engleski

Removal of copper ions in wastewater by geopolymers synthesized from fly ash

The removal efficiency of copper ions in aqueous solutions was investigated by adsorption process on pure and modified geopolymer, synthesized from fly ash. A type F (as defined in ASTM C618) fly ash from the Croatian power plant Plomin 2 (Plomin) was used in the present study. The batch experiments were carried out as a function of solute concentration at constant temperature (296 K) and particle size (90-500 μm). The sorption capacity of copper ions increases with the initial concentrations of solute and for the modified geopolymer it reaches its maximum value at qe = 0.712 mmol/g and for the pure geopolymer it reaches its maximum value at qe = 0.814 mmol/g. Kinetic studies based on Lagergren pseudo-first order, Ho pseudo-second order, Ritchie second-order and Elovich rate equations were used to test experimental rate data. All the models were analyzed using nonlinear regression technique. The results obtained indicate that, both, pure geopolymer and modified geopolymer could be used as alternative materials for the wastewater treatment. Nevertheless, pure geopolymer shows slightly better efficiency. Kinetic study has shown that the best fit is achieved when the Elovich model was applied.

geopolymers; cooper; kinetics

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