Revolutionary Wetlands Purify Sewage, Boosting Water Quality and Ecosystem Health
A study compared how well horizontal and vertical constructed wetlands with bamboo charcoal and gravel cleaned up domestic sewage. The horizontal wetland removed 72.2% of COD, 47.8% of TN, and 59.8% of TP, while the vertical one removed 75.0% of COD, 48.1% of TN, and 58.2% of TP. The longer the sewage stayed in the wetlands, the more COD was removed. TN and TP removal were best at 3.5 days and 2 days, respectively. Bacteria were more in the horizontal wetland, while fungi were more in the vertical one. Both bacteria and fungi increased with longer sewage retention time.