Fig. 2
(a) XRD patterns of (1) raw volcanic tuff (VT), (2) acid-treated volcanic tuff (VT1), (3) iron-treated volcanic tuff (Fe_VT), (4) iron-treated volcanic tuff after five reuse cycles with RB5 (Fe_VT R) and (5) iron-treated volcanic tuff after five reuse cycles in the presence of 10 mM H2O2 (Fe_VT + H2O2 R). The C and Q annotations correspond to the clinoptilolite and quartz mineralogical phases. (b) Raman and (c) FT-IR spectra of volcanic tuff and modified materials.
