] Ions with Crab Shell Particles from Aqueous Solutions

Crab shell particles were tested for its ability to remove Zn 2+ ions from aqueous solution and were evaluated in a batch reactor and in a fixed-bed column. The binding of Zn 2+ ions by crab shell was found to be affected significantly by pH, with maximum sorption capacity 71.46 mg/g observed at pH 4.5. The sorption isotherm of Zn 2+ ions on crab shell particles was modeled on the application of Langmuir followed by Sips, Redlich-Peterson and Freundlich. It was observed from the kinetic data that the biosorption process using crab shells follow Pseudo-second-order kinetics. The influence of temperature on metal uptake showed that sorption process is favorable at room temperature and increasing temperature decreases the Zn 2+ ion uptake. The influence of the co-ions (Na + , K + , Ca 2+ and Mg 2+ ) along with the Zn 2+ ion present in the aqueous solution was also studied. A glass column (2 cm I.D and 35 cm height) was used to study the continuous zinc biosorption performance of crab shell particles with different bed heights. At 25 cm (bed height), 5 mL/min (flow rate) and 100 mg/L (initial lead concentration), crab shell particles exhibited Zn 2+ ions uptake of 43.83 mg/gm.