Minimizing of Greenhouse Gas Emissions from a Subsurface Flow Constructed Wetland

Abstract

In this study, the level of carbon dioxide, methane and nitrous oxide emissions from a horizontal subsurface flow constructed wetland were monitored and greenhouse gas emissions were estimated by using a newly developed model. The effects of three different plant species on greenhouse gas emissions were investigated. Cyperus esculentus (Zone I), Typha latifolia (Zone II) and Phragmites australis (Zone III) were selected as the experimental species. Greenhouse gas emissions were sampled twelve times totally by using the closed chamber method between January and December. The highest level of emission was measured for nitrous oxide emission, released from Zone I in August (10,8371 kg CO2e/d). The lowest level of emission was measured for carbon dioxide emission (0,0156 kg CO2e/d) at Zone III in January. The results revealed that Cyperus esculentus has the highest greenhouse gas emission and the highest Global Warming Potential. All greenhouse gas emissions were influenced from different plant species. Phragmites australis could be used for minimizing the level of greenhouse gas emissions as it has the lowest level of greenhouse gas emission and Global Warming Potential. Finally, the possible level of greenhouse gas emission is estimated by using Monte Carlo simulation if the wetland is vegetated with only Phragmites australis. Approximately 33% of greenhouse gas emissions could be reduced if the wetland is vegetated onlywith Phragmites australis.