Table 2.

Experimental parameters.

Sample	FeCl3·6H2O (mol)	FeCl2·4H2O (mol)	BOH (mol)	Final pH
S1	0.02	0.01	0.08 (NaOH) **	10.34
S2	0.02	0.01	0.085 (NaOH)	11.94
S3	0.02	0.01	0.09 (NaOH)	12.08
S4	0.02	0.01	0.095 (NaOH)	12.20
S5	0.02	0.01	0.1 (NaOH)	12.60
F1Na	0.02	0.01	0.08 (NaOH) **	9.4
F3Na	0.02	0.01	0.09 (NaOH)	10.7
F5Na	0.02	0.01	0.1 (NaOH)	11.8
F3K	0.02	0.01	0.09 (KOH)	–
F3TEA	0.02	0.01	0.09 (TEAOH)	–
* F3TEA	0.02	0.01	0.09 (TEAOH)	–

^* Fast and reverse addition of solution containing ferric and ferrous ions into the TEAOH-containing solution; ^** stoichiometric amount of base.