CHARACTERIZATION OF CLAY AND KAPOK AS OIL SORBENTS

Clay such as bentonite, montmorillonite and sepiolite have high sorption properties,
surface area, porosity and cation exchange capacity which make them potential materials
as oil and heavy metals adsorbent. Ceiba pentadra (L.) Gaertn. or locally known as
kapok has large and non-collapsing hollow lumens that enable oil sorption. Kapok also
exhibits excellent hydrophobic-oleophilic characteristic.The objectives of this study
were to investigate the efficiency of clay and kapok for Palm oil mill effluent (POME)
sorption and to analyze the characteristics of clay and kapok since POME contains about
4000-6000 mg/L of oil and grease that must be reduced to 50 mg/1 of DOE permissible
limit before it can be discharged into waterways. Several methods are used for
characterization such as Fourier Transform Infrared Spectrophotometer (FTIR) and
Thermogravimetric analysis (TGA). Montmorillonite clay and kapok were packed in the
column at different packing density until they were saturated and achieved complete
sorption of POME. POME dripped from column was analyzed for its oil and grease
content and compared with the raw POME. After sorption analysis was done, clay and
kapok were dried and characterized by using FTIR and TGA. Higher packing density
showed lower sorption capacity of POME because sorbent material was less loosely
packed. Kapok at 0.10 g/cm3 showed the highest sorption capacity of POME and
percentage of oil removed as compared to clay and double packing sorbents of treated
clay with sulfuric acid and kapok. Based on the FTIR and TGA, the increment in
transmittance percentage showed the occurrence of oil sorption in clay and kapok.
Therefore, clay and kapok have shown great potential as oil sorbent in terms of its high
sorption capability.
Keywords: clay, sorption, montmorillonite, kapok, hydrophobic-oleophilic, POME,
FTIR, TGA