Mapping the Terrain for Pathogen Persistence and Proliferation in Non-potable Reuse Distribution Systems: Interactive Effects of Biofiltration, Disinfection, and Water Age

2021 ◽  
Vol 55 (18) ◽  
pp. 12561-12573
Author(s):  
Sudeshna Ghosh ◽  
Ni Joyce Zhu ◽  
Erin Milligan ◽  
Joseph O. Falkinham ◽  
Amy Pruden ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Interactive Effects ◽  
Water Age ◽  
Potable Reuse ◽  
Pathogen Persistence

Removal of trihalomethanes from high organic matter water sources using aeration: a feasibility study

2020 ◽  
Vol 55 (2) ◽  
pp. 184-197
Author(s):  
Saeideh Mirzaei ◽  
Beata Gorczyca
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Feasibility Study ◽  
Distribution Systems ◽  
Water Age ◽  
Treated Water ◽  
Canadian Guideline ◽  
Viable Solution ◽  
By Products

Abstract In this study, diffused aeration was applied to remove trihalomethane (THM) compounds from chlorinated, treated water containing high dissolved organic carbon (DOC) of 6.8 ± 1.2 mg/L. Increasing air-to-water volumetric ratio (rA/W) from 16 to 39 enhanced total THM (TTHM) removal from 60 to 70% at 20 °C and from 30 to 50% at 4 °C. Although bromodichloromethane has lower Henry's law constant than chloroform (CF), it was removed by a higher degree than CF in some aeration trials. Albeit obtaining high removals in aeration, TTHM reformed, and their concentration surpassed the Canadian guideline of 100 ppb in about 24 hours at 20 °C and 40 hours at 10 °C in all attempted air-to-water ratios. The water age in the system investigated in this study varied from 48 hours in midpoint chlorine boosting stations to 336 hours in the nearest endpoint. This study showed that THM removal by aeration is not a viable solution to control the concentration of these disinfection by-products in high-DOC treated water and in distribution systems where water age exceeds 24 hours; unless, it is going to be installed at the distribution endpoints.

Improving Water Age in Distribution Systems by Optimal Valve Operation

2021 ◽  
Vol 147 (8) ◽  
pp. 04021046
Author(s):  
Bruno Brentan ◽  
Laura Monteiro ◽  
Joana Carneiro ◽  
Dídia Covas
Keyword(s):  
Distribution Systems ◽  
Water Age ◽  
Valve Operation

scholarly journals Interactive Effects of Copper Pipe, Stagnation, Corrosion Control, and Disinfectant Residual Influenced Reduction of Legionella pneumophila during Simulations of the Flint Water Crisis

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 730 ◽  
Author(s):  
Rebekah L. Martin ◽  
Owen R. Strom ◽  
Amy Pruden ◽  
Marc A. Edwards
Keyword(s):  
Water Chemistry ◽  
Legionella Pneumophila ◽  
Distribution Systems ◽  
Interactive Effects ◽  
Residual Chlorine ◽  
Drinking Water Source ◽  
Corrosion Control ◽  
Copper Pipe ◽  
Chlorine Demand ◽  
Flint River

Flint, MI experienced two outbreaks of Legionnaires’ Disease (LD) during the summers of 2014 and 2015, coinciding with use of Flint River as a drinking water source without corrosion control. Using simulated distribution systems (SDSs) followed by stagnant simulated premise (i.e., building) plumbing reactors (SPPRs) containing cross-linked polyethylene (PEX) or copper pipe, we reproduced trends in water chemistry and Legionella proliferation observed in the field when Flint River versus Detroit water were used before, during, and after the outbreak. Specifically, due to high chlorine demand in the SDSs, SPPRs with treated Flint River water were chlorine deficient and had elevated L. pneumophila numbers in the PEX condition. SPPRs with Detroit water, which had lower chlorine demand and higher residual chlorine, lost all culturable L. pneumophila within two months. L. pneumophila also diminished more rapidly with time in Flint River SPPRs with copper pipe, presumably due to the bacteriostatic properties of elevated copper concentrations caused by lack of corrosion control and stagnation. This study confirms hypothesized mechanisms by which the switch in water chemistry, pipe materials, and different flow patterns in Flint premise plumbing may have contributed to observed LD outbreak patterns.

scholarly journals Dynamic Hydraulics in a Drinking Water Distribution System Influence Suspended Particles and Turbidity, But Not Microbiology

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 109
Author(s):  
Emmanuelle I. Prest ◽  
Peter G. Schaap ◽  
Michael D. Besmer ◽  
Frederik Hammes
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Age ◽  
Short Term ◽  
Drinking Water Distribution Systems ◽  
Hydraulic Conditions ◽  
Drinking Water Distribution ◽  
Particle Counts

Spatial and short-term temporal changes in water quality as a result of water age and fluctuating hydraulic conditions were investigated in a drinking water distribution system. Online measurements of total and intracellular adenosine tri-phosphate (ATP), total and intact cell concentrations measured with flow cytometry (FCM), turbidity, and particle counts were performed over five weeks at five subsequent locations of the distribution system. The high number of parallel FCM and ATP measurements revealed the combined effect of water age and final disinfection on spatial changes in microbiology in the system. The results underlined that regular daily dynamics in flow velocities are normal and inevitable in drinking water distribution systems, and significantly impact particle counts and turbidity. However, hydraulic conditions had no detectable impact on the concentration of suspended microbial cells. A weak correlation between flow velocity and ATP concentrations suggests incidental resuspension of particle-bound bacteria, presumably caused by either biofilm detachment or resuspension from sediment when flow velocities increase. The highly dynamic hydraulic conditions highlight the value of online monitoring tools for the meaningful description of short-term dynamics (day-scale) in drinking water distribution systems.

