engleski

Influence of initial pH of solution on cadmium removal by natural and iron-modified zeolite

The uptake of cadmium ions on natural zeolite (NZ) and iron-modified zeolite (IMZ) has been examined from aqueous cadmium solutions of different initial pH values. For both samples, the initial pH from acidic and slightly alkaline solutions tends to become neutral after cadmium uptake. The optimum pH range for cadmium uptake for both samples is pH=4-7. Up to pH=4, the competitive effect of H+ with Cd2+ is dominant, while at pH>7 the precipitation of cadmium hydroxide takes place. The obtained removal capacity for IMZ is three-to-four times higher then for NZ.

zeolite ; iron-modified zeolite ; cadmium removal ; ion exchange

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