Initial Test of a Subsurface Constructed Wetland with Green Sorption Media for Nutrient Removal in On-site Wastewater Treatment Systems

Conventional on-site wastewater treatment systems are no longer able to fully meet the needs of coping with the impacts of the variegated pollutants with which they are confronted. Without proper nitrification and denitrification, this implies a large fraction of nutrient loads such as nitrogen and phosphorus will flow into groundwater aquifers adversely affecting the water quality and public health. Constructed wetland, a cost-effective small-scale wastewater treatment system with low energy, maintenance requirements and operational costs may well fill the current gaps. In Phase I of this study, a subsurface constructed wetland system designed as an integral part of a performance-based passive on-site wastewater treatment system was proved effective after receiving septic wastewater flow. Using a suite of selected plant species, it is configured to handle 189 liters per day (50 GPD) of influent for a wastewater treatment and reuse study using green sorption media (recycled and natural materials) at a test center located at the University of Central Florida (UCF). During the three-month test run, the system achieved a removal efficiency of 75.4% in total nitrogen (TN) and 94.9% in total phosphorus (TP). Overall, the removal efficiency of TN and TP in an integrated septic tank and constructed wetland (ST/CW) system became as high as 81.3% and 95.8%, respectively