Biosorption of Cu~(2+) and Zn~(2+) by immobilized biosorbents: Study of the biosorbent stability and capacity

摘要

The utilization of biosorbent immobilized in polymer matrix is studied to widen the biosorption application in the recent practice. These biosorbents have the right size, mechanical strength, rigidity and porosity. In this work the algae immobilized in calcium alginate were used as biosorbent. The stability of immobilized biosorbents in acidic solutions (pH 1; 2.5 and 5) was observed. Three differently prepared groups of immobilized beads (gel, dry and dry dipped in water for 12 hours before the experiment) were used. All groups of beads were stabile in the weak pH solutions but low pH (pH = 1) caused disintegration of beads. Apparently low pH is not suitable for application of biosorbents immobilized in calcium alginate. Biosorption of copper and zinc from the single and binary metals was also studied. Higher capacity of biosorption (36.7 mg ? g~(-1)) was found for copper ions in comparison with the zinc ions where the maximum observed biosorption capacity was 27 mg ? g~(-1). The presence of another ion decreased the biosorption capacity of both studied metals. The maximum biosorption capacity from two-ion solution was 32.6 and 10.5 mg ? g~(-1) for Cu and Zn, respectively.