422
Alcalde et al.
After rocky pond
10E.OOr-----------------------~--------------------------,
10E+04
/' .-----.. ------. . -----., .. ,
1 OE+03
1 OE+02
1,OE+01
•
•• - --::-;;-~-t==;;;.a ___
.'
-....--__ F+
___ SomallC collphages
- .. - . Fecal COI~orms
10E+OO+---~----~----~--~----_r----r_--~----~----r_--_i
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Fig: 8. Seasonal variation of the content of the three indicators monitored in the rocky
pond effluent
After stabilization reservoir
10E.~----------------------------------------------------,
F+
___ Somatic coI.phages
- .. - . Fecal col./orms
•
10E+~----~--~----r_--~--~----~--~----~--_r----r_--~
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Fig. 9. Seasonal variation of the content of the three indicators monitored in the
stabilization reservoir effluent
The results show the significant effect of temperature in pathogen indicators
removal for the facultative, maturation and rocky ponds. This observation is in
accordance with previous works conducted by Marais (1974), Pearson et al.
(1987) Mills et al. (1992) and Saqqar and Pescod (1992) where temperature is
found one of the most important environmental parameters involved in
microorganisms removal in WSP. Temperature presumably will increase
metabolic activity and thus susceptibility to toxic substances (Pearson et al. 1987).
It does not seem to have a significant effect on the temperature in the anaerobic
pond, although for coliform removal rate the relation is significant, the P-value is