Ability of humans to smell geosmin, 2-MIB and nonadienal in indoor air when using contaminated drinking water

2007 ◽  
Vol 55 (5) ◽  
pp. 249-256 ◽  
Author(s):  
P. Ömür-Özbek ◽  
J.C. Little ◽  
A.M. Dietrich
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Indoor Air ◽  
Threshold Concentration ◽  
Raw Water ◽  
Threshold Values ◽  
Concentration Data ◽  
Customer Complaints ◽  
Odour Threshold ◽  
Contaminated Drinking Water

The most common compounds responsible for off flavours are geosmin, 2-MIB, and nonadienal which are poorly removed by conventional water treatment operations and hence result in customer complaints. Because these odourants are moderately volatile and have very low odour threshold values, it is necessary to determine their concentrations in air when water is used indoors. If the detectable aqueous concentrations for these odourants are known, the utilities may take action to treat their water at times when the concentration of the raw water exceeds the threshold concentration. To predict the concentration in the shower stall and bathroom air after showering, recently published Henry's law constants for the selected odourants and a model developed to determine the volatilization of the odourous compounds by applying two-resistance theory were used. Then the results were compared with the odour threshold concentration data to determine under which conditions the odourants become detectable. For parameters representing a typical bathroom and shower stall setting, the results showed that the odourants become detectable when the aqueous concentration of geosmin and nonadienal exceed 10 ng/L at 42 °C. As the aqueous concentration increases, geosmin and nonadienal become detectable at lower temperatures, however 2-MIB is only detectable above 20 ng/L and at 42 °C.

scholarly journals Comparing inhalation and ingestion exposure to chemical contaminants and odorants in mixtures

2017 ◽  
Vol 18 (5) ◽  
pp. 1739-1746
Author(s):  
D. L. Gallagher ◽  
K. Phetxumphou ◽  
A. M. Dietrich
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Minor Component ◽  
Biological Properties ◽  
Threshold Concentration ◽  
Water Utility ◽  
Chemical Spills ◽  
Odour Threshold ◽  
Trans Methyl ◽  
Cis And Trans

Abstract Chemical spills polluting drinking water are often mixtures with each chemical having unique characteristics for partitioning, toxicity, and odour leading to significant differences in human risk exposures. A 2014 chemical spill of crude (4-methylcyclohexyl)methanol (MCHM) resulted in a $126 million USD fine to the water utility. The spill consisted of at least ten chemicals including 34% cis- and 60% trans-4-MCHM and 0.7% cis- and 0.3% trans-methyl-4-methylcyclohexanecarboxylate (MMCHC). While a very minor component, trans-MMCHC contributed substantially to odour because of its high Henry's Law Constant, 2.23 × 10−2 at 40 °C showering, and low odour threshold concentration (OTC), 0.02 ppb-v, air. Using USEPA risk assessment parameters in a 15-minute shower model with influent concentration of 42 ppb-aq cis- and trans-4-MMCHC, representative of initial spill concentrations in the distribution system, adult ingestion and inhalation for trans-MMCHC were almost equal, 4.00 × 10−4 and 4.26 × 10−4 mg/kg/d, respectively. For children, inhalation doses exceeded ingestion dose: 1.72 × 10−3 mg/kg/d versus 0.93 × 10−3 mg/kg/day trans-MMCHC. This exposure assessment with varying OTC for crude MCHM chemicals reinforces considering chemical, physical, and biological properties of all chemicals in the spill. Consumers aware of their exposure to chemicals in drinking water lost consumer confidence; the water utility was required to compensate individuals and businesses for financial losses.

scholarly journals Cyanobacteria and microcystin contamination in untreated and treated drinking water in Ghana

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Gloria Naa Dzama Addico ◽  
Jörg D. Hardege ◽  
Jiri Kohoutek ◽  
Kweku Amoaku Atta DeGraft-Johnson ◽  
Pavel Babica
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Human Health ◽  
Metropolitan Area ◽  
Cyanobacterial Blooms ◽  
Maximal Concentration ◽  
Raw Water ◽  
Treated Water ◽  
Treated Drinking Water ◽  
Who Guideline

<p>Although cyanobacterial blooms and cyanotoxins represent a worldwide-occurring phenomenon, there are large differences among different countries in cyanotoxin-related human health risk assessment, management practices and policies. While national standards, guideline values and detailed regulatory frameworks for effective management of cyanotoxin risks have been implemented in many industrialized countries, the extent of cyanobacteria occurrence and cyanotoxin contamination in certain geographical regions is under-reported and not very well understood. Such regions include major parts of tropical West and Central Africa, a region constisting of more than 25 countries occupying an area of 12 million km<sup>2</sup>, with a total population of 500 milion people. Only few studies focusing on cyanotoxin occurrence in this region have been published so far, and reports dealing specifically with cyanotoxin contamination in drinking water are extremely scarce. In this study, we report seasonal data on cyanobacteria and microcystin (MC) contamination in drinking water reservoirs and adjacent treatment plants located in Ghana, West Africa. During January-June 2005, concentrations of MCs were monitored in four treatment plants supplying drinking water to major metropolitan areas in Ghana: the treatment plants Barekese and Owabi, which serve Kumasi Metropolitan Area, and the plants Kpong and Weija, providing water for Accra-Tema Metropolitan Area. HPLC analyses showed that 65% samples of raw water at the intake of the treatment plants contained intracellular MCs (maximal detected concentration was 8.73 µg L<sup>-1</sup>), whereas dissolved toxins were detected in 33% of the samples. Significant reduction of cyanobacterial cell counts and MC concentrations was achieved during the entire monitoring period by the applied conventional water treatment methods (alum flocculation, sedimentation, rapid sand filtration and chlorination), and MC concentration in the final treated water never exceeded 1 µg L<sup>-1</sup> (WHO guideline limit for MCs in drinking water). However, cyanobacterial cells (93-3,055 cell mL<sup>-1</sup>) were frequently found in the final treated water and intracellular MCs were detected in 17% of the samples (maximal concentration 0.61 µg L<sup>-1</sup>), while dissolved MCs were present in 14% of the final treated water samples (maximal concentration 0.81 µg L<sup>-1</sup>). It indicates a borderline efficiency of the water treatment, thus MC concentrations in drinking water might exceed the WHO guideline limit if the treatment efficiency gets compromised. In addition, MC concentrations found in the raw water intake might represent significant human health risks for people living in areas with only a limited access to the treated or underground drinking water.</p>

scholarly journals OPTIMIZATION OF THE DRINKING WATER TREATMENT PROCESS OF A SUGAR PLANT STATION IN COTE DIVOIRE

2021 ◽  
Vol 9 (01) ◽  
pp. 512-524
Author(s):  
Konan Lopez Kouame ◽  
◽  
Nogbou Emmanuel Assidjo ◽  
Andre Kone Ariban ◽  
◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Process ◽  
Polynomial Regression ◽  
Drinking Water Treatment ◽  
Optimal Dose ◽  
Raw Water ◽  
Water Treatment Process ◽  
Jar Test ◽  
Coagulation And Flocculation

This article presents an optimization of the drinking water treatment process at the SUCRIVOIRE treatment station. The objective is to optimize the coagulation and flocculation process (fundamental process of the treatment of said plant)by determining the optimal dosages of the products injected and then proposes a program for calculating the optimal dose of coagulant in order to automatically determine the optimal dose of the latter according to the raw water quality. This contribution has the advantage of saving the user from any calculations the latter simply enters the characteristics of the raw effluent using the physical interface of the program in order to obtain the optimum corresponding coagulant concentration. For the determination of the optimal coagulant doses, we performed Jar-Test flocculation tests in the laboratory over a period of three months. The results made it possible to set up a polynomial regression model of the optimal dose of alumina sulfate as a function of the raw water parameters. A program for calculating the optimal dose of coagulant was carried out on Visual Basic. The optimal doses of coagulant obtained vary from 25, 35, 40 and 45 mg/l depending on the characteristics of the raw effluent. The model obtained is: . Finally, verification tests were carried out using this model on the process. The results obtained meet the WHO drinkability standards for all parameters for a settling time of two hours.

scholarly journals Simulation of NOM events in pilot plant evaluation of DAF/Ozone/BAC for drinking water treatment

2017 ◽  
Vol 17 (6) ◽  
pp. 1793-1800
Author(s):  
Y. Yan ◽  
M. Carter ◽  
A. Mercer
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Pilot Plant ◽  
Drinking Water Treatment ◽  
Natural Occurrence ◽  
Raw Water ◽  
Humic Materials ◽  
Pilot Investigation ◽  
Brewing Method ◽  
Plant Evaluation

