摘要
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.
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.
基金
supported by the National Science Foundation for Innovative Research Group of China(No.51121003)
the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20110003110023)
the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control of China