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J.H.G. Vreeburg

Other affiliations: Delft University of Technology
Bio: J.H.G. Vreeburg is an academic researcher from Wageningen University and Research Centre. The author has contributed to research in topics: Water quality & Water flow. The author has an hindex of 13, co-authored 44 publications receiving 546 citations. Previous affiliations of J.H.G. Vreeburg include Delft University of Technology.

Papers
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Journal ArticleDOI
TL;DR: The composition and correlation of bacterial communities from different phases helped to locate where most of the bacteria are and understand the interactions among these phases, and relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system were revealed.
Abstract: The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments inside loose deposits structures for bacteria to grow. Moreover, loose deposits protect the associated bacteria from disinfectants, and due to their mobility, the associated bacteria reach taps easily.

186 citations

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TL;DR: In this article, a stochastic demands-based network water quality model is proposed for assessing water quality in the drinking water distribution system, which is probabilistic in nature.
Abstract: Today, there is a growing interest in network water quality modelling. The water quality issues of interest relate to both dissolved and particulate substances. For dissolved substances the main interest is in residual chlorine and (microbiological) contaminant propagation; for particulate substances it is in sediment leading to discolouration. There is a strong influence of flows and velocities on transport, mixing, production and decay of these substances in the network. This imposes a different approach to demand modelling which is reviewed in this article. For the large diameter lines that comprise the transport portion of a typical municipal pipe system, a skeletonised network model with a top-down approach of demand pattern allocation, a hydraulic time step of 1 h, and a pure advection-reaction water quality model will usually suffice. For the smaller diameter lines that comprise the distribution portion of a municipal pipe system, an all-pipes network model with a bottom-up approach of demand pattern allocation, a hydraulic time step of 1 min or less, and a water quality model that considers dispersion and transients may be needed. Demand models that provide stochastic residential demands per individual home and on a one-second time scale are available. A stochastic demands based network water quality model needs to be developed and validated with field measurements. Such a model will be probabilistic in nature and will offer a new perspective for assessing water quality in the drinking water distribution system.

59 citations

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TL;DR: In this paper, the authors proposed a velocity criterion to the conventional design criteria, which leads to a branched lay out of distribution networks, that perform better with respect to water quality, continuity of supply and investment costs.
Abstract: Resuspension of accumulated particles in residential networks is the main cause for customers to complain to the water company about the water quality. Preventing the particles from accumulating in these networks can be achieved by high velocities in pipes. Adding this velocity criterion to the conventional design criteria leads to a branched lay out of distribution networks, that perform better with respect to water quality, continuity of supply and investment costs. In close cooperation with fire brigades the conventional fire flow requirements were challenged. Based on modern building codes, it proved possible to reduce the capacity of fire-hydrants to 8.3 l/s (30 m 3 /h) in newly built areas. Six years after the introduction of the velocity criterion the characteristics of the newly laid networks have changed resulting in smaller diameter pipes and reduced length of networks. The amount of 100/110 mm pipes have dropped from 55% of the total length to 45% of total length. The total investment costs for new networks have dropped by 20% in the Netherlands.

41 citations

Journal ArticleDOI
TL;DR: In this article, an "all pipes" hydraulic model of a DMA-sized drinking water distribution system with two types of demand allocations was constructed with conventional op-down approach, i.e., a demand multiplier pattern from the booster station is allocated to all demand nodes with a correction factor to account for the average water emand on that node, and a bottom-up approach of demand allocation, each individual home is represented by one demand node with its own tochastic water demand pattern.
Abstract: An “all pipes” hydraulic model of a DMA-sized drinking water distribution system was onstructed with two types of demand allocations. One is constructed with the conventional op-down approach, i.e. a demand multiplier pattern from the booster station is llocated to all demand nodes with a correction factor to account for the average water emand on that node. The other is constructed with a bottom-up approach of demand allocation, i.e., each individual home is represented by one demand node with its own tochastic water demand pattern. The stochastic water demand patterns are constructed with an end-use model on per second basis and per individual home. The flow entering the test area was easured and a tracer test with sodium hloride was performed to measure travel imes. The two models were evaluated on the predicted sum of demands and travel times, compared with what was measured in the test area. The new bottom-up approach performs at least as well as the conventional top down approach with respect to total demand and travel times, without the need for any flow measurements or calibration measurements. The bottom-up approach leads to a stochastic method of hydraulic modelling and gives insight into the variability of travel times as an added feature beyond the conventional way of modelling.

