Effluent Recirculation for Contaminant Removal in Constructed Wetlands Under Uncertainty: A Stochastic Numerical Approach Based on Monte Carlo Methodology

The problem of the alternative operational technique concerning effluent re-circulation in Horizontal Subsurface Flow Constructed Wetlands (HSF CW), and the possibility of this technique to remove efficiently pollutants under uncertainty, is investigated numerically in a stochastic way. Uncertain-but-bounded input-parameters are considered as interval parameters with known upper and lower bounds. This uncertainty is treated by using the Monte Carlo method. A typical pilot case of an HSF CW concerning Biochemical Oxygen Demand (BOD) removal is presented and numerically investigated. The purpose of the present study is to compare the relevant numerical results obtained under parameter uncertainty and concerning HSF CW operation with and without the effluent recirculation technique.