In this study unidirectional flushing (UDF) was conducted to improve the effectiveness of deposit removal from internal pipe walls and to provide information on pipe networks to enable operators to implement flushing in field. Four ductile cast iron pipes with epoxy-lined and cement-lined were selected for the practice of UDF. Water pressure was measured using a data logger equipped with a pressure gauge. The normal flow velocities of the networks were found to be 0.12 m/sec or below in the study area. Flushing velocities ranged from 1.07 m/sec to 2.78 m/sec by using a blow-off valve for discharge. The discharged water was taken in five-minute intervals to measure water quality parameters: turbidity, residual chlorine, pH, temperature and conductivity in the field; metals, inorganic ions, total suspended solids and heterotrophic plate count bacteria in the laboratory. The practice of periodic UDF as preventive maintenance is expected to contribute to enhancement of safety and stability of the water supply. It was indicated that part of the biofilm could be removed with the sediments in the pipe by UDF since the removal of HPC bacteria was correlated with total suspended solids (TSS) (R2=0.90). The coefficient of determination (R2) between turbidity and TSS is 0.90 except for one outlier. Sediment removal could be estimated from the turbidity data of flushed water in the field using the equation of the relationship between turbidity and TSS.
Article navigation
Research Article|
February 01 2011
Application of unidirectional flushing in water distribution pipes
Jae Chan Ahn
;
1
Waterworks Research Institute, Seoul Metropolitan Government, 552-1 Cheonhodaero Gwangjingu, Seoul 143-820, Korea
Tel: 82-2-3146-5758 Fax: 82-2-3146-5708; E-mail: anjchan@seoul.go.kr
Search for other works by this author on:
Su Won Lee
;
Su Won Lee
1
Waterworks Research Institute, Seoul Metropolitan Government, 552-1 Cheonhodaero Gwangjingu, Seoul 143-820, Korea
Search for other works by this author on:
Kevin Y. Choi
;
Kevin Y. Choi
1
Waterworks Research Institute, Seoul Metropolitan Government, 552-1 Cheonhodaero Gwangjingu, Seoul 143-820, Korea
Search for other works by this author on:
Ja Yong Koo
;
Ja Yong Koo
2
Department of Environmental Engineering, University of Seoul, 13 Siripdaegil Dongdaemoon, Seoul 130-743, Korea
Search for other works by this author on:
Hyun Jeong Jang
Hyun Jeong Jang
1
Waterworks Research Institute, Seoul Metropolitan Government, 552-1 Cheonhodaero Gwangjingu, Seoul 143-820, Korea
Search for other works by this author on:
Journal of Water Supply: Research and Technology-Aqua (2011) 60 (1): 40-50.
Article history
Received:
February 23 2009
Accepted:
August 25 2010
Citation
Jae Chan Ahn, Su Won Lee, Kevin Y. Choi, Ja Yong Koo, Hyun Jeong Jang; Application of unidirectional flushing in water distribution pipes. Journal of Water Supply: Research and Technology-Aqua 1 February 2011; 60 (1): 40–50. doi: https://doi.org/10.2166/aqua.2011.013
Download citation file:
Close
Citation
Jae Chan Ahn, Su Won Lee, Kevin Y. Choi, Ja Yong Koo, Hyun Jeong Jang; Application of unidirectional flushing in water distribution pipes. Journal of Water Supply: Research and Technology-Aqua 1 February 2011; 60 (1): 40–50. doi: https://doi.org/10.2166/aqua.2011.013
Download citation file:
Close