Integrated graphical approach for selecting industrial water conservation projects

Sustainable water management is key to achieving sustainable development goals. Increasing water consumption prompts industrial plants to implement water conservation projects (WCPs) and improve the utilization efficiency of water resources. In this paper, we develop an integrated graphical method for the implementation of water conservation projects by considering both water-saving targets and investment costs with or without government subsidies. First, cost-benefit analysis for different projects is carried out. The unit water saving cost diagram is employed to rank the priority of implementation of each project. Then, the project combination that meets the expected water-saving goal is determined via water-saving pinch analysis. Finally, the water conservation potential and cost-benefit of the optimal project combination are estimated using the marginal cost curve diagram. Two scenarios are considered for the proposed graphical approach: with and without government subsidies. A chlor-alkali/polyvinyl chloride complex is used as an illustrative case study. The results indicate the proposed method can be used to screen out the feasible projects under the constraints of water-saving target and financial fund.