most frequent complaints to water distribution systems is the taste and odor of chlorine in consumer tap water. Chlorine is a common disinfectant used to inactivate and breakdown microbes and other contaminants. However, excess chlorine can result in an unpalatable chlorinous taste and odor. When water taste becomes too objectionable, consumers may search for alternative water sources, such as raw, untreated water that does not contain chemical additives. Raw, untreated water contains various contaminants, including disease-causing pathogens. To encourage consumers to drink treated tap water, and prevent disease, this study evaluated and compared the effectiveness of off-gassing, boiling and filtration as dechlorination methods for consumers to perform on their tap water. Method: Hach Method 8021 was performed to collect and analyse water samples following treatment with Off-gassing, Boiling and Filtration. Water samples were collected from BCIT SW1-1230. The Hach Pocket Colorimeter ™ II determined the free chlorine concentration of the water samples, and compared to a sample of untreated chlorinated tap water to see which method reduced chlorine concentrations the most. Results: Mean concentration of chlorine following off-gassing was determined to be 0.51 ppm, 0.24 ppm following boiling, and 0.55 ppm following filtration. It was determined that the boiling method was statistically significantly different from the mean values of chlorine concentration from the other two methods, as shown by the Kruskal-wallis test (P=0.000), and therefore was the most effective in dechlorinating tap water samples. This was further confirmed by the Scheffe’s Mutliple-Comparison Test and eyeball test. Conclusion: Based on the results, boiling water is the most effective method to dechlorinate potable tap water for consumer acceptability. The free chlorine levels found post-boiling were also found to be below the WHO’s threshold for tasting and smelling chlorine in drinking water (0.3 ppm), and above WHO’s minimum required 0.2 ppm chlorine residual. Therefore, drinking water following boiling will be safe for consumption, as well as free of chlorinous taste and smell. Public Health professionals can safely advise consumers of an effective method to encourage treated tap water consumption, and to discourage finding alternative water sources.  

Relationship between availability of basic amenities and proportion of Slum population in Maharashtra

2020 ◽  
Vol 6 (11) ◽  
pp. 1343-1354
Author(s):  
Dr. Sakreen Hasan
Keyword(s):  
Drinking Water ◽  
Tap Water ◽  
Policy Implications ◽  
Class I ◽  
Urban Centers ◽  
The Sustainable Development ◽  
Closed Drainage ◽  
The People ◽  
Basic Infrastructure ◽  
Slum Population

The urban centers offering diverse employment opportunities and means of livelihood are the main centers of attraction for migration. But the availability of infrastructure is low to accommodate the invariably growing population. The access to basic amenities like electricity, drinking water, toilet facility, wastewater outlet and clean fuel are critical determinants of quality of urbanization. And if it lacks, then it would facilitates the growth of slum.  In this paper it being tried to capture the interdependent relationship between basic amenities and slum population residing in the class I towns in Maharashtra; largest slum populated state of India. As the slum is all about the situation or condition in which the people of medium and lower strata are living. A detailed analysis of proportion of slum population and availability of amenities which includes good housing condition, treated tap water as the source of drinking water, electricity as the source of lightning, households having latrine and bathing facility within the premises, waste water outlet connected to closed drainage, and households availing the banking facilities. This may be a limitation of the study that only these indicators have been taken to assess the availability of amenities and to calculate the amenity index of class I towns of the state of Maharashtra. To achieve the sustainable development goal (Sustainable cities and communities), we have to control the growth of slum population and to combat the formation of slum; we have to analyze the situation of basic infrastructure provided in urban centers. Amenities and slum population has policy implications as to reduce the slum population, provide basic amenities to the households which will improve their standard of living and ultimately lead to reduction in growth of slum and check the future slum formation.

