A laboratory-scale investigation into the use of powdered iron for in situ removal of phosphorus from treated sewage effluent with constructed wetlands

Abstract

Incorporation of powdered iron into the root bed of experimental constructed wetlands removes phosphorus from treated sewage to levels that easily meet government guidelines for discharge into natural water bodies. Various combinations of powdered iron and sand were used to determine the best arrangement that removes the largest amount of phosphorus. Macrophytes fulfill a beneficial function by delivering oxygen to the root zone and by improving drainage in the wetland. In these wetlands, cattails (Typha latifolia L.) also take up phosphorus during growth and store significant quantities of it in their leaves.