Biosorption of anionic metal species

摘要

Anionic metal complexes, are very effectively bound by biomass types containing an abundance of amide groups. Readily available chitinous materials such as crab shells sorbed well anionic gold cyanide (AuCN_2~-), selenate (SeO_4~(2-)), chromate (CrO_4~2), and vanadate (VO_4~(3-)) at low pH. Equilibrium biosorption uptakes by acid-washed crab shells were up to 0.17 mmol Au/g (pH 3.5), 0.15 mmol Se/g (pH 3.0), 0.56 mmol Cr/g biomass (pH 2.0), 0.79 mmol V/g (pH 2.5). An increased ionic strength (IS as NaCl) suppressed the primary anion uptake as chloride ions competed for biosorbent protonated sites and higher IS reduced the activity of ions in solution.