Frontiers of Environmental Science & Engineering
Relationships of nitrous oxide fluxes with water quality parameters in free water surface constructed wetlands
1. College of Environmental Science & Engineering, Shandong University, Jinan 250100, China; 2. School of Resources & Environment, Qingdao Agricultural University, Qingdao 266109, China; 3. Environment Research Institute, Shandong University, Jinan 250100, China
The effects of chemical oxygen demand (COD) concentration in the influent on nitrous oxide (N O) emissions, together with the relationships between N O and water quality parameters in free water surface constructed wetlands, were investigated with laboratory-scale systems. N O emission and purification performance of wastewater were very strongly dependent on COD concentration in the influent, and the total N O emission in the system with middle COD influent concentration was the least. The relationships between N O and the chemical and physical water quality variables were studied by using principal component scores in multiple linear regression analysis to predict N O flux. The multiple linear regression model against principal components indicated that different water parameters affected N O flux with different COD concentrations in the influent, but nitrate nitrogen affected N O flux in all systems.