Biofilm formation potentials in drinking waters treated by different advanced treatment processes

2002 ◽  
Vol 2 (4) ◽  
pp. 97-104 ◽  
Author(s):  
S. Okabe ◽  
T. Kokazi ◽  
Y. Watanabe
Keyword(s):  
Water Treatment ◽  
Distribution System ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Treatment Plant ◽  
Biological Activated Carbon ◽  
Treatment Processes ◽  
Biological Treatments ◽  
The Impact

When biodegradable organic matter and other nutrients, such as ammonia and phosphorus, are not sufficiently removed during water treatment, bacteria may proliferate in the water distribution system. Bacterial regrowth deteriorates water quality (taste and odor), accelerates corrosion, and potentially increases the risk of microbial diseases. Therefore, this research was conducted to evaluate the impact of four different advanced water treatment processes, including biological treatments such as a rotating biofilm membrane reactor (RBMR) and a biological activated carbon (BAC) filter and ultrafiltration (UF), on reduction of nutrient levels and biofilm formation potentials of the treated water entering model distribution systems (annular reactors). Our results revealed that biological treatments significantly improved the “biostability” of water leaving from the treatment plant. On average, The RBMR and BAC filter reduced easily assimilable organic carbon (AOC) concentration by half when compared with conventional treatment (multi-media filtration; MF) and ultrafiltration (from 35-49 to 18-23 mg C L-1). Consequently, biofilm formation potential was reduced by a factor of 5 to 10 (from 3,200-5,100 to 490-710 pg ATP cm-2). With respect to “biostability” of water, ultrafiltration was less effective in reducing AOC concentrations. In addition, the impact of chlorine disinfection on biofilm accumulation and AOC levels in the distribution system were studied.

scholarly journals NOM characterization and removal at six Southern African water treatment plants

2009 ◽  
Vol 2 (2) ◽  
pp. 231-257 ◽  
Author(s):  
J. Haarhoff ◽  
M. Kubare ◽  
B. Mamba ◽  
R. Krause ◽  
T. Nkambule ◽  
...  
Keyword(s):  
Water Treatment ◽  
Process Design ◽  
Distribution Systems ◽  
Water Distribution ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Organic Pollution ◽  
Process Selection ◽  
Water Treatment Plants ◽  
The Impact

Abstract. Organic pollution is a major concern during drinking water treatment. Major challenges attributed to organic pollution include the proliferation of pathogenic micro-organisms, prevalence of toxic and physiologically disruptive organic micropollutants, and quality deterioration in water distribution systems. A major component of organic pollution is natural organic matter (NOM). The operational mechanisms of most unit processes are well understood. However, their interaction with NOM is still the subject of scientific research. This paper takes the form of a metastudy to capture some of the experiences with NOM monitoring and analysis at a number of Southern African Water Treatment Plants. It is written from the perspective of practical process selection, to try and coax some pointers from the available data for the design of more detailed pilot work. NOM was tracked at six water treatment plants using dissolved organic carbon (DOC) measurements. Fractionation of the DOC based on biodegradability and molecular weight distribution was done at a water treatment plant in Namibia. A third fractionation technique using ion exchange resins was used to assess the impact of ozonation on DOC. DOC measurements alone did not give much insight into NOM evolution through the treatment train. The more detailed characterization techniques showed that different unit processes preferentially remove different NOM fractions. Therefore these techniques provide better information for process design and optimisation than the DOC measurement which is routinely done during full scale operation at these water treatment plants. Further work will focus on streamlining and improving the reproducibility of selected fractionation techniques, characterization of NOM from different water sources, and synthesis of the results into a systematic, practical guideline for process design and optimisation.

Natural Organic Matter and Disinfectant By-Products (DBPs) Formation Potential in Agriculture Area in Malaysia

2015 ◽  
Vol 802 ◽  
pp. 513-518
Author(s):  
Nurazim Ibrahim ◽  
Hamidi Abdul Aziz ◽  
Mohd Suffian Yusoff
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Treatment Processes ◽  
By Products

Natural organic matter (NOM) in water reacts with chlorine or other disinfectants and form hazardous disinfectant by-products (DBPs). This study aimed to detect the presence of NOM in a conventional water distribution system using UV absorbance at 254 nm as a surrogate. Two water treatment plants were selected, namely, Jalan Baharu Water Treatment Plant (JBWTP) and Lubok Buntar Water Treatment Plant (LBWTP). Aside from determining the amount of NOM, the reduction of UV254after completing the series of treatments (coagulation, flocculation, sedimentation, filtration, and disinfection) was also observed. The presence of UV254in both raw water and treated water samples confirmed the presence of NOM. The concentration of UV254recorded at JBWTP and LBWTP were 0.14 and 0.13 cm−1, respectively. After the treatment processes, the concentration was reduced to 0.04 cm−1for JBWTP and 0.03 cm−1for LBWTP. These results indicated that the water supply in both plants contains DBP precursors and implied the possibility of DBP formation in the system. Moreover, the percentage reduction of UV254recorded were 69% and 75% for JBWTP and LBWTP, respectively.

