EXPERIMENTAL EVALUATION OF A NATURAL HOLLOW HYDROPHOBIC-OLEOPHILIC FIBER FOR ITS POTENTIAL APPLICATION IN NAPL SPILL CLEANUP1

Abstract

ABSTRACT Non-aqueous phase liquid (NAPL) spills on water and land are of major environmental concern. One of the most economical and efficient means for the removal of the spilled NAPL is to use hydrophobic-oleophilic sorbents. Natural, agricultural products have potential to be a substitute for commercial synthetic absorbents in NAPL pickup and recovery. One of these natural agro-products that have excellent oil sorption capacities is Kapok (Ceiba pentandra), a cellulosic silky-cotton fiber. This paper presents the sorption capacities of Kapok, the reusability of Kapok and its hydrophobicity-oleophilicity for various NAPLs. Both loose and packed Kapok assemblies were examined. The NAPLs investigated were tetrachloroethylene (PCE), diesel and HD-30 engine oil (HD-30). The NAPL sorption capacities of packed Kapok assemblies were found to be 75, 55 and 45 g/g for PCE, HD-30 and diesel, respectively. Two-thirds of the sorption capacities of virgin packed Kapok assemblies could be retained even at the 8th reuse cycle. Oil sorption capacities of the loose Kapok assembly reached 115 and 45 g/g for HD-30 and diesel, respectively, on dynamic water surface. No thin oil film on water surface was observed after NAPL sorption, when initial oil added in water was less than 30 g/500 mL and 1 g loose Kapok assembly was used.