Surface properties characterization of local Eichornia crassipes biosorbent

Eichornia crassipes is potentially used as biosorbent of high metal. There are still incomplete data about the surface properties of local Eichornia crassipes biomass. The objective of this research is to obtain surface acidity, specific surface area, and pore structure of Eichornia crassipes biosorbent. Eichornia crassipes plant obtains form Selorejo belly Ngantang District area of Malang, East Java, Indonesia. Samples characterized were root, stem and leaf part. Surface acidity characterization was carried out on unwashed and washed samples by variation of HCl. Surface acidity was determined by acid-base titration, the specific surface area was measured by methylene blue and stereological analysis method and pore structure were analyzed by optical and SEM. The results showed that surface acidity of unwashed biosorbent on the root, stem, and leaf was small compared to surface acidity of washed biosorbent. The specific surface area of root, stem and leaf measured by methylene blue method seemed alike. Stereological analysis of specific surface area showed a more varying number. Pore structure described by SEM for root was in the form of a round hole, trilateral and spasmodic, whereas the stem pores were resembling to a piece of broken pipe while leaf pores were a coral stone-like.