scholarly journals Analysis of chemical stability of tap water in terms of required level of technological safety

2017 ◽  
Vol 43 (4) ◽  
pp. 3-12 ◽  
Author(s):  
Katarzyna Pietrucha-Urbanik ◽  
Barbara Tchórzewska-Cieślak ◽  
Dorota Papciak ◽  
Izabela Skrzypczak
Keyword(s):  
Water Treatment ◽  
Water Supply ◽  
Chemical Stability ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Corrosion Properties

AbstractThe main goal of this work is to show the new approach to determining safety technological levels (SLs) in terms of water quality and its chemical stability, as well as issues of water corrosion properties in water distribution systems (WDSs), due to the fact that water supply pipes are prone to corrosion. In the paper the methodology of determining the risk associated with threat to technical infrastructure was considered. The concept was studied on the basis of real operational data from the water treatment plant. The probability of exceeding the individual parameters for WTPI is slightly larger than for WTPII, which means that this water treatment process may cause lack of chemical stability in the water supply network. Operators should anticipate in the process of designing water distribution system, using proper materials, as to ensure an adequate level of safety from the water source to the water recipient. It should be noted that it is necessary to adjust the material of internal installation of water supply networks to the parameters of the water. At present, there are no correlations between the designing step and water parameters. It was concluded that to protect the water supply infrastructure, which belongs to critical infrastructure, water company should put more emphasis on distribution of stable water that has not potentially corrosion properties. Some suggestions were made for the protection of WDS and to ensure safety of system functioning and long-term usability of water pipes.

Residual chlorine management in water distribution systems using network modelling techniques: case study in Seoul City

2004 ◽  
Vol 4 (5-6) ◽  
pp. 421-429
Author(s):  
J.C. Ahn ◽  
Y.W. Kim ◽  
K.S. Lee ◽  
J.Y. Koo
Keyword(s):  
Water Treatment ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Residual Chlorine ◽  
Network Modelling ◽  
Using Data ◽  
One Year

Twelve sampling locations in a network from a water treatment plant to consumers' taps were selected for measuring residual chlorine loss, THMs, TOC, etc. and 24 hour sampling in the locations was conducted on a bimonthly basis for one year. Chlorine bulk decay and THM formation tests were carried out by bottle tests under controlled temperatures for three locations: a water treatment plant, a large service reservoir, and a pumping station. Water quality modelling of chlorine loss in the distribution system was performed using data collected in the field study. This study contributed to the improvement of chlorine management in the distribution system by providing information for operators to maintain a minimum level of chlorine residual in a service reservoir.

scholarly journals NOM characterization and removal at six Southern African water treatment plants

2010 ◽  
Vol 3 (1) ◽  
pp. 53-61 ◽  
Author(s):  
J. Haarhoff ◽  
M. Kubare ◽  
B. Mamba ◽  
R. Krause ◽  
T. Nkambule ◽  
...  
Keyword(s):  
Water Treatment ◽  
Distribution Systems ◽  
Water Distribution ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Organic Pollution ◽  
Process Selection ◽  
Water Treatment Plants ◽  
The Impact

Abstract. Organic pollution is a major concern during drinking water treatment. Major challenges attributed to organic pollution include the proliferation of pathogenic micro-organisms, prevalence of toxic and physiologically disruptive organic micro-pollutants, and quality deterioration in water distribution systems. A major component of organic pollution is natural organic matter (NOM). The operational mechanisms of most unit processes are well understood. However, their interaction with NOM is still the subject of scientific research. This paper takes the form of a meta-study to capture some of the experiences with NOM monitoring and analysis at a number of Southern African Water Treatment Plants. It is written from the perspective of practical process selection, to try and coax some pointers from the available data for the design of more detailed pilot work. NOM was tracked at six water treatment plants using dissolved organic carbon (DOC) measurements. Fractionation of the DOC based on biodegradability and molecular weight distribution was done at a water treatment plant in Namibia. A third fractionation technique using ion exchange resins was used to assess the impact of ozonation on DOC. DOC measurements alone did not give much insight into NOM evolution through the treatment train. The more detailed characterization techniques showed that different unit processes preferentially remove different NOM fractions. Therefore these techniques provide better information for process design and optimisation than the DOC measurement which is routinely done during full scale operation at these water treatment plants.

