| Water quality although acceptable when it leaves the treatment plant may deteriorate before it reaches the users through drinking water distribution netwok. In the planning and control of water quality in distribution systems, it is useful to know the time history and eventual spatial distribution of water quality substances in the network.Firstly, two methodologies for finding the optimal layout of a detection system in a municipal water network is formulated and demonstrated. One is based on the concept of DC (demand coverage), the other is based on DD(detected domain). Water quality data collected from these monitoring stations can be more representative in indicating the characteristic of water quality in the distribution network.Then models of flow modality and deterioration kinetics of waterborne substances in distribution network are discussed. Models of chlorine residual kinetics characterize chlorine decay as a combination of first-order or second-order decay in the bulk liquid and first-order decay reactions at the pipe wall. This paper also presented a model that predicts total trihalomethanes(TTHMs) based on the consumption of chlorine.To model the contaminant transport problem in drinking water distribution systems, an event-driven method is proposed in the third part of the thesis. The solution of the time varying water quality problem is obtained in an event-oriented system simulation framwork that determines the optimal pipe segmentation scheme with the smallest number of segments necessary to carry out the simulation process. It is predicated on the material mass balance accounting for transport and kinetics reaction process. Perfect advective one-dimensional displacement with complete mixing of material at the network nodes is assumed.finally, the performance of the methods presented above is demonstrated by application to an example water distribution network. The modeling outcome shows good correspondence with observed field data. |
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