scholarly journals Enhanced Water Age Performance Assessment in Distribution Networks

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2574
Author(s):  
Laura Monteiro ◽  
Ricardo Algarvio ◽  
Dídia Covas
Keyword(s):  
Water Quality ◽  
Performance Assessment ◽  
Reference Values ◽  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Networks ◽  
Operating Conditions ◽  
Water Age ◽  
Major Improvement ◽  
Age Limits

Water age is frequently used as a surrogate for water quality in distribution networks and is often included in modelling and optimisation studies, though there are no reference values or standard performance functions for assessing the network behaviour regarding water age. This paper presents a novel methodology for obtaining enhanced system-specific water age performance assessment functions, tailored for each distribution network. The methodology is based on the establishment of relationships between the chlorine concentration at the sampling nodes and simulated water age. The proposed methodology is demonstrated through application to two water distribution systems in winter and summer seasons. Obtained results show a major improvement in comparison with those obtained by published performance functions, since the water age limits of the performance functions used herein are tailored to the analysed networks. This demonstrates that the development of network-specific water age performance functions is a powerful tool for more robustly and reliably defining water age goals and evaluating the system behaviour under different operating conditions.

scholarly journals Assessment of water quality modelling capabilities of EPANET multiple species and pressure-dependent extension models

2013 ◽  
Vol 13 (4) ◽  
pp. 1161-1166 ◽  
Author(s):  
Alemtsehay G. Seyoum ◽  
Tiku T. Tanyimboh ◽  
Calvin Siew
Keyword(s):  
Water Quality ◽  
Distribution Systems ◽  
Operating Conditions ◽  
Quality Analysis ◽  
Future Research ◽  
Operating Pressure ◽  
Quality Model ◽  
Water Age ◽  
First Order ◽  
Multiple Species

The need for accurately predicting water quality through models has increasingly been crucial in meeting rigorous standards and customer expectations. There are several endeavours on developing robust water quality models for water distribution systems. In this paper, two variants of the EPANET 2 water quality model have been assessed to inform future research. The models are the multiple species extension EPANET-MSX and the pressure-dependent extension EPANET-PDX. Water quality analysis was conducted on a hypothetical network considering various operating pressure conditions. Different kinetic models were employed to simulate water quality. First order, limited first order and zero order models were used for predicting chlorine residual, disinfection by-products (DBPs) and water age respectively. Generally, EPANET-MSX and EPANET-PDX provided identical water quality results for normal operating conditions with adequate pressure but different results for pressure-deficient networks. Also, a parallel first order model with fast and slow reacting components was used for chlorine decay and DBPs using the EPANET-MSX model for a network operating under normal pressure conditions.

scholarly journals Impact of variable speed pumps on water quality in distribution systems

Water SA ◽  
2018 ◽  
Vol 44 (3 July) ◽  
Author(s):  
Moustafa S Darweesh
Keyword(s):  
Water Quality ◽  
Distribution Systems ◽  
Water Distribution ◽  
Average Rate ◽  
Extended Period ◽  
Distribution Networks ◽  
Residual Chlorine ◽  
Variable Speed ◽  
Water Age ◽  
The Impact

Water quality has become a prominent issue in the study of water distribution networks. Variable speed pumps (VSPs) can control and improve the performance of water distribution systems. However, they may have effects on the water quality. The objective of this study was to investigate the impact of VSPs on water quality. The EPANET water quality simulator was applied for modelling water age and chlorine residual in a distribution network. In addition, intrusion of an active contaminant and analysis of leakage effects on residual chlorine concentration were performed through extended period simulations. Results indicate that VSPs may have negative impacts on water quality, including increased water age during low consumption times, and reduced disinfectant residuals at peak hours. In addition, the average rate of chlorine decay for fixed speed pumps (57%) is higher than that for VSPs (54%) when a conservative contaminant (sewage water) is considered.

scholarly journals The Impact of Pressure Management Techniques on the Water Age in an Urban Pipe Network—The Case of Kos City Network

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 699 ◽  
Author(s):  
Anastasia Kravvari ◽  
Vasilis Kanakoudis ◽  
Menelaos Patelis
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Optimization Criterion ◽  
Maximum Pressure ◽  
Pressure Management ◽  
Water Age ◽  
City Water ◽  
The Impact

The goal of this article is to study the impact that pressure management in distribution systems has, on the quality of the supplied water in terms of its water age, using the water distribution network of Kos city, capital of Kos Island in Greece was used as the case study network. This was achieved through network simulation using the Watercad V8i software, followed by the division of the network in district metered areas (DMA) and the placement of pressure reducing valves (PRV) in the entering nodes of each DMA. Research aimed also to optimize DMAs’ borders using the water age as the optimization criterion, instead of maximum pressure reduction. Different scenarios were tested on the calibrated and validated hydraulic model of Kos city water distribution network.

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