Dygnsvariation av metanemission från en anlagd våtmark
Environmental chemistryMethane emissionEmergent macrophytesTypha latifoliaConstructed wetlandsGas transportStatic chamber techniqueMiljökemi
The aim of the study was to investigate if methane emission in a constructed wetland changed in a diurnal pattern correlating to temperature, humidity or light conditions. The gas measurements were carried out with a static chamber technique. The wetland (in Nykvarn outside of Linköping, Sweden) takes care of wastewater to reduce the nitrogen loads. Measurements were carried out at three different occasions in the summer of 1998 on two sites in the wetland. One site was close to the inflow, inhabited by Lemnaceae, and another site was located further downstream inhabited by the emergent macrophyte Typha latifolia. The results showed a variation, but no discernible diurnal pattern. The Typha site had a methane emission rate of 166 mg CH4 m-2d-1 and the Lemnaceae site had an methane emission rate of 712 mg CH4 m-2d-1. In all experiments at the Typha site, the highest methane emission rate was obtained at sunrise.