scholarly journals Assessing the Effect of Changing Ambient Air Temperature on Water Temperature and Quality in Drinking Water Distribution Systems

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1916
Author(s):  
Yuchuan Lai ◽  
David A. Dzombak

Drinking water distribution systems (DWDS) are affected by climate change and this work aimed to assess the effect of changing ambient air temperature on the water temperature and various water quality parameters in DWDS. A water temperature estimation model was identified and evaluated at seven specific locations in the U.S. and water quality parameters were assessed with a case study for Washington D.C. Preliminary estimation of changes in water temperature and two temperature-related parameters (the chlorine decay rate and bacterial activity) were developed for 91 U.S. cities using local air temperature observations and projections. Estimated water temperature changes in DWDS are generally equivalent to air temperature changes on an annual average basis, suggesting modest changes for the assessed historical periods and possibly more intensified changes in the future with greater increase in air temperature. As higher water age can amplify the temperature effect and the effects of temperature on some water quality parameters can be inter-related, yielding an aggregated effect, evaluation of extreme cases for DWDS will be of importance. In responding to changing climate conditions, assessments of DWDS water temperature changes and resulting impacts on water quality merit more attention to ensure appropriate adaptation of DWDS design and management.

2015 ◽  
Vol 61 (12) ◽  
pp. 965-976 ◽  
Author(s):  
Daniel B. Scott ◽  
Michele I. Van Dyke ◽  
William B. Anderson ◽  
Peter M. Huck

The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence–absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems.


Water SA ◽  
2019 ◽  
Vol 45 (2 April) ◽  
Author(s):  
Denis Nono ◽  
Phillimon T Odirile ◽  
Innocent Basupi ◽  
Bhagabat P Parida

Assessment of probable causes of chlorine decay in water distribution systems of Gaborone city, Botswana Gaborone city water distribution system (GCWDS) is rapidly expanding and has been faced with the major problems of high water losses due to leakage, water shortages due to drought and inadequate chlorine residuals at remote areas of the network. This study investigated the probable causes of chlorine decay, due to pipe wall conditions and distribution system water quality in the GCWDS. An experimental approach, which applied a pipe-loop network model to estimate biofilm growth and chlorine reaction rate constants, was used to analyse pipe wall chlorine decay. Also, effects of key water quality parameters on chlorine decay were analysed. The water quality parameters considered were: natural organic matter (measured by total organic carbon, TOC; dissolved organic carbon, DOC; and ultraviolet absorbance at wavelength 254, UVA-254, as surrogates), inorganic compounds (iron and manganese) and heterotrophic plate count (HPC). Samples were collected from selected locations in the GCWDS for analysis of water quality parameters. The results of biofilm growth and chlorine reaction rate constants revealed that chlorine decay was higher in pipe walls than in the bulk of water in the GCWDS. The analysis of key water quality parameters revealed the presence of TOC, DOC and significant levels of organics (measured by UVA-254), which suggests that organic compounds contributed to chlorine decay in the GCWDS. However, low amounts of iron and manganese (< 0.3 mg/L) indicated that inorganic compounds may have had insignificant contributions to chlorine decay. The knowledge gained on chlorine decay would be useful for improving water treatment and network operating conditions so that appropriate chlorine residuals are maintained to protect the network from the risks of poor water quality that may occur due to the aforementioned problems.


2019 ◽  
Vol 19 (6) ◽  
pp. 1785-1792 ◽  
Author(s):  
Silvia Tinelli ◽  
Ilan Juran

Abstract This research aims to simulate bio-contamination risk propagation under real-life conditions in the water distribution system (WDS) of Lille University's Scientific City Campus (France), solving the source identification and the response modeling. Neglecting dynamic reactions and not considering the possible chemical decay of most of the contaminants leads to an overestimation of the exposed population. Therefore, unlike the available event detection models, this study considers the interrelated change of several water-quality parameters such as free chlorine concentration, pH, alkalinity, and total organic carbon (TOC) resulting from the pollutants blending. In fact, starting from regular WDS monitoring, the baseline thresholds for each of the mentioned parameters are established; then, significant deviations from the baseline are used as indication for contaminations. For this reason, the purpose of the research was to develop and demonstrate the feasibility of an artificial intelligence (AI)-based smart monitoring system that will effectively enable water operators to ensure a quasi real-time quality control for early chemical and/or bio-contamination detection and preemptive risk management. Advanced pattern recognizers, such as Support Vector Machines (SVMs), and innovative sensing technology solutions, such as Artificial Neural Network (ANN), have been used for this purpose, identifying the anomalies and the severity-level assessment.


Author(s):  
Katherine Eddings ◽  
Durga D Poudel ◽  
Timothy W. Duex ◽  
Robert Miller ◽  
J. Calvin Berry

Climate change impacts on rising temperatures, changes on rainfall patterns, drought, flooding, sea level rise, glacier melts, and incidence of diseases and parasites are reported worldwide in recent decades. This study investigates the effects of changing climatic conditions – particularly air temperature and precipitation, on surface water temperatures and other water quality parameters, such as the conductivity, dissolved oxygen (DO), pH, and turbidity. A statistical analysis was performed on air temperature and precipitation data from 1980 to 2005 to determine the changing climatic conditions. The water quality data for four waterbodies in southwestern Louisiana was also analyzed to examine trends between the air temperature and surface water temperatures, precipitation and surface water temperatures, and precipitation and water quality parameters. There was an unexpected increase in surface water temperature with an increase in precipitation. As the precipitation and air temperature increased, so did the surface water temperature. This increase in surface water temperature was correlated with decrease in DO levels. The increase in precipitation also correlated with an increase in pH and turbidity in Bayou Plaquemine Brule. This study’s findings could be utilized in a dynamic climate modeling system to provide more accurate predictions of climate change in southwestern Louisiana.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wei Chen ◽  
Xiao Hao ◽  
JianRong Lu ◽  
Kui Yan ◽  
Jin Liu ◽  
...  

