Identification of new odorous compounds in Swedish water: mixed haloanisoles and phenolic precursors

2007 ◽  
Vol 55 (5) ◽  
pp. 185-193 ◽  
Author(s):  
E. Corbi ◽  
D. Benanou ◽  
J. Cantet ◽  
J.C. Tabet
Keyword(s):  
Residence Time ◽  
Distribution System ◽  
Tap Water ◽  
Critical Factors ◽  
Different Types ◽  
Different Seasons ◽  
Odour Threshold ◽  
Odorous Compounds

Mixed chlorobromoanisoles have recently been recognized as new potential odorous compounds in tap water. The odour threshold concentrations (OTCs) of these compounds are close to the sub ng/L (ppt) and associated descriptors are “earthy, musty, rubber”. During a “swampy, musty” episode in water of the Norrtälje district (Sweden), 2,4,6-mixed chlorobromoanisoles and their phenolic precursors were identified. These compounds were synthesised in order to quantify them in different types of waters. Samplings were performed during two different seasons. Results show that whatever the season, mixed haloanisoles and their precursors were present. Chlorination, biofilm activity and residence time in the distribution system seem to be critical factors for the appearance of such compounds.

scholarly journals Identification of Factors Affecting Bacterial Abundance and Community Structures in a Full-Scale Chlorinated Drinking Water Distribution System

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 627 ◽  
Author(s):  
Vanessa Dias ◽  
Audrey-Anne Durand ◽  
Philippe Constant ◽  
Michèle Prévost ◽  
Emilie Bédard
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Residence Time ◽  
Distribution System ◽  
Bacterial Community Structure ◽  
Water Distribution ◽  
Tap Water ◽  
Treated Water ◽  
Drinking Water Distribution ◽  
Chlorinated Drinking Water

Disentangling factors influencing suspended bacterial community structure across distribution system and building plumbing provides insight into microbial control strategies from source to tap. Water quality parameters (residence time, chlorine, and total cells) and bacterial community structure were investigated across a full-scale chlorinated drinking water distribution system. Sampling was conducted in treated water, in different areas of the distribution system and in hospital building plumbing. Bacterial community was evaluated using 16S rRNA gene sequencing. Bacterial community structure clearly differed between treated, distributed, and premise plumbing water samples. While Proteobacteria (60%), Planctomycetes (20%), and Bacteroidetes (10%) were the most abundant phyla in treated water, Proteobacteria largely dominated distribution system sites (98%) and taps (91%). Distributed and tap water differed in their Proteobacteria profile: Alphaproteobacteria was dominant in distributed water (92% vs. 65% in tap waters), whereas Betaproteobacteria was most abundant in tap water (18% vs. 2% in the distribution system). Finally, clustering of bacterial community profiles was largely explained by differences in chlorine residual concentration, total bacterial count, and water residence time. Residual disinfectant and hydraulic residence time were determinant factors of the community structure in main pipes and building plumbing, rather than treated water bacterial communities.

Evaluation of the disinfection potential of low chlorine concentrations in tap water using immobilised enterococcus faecium in a continuous flow device

1997 ◽  
Vol 35 (11-12) ◽  
pp. 77-80 ◽  
Author(s):  
A. Wiedenmann ◽  
M. Braun ◽  
K. Botzenhart
Keyword(s):  
Distribution System ◽  
Enterococcus Faecium ◽  
Continuous Flow ◽  
Tap Water ◽  
Test System ◽  
Batch Experiments ◽  
Membrane Filters ◽  
Upper Limit ◽  
Flow Device ◽  
Faecal Streptococci

A simple continuous flow device in which bacteria were immobilised on membrane filters and flushed with tap water with free chlorine residuals of 0.05, 0.1, 0.2 and 0.4mg/L at pH 7.7 and 10°C, has been used for disinfection experiments with faecal streptococci. A 99.99% reduction of Enterococcus faecium was observed between 3.4–5.2min (0.05mg/L), between 2.8–4.1min (0.1mg/L), between 1.7–3.1min (0.2mg/L) and between 0.8–2.1min (0.4mg/L). CT-products covered a range of 0.17 (0.05mg/L, lower limit) up to 0.85mg/L/min (0.4mg/L, upper limit). The test system is suggested as a more reliable alternative to batch experiments when the disinfection potential of low chlorine concentrations acting for several minutes has to be evaluated. The system cannot be used to demonstrate exact reduction kinetics but it allows the calculation of CT values and the evaluation of the disinfection potential of chlorinated water at any point of a distribution system where initial chlorine concentrations may have already remarkably declined.

