Phosphorylated cation‐exchangers from cotton stalks and their constituents

Cation‐exchangers were prepared by phosphorylation of cotton stalks and their isolated constituents (lignin, soda‐anthraquinone pulp, and bleached cellulose pulp). FTIR spectra of the phosphorylated materials showed new absorption bands at 950–1200 cm−1 of the COP bonds as a result of phosphorylation. The adsorption of different heavy metal ions (lead, copper, nickel, cobalt, chromium, and cadmium) at different metal ion concentrations (50–1500 μg) by the phosphorylated cotton stalks was studied. The adsorption of metal ions by the phosphorylated cotton stalks increased by increasing their concentration. The binding capacity of phosphorylated cellulose, lignin, and soda‐anthraquinone pulp was measured at 1000 μg metal ion concentration. The adsorption of the different heavy metal ions by phosphorylated‐lignin and ‐bleached cellulose pulp was higher than that of phosphorylated cotton stalks. Thermogravimetric analysis of the raw and phosphorylated cotton stalks showed that the resistance of the phosphorylated cotton stalks to thermal degradation was higher than that of raw cotton stalks (lower rate of weight loss), despite the lower degradation onset temperature of the phosphorylated cotton stalks.