Chemical modification of the cellulose for an application in the waste waters treatment

الملخص EN

The shortage of the water resources and the pollution which is growing these last years, constitute the prime motivation for searching any alternative resources.

This study consists to modify the cellulose by grafting of the amidoxime groups in order to use it for the adsorption of the Cu (II), Cr (III) and supplied ions which exist in the industrial effluents.

The cellulose is an abundant biodegradable polymer ; the amidoxime groups have a strong complication power towards heavy metal ions.

The grafting is achieved in two steps: cyanoethylation and amidoximation which are confirmed by FT-IR.

The optimum conditions of the two reactions are determined by the kjeldahl’s method and by FT-IR.

The amidoxime quantity is determined by measuring the quantity of the amine functions by HCl.

The application of the modified cellulose is intended for the adsorption of the metal ions Cu (II) and Cr (III) and supplied ions 'S2-' in a double adsorption.

The FT-IR analysis reveals that the fixing of metal captions is based on the complication of the latter with the ligands of the adsorbent.

The optimum adsorption was recorded at pH = 6 for a contact time of 5 hours and an initial concentration of 10-1 M in metals.

Desorption of fixed metals is possible by the EDTA, and the reuse of the adsorbent confirms the effectiveness of regeneration of the adsorbent.