Biomass is known as a low-cost adsorbents and there is a need for the development of synthesis method further increase its efficient applications. In this work, a macroporous nanocomposite biomass was synthesized by natural polymer (Xanthan gum) and silicate. The resulting nanocomposite was characterized with XRD, SEM, TEM, BET and FTIR. The analysis confirmed that the functions silicate groups were successfully introduced and the nanocomposite not only showed a special macroporous structure but also showed a better cation exchange capacity which helps to retain cation ions. What's more, in order to investigate the adsorption capacity of the biomass, adsorption experiments were considered. The experiment results revealed that nanocomposite showed a high-efficiency adsorption capacity to remove toxic ions such as arsenic, chromium, mercury and cadmium. (C) 2015 Elsevier Ltd. All rights reserved.