THE ROLE OF PLANTS IN ECOLOGICALLY ENGINEERED WASTE-WATER TREATMENT SYSTEMS

A Solar Aquatic System(TM) (SAS) septage treatment facility with aquac ulture and constructed marsh components operated as a pilot facility f rom 1989 through 1992. The nitrogen loadings to the aquaculture subsys tem were 15.6 gN m(-2) day(-1). Sixty-eight percent of the nitrogen wa s removed, with 4% of the removal by vegetative uptake. The nitrogen l oading to the marsh subsystem was 5.23 gN m(-2) day(-1). Thirty-eight percent of the nitrogen was removed, with 1% of the removal by vegetat ive uptake. Although responsible for only a fraction of the nitrogen r emoval, the productivity of the plants in the SAS was comparable to th at of plants in less heavily loaded wetland systems reported in the li terature. The nitrogen content of plants in the SAS was higher than of plants in a heavily loaded system. Comparisons are made among three w etland systems with loadings ranging from 0.44 to 1.83 gN m(-2) day(-1 ) where up to 30% of the nitrogen was removed by the plants.