Characterization of NOM in a drinking water treatment process train with no disinfectant residual

2009 ◽  
Vol 9 (4) ◽  
pp. 379-386 ◽  
Author(s):  
S. A. Baghoth ◽  
M. Dignum ◽  
A. Grefte ◽  
J. Kroesbergen ◽  
G. L. Amy

For drinking water treatment plants that do not use disinfectant residual in the distribution system, it is important to limit availability of easily biodegradable natural organic matter (NOM) fractions which could enhance bacterial regrowth in the distribution system. This can be achieved by optimising the removal of those fractions of interest during treatment; however, this requires a better understanding of the physical and chemical properties of these NOM components. Fluorescence excitation-emission matrix (EEM) and liquid chromatography with online organic carbon detection (LC-OCD) were used to characterize NOM in water samples from one of the two water treatment plants serving Amsterdam, The Netherlands. No disinfectant residual is applied in the distribution system. Fluorescence EEM and LC-OCD were used to track NOM fractions. Whereas fluorescence EEM shows the reduction of humic-like as well as protein-like fluorescence signatures, LC-OCD was able to quantify the changes in dissolved organic carbon (DOC) concentrations of five NOM fractions: humic substances, building blocks (hydrolysates of humics), biopolymers, low molecular weight acids and neutrals.

2010 ◽  
Vol 77 (3) ◽  
pp. 1041-1048 ◽  
Author(s):  
Frederik Hammes ◽  
Nico Boon ◽  
Marius Vital ◽  
Petra Ross ◽  
Aleksandra Magic-Knezev ◽  
...  

ABSTRACTPellet softening reactors are used in centralized and decentralized drinking water treatment plants for the removal of calcium (hardness) through chemically induced precipitation of calcite. This is accomplished in fluidized pellet reactors, where a strong base is added to the influent to increase the pH and facilitate the process of precipitation on an added seeding material. Here we describe for the first time the opportunistic bacterial colonization of the calcite pellets in a full-scale pellet softening reactor and the functional contribution of these colonizing bacteria to the overall drinking water treatment process. ATP analysis, advanced microscopy, and community fingerprinting with denaturing gradient gel electrophoretic (DGGE) analysis were used to characterize the biomass on the pellets, while assimilable organic carbon (AOC), dissolved organic carbon, and flow cytometric analysis were used to characterize the impact of the biological processes on drinking water quality. The data revealed pellet colonization at concentrations in excess of 500 ng of ATP/g of pellet and reactor biomass concentrations as high as 220 mg of ATP/m3of reactor, comprising a wide variety of different microorganisms. These organisms removed as much as 60% of AOC from the water during treatment, thus contributing toward the biological stabilization of the drinking water. Notably, only a small fraction (about 60,000 cells/ml) of the bacteria in the reactors was released into the effluent under normal conditions, while the majority of the bacteria colonizing the pellets were captured in the calcite structures of the pellets and were removed as a reusable product.


2008 ◽  
Vol 8 (3) ◽  
pp. 297-304 ◽  
Author(s):  
A. W. C. van der Helm ◽  
L. C. Rietveld ◽  
Th. G. J. Bosklopper ◽  
J. W. N. M. Kappelhof ◽  
J. C. van Dijk

Optimization for operation of drinking water treatment plants should focus on water quality and not on environmental impact or costs. Using improvement of water quality as objective for optimization can lead to new views on operation, design and concept of drinking water treatment plants. This is illustrated for ozonation in combination with biological activated carbon (BAC) filtration at drinking water treatment plant Weesperkarspel of Waternet, the water cycle company for Amsterdam and surrounding areas. The water quality parameters that are taken into account are assimilable organic carbon (AOC), dissolved organic carbon (DOC) and pathogens. The operational parameters that are taken into account are the ozone dosage and the regeneration frequency of the BAC filters. It is concluded that ozone dosage and regeneration frequency should be reduced in combination with application of newly developed insights in design of ozone installations. It is also concluded that a new concept for Weesperkarspel with an additional ion exchange (IEX) step for natural organic matter (NOM) removal will contribute to the improvement of the disinfection capacity of ozonation and the biological stability of the produced drinking water.


