Material selection for landfill leachate piping by using a grey target decision-making approach.

Landfill leachate, due to its quantity and inherent risk, is generally collected and transported by piping system for advanced treatment. During the piping, the pipe materials may react with leachate, resulting in corrosion and scaling. In order to reduce possible failures and mitigate the associated consequences, this study provides an indicator system for material selection to aid the pipe system design. The material functional, economic, and environmental attributes are incorporated into the indicator system, to perform a precise selection of commercial drainage pipe materials, thus improving empirically oriented selection. Four common drainage pipe materials including high-density polyethylene (HDPE), polyvinyl chloride (PVC), galvanized steel, and seamless steel are taken as the material alternatives for the selection. Based upon their experimental data, a grey target decision-making framework is employed to perform the priority ranking of the materials. The results indicate that HDPE has the best performance, followed by PVC, galvanized steel, and seamless steel. This study discusses the validity of the selection results and the applicability of the proposed method, to provide insight into  leachate piping system design.