Column Study for the Removal of Colour from Batik Printing Effluent using Wastewater Sludge Carbon

In wastewater treatment plant, sludge is one of the final products, channelled
to dry bed which will be disposed regularly to waste disposal site. In another hand,
batik printing industries in Malaysia does not have specified law addressed on colour
treatment of dyed effluent before disposed to water bodies, which causes water
pollution. This study utilizes the use of wastewater sludge carbon (WSC) as
adsorbent, derived from sludge of a wastewater treatment plant to remove the colour
of dyed effluent from batik printing industries. The sludge was collected from dry
bed, the moisture was removed and then the sludge was burned in muffle furnace
with temperature of 700°
C
for an hour to produce WSC. WSC produced was
grounded and sieved to obtain Powdered WSC with sizes of 150 µm and 212 µm.
The project continues by preparing three columns, with three different bed depths of
5 cm, 8 cm and 12 cm. Two set of column studies was conducted with different flow
rate of 70 ml per hour, 36 ml per hour and16ml per hour. Peristaltic pump and in
flow was monitored regularly to avoid discontinuity of the flow into the columns.
The treated batik effluent was collected hourly and the colour (PtCo) of the treated
effluent was measured using spectrophotometer. The effect of different bed depth and
different flow rate against time on the removal of colour was observed and analysed.
Thomas and Adams-Bohart model was applied to experimental data to predict the
column performance theoretically. Wastewater Carbon Sludge (WSC) was found to
be functioning as adsorbent well. Removal of colour shows that WSC able to remove
the colour from batik wastewater up to 100 % removal and its efficiency increased as
the residence time of wastewater onto WSC increased. Results obtained could be
appreciated for removing colour of dyed effluent from batik industry using activated
carbon derived from sludge of wastewater treatment plant.