Influence of intermittent aeration and organic loading rate on lab-scale constructed wetland systems treating synthetic wastewater

Abstract

AbstractBy coupling the intermittent characteristics of rural sewage discharge and solar energy density, the performance responses of lab-scale tidal flow constructed wetland (TF) and conventional vertical flow constructed wetland (VF) to different organic loading rates (OLRs) (166.3, 300.9, 451.2, 602.4, and 751.2 g/m2 d) in synthetic domestic sewage treatment were investigated to study its feasibility to replace conventional aeration and reduce the dependence of wastewater treatment plants on the grid in this study. Artificial aeration was conducted based on simulating photovoltaic aeration. The increase in OLR promoted the removal performances for the chemical oxygen demand (COD) and ammonia–nitrogen (-N) in TF, which could be up to 95.7 and 97.2%, respectively, under OLR of 751.2 g/m2 d. Excess organic carbons inhibited -N removal through competition for oxygen available in VF, where the COD removal efficiency could be 89.6% while low -N removal (40%) was obtained under OLR 751.2 g/m2 d. With the incr...