Coupling compositional data analysis (CoDA) with hierarchical cluster analysis (HCA) for preliminary understanding of the dynamics of a complex water distribution system: the Naples (south Italy) case study

2021 ◽  
Author(s):  
Pooria Ebrahimi ◽  
Stefano Albanese ◽  
Leopoldo Esposito ◽  
Daniela Zuzolo ◽  
Domenico Cicchella
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Compositional Data ◽  
Tap Water ◽  
Hierarchical Cluster ◽  
Compositional Data Analysis ◽  
Anthropogenic Pressure ◽  
South Italy ◽  
Global Concern

Providing safe tap water has been a global concern. Water scarcity, the ever-increasing water demand, temporal variation of water consumption, aging urban water infrastructure and anthropogenic pressure on the water...

scholarly journals Evaluating Critical Factors Influencing the Reliability of Emergency Logistics Systems Using Multiple-Attribute Decision Making

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1115 ◽  
Author(s):  
Peng Jiang ◽  
Yixin Wang ◽  
Chao Liu ◽  
Yi-Chung Hu ◽  
Jingci Xie
Keyword(s):  
Decision Making ◽  
Distribution System ◽  
Multiple Attribute Decision Making ◽  
Supply System ◽  
Critical Factors ◽  
Logistics System ◽  
Factors Influencing ◽  
Emergency Logistics ◽  
Multiple Attribute ◽  
Coordination System

The infectious disease COVID-19 has swept across the world in 2020, and it continues to cause massive losses of life and severe economic problems in all countries. Providing emergency supplies such as protective medical equipment and materials required to secure people’s livelihood is thus currently prioritized by governments. Establishing a reliable emergency logistics system is critical in this regard. This paper used the Delphi method to design a formal decision structure to assess emergency logistics system reliability (ELSR) by obtaining a consensus from a panel of experts. Assessing ELSR is a typical multiple-attribute decision making (MADM) problem, and the related MADM methods are usually on the basis of symmetry principles. A hybrid MADM model, called the Decision Making Trial and Evaluation Laboratory (DEMATEL)-based Analytical Network Process (D-ANP), was developed to identify the critical factors influencing ELSR. An analysis of empirical evidence showed that the emergency logistics command and coordination system and the emergency material supply system play important roles in ELSR, while the emergency logistics transportation and distribution system and the emergency information system are not so important. This conclusion is different from previous research about traditional disaster emergency logistics. Moreover, the cause–effect relationships among the key factors indicated that the system of command and coordination for emergency logistics and the supply system for emergency materials should be improved. Accordingly, effective suggestions for emergency logistics services for epidemic prevention are provided in this paper. The main contributions of this paper are (1) establishing a comprehensive and systematic evaluating index of ELSR for epidemic prevention; (2) employing a kind of structured, namely D-ANP, to identify the critical factors with non-commensurable and conflicting (competing) characteristics; and (3) comparing the differences of reliable criteria between the emergency logistics of epidemic prevention and the traditional disaster emergency logistics.

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.

Presence and formation of disinfection by-products in Cairo residential water supply

2009 ◽  
Vol 9 (2) ◽  
pp. 113-120 ◽  
Author(s):  
E. H. Smith ◽  
K. E. El-Deen
Keyword(s):  
Natural Organic Matter ◽  
Distribution System ◽  
Tap Water ◽  
Residential Community ◽  
Chlorine Disinfection ◽  
Sampling Program ◽  
The Impact ◽  
By Products ◽  
The U.S ◽  
Residential Water

A sampling program was conducted in a residential community in Cairo, Egypt in order to determine the presence of chlorine disinfection by-products (DBPs) in treated water and to observe the impact of the distribution system on DBP levels. Five campaigns were conducted over a 15-month period during 2005–2006. Trihalomethanes (THMs) and haloacetic acids (HAAs) exceeded local and international limits depending upon the season. Tap water concentrations of THMs were considerably higher in summer than during the rest of the year. In the Summer 2005 event, the average for the 20 tap water locations was 158 μg/l Total-THMs, well in excess of the U.S. EPA limit of 80 μg/L and the current Egyptian standard of 100 μg/l; all 20 locations exceeded the 100 μg/l limit. For the following event in late Fall 2005, the average dropped to 84 μg/l with 11 and 6 sites exceeding the U.S. EPA and Egyptian limits, respectively. HAA levels tended to be complementary to Total-THM values in that they were lower in summer but higher during fall and spring. The U.S. EPA limit on a select set of 5 HAAs (HAA5) is 60 μg/l (Egypt does not currently regulate HAAs). The average for HAA5 in the Summer 2005 event was 52 μg/l with 8 of the 20 tap samples equalling or exceeding the 60 μg/l standard. By contrast, in Fall 2005, the HAA5 average increased to 89 μg/l, with 15 of 20 sites exceeding the limit. THM and HAA concentrations generally increased with distance from the WTP along a targeted distribution main, while chlorine and natural organic matter tended to decrease.

scholarly journals The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System

2018 ◽  
Vol 15 (8) ◽  
pp. 1756 ◽  
Author(s):  
Pirjo-Liisa Rantanen ◽  
Ilkka Mellin ◽  
Minna Keinänen-Toivola ◽  
Merja Ahonen ◽  
Riku Vahala
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
Drinking Water Distribution System ◽  
Ammonium Oxidation ◽  
Water Age ◽  
Sampling Campaign ◽  
Drinking Water Distribution

