Sorption of oils onto dry aquatic plant biomass

摘要

The sorption of oils and other organic substances onto the dry biomass of the macrophyte Salvinia herzogii was studied. In addition, the studies included the physical, chemical, and physico-chemical characterization of this sorhent in unworked form. The sorption results obtained were compared to that obtained with a commercial oil sorbent, Peat Sorb, a processed peat. The S. herzogii biomass displayed 2.0 to 2.5 times the sorptive capacity for oils than did the commercial sorbent. The principal factors that control the sorption process are the hydrophobicity of the biomass, the biomass particle size, the chemico-physical composition of the plant and the sorbate, and the capillarity displayed by the plant biomass. The first two items and in part the third are related, the leaves of the plant, primarily the fraction> 1 mm, contain a majority of the hydrophobic sites. The roots, however, are of much smaller particle size and contain a smaller percentage of hydrophobic sites and contain most of the ash. The chemico-physical and the capillarity of the plants are related. The pores and hair like surfaces of the different parts of the plant determine the capillarity of the plant parts. Together, the hydrophobicity and the pore structure of the plant and its parts are responsible for the oil sorption. The economic and technical implications of the practical use of this plant are considered in the final discussion.