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Effect of Flow Velocity on Chlorine Decay in Water Distribution Network:A Pilot Loop Study


Affiliations
1 Centre for Environment and Development, Ashoka Trust for Research in Ecology and the Environment, Jakkur, Bengaluru 560 064, India
2 Department of Civil Engineering, Indian Institute of Science, Bengaluru 560 012, India
 

Experiments were run in the pipe loop setup to estimate bulk and wall chlorine decay rates under varying flow and chlorine levels for groundwater. A recirculating loop of 50 mm inner diameter polyvinyl chloride pipe and a variable flow pump with feed and recirculation tank were used to design a pipe loop. Sodium hypochlorite was introduced as free chlorine into the test water. The study came up with three important findings: (a) bulk chlorine decay rate in test water decreased with increase in chlorine levels, which is attributed to the type and level of organic matter present in test water. (b) Chlorine decay rate in pilot loop setup increased with increase in flow velocity. The result showed that under turbulent conditions, in addition to chlorine, mass flux transfer from bulk to wall and biofilm removal from pipe surface contributed to chlorine decay. We also noted that with increase in flow velocity the contribution of bulk reaction to total chlorine decay in pipe loop decreased. (c) ANOVA test on experimental dataset showed that as compared to initial chlorine levels, flow velocity has statistically significant effect on chlorine dissipation in a pipe loop. We also found that after turbulent flow is achieved, the effect of flow velocity on the wall decay is negligible.

Keywords

Chlorine Decay, Pipe Loop Setup, Reynolds Number, Water Distribution Systems.
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  • Totsuka, N., Trifunovic, N. and Vairavamoorthy, K., Intermittent urban water supply under water starving situations. In 30th WEDC International Conference: People-centred Approaches to Water and Environmental Sanitation, Vientiane, Lao PD, 2004.

  • Lehtola, M. J., Laxander, M., Miettinen, I. T., Hirvonen, A., Vartiainen, T. and Martikainen, P. J., The effects of changing water flow velocity on the formation of biofilms and water quality in pilot distribution system consisting of copper or polyethylene pipes. Water Res., 2006, 40, 2151–2160.

  • Manuel, C. M., Nunes, O. C. and Melo, L. F., Dynamics of drinking water biofilm in flow/non-flow conditions. Water Res., 2007, 41, 551–562.

  • Kilb, B., Lange, B., Schaule, G., Flemming, H.-C. and Wingender, J., Contamination of drinking water by coliforms from biofilms grown on rubber-coated valves. Int. J. Hyg. Environ. Health, 2003, 206, 563–573.

  • Juhna, T. et al., Detection of Escherichia coli in biofilms from pipe samples and coupons in drinking water distribution networks. Appl. Environ. Microbiol., 2007, 73, 7456–7464.

  • Rossman, L. A., The effect of advanced treatment on chlorine decay in metallic pipes. Water Res., 2006, 40, 2493–2502.

  • Mutoti, G., Dietz, J. D., Arevalo, J. and Taylor, J. S., Combined chlorine dissipation: pipe material, water quality, and hydraulic effects. J. Am. Water Works Assoc., 2007, 99, 96–106.

  • Sastry, G. S., Urban Water Supply and Demand: A Case Study of Bangalore City, Working paper 47, Institute for Social and Economic Change, ISEC, 2004.

  • Munavalli, G. R. and Kumar, M. M., Water quality parameter estimation in steady-state distribution system. J. Water Resour. Plan. Manag., 2003, 129, 124–134.

  • Munavalli, G. R. and Kumar, M., Water quality parameter estimation in a distribution system under dynamic state. Water Res., 2005, 39, 4287–4298.

  • Fisher, I., Kastl, G. and Sathasivan, A., Evaluation of suitable chlorine bulk-decay models for water distribution systems. Water Res., 2011, 45, 4896–4908.

  • Asséré, A., Oulahal, N. and Carpentier, B., Comparative evaluation of methods for counting surviving biofilm cells adhering to a polyvinyl chloride surface exposed to chlorine or drying. J. Appl. Microbiol., 2008, 104, 1692–1702.

  • Jang, H. J. and Ka, J. O., Effects of diverse water pipe materials on bacterial communities and water quality in the annular reactor. J. Microbiol. Biotechnol., 2011, 21, 115–123.

  • Rozej, A., Cydzik-Kwiatkowska, A., Kowalska, B. and Kowalski, D., Structure and microbial diversity of biofilms on different pipe materials of a model drinking water distribution systems. World J. Microbiol. Biotechnol., 2015, 31, 37–47.

  • Telgmann, U., Horn, H. and Morgenroth, E., Influence of growth history on sloughing and erosion from biofilms. Water Res., 2004, 38, 3671–3684.

  • Wingender, J. and Flemming, H. C., Contamination potential of drinking water distribution network biofilms. Water Sci. Technol., 2004, 49, 277–286.

  • Sashikumar, N., Mohankumar, M. S. and Sridharan, K., Modelling an intermittent water supply. In Proceedings of World Water and Environmental Resources Congress, Philadelphia, Pennsylvania, United States, 1–11, 22–23 June 2003.


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  • Effect of Flow Velocity on Chlorine Decay in Water Distribution Network:A Pilot Loop Study

Abstract Views: 369  |  PDF Views: 146

Authors

Priyanka Jamwal
Centre for Environment and Development, Ashoka Trust for Research in Ecology and the Environment, Jakkur, Bengaluru 560 064, India
M. S. Mohan Kumar
Department of Civil Engineering, Indian Institute of Science, Bengaluru 560 012, India

Abstract


Experiments were run in the pipe loop setup to estimate bulk and wall chlorine decay rates under varying flow and chlorine levels for groundwater. A recirculating loop of 50 mm inner diameter polyvinyl chloride pipe and a variable flow pump with feed and recirculation tank were used to design a pipe loop. Sodium hypochlorite was introduced as free chlorine into the test water. The study came up with three important findings: (a) bulk chlorine decay rate in test water decreased with increase in chlorine levels, which is attributed to the type and level of organic matter present in test water. (b) Chlorine decay rate in pilot loop setup increased with increase in flow velocity. The result showed that under turbulent conditions, in addition to chlorine, mass flux transfer from bulk to wall and biofilm removal from pipe surface contributed to chlorine decay. We also noted that with increase in flow velocity the contribution of bulk reaction to total chlorine decay in pipe loop decreased. (c) ANOVA test on experimental dataset showed that as compared to initial chlorine levels, flow velocity has statistically significant effect on chlorine dissipation in a pipe loop. We also found that after turbulent flow is achieved, the effect of flow velocity on the wall decay is negligible.

Keywords


Chlorine Decay, Pipe Loop Setup, Reynolds Number, Water Distribution Systems.

References





DOI: https://doi.org/10.18520/cs%2Fv111%2Fi8%2F1349-1354