Water treatment to reduce internal corrosion in the drinking water distribution system in Oslo

2001 ◽  
Vol 1 (3) ◽  
pp. 91-96 ◽  
Author(s):  
L.J. Hem ◽  
E.A. Vik ◽  
A. Bjørnson-Langen
Keyword(s):  
Water Treatment ◽  
Corrosion Rate ◽  
Distribution System ◽  
Water Distribution ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Corrosion Monitoring ◽  
Copper Corrosion ◽  
Iron Corrosion ◽  
Internal Corrosion

In 1995 the new Skullerud water treatment plant was put into operation. The new water treatment includes colour removal and corrosion control with an increase of pH, alkalinity and calcium concentration in addition to the old treatment, which included straining and chlorination only. Comparative measurements of internal corrosion were conducted before and after the installation of the new treatment plant. The effect of the new water treatment on the internal corrosion was approximately a 20% reduction in iron corrosion and a 70% reduction in copper corrosion. The heavy metals content in standing water was reduced by approximately 90%. A separate internal corrosion monitoring programme was conducted, studying the effects of other water qualities on the internal corrosion rate. Corrosion coupons were exposed to the different water qualities for nine months. The results showed that the best protection of iron was achieved with water supersaturated with calcium carbonate. Neither a high content of free carbon dioxide or the use of the corrosion inhibitor sodium silicate significantly reduced the iron corrosion rate compared to the present treated water quality. The copper corrosion rate was mainly related to the pH in the water.

Practical Guide to Determine the Impact of Radon and Other Radionuclides on Water Treatment Processes

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Environmental Protection Agency ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Packed Tower ◽  
Treatment Processes ◽  
Radioactivity Exposure ◽  
The Impact ◽  
Percent Removal

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.

scholarly journals Exergy Evaluation of a Water Distribution System

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6221
Author(s):  
Jedrzej Bylka ◽  
Tomasz Mróz
Keyword(s):  
Water Treatment ◽  
Energy Loss ◽  
Water Supply ◽  
Case Studies ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Supply System ◽  
Water Supply System

The water supply system is one of the most important elements in a city. Currently, many cities struggle with a water deficit problem. Water is a commonly available resource and constitutes the majority of land cover; however, its quality, in many cases, makes it impossible to use as drinking water. To treat and distribute water, it is necessary to supply a certain amount of energy to the system. An important goal of water utility operators is to assess the energy efficiency of the processes and components. Energy assessments are usually limited to the calculation of energy dissipation (sometimes called “energy loss”). From a physical point of view, the formulation of “energy loss” is incorrect; energy in water transport systems is not consumed but only transformed (dissipated) into other, less usable forms. In the water supply process, the quality of energy—exergy (ability to convert into another form)—is consumed; hence, a new evaluation approach is needed. The motivation for this study was the fact that there are no tools for exergy evaluation of water distribution systems. A model of the exergy balances for a water distribution system was proposed, which was tested for the selected case studies of a water supply system and a water treatment station. The tool developed allows us to identify the places with the highest exergy destructions. In the analysed case studies, the highest exergy destruction results from excess pressure (3939 kWh in a water supply system and 1082 kWh in a water treatment plant). The exergy analysis is more accurate for assessing the system compared to the commonly used energy-based methods. The result can be used for assessing and planning water supply system modernisation.

Variations of DBPs precursors according to location within the distribution system

2009 ◽  
Vol 9 (4) ◽  
pp. 413-421
Author(s):  
C. Beaulieu ◽  
M. J. Rodriguez ◽  
J.-B. Sérodes
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Spatial Behavior ◽  
Haloacetic Acids ◽  
Formation Potential ◽  
The Impact ◽  
By Products

Little information is available on the evolution of remaining organic matter (ROM) in a water distribution system (WDS) and its impact on the generation of disinfection by-products (DBPs). This research involves the characterization, through sample fractionation processes and experimental chlorination tests, of the reactivity of DBP precursors occurring within a WDS. The study is based on samples collected in various locations of a WDS during a complete year. For each sample, six fractions were generated to determine their potential for formation of trihalomethanes (THMs) and haloacetic acids (HAAs). Fractionation processes on ROM demonstrated that the spatial behavior of precursors for THMs differs from that for precursors of HAAs. In addition, experimental chlorination tests showed that the reactivity of the investigated fractions, in terms of DBP formation potential (DBPfp), was different from each other according to location in the WDS. DBPfp for the studied fractions changed drastically during water treatment. However, changes of DBPfp for fractions were relatively low between the beginning and the extremity of the distribution system. Since the results of this research confirm that the ability to produce DBPs is related to the nature of the fractions, they could be useful to evaluate the impact of re-chlorination on DBP formation in a WDS.

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