An Intensified Hybrid Constructed Wetland for Polluted Channel Water Treatment

摘要

A hybrid system integrated by anaerobic filter-baffled subsurface horizontal constructed wetland (AFwet) was studied for treating polluted channel water, varying the hydraulic retention time (HRT) from 8 to 2 days. A conventional wetland (CW) and baffled conventional wetland (bCW) were used as control systems. The higher COD and ammonium nitrogen removal efficiencies were achieved at HRT of 8 days, of which the AFwet system was the best. At HRT of 2 days, COD removals for CW, bCW, and AFwet system were 54.22, 72.96, and 80.68, respectively, whereas the ammonium removals were 34.16, 50.07, and 95.97, correspondingly. The experimental results showed that the anaerobic filter intensified the ammonium removal, achieving removal efficiencies above 90. The smallest footprint of 2.2 m(2)/PE (population equivalent) was obtained at hydraulic loading rate (HLR) of 0.14 m(2)/m(3) day and organic loading rate (OLR) of 36.2 g COD/m(2) day. Nowadays, footprint and pollutant removal are significant indicators for the choice of constructed wetland.