A high activity of Ti/SnO-Sb electrode in the electrochemicaldegradation of 2,4-dichlorophenol in aqueous solution

Electrochemicaldegradation of2,4-dichlorophenol (2,4-DCP) in aqueous solutionwas investigated over Ti/SnO2-Sb anode. The factors influencing thedegradation rate, such as applied currentdensity (2-40 mA/cm2 ), pH (3-11) and initial concentration (5-200 mg/L)were evaluated. Thedegradation of2,4-DCP followed apparent pseudo first-order kinetics. Thedegradation ratio on Ti/SnO2 -Sb anode attained > 99.9% after 20 min of electrolysis at initial 5-200 mg/L concentrations at a constant currentdensity of 30 mA/cm2 with a 10 mmol/L sodium sulphate (Na2SO4 ) supporting electrolyte solution. The results showed that 2,4-DCP (100 mg/L)degradation and total organic carbon (TOC) removal ratio achieved 99.9% and 92.8%, respectively, at the optimal conditions after 30 min electrolysis. Under this condition, thedegradation rate constant (k) and thedegradation half-life (t1/2 )were 0.21 min1 and (2.8 ± 0.2) min, respectively. Mainly carboxylic acids (propanoic acid, maleic acid, propanedioic acid, acetic acid and oxalic acid) weredetected as intermediates. The energy efficiencies for2,4-DCPdegradation (5-200 mg/L)with Ti/SnO2-Sb anode ranged from 0.672 to 1.602 g/kWh. The Ti/SnO2-Sb anodewith a high activity to rapid organic oxidation could be employed todegrade chlorophenols, particularly2,4-DCP inwastewater.