one of gravel ‘‘2’’, granulometry between 19
and 25 mm, corresponding to 1/4 of total height, plus another layer
of gravel 0, granulometry between 4.8 and 9.5 mm, with the same
height. In one of the 1000 L recipients (constructed wetland), aquatic
macrophytes buds of the T. domingensis species were cultivated.
The drainage, made through the action of the gravity in the inferior
part of the system, allowed the direct contact of the contaminated
water with the gravel and the roots of the plants. The second
recipient was kept without any plants to be used as a control
experiment.