Thesis for Master of Science
Gabriela Silva
“Depuração de lixiviados de um aterro sanitário em leitos construídos de macrófitas”
MSc. in Biotechnology (Biochemical Engineering), IST, 2004
Supervisor:
S.
Martins-Dias
As
a consequence of the population development of the last decades, the mass of
solid wastes produced globally is increasing at a rapid place.
In
the last years,
Landfill
leachates are generated by solid waste interaction with precipitation. The
leachate is characterized by an enormous variability of components resulting
from the physical, chemical and biological reactions that occur in the
decomposition of solid wastes within the landfill. The leachate may migrate from
the refuse and contaminate the surface water and groundwater, potentially
impacting aquatic ecosystems and human health.
Current
landfill design demands the presence of leachate collection systems so that they
can be conveyed to one or more locations for correct treatment.
Artificial
wetlands are one of the systems used to treat landfill leachates, is an
ecotechnology that replicates physical chemical and biological processes that
occur in natural wetlands which are responsible for the removal and
transformation of contaminants producing a minimal impact in human health and
environment.
The
aim of this study was to evaluate the efficiency of artificial wetlands in the
removal of organic compounds (COD), nitrogen (N) and total suspended solids (TSS)
because landfill leachates are characterized by very high concentrations of
these components.
The leachate of Mato da Cruz and Leiria Landfills was characterized and the removal efficiency of COD, N and TSS was analyzed and study using the pilot bed in IST and the bed of Valorlis in Alcanadas. Both beds are vertical flow planted with Phragmites australis and were operated full oxygenated. The results have demonstrated that these systems are very suitable for the treatment of landfill leachates.