In order to solve the problems of high labor cost, long detection period, and low degree of information in current water environment monitoring, this paper proposes a lake water environment monitoring system based on LoRa and Internet of Things technology. The system realizes remote collection, data storage, dynamic monitoring, and pollution alarm for the distributed deployment of multisensor node information (water temperature, pH, turbidity, conductivity, and other water quality parameters). Moreover, the system uses STM32L151C8T6 microprocessor and multiple types of water quality sensors to collect water quality parameters in real time, and the data is packaged and sent to the LoRa gateway remotely by LoRa technology. Then, the gateway completes the bridging of LoRa link to IP link and forwards the water quality information to the Alibaba Cloud server. Finally, end users can realize the water quality control of monitored water area by monitoring management platform. The experimental results show that the system has a good performance in terms of real-time data acquisition accuracy, data transmission reliability, and pollution alarm success rate. The average relative errors of water temperature, pH, turbidity, and conductivity are 0.31%, 0.28%, 3.96%, and 0.71%, respectively. In addition, the signal reception strength of the system within 2 km is better than -81 dBm, and the average packet loss rate is only 94%. In short, the system’s high accuracy, high reliability, and long distance characteristics meet the needs of large area water quality monitoring.


2017 ◽  
Vol 7 (1) ◽  
pp. 47-57
Author(s):  
Ganesh Bahadur Thapa ◽  
Joydeb Pal

Tarahara Fish Farm includes 37 large ponds as a fish super zone. Physicochemical parameters viz., air and water temperature, pH, DO, BOD, CO2, Cl-, TA and TH of these ponds were studied for two years (Nov. 2008 to Oct. 2010). The air temperature had positive and significant correlation with water temperature (r=0.893, P<0.01) but inverse and significant correlation with DO (r = - 0.669 P<0.05) and TH (r = - 0.673, P<0.05). Both air and water temperature showed a decreasing trend during the winter months of November to January and again September to October in both years. Similarly, positive and significant correlation showed by pH with DO (r =0.660, P<0.05) and BOD (r =0.846, P<0.05); by free CO2 with DO (r=0.854, P<0.01), chloride (r=0.648, P<0.05) and TA (r=0.616, P<0.05); by DO with TA (r =0.715, P<0.01) and chloride (r =0.625, P<0.05) and by TH with TA (r= 0.592, P<0.05) but inverse and significant correlation showed by pH with water temperature (r =-0.671, P<0.05); by free CO2 with BOD (r=-0.627, P<0.05) and by DO with BOD (r = -0.810, P <0.01). The water quality parameters were within suitable range for the fish growth and breeding with small fluctuations in different months during the first and second years. Physico-chemical parameters significantly (P<0.01; 0.05) differed between different months. However, no mass mortality of fish was recorded from this site. So, the area selected as fish super zone is fruitful to meet the expected production level of fishes and fish seeds in peripheral areas.


2018 ◽  
Vol 4 (12) ◽  
pp. 2080-2091 ◽  
Author(s):  
Isabel Douterelo ◽  
Carolina Calero-Preciado ◽  
Victor Soria-Carrasco ◽  
Joby B. Boxall

This research highlights the potential of whole metagenome sequencing to help protect drinking water quality and safety.


2015 ◽  
Vol 13 (3) ◽  
pp. 859-869 ◽  
Author(s):  
Ali Akbar Babaei ◽  
Leila Atari ◽  
Mehdi Ahmadi ◽  
Kambiz Ahmadiangali ◽  
Mirzaman Zamanzadeh ◽  
...  

Trihalomethanes (THMs) were the first disinfection by-products discovered in drinking water and are classified as probable carcinogens. This study measures and models THMs formation at two drinking water distribution systems (WDS1 and WDS2) in Ahvaz City, Iran. The investigation was based on field-scale investigations and an intensive 36-week sampling program, from January to September 2011. The results showed total THM concentrations in the range 17.4–174.8 μg/L and 18.9–99.5 μg/L in WDS1 and WDS2, respectively. Except in a few cases, the THM concentrations in WDS1 and WDS2 were lower than the maximum contaminant level values. Using two-tailed Pearson correlation test, the water temperature, dissolved organic carbon, UV254, bromide ion (Br−), free residual chlorine, and chlorine dose were identified as the significant parameters for THMs formation in WDS2. Water temperature was the only significant parameter for THMs formation in WDS1. Based on the correlation results, a predictive model for THMs formation was developed using a multiple regression approach. A multiple linear regression model showed the best fit according to the coefficients of determination (R2) obtained for WDS1 (R2 = 0.47) and WDS2 (R2 = 0.54). Further correlation studies and analysis focusing on THMs formation are necessary to assess THMs concentration using the predictive models.


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