ANOVA was applied to provide an optimum combination of the vegetated channel parameters and consequently TSS and turbidity removal. The response surface quadratic model resulted from ANOVA about TSS removal in vegetated channel is presented in Table 5. The significant model terms are 4. Conclusions
In this research the effect of flow velocity, vegetation density, and length of vegetation in a vegetated channel on TSS and turbidity removal was studied. Statistical optimization model (response surface methodology couple with central composite design) overcomes the limitation of classical methods and was successfully employed to obtain the optimum process conditions while the interactions between process variables were demonstrated. The following conclusions were drawn from this study: