Optimization of the phytoremediation conditions of wastewater in post-treatment by and : kinetic model for pollutants removal.

This study aims at determining the optimal conditions for pollutants removal in wastewater using and as appropriate aquatic plants for a post-treatment by phytoremediation. From factors such as residence time, plant density and initial PO concentration, four responses, i.e. the removal efficiency of PO, NO, NH and the chemical oxygen demand (COD) were followed, using complete factorial design. After validation of the regression models by the statistical analyses, optimal conditions were obtained by using the global desirability function. Global desirabilities of 0.96 and 0.97 were respectively obtained for and for a residence time of 30 days, a plant density of 60 feet/m and an initial PO concentration of 10 mg/L. Using this corresponds to the elimination of 94.2% of PO; 93.3% of NO; 95.0% of NH and 63.6% of COD. In the case of , 93.9% of PO; 83.4% of NO, 99.5% of NH and 84.4% of COD were removed. Finally, under the used conditions, are able to better eliminate phosphorus and nitrates, while are very effective in removing NH and COD.