Removal of transition metal ions from aqueous solution using dialdehyde phenylhydrazine starch as adsorbent

Dialdehyde phenylhydrazine starch (DASPH) was synthesized by reacting dialdehyde starch (DAS) with phenylhydrazine (PH) and it was characterized by Brunauer-Emmett-Teller (BET), scanning electron microscope, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques. FT-IR of DASPH revealed the incorporation of the Schiff Base group (C = N) group and the disappearance of the C = O (carbonyl) group. The adsorption behaviors of transition metal ions (Cd(2+), Zn(2+), Pb(2+) and Cu(2+)) were investigated as a function of pH and adsorption time. The results indicated that pH 5.0 and 120 min were the optimal conditions. Experimental results revealed that the maximum adsorption capacity of DASPH for the four transition metal ions was as follows: Cd(2+) (4.9 mmol/g) > Zn(2+) (3.3 mmol/g) >Pb(2+) (1.7 mmol/g) >Cu(2+) (0.83 mmol/g). In addition, the regeneration method of DASPH was also studied.