Cost optimization of industrial wastewater reuse systems

Reuse of industrial wastewater is an important strategy for reducing freshwater consumption and wastewater generation. This paper outlines a methodology for assessing the economic performance of industrial wastewater reuse systems that involve water upgrading. From an economic perspective, wastewater reuse reduces the costs of freshwater supply and wastewater disposal. Reusing significant quantities of wastewater typically involves regeneration/ treatment of the available wastewater to meet the higher water quality requirements of water-using activities. However, the cost of wastewater regeneration/ treatment rises exponentially with increasing contaminant removal efficiency. This paper demonstrates the importance of balancing these competing cost factors (freshwater and wastewater disposal costs vs wastewater regeneration/ treatment cost), which are functions of the post-regeneration/post-treatment contaminant concentration. The proposed cost optimization procedure can be used to minimize the total cost of a wastewater reuse system with either wastewater regeneration reuse or wastewater treatment reuse.