Removal of nutrient and bacteria in pilot-scale constructed wetlands

WOS: 000248234300011PubMed ID: 17616883Three pilot- scale horizontal- subsurface. ow ( H- SSF), surface. ow ( SF), and free water surface. ow ( FWS) constructed wetland system designs were installed and evaluated to determine the effectiveness of constructed wetlands to treat tertiary effluent wastewater generated from Pasakoy Advanced Biological Wastewater Treatment Plant ( PABWWTP). The average ammonia- nitrogen ( NH4+) removal efficiencies of % 49 to 52% were observed in all three system designs. Average NO3- removal efficiency was approximately 58% in the SF system design, suggesting that this design had the highest denitrification rate. Total phosphorus ( TP) removal efficiency was the highest ( approximately 60%) in the h- SSF system, possibly due to substrate ( gravel). Systems were capable of removing approximately 94% of fecal coliform ( FC) bacteria. Removal rate coefficients ( k(20), 1/ day) in the H- SSF, the FWS and the SF systems were estimated for NH4+, NO3-, TP and FC. The average nutrient removal efficiencies were found higher in the summer periods except for the FC. The results of statistical analyses indicated that nutrient removals were affected by temperature, hydraulic residence time ( HRT), and nitrogen loading rate ( NLR)