Table 1.

Ferrate concentrations, efficiencies, and specific energy consumption for several works using NaOH 20 mol dm⁻³ as electrolyte (ns = not stated).

Current density Am−2	NaOH mol/L	Anode iron content %	FeO4−2 mmol/dm3	Efficiency (%)	EC kWh kg−1	Time (min)	Reference
14.7	20	99.195	1.74	89.5	2.616	90	Barisci 2014[26]
36	20	ns	2.16	43	6.3	25	Alsheyab 2010 [31]
168	20	99.65	200	68	9	120	This study
1000	20	ns	57.5	ns	2.01	ns	Castañeda 2020 [36]
ns	20	99.195	2.26	>70	<2.9	90	Barisci 2018[37]