2. Iron consumption decreases with increasing initial concentration
of hexavalent chromium ions, and increases with
increasing initial pH of the solution and the current.By
studying the effect of sodium chloride, it was found that
iron consumption decreases with increasing sodium chloride
concentration from 0.5 to 1.5 g/L. Beyond 1.5 g/L,
the iron consumption increases.
3. Energy consumption and the operating cost decreases with
increasing initial concentration of hexavalent chromium
and sodium chloride concentration, and increases with
increasing initial pH of the solution and the applied
current.
4. The optimum conditions for the EC process by using the
present cell based on minimum initial hexavalent chromium
concentration, energy consumption and operating cost
were 100 mg of hexavalent chromium ions/l, 0.55 A, 1.5 g
of sodium chloride/l and pH of 1.