Abstract Pilot plant testing is invaluable for ascertaining the robustness of water treatment processes against raw water quality events such as turbidity and colour spikes, whether it be for stress testing of an existing process or designing of a new process. Unfortunately, the natural occurrence of such events (particularly colour) can be difficult to predict and commercial humic materials generally fail to closely match the indigenous natural organic matter (NOM) present in the raw water. Therefore, it is highly desirable to be able to simulate NOM event conditions. This paper describes a simple brewing method that we developed and used in our recent pilot plant evaluation of a proposed DAF/Ozone/BAC process for drinking water treatment. Using this method we successfully prepared, by using fallen leaves etc. collected from the local catchment area, large quantities of a concentrated NOM stock solution with its specific ultraviolet absorbance (SUVA), when diluted, very close to the median SUVA of historical NOM events. The brewed solution showed broadly similar NOM characteristics to those of the raw water encountered during the pilot investigation period in terms of molecular weight distribution and fractionation. The coagulation behaviour was also examined for the spiked and non-spiked raw water.

scholarly journals Predicting the residual aluminum level in water treatment process

2012 ◽  
Vol 5 (1) ◽  
pp. 243-264
Author(s):  
J. Tomperi ◽  
M. Pelo ◽  
K. Leiviskä
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Prediction Models ◽  
Treatment Plant ◽  
Warning System ◽  
High Dose ◽  
Raw Water ◽  
Residual Aluminum ◽  
Study Results ◽  
Ann Models

Abstract. In water treatment processes, aluminum salts are widely used as coagulation chemical. High dose of aluminum has been proved to be at least a minor health risk and some evidence points out that aluminum could increase the risk of Alzheimer's disease thus it is important to minimize the amount of residual aluminum in drinking water and water used at food industry. In this study, the data of a water treatment plant (WTP) was analyzed and the residual aluminum in drinking water was predicted using Multiple Linear Regression (MLR) and Artificial Neural Network (ANN) models. The purpose was to find out which variables affect the amount of residual aluminum and create simple and reliable prediction models which can be used in an early warning system (EWS). Accuracy of ANN and MLR models were compared. The new nonlinear scaling method based on generalized norms and skewness was used to scale all measurement variables to range [−2...+2] before data-analysis and modeling. The effect of data pre-processing was studied by comparing prediction results to ones achieved in an earlier study. Results showed that it is possible to predict the baseline level of residual aluminum in drinking water with a simple model. Variables that affected the most the amount of residual aluminum were among others: raw water temperature, raw water KMnO4 and PAC / KMnO4-ratio. The accuracies of MLR and ANN models were found to be almost equal. Study also showed that data pre-processing affects to the final prediction result.

scholarly journals SONOMICROBIOLOGY OF RAW WATER AT THE TREATEMENT BY AIR-JET GENERATORS

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
CARMEN CIRNU ◽  
ANCA STEFAN ◽  
GEORGE BALAN
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Effect ◽  
Raw Water ◽  
Treatment Technology ◽  
Air Jet ◽  
Sonic Treatment ◽  
Ultrasound Generator ◽  
Water Plants ◽  
Microbiological Indicators

<p>The paper presents the sonic treatment effect on the microbiological indicators of the raw water, namely total germ number, Streptococci number, total coli forms and fecal coli forms. Also, the paper comprises the sonic installation which includes the vertical reactor and the air-jet ultrasound generator. The results allow the development of a new raw water treatment technology that will eliminate the actually two-stage treatment - filtration and chlorination, for the drinking water plants. </p>

scholarly journals UJI COBA PROSES KOAGULASI-FLOKULASI AIR BAKU UNTUK PDAM DANAU TELOKO DAN TELUK GELAM DI KAYU AGUNG KABUPATEN OKI PROPINSI SUMATERA SELATAN

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Petrus Nugro Rahardjo
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Quality Standards ◽  
Synthetic Polymer ◽  
Raw Water ◽  
Aluminum Sulphate ◽  
Optimum Ph ◽  
Trial Test

Regional Drinking Water Company (PDAM) of County Ogan Komering Ilir has two problematic water treatment units. The first is located in Danau Teloko and the other is in the Teluk Gelam. The main problem is that many organic pollutants (namely peat water) contained in raw water. Therefore, PDAM can not be optimal to supply all the needs of drinking water for the community. PDAM have tried to treat the raw water of peat with the process of flocculation and coagulation, but the results did not meet quality standards as drinking water. This research is a trial test to obtain the optimum condition for flocculation and coagulation processes in water treatment. The results were very succesful and get the optimum pH is about 7.5 and a chemical dose of 80 ppm Aluminum Sulphate as the coagulant. Turbidity of water produced is 4 NTU and visually looks very clean. Better to add a synthetic polymer (PAC) as an additive to the process of flocculation and coagulation. Based on calculations, PDAM Danau Teloko will require the amount of coagulant (Aluminum Sulphate) 138.24 kg per day to produce 40 liters of drinking water per second. Keywords : Raw Water, Flocculation, Coagulation,  Water Treatment Plant

Sign in / Sign up

Export Citation Format

Share Document