How Temperature Affects Wastewater Nitrate Removal in a Bioelectrochemically Assisted Constructed Wetland System

摘要

A novel bioelectrochemically assisted constructed wetland system (BECW) was investigated using a laboratory-scale experimental apparatus for treating nitrate-contaminated water without an organic carbon source. The BECW was operated at 29 +/- 1 and 18 +/- 1 degrees C, respectively, to explore the effects of temperature on the autotrophic denitrification process. The results showed that higher TN removal efficiency (76.30 +/- 5.08%) was obtained at higher temperature when compared to a lower temperature (48.18 +/- 4.40%). The effluent concentrations of NO2--N and NH4+-N at 18 +/- 1 degrees C were 0.40 +/- 0.11 and 0.50 +/- 0.42 mg N whereas those at 29 +/- 1 degrees C could be neglected. Besides, significant accumulations of NO2--N and NH4+-N were observed in the cathode region at 18 +/- 1 degrees C through quantifying different forms of nitrogen that varied along the flow path.