Interaction of Heavy Metals With Chitin and Chitosan. Ii. Cadmium and Zinc.

Application of Chitosan for Treatment of Wastewaters

“…The uptake of Cd(II) (Jha et al 1988;Suder and Wightman 1983) and Cr(III) (Maruca et al 1982) ions by chitosan decreased with decreasing pH. These results suggest that hydronium ions compete with metal ions for available amino sites on chitosan (Rorrer et al 1993).…”

“…The free amino group in chitosan was considered to be much more effective for binding metal ions than the acetyl groups in chitin (Eiden et al 1980;Maruca et al 1982;Muzzarelli and Tubertini 1969;Suder and Wightman 1983;Yang and Zall 1984). This information leads us to consider that the greater free amino group content of chitosan should give higher metal ion adsorption rates.…”

“…The formation of adsorbed metal clusters is supported by Eiden et al (1980) and Maruca et al (1982), who observed Cr-containing nodules on the surface of Cr(III)-equilibrated chitosan powder using SEM/EDAX (scanning electron microscope/energy dispersive analysis of X-rays) analysis. Maruca et al (1982) and Suder and Wightman (1983) further investigated the uptake mechanism of Cr(III), Cd(II), and Zn(II) by chitin and chitosan using SEM/EDAX analysis, and concluded that a combination of nodular formation, ion adsorption, and ion absorption accounts for the total uptake. Source: Nair and Madhavan (1982).…”

“…Table 4 shows literature references studied for adsorption of heavy metals by chitosan and its derivatives. ,4,5,9,10,12,15,22,27,28,29,30,32 Cr 1,3,5,6,10,12,13,14,20,30 Cu 1,4,5,7,8,9,10,11,12,13,15,17,19,20,22,23,25,26,27,29,30,32,33 References: 1, Masri et al (1974); 2, Suder and Wightman (1983); 3, Eiden et al (1980);4, Mitani et al (1991); 5, Madhavan and Nair (1978);6, Maruca et al (1982); 7, Koyama and Taniguchi (1986); 8, Kurita et al (1988);9, Ishii et al (1995); 10, Coughlin et al (1990);…”