35 citations

Journal ArticleDOI
TL;DR: In this article, a heuristic burst detection method, which continuously compares measured and expected values of water demands and pressures, was proposed to minimize the negative consequences of pipe bursts, an early detection is necessary.
Abstract: Pipe bursts in a drinking water distribution system lead to water losses, interruption of supply, and damage to streets and houses due to the uncontrolled water flow. To minimize the negative consequences of pipe bursts, an early detection is necessary. This paper describes a heuristic burst detection method, which continuously compares measured and expected values of water demands and pressures. The expected values of the water demand are generated by an adaptive water demand forecasting model, and the expected values of the pressures are generated by a dynamic pressure drop - demand relation estimator. The method was tested off-line on a historic dataset of 5 years of water flow and pressure data in three supply areas (with 650, 11,180 and 130,920 connections) in the western part of the Netherlands. In the period 274 bursts were reported of which, based on the definition we propose in this paper, 38 were considered as relatively larger bursts. The method was able to detect 50, 25.9 and 7.8% in the considered areas related to all bursts, and around 80% in all three areas related to the subset of relatively larger bursts. The method generated false alarms on 3% of the evaluated days on average.

27 citations


Cited by
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TL;DR: Water-based Legionella and non-tuberculous mycobacteria probably dominate health burden at exposure points following the various societal uses of drinking water, and next-generation sequencing and polymerase chain reaction approaches are on the cusp of changing that.
Abstract: A relatively short list of reference viral, bacterial and protozoan pathogens appears adequate to assess microbial risks and inform a system-based management of drinking waters. Nonetheless, there are data gaps, e.g. human enteric viruses resulting in endemic infection levels if poorly performing disinfection and/or distribution systems are used, and the risks from fungi. Where disinfection is the only treatment and/or filtration is poor, cryptosporidiosis is the most likely enteric disease to be identified during waterborne outbreaks, but generally non-human-infectious genotypes are present in the absence of human or calf fecal contamination. Enteric bacteria may dominate risks during major fecal contamination events that are ineffectively managed. Reliance on culture-based methods exaggerates treatment efficacy and reduces our ability to identify pathogens/indicators; however, next-generation sequencing and polymerase chain reaction approaches are on the cusp of changing that. Overall, water-based Legionella and non-tuberculous mycobacteria probably dominate health burden at exposure points following the various societal uses of drinking water.

297 citations

Journal ArticleDOI
TL;DR: It is concluded that combining UV-irradiation with advanced oxidative processes may enhance the removal of ARB and ARGs, while disinfection may promote horizontal gene transfer from environmental ARB to pathogens.

296 citations

Journal ArticleDOI
TL;DR: How knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to maintain good drinking water microbial quality up to consumer’s tap is discussed.
Abstract: Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to maintain good drinking water microbial quality up to consumer’s tap. A new definition and methodological approach for biological stability is proposed.

290 citations

Journal ArticleDOI
TL;DR: In this article, a water demand end-use model was developed to predict water demand patterns with a small time scale (1 s) and small spatial scale (residence level).
Abstract: A water demand end-use model was developed to predict water demand patterns with a small time scale (1 s) and small spatial scale (residence level). The end-use model is based on statistical inform...

270 citations

Journal ArticleDOI
TL;DR: Management of biofilm growth in water distribution systems requires an integrated approach, starting from the treatment of water prior to entering the networks to the potential implementation of "biofilm-limiting" operational conditions and, finally, ending with the careful selection of available technologies for biofilm monitoring and control.
Abstract: In drinking water distribution systems (DWDS), biofilms are the predominant mode of microbial growth, with the presence of extracellular polymeric substance (EPS) protecting the biomass from environmental and shear stresses. Biofilm formation poses a significant problem to the drinking water industry as a potential source of bacterial contamination, including pathogens, and, in many cases, also affecting the taste and odor of drinking water and promoting the corrosion of pipes. This article critically reviews important research findings on biofilm growth in DWDS, examining the factors affecting their formation and characteristics as well as the various technologies to characterize and monitor and, ultimately, to control their growth. Research indicates that temperature fluctuations potentially affect not only the initial bacteria-to-surface attachment but also the growth rates of biofilms. For the latter, the effect is unique for each type of biofilm-forming bacteria; ammonia-oxidizing bacteria, for examp...

268 citations