A new type of glass colorant prepared with Cr3+ and Cu2+ adsorbed from waste water by modified sands

Abstract A new type of glass colorant was developed by adsorbing Cr 3 + , Cu 2 + and mixed Cr 3 + /Cu 2 + ions from synthetic waste water using delicately designed sand-based adsorbents, in which sand was first coated with porous silica followed by amino functionalization. The results show that the modified sands had increased surface areas and adsorption capacities toward metal ions in water. The used adsorbents together with the adsorbed ions were applied in preparing color glasses. The amino functionalization of the sand led to the formation colorants with high contents of metal ions and the amounts of metal ions retained on the used adsorbents affected the color of the obtained glasses. It is also proved that the anions accompanying with Cr 3 + in the waste water did not influence the colorization effect of the metal ions. The colorization ions are homogeneously distributed in sand and do not need to pre-mix with other raw materials in glass batches.