Adsorption of Pb(Ⅱ) by cuttlebone-derived materials and its stability

Abstract

This work mainly studied the Pb(Ⅱ) adsorption properties of cuttlebone-derived materials and the effects of adsorption time, initial solution concentration, and material aging. Cuttlebone is a fishery waste, which is mainly composed of calcium carbonate, and β-chitin. The cuttlebone derivative was prepared by high-temperature carbonization and deacetylation. The results showed that the adsorption of Pb(Ⅱ) by carbonized and deacetylated cuttlebone derivatives was significantly improved from 1644 mg/g to 2216 mg/g and 2118 mg/g, respectively. It resulted that high-temperature carbonization promoted the crystal change of calcium carbonate in cuttlebone from aragonite crystal to calcite crystal, and the latter has a stronger ion exchange capacity for Pb(Ⅱ) than the former. Deacetylation promoted the conversion of chitin in cuttlebone to chitosan, which is beneficial to complexing Pb(Ⅱ) and further improving the adsorption performance. The adsorption kinetics and isotherms of Pb(Ⅱ)on cuttlebone-derived materials conform to the quasi-second-order kinetic model and Langmuir model, respectively. After freeze-thaw aging and hydrogen peroxide aging, the adsorption capacity of Pb(Ⅱ) has been further improved, indicating that the derived materials of cuttlebone are relatively stable. Based on this study, the derived materials of cuttlebone have the potential to treat Pb(Ⅱ) ions in wastewater.