Continuous flow photo-Fenton treatment of ciprofloxacin in aqueous solutions using homogeneous and magnetically recoverable catalysts.
The degradation of ciprofloxacin was studied in aqueous solutions by using a continuous flow homogeneous photo-Fenton process under simulated solar light. The effect of different operating conditions on the degradation of ciprofloxacin was investigated by changing the hydrogen peroxide (0-2.50 mM) and iron(II) sulphate (0-10 mg Fe L(-1)) concentrations, as well as the pH (2.8-10), irradiance (0-750 W m(-2)) and residence time (0.13-3.4 min) of the process. As expected, the highest catalytic activity in steady state conditions was achieved at acidic pH (2.8), namely 85 % of ciprofloxacin conversion, when maintaining the other variables constant (i.e. 2.0 mg L(-1) of iron(II), 2.50 mM of hydrogen peroxide, 1.8 min of residence time and 500 W m(-2) of irradiance). Additionally, magnetite magnetic nanoparticles (ca. 20 nm of average particle size) were synthesized, characterized and tested as a possible catalyst for this reaction. In this case, the highest catalytic activity was achieved at natural pH, namely a 55 % average conversion of ciprofloxacin in 1.8 min of residence time and under 500 W m(-2). Some of the photocatalytic activity was attributed to Fe(2+) leaching from the magnetic nanoparticles to the solution.
LCM-Laboratory of Catalysis and Materials-Associate Laboratory LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, R. Dr. Roberto Frias s/n, 4200-465, Porto, Portugal.
Maria J
MJ
Lima
M Enis
ME
Leblebici
Madalena M
MM
Dias
José Carlos B
JC
Lopes
Cláudia G
CG
Silva
Adrián M T
AM
Silva
Joaquim L
JL
Faria
D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002384:Catalysis; D002939:Ciprofloxacin / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D058185:Magnetite Nanoparticles; D010782:Photolysis; D013472:Sunlight; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D000900:Anti-Bacterial Agents; C045076:Fenton's reagent; D058185:Magnetite Nanoparticles; D014874:Water Pollutants, Chemical; D002939:Ciprofloxacin; D006861:Hydrogen Peroxide; D007501:Iron