Intensification of fenton process by ultrasonic waves in humic acid degradation from aqueous solutions

Abstract

Aims: The present study aimed to evaluate the degradation efficiency of humic acid (HA) as a persistent pollutant from the aqueous solution by the Fenton oxidation process intensified with ultrasonic (US) waves. Materials and Methods: A pilot plant equipped with a magnetic stirrer and bar and US device was constructed. The influent with a prespecified concentration of HA was transferred into the reactor and sampled with time intervals. The effect of influencing parameters such as solution pH, reaction time, concentration of H2O2 and Fe, US power, and initial HA concentration on degradation efficiency was systematically investigated. Results: The results showed that by increasing the reaction time from 5 to 10 min, the degradation efficiency was significantly enhanced (10%), while the degradation was not apparently improved by progressing the reaction time to 55 min. At an optimal solution of pH of 3, the induction of US increased the degradation efficiency of HA by about 25%. Overall, the increase in the concentration of H2O2 and Fe led to degradation efficiency improvement, 12% and 15.9%, respectively. Conclusion: Based on the obtained results, the intensified-Fenton process by the US can be proposed as a fact and relative process for the degradation of HA.

Keywords

• dissolved organic carbon
• fenton process
• humic acid
• hydrogen peroxide
• ultrasonic waves