Carbon capture and sequestration by a treatment wetland

An understanding of detailed kinetic of CO2 removal by plants can lead to an effective design of the phytoremediation process for anthropogenic CO2 reduction. This study examines the CO2 removal rates of five wetland plants (Cyperus alternifolius, Dracaena fragrans, Iris ensata, Iris setosa and Thalia dealbata) by using saturation reaction and first-order reaction kinetic equations. It was determined that the elevation of CO2 levels stimulated the plant-CO2 uptake rate. The maximum CO2 removal rates (k) of plants were found to range between 0.76 and 1.21 g m−2 h−1. The magnitude of first-order kinetic coefficient of plants (k′) had a close relationship with CO2 level at half-velocity (K). For consistency, the same kinetics were applied to the continuous flow experiment. A saturation kinetic approach was well suited to estimate the removal rate of CO2 in continuous flow system, while a first-order kinetic approach was limited to inflow CO2 levels below 500 ppm.