The sorption of ions Cu(II) by carbon sorbent MIU-C4

Abstract

The sorption properties of carbon sorbent MIU-C4 in relation of copper ions were studied. The study was carried out using a model solution of copper(II) sulfate containing additionally 400 mg/l of sodium sulfate. The determined specific surface area of the investigated sample of carbon sorbent MIU-C4 was near 22.27 m²/g, specific surface area of pores was 0.25 m²/g. At introduction of MIU-C4 into the model solution slight increasing in pH of the solution was observed. It was shown that carbon sorbent MIU-C4 may remove copper ions from polluted waters due to their physical adsorption on surface of the sorbent, and the sorption process is well described by the Langmuir equation. The parameters of this equation were determined for different pH of the model solution. It was established that adsorption of ions Cu²⁺ onto surface of MIU-C4 increases when pH of solution increases from 4 to 6.7 (the ranges of рН<4 and pH>6.7 were not investigated). This effect is caused by increasing of the adsorption capacity of MIU-C4. So for pH=4 the adsorption capacity of MIU-C4 is near 0.265 mg/g or 0.012 mg/m², for pH=5 – 1.981 mg/g or 0.044 mg/m², for pH=6 – 2.300 mg/g or 0.103 mg/m², and for pH=6.7 – 3.307 mg/g or 0.149 mg/m². The growth of the sorption equilibrium constant is also observed.

The comparison of sorption properties of MIU-C4 with analogous data for other carbon and mineral sorbents was also carried out. It is found that the adsorption capacity of MIU-C4 for ions Cu²⁺ in dimension of mg/g is near of analogous ones for other sorbents.