Abstract
Recent works on the adsorptive removal of heavy metals and recovery of valuable materials by the effective use of various biomass wastes generated in agriculture and forestry and their related industries were introduced. Among them, effective use of orange juice residue in particular was focused. Two types of adsorbents were prepared from raw orange juice residue. One was prepared by saponifying with calcium hydroxide solution. This type of adsorbent is effective not only for the removal of cationic heavy metals like lead (II) but also for the removal or recovery of oxo anions like arsenic and phosphorus by loaded with zirconium (IV) in advance. Another is that prepared with concentrated sulfuric acid. Gold is highly selectively adsorbed on this adsorbent from hydrochloric acid solution to be formed as fine gold particles.