2021 ◽  
Vol 53 (3) ◽  
pp. 210307
Author(s):  
Sandhya Babel ◽  
Hakk Dork

Micro-plastics (MP) contamination in drinking water has become a global concern. Its negative impacts on human health have been reported. This study identified the presence of MP in two different drinking water treatment plants (WTP) in Phnom Penh, Cambodia, and investigated their removal efficiency. Samples were collected from the inlet, sedimentation, sand filtration, and distribution tank to quantify the removal by each unit. An optical microscope and a fluorescence microscope were used to detect the MP in four size fractions: 6.5-20, 20-53, 53-500, and >500 µm. Fourier transform infrared spectroscopy (FT-IR) was used to identify the polymer type for particles with size fractions of 53-500 and >500 µm. The results showed that the MP counted in WTP1 were 1180.5 ± 158 p/L in the inlet and 521 ± 61 p/L in the distribution tank. In WTP2, the MP counted were 1463 ± 126 p/L in the inlet and 617 ± 147 p/L in the distribution tank. The smaller size fraction of 6.5-20 µm predominated at each sampling location. Fragments were the most abundant morphology compared to fibers in all sampling points of both plants. PET predominated and the overall percentages for the inlet tank were 28.8% and 26%, followed by PE with 27.1% and 20.8% in WTP1 and WTP2, respectively. Other common polymer types were PP, PA, PES, and cellophane, while all others accounted for less than 5%. The results of the study showed that a significant number of MP remained in the water distribution system.


2011 ◽  
Vol 6 (2) ◽  
Author(s):  
Laurence Durand-Bourlier ◽  
Amandine Tinghir ◽  
Philippe Masereel ◽  
Sylvie Baig

Belgium is increasingly encountering drinking water problems because of resource scarcity and because of the quality of surface water from rivers and canal, which are often highly degraded. High organic matter concentrations are found and treated water has non-satisfying organic contents. This has a direct impact on THM formation and bacteria regrowth in the supply network. With more and more stringent regulations, organic matters concentration level in drinking water must be reduced. Nanofiltration (NF) is a suitable method for organic matter removal with reduction efficiency sometimes higher than 90 % (Orecki et al. 2004). It can be more effective than conventional technologies like activated carbon adsorption (Coté et al. 1996). This is a reason for upgrading old treatment plants by using NF treatment as a polishing step. Two drinking water treatment plants located in Eupen and La Gileppe in Belgium needed to be upgraded. These both plants treat surface water from dams and are equipped with a conventional clarification. A pilot study was carried out to compare different treatment files to remove Total Organic Carbon (TOC) and Biologically Degradable Organic Carbon (BDOC). NF process has been finally chosen. The aim of the paper is to report and discuss data supporting the choice of NF from pilot scale study and next full-scale performances of both upgraded drinking water treatment plants. The whole demonstrates the interest of NF as a suitable technology organic matter removal.


2014 ◽  
Vol 71 (4) ◽  
pp. 597-604 ◽  
Author(s):  
Sabrina Sorlini ◽  
Maria Cristina Collivignarelli ◽  
Federico Castagnola ◽  
Barbara Marianna Crotti ◽  
Massimo Raboni

Critical barriers to safe and secure drinking water may include sources (e.g. groundwater contamination), treatments (e.g. treatment plants not properly operating) and/or contamination within the distribution system (infrastructure not properly maintained). The performance assessment of these systems, based on monitoring, process parameter control and experimental tests, is a viable tool for the process optimization and water quality control. The aim of this study was to define a procedure for evaluating the performance of full-scale drinking water treatment plants (DWTPs) and for defining optimal solutions for plant upgrading in order to optimize operation. The protocol is composed of four main phases (routine and intensive monitoring programmes – Phases 1 and 2; experimental studies – Phase 3; plant upgrade and optimization – Phase 4). The protocol suggested in this study was tested in a full-scale DWTP placed in the North of Italy (Mortara, Pavia). The results outline some critical aspects of the plant operation and permit the identification of feasible solutions for the DWTP upgrading in order to optimize water treatment operation.


2017 ◽  
Vol 83 (11) ◽  
Author(s):  
Benjamin Horemans ◽  
Bart Raes ◽  
Hannelore Brocatus ◽  
Jeroen T'Syen ◽  
Caroline Rombouts ◽  
...  

