A study on establishing an optimal water network in a dyeing and finishing industrial park

The problem caused by large water consumption in a dyeing and finishing industrial park needs to be solved urgently. In this paper, a mathematical programming model for water integration in the dyeing and finishing industrial park (DFIP) is established. This model can optimize the water network on the basis of the minimum total annual cost. The superstructure, base of the formulas, considers shared multistage wastewater treatment facilities according to the real situation of DFIP, which is not involved in the previous study. It allows the wastewater reuse in the same plant and the water exchange with different plants. The treated water from each stage of shared multistage treatment facilities could be segregated and directed to the plants for reuse, to the next stage for advanced treatment, and/or discharged to the environment. In addition, this study also develops a water metabolism analytical method to ensure the practicability of the model. It mainly functions as analyzing the wastewater quality and water quality requirement for dyeing and finishing plant, which aims at both exploring potential water recovery and amending impractical water connections. The results obtained in a practical example indicate that the water reuse rate of the optimized water network reaches up to 73 % and the total annual cost can be decreased by 54 %.