The Role of Wetland Ecosystems to Reduce the Concentration of Nitrate in Groundwater

Abstract

Nitrate is a compound very soluble in water. Ichikawa city is one of the cities that have a pear farming. In this city, there was a wetland where this area was surrounded by pear farming in upland areas. There were 3 sites (S4, R2, and S14) in this area.S4 and S14 were close to pear farming, but R2 was in the middle of wetland. We used piezometers with different depth (1m, 2m, and 3m) in each site. The focus in this study is identification the role of wetland ecosystem as a green infrastructure to reduce nitrate concentration. Groundwater flow in the wetland comes from pear farming with 2 flow direction. First, groundwater comes from S4 with average nitrate concentration was 185.73 mg/L and average DO concentration 6.37 mg/L. Second, groundwater comes from S14 with average nitrate concentration was 190.29 mg/L and average DO concentration 7.00 mg/L. All this direction flow to the middle of wetland (R2) with average nitrate concentration was 3.46 mg/L and average DO concentration 1.52 mg/L.