We studied the seasonal variation of nitrite exposure in a drinking water distribution system (DWDS) with monochloramine disinfection in the Helsinki Metropolitan Area. In Finland, tap water is the main source of drinking water, and thus the nitrite in tap water increases nitrite exposure. Our data included both the obligatory monitoring and a sampling campaign data from a sampling campaign. Seasonality was evaluated by comparing a nitrite time series to temperature and by calculating the seasonal indices of the nitrite time series. The main drivers of nitrite seasonality were the temperature and the water age. We observed that with low water ages (median: 6.7 h) the highest nitrite exposure occurred during the summer months, and with higher water ages (median: 31 h) during the winter months. With the highest water age (190 h), nitrite concentrations were the lowest. At a low temperature, the high nitrite concentrations in the winter were caused by the decelerated ammonium oxidation. The dominant reaction at low water ages was ammonium oxidation into nitrite and, at high water ages, it was nitrite oxidation into nitrate. These results help to direct monitoring appropriately to gain exact knowledge of nitrite exposure. Also, possible future process changes and additional disinfection measures can be designed appropriately to minimize extra nitrite exposure.

scholarly journals Application of model fitting technique to enhance bacterial regrowth potential (BRP) measurement for drinking water supply monitoring

2021 ◽  
Author(s):  
Wenjin Xue ◽  
Christopher W. K. Chow ◽  
John van Leeuwen
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Samples ◽  
Distribution System ◽  
Distribution Systems ◽  
Tap Water ◽  
Treatment Plant ◽  
Drinking Water Supply ◽  
Water Supply Systems ◽  
Bacterial Regrowth

Abstract The bacterial regrowth potential (BRP) method was utilised to indirectly measure the assimilable organic carbon (AOC) as an indicator for the assessment of the microbial regrowth potential in drinking water distribution systems. A model using various microbial growth parameters was developed in order to standardise the experimental interpretation for BRP measurement. This study used 82 experimental BRP data sets of water samples collected from the water treatment plant to locations (customer taps) in the distribution system. The data were used to model the BRP process (growth curve) by a data fitting procedure and to obtain a best-fitted equation. Statistical assessments and model validation for evaluating the equation obtained by fitting these 82 sets of data were conducted, and the results show average R2 values were 0.987 for treated water samples (collected at the plant prior to chlorination) and 0.983 for tap water (collected at the customer taps). The F values obtained from the F-test are all exceeded their corresponding F critical values, and the results from the t-test also showed a good outcome. These results indicate this model would be successfully applied in modelling BRP in drinking water supply systems.

scholarly journals Sexual and Vegetative Propagation of Hypericum empetrifolium Willd. subsp. empetrifolium

2018 ◽  
Vol 47 (2) ◽  
pp. 282-287
Author(s):  
Anastasia AKOUMIANAKI-IOANNIDOU ◽  
Ekaterini GERASIMIDOU ◽  
Alexandra SALTA ◽  
Ioannis ROUSSIS ◽  
Dimitrios BILALIS
Keyword(s):  
Significant Interaction ◽  
Incubation Temperature ◽  
Tap Water ◽  
Hormone Treatment ◽  
Germination Percentage ◽  
Stem Cuttings ◽  
Treatment Control ◽  
Asexual Propagation ◽  
Different Types ◽  
Pharmaceutical Properties

Hypericum empetrifolium Willd. subsp. empetrifolium is an evergreen small shrub with small elongated decorative leaves and small yellow flowers in inflorescences, characterized for several pharmaceutical properties. In the present study, a first approach on the sexual and asexual propagation of this species was performed. Seeds, subjected to different types of pre-treatments [soaked in tap water; 50, 100 or 150 mg L-1 GA3 for 30 min and no treatment (control)], cultured for germination in petri dishes at 5, 10, 15, 20, 25, and 30 °C. Seed germination was only affected by temperature and the best result was obtained at 15 °C (71.2%). A significant interaction was found between pre-treatments and incubation temperature with the highest germination percentage (82%) occurred when the seeds soaked in 100 mg L-1 GA3 solution for 30 min and incubated at 20 °C constant temperature. Moreover, the germination speed was fastest from 20 to 25 °C (T50= 9.84 and 9.56 days for 20 and 25 °C, respectively). For asexual propagation, apical stem cuttings were taken at four different periods (4 seasons) and treated with IBA at concentrations of 0, 1000, 2000 and 3000 mg L-1. The cuttings were planted in a peat/perlite mixture 1:1 v/v in plastic square plug trays in order to study the rooting percentage. Winter was the most appropriate season for cuttings collection (100% rooting percentage) and dipping in 1000 or 2000 mg L-1 IBA (72% and 73%, respectively) was the best rooting hormone treatment.

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