Phosphorylated collagen fibre: preparation and use for adsorbing heavy metalls

Phosphorylated collagen fibre (P-CF) was prepared using phosphorus oxychloride as a phosphorylating reagent. Solid state 31 P-NMR and FTIR analysis proved that phosphate groups were bound with amino groups of collagen fibre. As a novel fibrous adsorbent, P-CF performed to be an effective adsorbent for metal ions, such as Pb 2+ , Cd 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ and UO 2 2+ . By using Cd 2+ as probe ion, the fundamental adsorption behaviours of P-CF to metal ions were investigated. The adsorption capacity was significantly influenced by pH value, and the optimal pH for adsorbing Cd 2+ located in the pH range of 3.83-6.00. The adsorption isotherms of Cd 2+ were well fitted by the Langmuir equation. The adsorption capacity was increased with the increase of temperature. The adsorption kinetics was satisfactorily described by the pseudo-second-order rate model, implying that the chemical adsorption of P-CF to Cd 2+ is the rate controlling step. Moreover, P-CF can be easily desorbed using dilute HNO 3 solution.