Optimal Location of Booster Disinfection Stations in a Water Distribution System: A Two-Stage Stochastic Approach

摘要

Secondary or booster disinfection consists of the addition of disinfectant at distinct locations distributed throughout a water distribution system. This work describes a stochastic approach for the optimal location of booster disinfection stations in water distribution networks. The model minimizes the expected total cost involving the installation of booster stations and the mass of disinfectant needed to satisfy the residual concentration constraints within the network. Inherent uncertainties such as water demand and the chemical reactions of the disinfectant taking place on the system indirectly incorporate uncertainties on the model parameters. Hence, the problem has been reformulated as a first-stage-integer two-stage stochastic mixed integer linear program with recourse. The parameters needed for the solution are obtained through the water quality simulator EPANET 2.0. The resulting formulation has been solved through a generalized framework based on the stochastic decomposition algorithm. The framework integrates the GAMS modeling environment, the EPANET simulator, sampling code (FORTRAN) to handle uncertainties and a C++ master program. The paper describes the model and the solution framework, and compares deterministic and stochastic optimal solutions.