Column Study for Removal of Colour from Palm Oil Mill Effluent using Wastewater Sludge Carbon

Palm oil mill industry in Malaysia has been growing rapidly and the effluent has
been concerning to the environment since it has brownish colour that will be later
discharged to receiving water bodies. Furthermore, the production of wastewater sludge
is expected to increase due to high number of population and it has carbonaceous
properties that make an excellent quality of an adsorbent. The removal of colour from
Palm Oil Mill Effluent (POME) using carbon derived from wastewater sludge was
investigated using fixed bed column study with different bed depth of 5, 10 and 15 cm
and using varying flow rate of 25, 50 and 100 mL/hr. The removal of colour was the
highest by using higher volume of bed depth and slower flow rate. The Adams-Bohart
model and Yoon-Nelson kinetic models were used to analyze the column performance.
The rate constant for Adams Bohart model decreases with the increment of bed depth.
Adsorption capacity for the adsorption of colour obtained from Adams-Bohart model
ranged from 2676.19 mg/L up to 8938.78 mg/L. The maximum adsorption capacity
increase with smaller bed depth. For Yoon-Nelson model, the rate constant decrease with
increase in bed depth. The time required for 50% breakthrough obtained from the model
ranged from 17.01 mins up to 104.17 mins for all three bed depth tested. The time has
increases with increase in bed depth. The experimental data was found to be best
described using both models as it shows high range of R
2
value.