Pernambuco

Floating wetlands for public wastewater treatment in Pernambuco, Brazil

The first prototypes (using PVC pipes) were deployed on April 28, 2022, at the ETE Rendeiras, COMPESA’s wastewater treatment plant in the city of Caruaru (Pernambuco, Brazil).

These floating wetlands prototypes contained plugs of two aquatic plant species: the water hyacinth (Eichornia crassipes) and the water lettuce (Pistia stratiotes).

On April 29, another prototype (using pallets made from gray polypropylene plastic) was deployed, also using E. crassipes and P. stratiotes.

Below are the prototypes four days later, on May 3, with some plant plugs showing signs of damaged (likely by a local herbivore) and dehydration (especially the plugs of P. stratiotes).

By May 10 (12 days after deployment), almost all plugs of P. stratiotes had died.

By May 24, all plant plugs from the first two prototypes had died.

Plugs of E. crassipes (water hyacinth) continued to develop, producing flowers in early June. To reduce the grazing pressure, a protective nylon net was installed on June 7.

E. crassipes thrived throughout the months of June and July, as can be seen in the time-series below:

Given the success of E. crassipes, new floating pallets were prepared for deployment.

On September 30, a variety of ornamental species were deployed at the maturation pond of the ETE Rendeiras: Thaumatophyllum xanadu, Pennisetum setaceum, and Dianella tasmanica.