Keywords: 
• ultrasound /
• Fe0 /
• p-chloroaniline /
• degradation

Abstract: The objective of this work is to explore the influence of solution pH and solute concentration on the p-chloroaniline degradation by ultrasound/Fe0. The degradation efficiencies of p-chloroaniline in the pH range 3～11 and the concentration range 0.1～0.4 mmol/L were investigated in the ultrasound/Fe0 system. The results showed that the optimal pH was 9 for degradation of pchloroaniline. The degradation efficiencies of p-chloroaniline reached 83.2%, 63.5% and 36.1% at the initial concentration of 0.1, 0.2 and 0.4 mmol/L (HRT=180 min), respectively. Degradation of p-chloroaniline in the systems of iron powder, ultrasound and ultrasound/Fe0 was also compared, which showed that the degradation complied the pseudo-first-order reaction. The rate constants were 6.83×10-4, 3.95×10-3 and 1.01×10-2min-1 for the three systems, respectively, and the enhancement factor of p-chloroaniline degradation was around 218%，which indicated that ultrasound and Fe0 had synergistic effect on the degradation of p-chloroaniline. Degradation efficiency of p-chloroaniline could be restrained with the addition of hydroxyl radical capture (n-butanol), which indicated that in the ultrasound/Fe0 system p-chloroaniline was degraded primarily by the hydroxyl oxidation process.