ECOLOGICAL AND PHYSIOLOGICAL ASSESSMENT OF CHEMICAL COMPOSITION OF DRINKING TAP WATER IN KHANTY-MANSIYSK AND SALEKHARD

2020 ◽  
pp. 159-167
Author(s):  
V.V. Lapenko ◽  
L.N. Bikbulatova ◽  
E.M. Ternikova
Keyword(s):  
Drinking Water ◽  
Chemical Composition ◽  
Water Samples ◽  
Tap Water ◽  
Iron Concentration ◽  
Absorption Spectrometry ◽  
Northern Region ◽  
Transport Processes ◽  
Magnesium Concentration ◽  
Geochemical Environment

Water is very important for humans, as it is a solvent for metabolic products. Moreover, it is necessary for metabolism, biochemical and transport processes. The elemental status in persons depends on the geochemical environment and consumption of bioelements with food and water. The aim of the paper is to conduct a comprehensive assessment of chemical composition of drinking tap water in Khanty-Mansiysk and Salekhard. Materials and Methods. The chemical composition of 100 samples of drinking tap water was analyzed by atomic absorption spectrometry, spectrophotometry and capillary electrophoresis. All in all, there were 50 samples from Khanty-Mansiysk and 50 samples from Salekhard. The results were compared with Sanitary Rules and Norms 2.1.4.1074-01. Results. Drinking tap water in Salekhard contains a significantly higher concentration of iron, which is much above the maximum allowable concentration, if compared to water samples in Khanty-Mansiysk (p=0.03). In the cities under consideration, the water undergoes high-quality reagent-free treatment. However, the deterioration of the water supply networks in Salekhard is 3 times as high as in Khanty-Mansiysk. Calcium and magnesium concentration in water samples from Khanty-Mansiysk is 5.6 and 3.9 times lower than the MAC; in water samples from Salekhard calcium concentration is 6.3 (p=0.008) and magnesium concentration 4.6 (p<0.001) times lower than the MAC. Conclusion. The consumption of ultra-fresh drinking water leads to low intake of bioelements, which are a part of enzymes contributing to the human antioxidant defense and can result in manifestation of cardiovascular diseases. This is especially true for Salekhard with very soft drinking water and high iron concentration, which excess can exhibit prooxidant properties. Keywords: tap water, bioelements, northern region, antioxidants. Вода является важнейшим соединением для человека: необходима в качестве растворителя продуктов метаболизма и протекания обменных, биохимических и транспортных процессов. Элементный статус организма человека зависит от геохимического окружения и поступления биоэлементов с пищей и водой. Цель. Провести комплексную оценку химического состава водопроводной воды городов Ханты-Мансийск и Салехард. Материалы и методы. Методами атомно-абсорбционной спектрометрии, спектрофотометрии и капиллярного электрофореза проанализирован химический состав 100 проб водопроводной воды: по 50 из Ханты-Мансийска и Салехарда. Результаты сравнивали с СанПиН 2.1.4.1074-01. Результаты. В водопроводной воде Салехарда установлена превышающая ПДК и достоверно более высокая концентрация железа сравнительно с водой Ханты-Мансийска (р=0,03). При условии качественной безреагентной водоподготовки в изучаемых городах это обусловлено изношенностью водопроводных сетей в Салехарде, более чем в 3 раза превышающей этот показатель в Ханты-Мансийске. Концентрация кальция и магния в воде Ханты-Мансийска в 5,6 и 3,9 раза ниже ПДК; в воде Салехарда – в 6,3 (р=0,008) и 4,6 (р<0,001) раза ниже ПДК соответственно. Заключение. Употребление ультрапресной питьевой воды на фоне очень малого поступления с водой биоэлементов, входящих в состав ферментов антиоксидантной защиты организма человека, может привести к манифестации кардиоваскулярных заболеваний. Это особенно актуально для г. Салехарда с очень мягкой питьевой водой с повышенным содержанием железа, избыток которого может проявлять прооксидантные свойства. Ключевые слова: водопроводная вода, биоэлементы, северный регион, антиоксиданты.

Lead removal from drinking water - development and validation of point-of-use treatment devices

2002 ◽  
Vol 2 (5-6) ◽  
pp. 209-216
Author(s):  
R. Sublet ◽  
A. Boireau ◽  
V.X. Yang ◽  
M.-O. Simonnot ◽  
C. Autugelle
Keyword(s):  
Drinking Water ◽  
Fixed Bed ◽  
Field Testing ◽  
Lead Removal ◽  
Ministry Of Health ◽  
Point Of Use ◽  
Taste And Odor ◽  
Wide Range ◽  
Lead Levels ◽  
Safety Considerations

