DINIZ, M. J. L.; http://lattes.cnpq.br/3402862639884384; DINIZ, Maria José Leite.
Resumen:
A pilot-scale experimental sewage treatment system made up of four deep (2.3 m)
primary facultative ponds each having a hydraulic retention time of 15 days being
loaded with 330 kg BOD5 ha.d. was operated at EXTRABES (Experimental Station
for the Biological Treatment of Sewage), Campina Grande City (7° 13 '11" S,
35°52*31" W, 550 m above mear sea level), Paraiba State, northeast Brazil. Two
ponds (F27 and F30) were designed with parallel longitudinal baffles and one (F29)
with round-the-corner baffles being F28 (without baffles) maintained as a control
reactor. The investigative work was carried out between October 1997 and
November 1998, on the basis of weekly determination of BOD5, COD, suspended
solids and faecal coli forms and the ancillary parameters temperature, pH, dissolved
oxygen and chlorophyll a in grab samples of pond effluents, collected at 8 a. m., and
daily composite samples of raw sewage.
Data on faecal coliforms, BOIX COD and suspended solids concentrations and
removals showed that baffles only tended to upgrade pond performance, particularly
the type round-the-corner in pond F29, but any significant difference could not be
demonstrated through one-way analysis of variance applied to them. So, from both
technical and economical points of view baffles do not appear to be indicated in
designing highly loaded deep primary facultative ponds treating sewage under
conditions similar to those observed herein.
