The procedure is described as follows: (1) 0.07 M of iron solution
was prepared by dissolving FeSO47H2O in 100 mL of ethanol
water (ethanol/water = 3/7, v/v) with addition of 0.5 g of PEG as
surfactant. (2) 50 mL of KBH4 reductant was added dropwise
(2 mL/min) to a solution containing activated carbon (4 g) and
FeSO47H2O under vigorous magnetic stirring. (3) The solution
was shaken for another 30 min [18,19] after addition of KBH4
was complete. (4) The NZVI/AC formed was filtered and alternately
rinsed with ethanol and degassed RO water three times each [18].
Fig. 1 shows a schematic diagram for synthesis of NZVI/AC.