Kinetic Modeling of Heavy Metals Adsorption on fixed bed Column

Document Type: Original Research Paper

Authors

Department of Chemical Engineering, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Nigeria

Abstract

The adsorption of lead (11) and copper (11) in a fixed bed column using activated carbon
prepared from nipa palm nut was investigated. Thomas model and Yoon and Nelson kinetic models were used to analyze the column performance. The rate constant for Thomas model increased with increase in flow rate and initial ion concentration but remained constant at varying bed height. Adsorption capacity for the adsorption of copper (11) obtained from Thomas model ranged from 3.417 to 17.224 mg/l for Thomas model and from 3.02 to 11.92mg/l for Yoon and Nelson model. Also the adsorption capacity for lead (11) adsorption calculated from Thomas model ranged from 6.937 to 75.59 mg/l and from 12.10 to 47.24 mg/l for Yoon and Nelson model. The maximum adsorption capacity increased with increase in flow rate and initial ion concentration but decreased with increase in bed height. For Yoon and Nelson model, the rate constant increased with increase in flow rate, initial ion concentration and bed height. The time required for 50% breakthrough decreased with increase in flow rate, bed height and initial ion concentration. The kinetic data fitted well to both models. The comparison of the experimental breakthrough curves to the breakthrough profiles calculated by Yoon and Nelson method showed a satisfactory fit for activated carbon prepared from nipa palm nut.

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