ABSTRACT Aminobacter sp. strain MSH1 grows on and mineralizes the groundwater micropollutant 2,6-dichlorobenzamide (BAM) and is of interest for BAM removal in drinking water treatment plants (DWTPs). The BAM-catabolic genes in MSH1 are located on plasmid pBAM1, carrying bbdA, which encodes the conversion of BAM to 2,6-dichlorobenzoic acid (2,6-DCBA) (BbdA+ phenotype), and plasmid pBAM2, carrying gene clusters encoding the conversion of 2,6-DCBA to tricarboxylic acid (TCA) cycle intermediates (Dcba+ phenotype). There are indications that MSH1 easily loses its BAM-catabolic phenotype. We obtained evidence that MSH1 rapidly develops a population that lacks the ability to mineralize BAM when grown on nonselective (R2B medium) and semiselective (R2B medium with BAM) media. Lack of mineralization was explained by loss of the Dcba+ phenotype and corresponding genes. The ecological significance of this instability for the use of MSH1 for BAM removal in the oligotrophic environment of DWTPs was explored in lab and pilot systems. A higher incidence of BbdA+ Dcba− MSH1 cells was also observed when MSH1 was grown as a biofilm in flow chambers under C and N starvation conditions due to growth on nonselective residual assimilable organic carbon. Similar observations were made in experiments with a pilot sand filter reactor bioaugmented with MSH1. BAM conversion to 2,6-DCBA was not affected by loss of the DCBA-catabolic genes. Our results show that MSH1 is prone to BAM-catabolic instability under the conditions occurring in a DWTP. While conversion of BAM to 2,6-DCBA remains unaffected, BAM mineralization activity is at risk, and monitoring of metabolites is warranted. IMPORTANCE Bioaugmentation of dedicated biofiltration units with bacterial strains that grow on and mineralize micropollutants was suggested as an alternative for treating micropollutant-contaminated water in drinking water treatment plants (DWTPs). Organic-pollutant-catabolic genes in bacteria are often easily lost, especially under nonselective conditions, which affects the bioaugmentation success. In this study, we provide evidence that Aminobacter sp. strain MSH1, which uses the common groundwater micropollutant 2,6-dichlorobenzamide (BAM) as a C source, shows a high frequency of loss of its BAM-mineralizing phenotype due to the loss of genes that convert 2,6-DCBA to Krebs cycle intermediates when nonselective conditions occur. Moreover, we show that catabolic-gene loss also occurs in the oligotrophic environment of DWTPs, where growth of MSH1 depends mainly on the high fluxes of low concentrations of assimilable organic carbon, and hence show the ecological relevance of catabolic instability for using strain MSH1 for BAM removal in DWTPs.


2010 ◽  
Vol 3 (1) ◽  
pp. 63-70 ◽  
Author(s):  
M. Z. Bieroza ◽  
J. Bridgeman ◽  
A. Baker

Abstract. Organic matter (OM) in drinking water treatment is a common impediment responsible for increased coagulant and disinfectant dosages, formation of carcinogenic disinfection-by products, and microbial re-growth in distribution system. The inherent heterogeneity of OM implies the utilization of advanced analytical techniques for its characterization and assessment of removal efficiency. Here, the application of simple fluorescence excitation-emission technique to OM characterization in drinking water treatment is presented. The fluorescence data of raw and clarified water was obtained from 16 drinking water treatment works. The reduction in fulvic-like fluorescence was found to significantly correlate with OM removal measured with total organic carbon (TOC). Fluorescence properties, fulvic- and tryptophan-like regions, were found to discriminate OM fractions of different removal efficiencies. The results obtained in the study show that fluorescence spectroscopy provides a rapid and accurate characterization and quantification of OM fractions and indication of their treatability in conventional water treatment.


2009 ◽  
Vol 2 (2) ◽  
pp. 259-278 ◽  
Author(s):  
M. Z. Bieroza ◽  
J. Bridgeman ◽  
A. Baker

Abstract. Organic matter (OM) in drinking water treatment is a common impediment responsible for increased coagulant and disinfectant dosages, formation of carcinogenic disinfection-by products, and microbial re-growth in distribution system. The inherent heterogeneity of OM implies the utilization of advanced analytical techniques for its characterization and assessment of removal efficiency. Here, the application of simple fluorescence excitation-emission technique to OM characterization in drinking water treatment is presented. The fluorescence data of raw and clarified water was obtained from 16 drinking water treatment works. The reduction in fulvic-like fluorescence was found to significantly correlate with OM removal measured with total organic carbon (TOC). Fluorescence properties, fulvic- and tryptophan-like regions, were found to discriminate OM fractions of different removal efficiencies. The results obtained in the study show that fluorescence spectroscopy provides a rapid and accurate characterization and quantification of OM fractions and indication of their treatability in conventional water treatment.


1986 ◽  
Vol 21 (3) ◽  
pp. 447-459 ◽  
Author(s):  
K.J. Roberts ◽  
R.B. Hunsinger ◽  
A.H. Vajdic

Abstract The Drinking Water Surveillance Program (DWSP), developed by the Ontario Ministry of the Environment, is an assessment project based on standardized analytical and sampling protocol. This program was recently instituted in response to a series of contaminant occurrences in the St. Clair-Detroit River area of Southwestern Ontario. This paper outlines the details and goals of the program and provides information concerning micro-contaminants in drinking water at seven drinking water treatment plants in Southwestern Ontario.


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