Phytoremediation is an emerging technology in
landfill leachate posttreatment. The evaluation of a system
composed of three natural wetlands. The wetlands vegetation
cover was monitored during 2 years by estimating
the coverage area of the macrophytes. Chemical analyzes
of the effluent were conducted monthly. The monitoring
and identification of macrophytes indicated that the vegetation
structure was represented by four species of higher
relative cover:
Pistia stratiotes
L. (water lettuce),
Echinochloa
polystachya
(Kunth) Hitchc. (creeping river grass),
Eichhornia crassipes
(Mart.) Solms (water hyacinth) and
Alternanthera philoxeroides
(Mart.) Griseb. The system of natural wetlands had an average efficiency of 75 % for
biochemical oxygen demand, 63 % for chemical oxygen
demand, 84 % for ammoniacal nitrogen, 89 % for total
nitrogen and 70 % for phosphorus. The concentrations of
heavy metals in the roots, as well as in the branches of
E.
crassipes and
E. polystachya, lead us to the conclusion that
such species perform phytoextraction for Cd and Pb
accumulating the metals in the biomass. The results show
that this is a viable alternative that can be associated with
forms of conventional treatment of leachate, such as the
treatment with aerobic and facultative ponds.
