Optimization of pump-treat-inject(PTI)design for the remediation of a contaminated aquifer: multi-stage design whit chance constraints

摘要

A large scale groundwater remediation project using pump-and-treat(PAT)or pump-treat-in- ject(PTI)cannot be designed as a single time-step operation, because of uncertainties associated with the system. The changes in concentrations in reality may differ significantly from predicted ones. Instead, a multi-stage decision process is formulated and solved as a two-level hierarchical optimization model. Cost serves as the objective function, while contaminant concentration and total cleanup time are constraints. The entire cleanup time is divided into several stages. The number of wells for both pumping and injection is treated as a decision variable in each design stage.