Abstract:
Efficiency of laboratory scale Packed Cage RBC for treatment of domestic
wastewater was studied. The experiments were conducted in a 43 - litre - cylindrical reactor.
The Packed Cage Drum, containing l-Ball polypropylene media (diameter 50 rnrn), was installed
in this reactor. About 40% of the volume of this drum was submersed in water. Surface area
of these media was all together 7.12 m2. The drum operated at a fixed speed of 3 rpm.
Domestic wastewater was synthesized in the laboratory. COD and HRT are the two variables
for this study, being 100, 200, 300 and 400 mg/I and 4, 6 and 8 hr., respectively.
The results show that the efficiency for COD removal decreased with increasing
organic loading and with decreasing HRT. At organic loading of 25.8-103.2 gCOD/day (areal
organic loading = 3.62-14.49 gCOD/m2 -davl, the percentage removal of both total and soluble
COD were 80.55-100% and 85.94-100%, respectively. At the highest areal organic loading and
the lowest HRT, the total and soluble COD of the effluent were reduced to 77.50+-0.05 mgtl
and 56.00+-3.94 mg/I, respectively. Thus, their percentage removal were 80.55% and 85.94%,
respectively. Dissloved oxygen in the system was found to increase with decreasing organic
loading and with increasing HRT. However, at the areal organic loading of 14.49 gCOD/m2 -dav,
the dissloved oxygen was still found to be 3.9 mg/l. In addition, suspended solid in the
effluent increased with increasing organic loading and with decreasing HRT. At 3.62-14.49
gCOD/m2 -day areal organic loading, the suspended solid in the effluent was 2-44 mg/l.