Preparation: |
prepared by slowly adding 250 mL of 0.05 M aluminum nitrate [Al(NO3)3] to 150 mL of 5 M KOH; 60 mL of this solution were transferred to a 1000-mL polypropylene bottle, 82.5 mL of 5 M KOH were added; 50 mL of 1 M Fe(NO3)3 quickly poured into the bottle and the volume was made up to a liter with deionized water; bottle was kept in an oven at 70°C for 2 weeks and shaken once a day (Lewis and Schwertman 1979) |