| dc.description.abstract | Study on the effect of varying initial COD concentration, hydraulic retention time
(HR T) of the reactor and height of medium to % reduction of chemical oxygen demand
(COD) arid mixed liquor suspended solid (MLSS) from tofu wastewater was conducted in
aerobic biofilter reactor by using gravel packing medium. The operation variables were the
COD influent (500, 750 and 1000 mg/L), the hydraulic retention time or HRT (5, 7 and 9
hours) and the height of medium (100 and 125 cm). The results of the experiment showed
that the reduction of COD was affected by hydraulic retention time (HRT), while the
reduction MLSS did not affected by HRT. The percentages of COD and MLSS removal have
increased as well as increasing of the height of bed, however, the percentages of COD and
MLSS removal have decreased as well as the increase of the concentration of COD influent.
The percentages of COD and MLSS removal were higher in 125 cm than 100 cm height of
biofilter bed. five to nine hours HRT .and the 500 mg/L of COD influent and 125 cm height of
bed gave the best total % reduction of COD and MLSS effluent. At this condition,
observation indicated that the average of COD and MLSS removal were 175,88 mg/L
(61,49%) dan 77,67 mg/L (71,34%), respectively. Although 5 to 9 hours HRT and the
concentration of COD influent 500 mg/I gave the best total COD and MLSS reduction,
however, it was not met to environmental standard quality (SKMenLH No.Kep0
51/MENLH/10/1995), especially the COD parameter (maximum COD and MLSS are 100
and 200 mg/L, respectively). | en_US |