Two lead removal water filters were developed to lower lead levels in drinking water below 10 μg.L-1 in order to meet the new regulation given by the European Directive 98-83, applicable in December 2013. An appropriate adsorbent was selected through a stringent research program among a wide range of media, and is composed of a synthetic zeolite and an activated carbon. Two prototypes were developed: the first is a faucet-mounted filter which contains a fixed bed of the adsorbent and a hollow fiber bundle, while the second is an under-sink cartridge made of a porous extruded block of carbon and adsorbent. Both are able to treat at least 1,000 litres of any water containing on average 100 to 150 μg Pb.L-1, by lowering the lead concentration below 10 μg.L-1. Once their safety considerations were addressed by an independent laboratory according to the French Ministry of Health recommendations, 20 prototypes were installed at consumers' taps in northeastern France. Their performance in terms of lead removal, HPC control and bad taste and odor reduction was followed for 6 months. This field testing program resulted in the validation of both prototypes which meet the new French Ministry of Health recommendations and assures that the filtered water is fully ED 98-83 compliant. Their commercialization will be launched first in France in middle 2002.

Enterovirus Concentration Using Automated Hollow Fiber Ultrafiltration

1982 ◽  
Vol 14 (4-5) ◽  
pp. 257-272 ◽  
Author(s):  
G Belfort ◽  
A Paluszek ◽  
L S Sturman
Keyword(s):  
Drinking Water ◽  
Hollow Fiber ◽  
Enhanced Recovery ◽  
Tap Water ◽  
Membrane Surface ◽  
Creeping Flow ◽  
Hollow Fibers ◽  
Virus Concentration ◽  
Concentration Technique ◽  
Solution Interface

The Automated Hollow Fiber Ultrafiltration (AHFU) method is proposed here as a simple, efficient and rapid virus concentration technique from tap and drinking water sources. The results reported here extend the testing of the AHFU method to include two Picornaviruses [Poliovirus 2 (vaccine) and Echovirus 1] and Reovirus 3. Their respective mean virus recoveries from between 3 and 100 l of tap water is 88 ± 26, 79 ± 60, and 104 ± 48%. Various approaches including membrane surface modification, changes in backwash hydrodynamics, modification of the feed and backwash composition, and the use of S35-methionine labelled Poliovirus 2, are used to study the recovery of sorbed Poliovirus 2 from the hollow fiber/solution interface. An increase in the backwash pH to between 9.5 and 10.5 significantly improved Poliovirus 2 recovery. This, together with the labelled experiments, indicates that the virus-membrane interactions are probably electrostatic in nature. Convective polarization during filtration probably brings the virus close enough to the surface for these interactions to occur since virus losses were not detected for a non-permeation recycle experiment. Because very low Reynold's numbers are used, the flow is in the creeping-flow-regime for both filtration and backwashing (axial and radial). Unless significantly higher Reynolds could be used, enhanced recovery due to purely hydrodynamic forces is unlikely. High Reynold's numbers, of course, are limited by the pressure constraints of the hollow fibers.

PTSA (pressure and thermal swing adsorption) method to remove trihalomethanes from drinking water

1997 ◽  
Vol 35 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Shigekazu Nakano ◽  
Tomoko Fukuhara ◽  
Masami Hiasa
Keyword(s):  
Drinking Water ◽  
Residual Chlorine ◽  
Remarkable Difference ◽  
Adsorption Method ◽  
Heating And Cooling ◽  
Point Of Use ◽  
Thermal Swing Adsorption ◽  
Long Time ◽  
Musty Odor ◽  
Vacuum Heating

It has been widely recognized that trihalomethanes (THMs) in drinking water pose a risk to human health. THMs can be removed to a certain extent by the conventional point-of-use (POU) unit which is composed of activated carbon (AC) and microfilter. But it's life on THMs is relatively shorter than on residual chlorine or musty odor. To extent the life of AC adsorber, pressure and thermal swing adsorption (PTSA) was applied by preferential regeneration of chloroform. PTSA was effective to remove THMs, especially chloroform. Adsorption isotherms of chloroform at 25 and 70°C showed a remarkable difference so that thermal swing was considered effective. Chloroform was also desorbed by reducing pressure. By vacuum heating at 70°C, chloroform was almost desorbed from AC and reversible adsorption was considered possible. A prototype of POU unit with PTSA was proposed. Regeneration mode would consist of dewatering, vacuum heating and cooling (backwashing). The unit was maintained in bacteriostatic condition and could be used for a long time without changing an AC cartridge.

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