ACUTE AND CHRONIC EFFECTS OF EAST & WEST TREATMENT PLANTS EFFLUENT.\' ON TIlAPIA ZILLIl (TERV.

ACUTE AND CHRONIC EFFECTS OF EAST & WEST TREATMENT

PLANTS EFFLUENT.\’ ON

TIlAPIA ZILLIl (TERV.

By
MOHAMED HASSAN MOURAD*
*Nationallnstitute of Oceanography and Fisheries, Alexandria, Egypt.
Key Words: Domestic sewage; Fish acute toxicity; Physiological responses;
Primary treatment.
ABSTRACT
The physico:’chemical characteristics qf East Treatment Plant l~fflllellt
(ETPE) and West Treatment Plallt E;f/lllent (Wl1)£j were studied Both
effluents contains considerable concentrations qf pollutants. Primal)!
treatment qfthese effluents were effective in removing most ofthese pollutallts.
The results qf acute toxicity tests to (ETPE) and (WTPE) showed that the
-I8-hr. TL m for Tilapia zillii Gav. were 85 % and -10 % (%vo/./vol.) before
treatment and 100 % and 60 % after treatment, respectively. Fish exposed to
sublethal concentration (25 %) (?f (£1PE) and (WTPE) after primw~v
treatment for 11 days exhibited a depression in feeding rate, changes in the
condition qf fish flesh, hepatosomatic illdex, blood glucose lel’els and
hemoglobill content in comparison lvith the control group. It could be
coneluded that both plants improved the situation hut they did not siglltficallt~J)
redllce all (?fthe pollutioll load