A Case Study on the Automatic Control of Chemical Dosing Processes for Full-Scale Drinking Water Treatment

Abstract:

During drinking water treatment, the chemical dosing processes, such as coagulant dosing process, ozone dosing process and chlorine dosing process are usually manually operated based on the operator knowledge and experience. However, due to the variations of water quality, water flow and process operational conditions and characteristics of large time-delay and nonlinear for the chemical dosing processes, it is difficult to adjust the chemical dosages in time by operators to keep the treated water quality stable, especially during the periods of rapid and frequent variations of water quality, water flow and process operational conditions. Thus, the improvements of control methods for the chemical dosing processes are essential to the operation of drinking water treatment plants. The Xiangcheng Water Treatment Plant in Suzhou, China has been utilizing the automatic control for chemical dosing processes since February 2012. Automatic controllers are designed respectively for the coagulant dosing process, ozone dosing process and chlorine dosing process. After the implementation of automatic control, operators are not necessary to keep constant attention. In addition, due to the improvements of control accuracies for the chemical dosing processes, the chemical dosages are reduced on the premise of ensuring safe water. Thus, both of the human resource costs and material costs can be saved. The practical control results demonstrate the efficiencies of proposed methods.

• Periodical: Applied Mechanics and Materials (Volumes 209-211)
• Pages: 1981-1985
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.209-211.1981
• Online since: October 2012
• Authors: Dong Sheng Wang, Xing Peng Zhou, Xiao Ming Mo, Yi Wang
• Keywords: Automatic Control, Chemical Dosing Process, Drinking Water Treatment, Full-Scale

References

[1] H.A. Marlowe and B.A. Beaudet: Journal of the American Water Works Association Vol. 84 (1992), pp.46-49.

[2] W.L. Bruce, A.H. Robert and C.H. Robert: Ozone: Sci. & Eng. Vol. 21 (1999), pp.465-476.

[3] S. Mazloum, S. Jasim, N. Biswas, K. Rakness and G. Hunter: Ozone: Sci. & Eng. Vol. 26 (2004), pp.125-140.

[4] C.E. Garcia, D.M. Prett and M. Morari: Automatica Vol. 25 (1989), p.335–348.

[5] Z. Zhao, X.H. Xia, J.C. Wang, J. Gu and Y.H. Jin: J. Process Control Vol. 13 (2003), pp.41-56.

[6] G. Özkan, A. Üser, H. Hapoglu and M. Alpbaz: Chem. Eng. J. Vol. 137 (2008), p.320–327.

[7] A. Koohestanian, M. Hosseini and Z. Abbasian: American-Eurasian J. Agric. & Environ. Sci. Vol. 4 (2008), p.266–273.

[8] S. Courtois: Tribune de l'eau Vol. 58 (2005), pp.3-8.

[9] X.W. Liu, Z.L. Chen, N. Zhou, J.M. Shen and M.M. Ye: J. Environ. Sci. Vol. 137 (2010), p.1897–1902.

[10] W.L. Bruce, A.H. Robert and C.H. Robert: Ozone: Sci. & Eng. Vol. 21 (1999), pp.465-473.

[11] M.J. Rodriguez and J.B. Serodes: Can. J. Civ. Eng. Vol. 23 (1996), pp.621-631.