Introduction:

Amorphous silicates are used as heavy metal adsorbents in aqueous solution.

Objective:

To determine adsorption isotherms in a heterogeneous system constituted for a Cu (II) ions aqueous solution and magnesium, calcium, aluminum and zinc amorphous silicates.

Materials and methods:

The mechanism that governs Cu (II) ions adsorption process from aqueous solutions in static regime over various silicon-based products with zeolitic behavior water in its structure, obtained by a gelation process, is exposed.

The ion adsorption process is carried out under certain conditions of acidity, temperature, Cu2 + ions concentration, particle diameter and interaction time. The solutions have a pH of 5.06 units. Stirring velocity was 300 rpm on an AGU-10 Bunsen mechanical stirrer at 25 oC.

A solution amount of 40 mL is mixed for 30 minutes with 0.2 g of corresponding metal silicate with the proposed stirring at 25 oC; it is then filtered, and the final concentration is determined by Atomic Absorption Spectroscopy.

Results and Discussion:

Langmuir's model for the adsorption isotherm has the best adjust for Cu (II) ions adsorption in aqueous solution.

Conclusions:

Calcium, zinc, magnesium and aluminum silicates are light materials and have moderate specific surface. They have Cu (II) ions moderate adsorption capacities in aqueous solution.

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