Statistical analysis shows that vegetation plays an important
role in treatment performance for E. coli and nutrients. With this
system combination (VF–HF) it is possible to get removal efficiencies
of 99% in Helminths eggs, 3 log units in total coliforms and
4 log units in E. coli. Soil matrix seen to be the main aspect for
Helminth eggs removal and perhaps the main removal mechanism
is filtration. Further research is necessary to measure the
efficiency of the evaluated treatment systems and its relation
with dissolved oxygen, redox potential, organic matter, loading
rates and assessing the effect of smaller diameter supporting
material.
Acknowledgments