Evaluation of Diurnal Dissolved Oxygen as an Indicator of Biodegradable Organic and Nitrogen Pollution in Constructed Wetlands

Various chemistry indicators (such as BOD₅, TN and NH₄⁺-N) have been used to identify changes in the performance of constructed wetlands (CW) treating wastewater. However, measurements of biochemical characteristics in CW are laborious. This study aims to investigate whether simple characteristics of diurnal dissolved oxygen are a useful indicator of biodegradable pollution in CW. The variation of DO concentration in substrate water and pollutants removal was examined using CW mesocosm. The results showed that both of DO concentration and oxygen consumption rate for organic matter and nitrogen were exhibited a diurnal periodic variation. The results documented the strong relationship between DO concentrations and simultaneous measurements of pollutants removal. Therefore, daily changes of DO in substrate water are useful indicators for performance of constructed wetlands.