Influence of plant types, bed media and feeding patterns on wastewater treatment performance of wetland roofs

Abstract

This study investigated the effects of two local plants (Wedelia Trilobata - WT, Axonopus Compressus - AC), feeding patterns (continuous and intermittent), and types of bed media (sand and charcoal) on the treatment performance of shallow bed subsurface flow wetland roofs (WRs). Results showed that changing plant from AC into WT led to an increase in removal rate by 6–12 % for COD and 11–13 % for total nitrogen (TN). The removal rate accelerated by 8 % for COD, 45–64 % for TN and 125 % for total phosphorus (TP) when changing from sand to charcoal as bed media. Continuous feeding mode enhanced the removal rate by 17–19 % for COD and 11–13 % for TN, compared to intermittent feeding mode. The findings suggested that the treatment capacity of WR was significantly affected by the type of plant, bed material and feeding pattern.