TRAJANO, A. S. A.; http://lattes.cnpq.br/9168394812685255; TRAJANO, Adriana Soraya Alexandria.
Résumé:
A pilot-scale experimental pond complex (System XVI) installed at
a site in the municipal wastewater treatment plant of Campina Grande city (7° 13
11" S, 35° 52' 31" W, 550 m above mean sea level), Paraíba state, northeast
Brazil, was investigated between 29/10/91 and 25/11/92 and from 02/12/93 to
14/09/94, under two distinct operational conditions (experiments I and II),
characterized by both surface organic loading and hydraulic retention time. The
experimental system comprised two anaerobic ponds,'five secondary facultative
ponds, one primary maturation pond, five secondary maturation ponds and four
tertiary maturation ponds designed in order to obtain several series of ponds
allowing a large number of combinations of both physical and operational features
to be tested.
The operational performance of the experimental complex,
particularly the secondary facultative and secondary and tertiary maturation ponds,
in terms of BOD, COD, SS, and faecal coliform removals and the variations of
dissolved oxygen, pH, ammonia, total sulphide and chlorophyll a, were evaluated
in both experiments and related to depth, length/breadth ratio, hydraulic retention
time and surface organic loading which was found to be the most important
parameter in designing series of ponds treating sewage.
Physical characteristics did not influence significantly the
operational performance of secondary facultative and maturation ponds becoming
their role more important at the level of tertiary maturation ponds.
