Oxidation Capability of Intermittently Loaded Vertical Flow Constructed Wetlands Set in Planted Canal Circulation Water

Abstract

We evaluated the capabilities of the intermittently loaded vertical flow constructed wetland (“VF wetland”) set in the planted canal circulation water as an oxidation system. Results show oxidation performance in the filter media with following properties. The water flow velocity was about 5-15L·s^-1·m^-2, CEC was more than 20cmol·kg^-1,  and NO₂-N concentration rose during one week to one month from filter media installation. Subsequently, the following process was carried out in 45min for a self-priming siphon operating cycle. NH₄-N was adsorbed to the filter media, with nitrification by nitrifying bacteria, and leaching from the filter media. Nitrogen removal by denitrification that progresses by nitrification by intermittent loaded vertical flow wetlands, and treated water circulated to the inlet of the planted canal. VF wetlands using suitable filter media can function as an effective energy-saving water purification oxidation system.