Disinfection byproduct formation kinetics of a water treatment plant on Kinmen Island

2015 ◽  
Vol 15 (6) ◽  
pp. 1200-1206
Author(s):  
Hsien-chun Ke ◽  
Hsin-hsin Tung

Chloramine has often been used as a chlorine alternative for trihalomethane (THM) and haloacetic acid (HAA) control. However, nitrogenous disinfection byproduct (N-DBP) formation and nitrification in distribution have always been major concerns in chloramination practices. On Kinmen Island, the high organic nitrogen content in raw water may increase the nitrogenous DBP formation. Simulated distribution system tests were conducted to explore the DBP formation kinetics in the distribution system. Lower haloacetonitrile (HAN4) formation (0.26 μg L−1) with chloramination than with chlorination (10.48 μg L−1) was observed from the 24 hours of reaction time. The nitrogen sources contributing to the dichloroacetonitrile (DCAN) formation kinetics were explored with 15N-chloramination. The results showed that nitrogen sourced from organic nitrogen was more dominant in DCAN formation with low chloramine dosage. This suggests that chloramine contributes to less DCAN formation in practice, especially for short distribution systems. In summary, the results provide evidence that simultaneous post-chloramination and pre-chlorination would be a feasible disinfection strategy applied to control regulated THM and HAA formation on Kinmen Island.

2019 ◽  
Vol 280 ◽  
pp. 05003
Author(s):  
Maxwell Meadows ◽  
Soni M. Pradhanang ◽  
Thomas B. Boving ◽  
Hichem Hadjeres

Nitrogenous disinfection by-products (N-DBPs) are emerging by-products that may be present in drinking water as by-products of water treatment plant (WTP) operations. Nitrosamines are N-DBPs that form by reaction of chloramine with certain organic nitrogen-containing compounds; however, the exact processes and environments in which nitrosamines form are still not well understood. Organic nitrogen precursors react within the WTP and distribution system, forming the toxic by-products during chloramination, or while in distribution. To best control the formation potential of nitrosamines, precursors must be removed from source water prior to chloramine disinfection. These nitrosamine forming precursors are abundant in source waters worldwide, presenting a need for further study of the mechanisms that reduce the formation potential of nitrosamines in chloramination WTPs.


2017 ◽  
Vol 43 (4) ◽  
pp. 3-12 ◽  
Author(s):  
Katarzyna Pietrucha-Urbanik ◽  
Barbara Tchórzewska-Cieślak ◽  
Dorota Papciak ◽  
Izabela Skrzypczak

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.


2004 ◽  
Vol 4 (5-6) ◽  
pp. 421-429
Author(s):  
J.C. Ahn ◽  
Y.W. Kim ◽  
K.S. Lee ◽  
J.Y. Koo

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.


2001 ◽  
Vol 1 (3) ◽  
pp. 91-96 ◽  
Author(s):  
L.J. Hem ◽  
E.A. Vik ◽  
A. Bjørnson-Langen

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.


1997 ◽  
Vol 36 (5) ◽  
pp. 317-324 ◽  
Author(s):  
M.J. Rodriguez ◽  
J.R. West ◽  
J. Powell ◽  
J.B. Sérodes

Increasingly, those who work in the field of drinking water have demonstrated an interest in developing models for evolution of water quality from the treatment plant to the consumer's tap. To date, most of the modelling efforts have been focused on residual chlorine as a key parameter of quality within distribution systems. This paper presents the application of a conventional approach, the first order model, and the application of an emergent modelling approach, an artificial neural network (ANN) model, to simulate residual chlorine in a Severn Trent Water Ltd (U.K.) distribution system. The application of the first order model depends on the adequate estimation of the chlorine decay coefficient and the travel time within the system. The success of an ANN model depends on the use of representative data about factors which affect chlorine evolution in the system. Results demonstrate that ANN has a promising capacity for learning the dynamics of chlorine decay. The development of an ANN appears to be justifiable for disinfection control purposes, in cases when parameter estimation within the first order model is imprecise or difficult to obtain.


Author(s):  
Wenjin Xue ◽  
Christopher W. K. Chow ◽  
John van Leeuwen

Abstract The bacterial regrowth potential (BRP) method was utilised to indirectly measure the assimilable organic carbon (AOC) as an indicator for the assessment of the microbial regrowth potential in drinking water distribution systems. A model using various microbial growth parameters was developed in order to standardise the experimental interpretation for BRP measurement. This study used 82 experimental BRP data sets of water samples collected from the water treatment plant to locations (customer taps) in the distribution system. The data were used to model the BRP process (growth curve) by a data fitting procedure and to obtain a best-fitted equation. Statistical assessments and model validation for evaluating the equation obtained by fitting these 82 sets of data were conducted, and the results show average R2 values were 0.987 for treated water samples (collected at the plant prior to chlorination) and 0.983 for tap water (collected at the customer taps). The F values obtained from the F-test are all exceeded their corresponding F critical values, and the results from the t-test also showed a good outcome. These results indicate this model would be successfully applied in modelling BRP in drinking water supply systems.


2001 ◽  
Vol 35 (14) ◽  
pp. 3483-3489 ◽  
Author(s):  
Lewis A Rossman ◽  
Richard A Brown ◽  
Philip C Singer ◽  
John R Nuckols

2018 ◽  
Vol 59 ◽  
pp. 00005
Author(s):  
Barbara Tchórzewska-Cieślak ◽  
Dorota Papciak ◽  
Katarzyna Pietrucha-Urbanik ◽  
Andżelika Pietrzyk

The subject of the work is the analysis and assessment of the risk of biological instability of water. The lack of water stability causes the increased susceptibility of the distribution system to secondary microbial contamination of water and constitutes a hazard for consumers’ health. The risk is expressed as the loss of water supply safety and distinguishes a failure of not meeting certain water quality parameters that can influence physico-chemical parameters and the bacteriological quality of the water supplied to the consumers. In the paper the method of analysing and evaluating the risk of loss of biostability of tap water is presented. The presented analysis was performed on the basis of the operating data from the water treatment plant.


Author(s):  
Vigain Harutunian ◽  
Anne Harutunian ◽  
Kegham A. Harutunian ◽  
Shant Harutunian

Axiomatic Design provides a set of axioms and corollaries to help make system design decisions. In this paper, the independence axiom is applied to evaluate alternate low pressure air (LPA) distribution system designs to serve the aeration basins of a wastewater treatment plant. The airflow to each air zone is defined as a functional requirement (FR) in the functional domain. A design parameter (DP) in the physical domain is selected to achieve each FR. The DPs include the LPA motor operated valve (MOV) damper positions and a process air blower inlet guide vane (IGV) position. Three design alternatives are developed and evaluated with the respect to the independence axiom. Each subsequent alternative attempts to reduce the amount of functional coupling. Reduced functional coupling in an LPA system results in a more stable treatment process and greater system longevity through reduced component wear.


Sign in / Sign up

Export Citation Format

Share Document