The Greenhouse: Aquatic and Soil Filters

After wastewater has passed through the constructed wetlands and is disinfected with ultraviolet light, it then enters the greenhouse to be further purified by aquatic plants and varying soil mixtures.

The greenhouse environment may at times concentrate water and cause salts to build up due to increased evapotranspiration. Researchers in the northeastern United States, where extensive work has been done with indoor treatment, have experienced this phenomenon. The salts that may accumulate should be diluted by the collection of rainfall within wetlands cell 1 and 2. Soil mixtures and plant types will be selected to store or transform the small concentrations of nutrients which remain.

The greenhouse contains six modular planter boxes (shown in above photo) with pull-out trays in which different soil combinations can be tested. A host of aquatic plants will be grown in water canals above the soil boxes.

Aquatic and soil filters in the rainforest-like environment of the greenhouse provide fertile territory for experiments with new combinations of designed ecosystems and with the effectiveness of particular aquatic plants and soil combinations in the treatment of wastewater.