Degradation of Low Concentrations of Formaldehyde in Sono Catalytic Ozonation Advanced Oxidation Processes using Zero-valent Iron

The purpose of the current study is to evaluate formaldehyde degradation ratio with various methods in a batch reactor. In this work, the ozonation, sonolysis (ultrasonic), and ozone sonolysis, sono catalytic ozonation (SCO), and nano zero-valent iron catalyst processes were investigated for removal of formaldehyde. In addition, the influence of important factors such as pH (5–9), ultrasonic power (60-140 W), ozone dosage (20–200 mg hr-1), NZVI dosage (50-400 mg L-1), and initial HCHO concentration (1–20 mg L-1) were tested. The results demonstrated that the SCO process was the most efficient one amongst the process considered. The effect of important factors were also tested on the efficiency of the SCO process and maximum removal (99%) was found at a pH of 5, ultrasonic power of 100 W, ozone dosage of 200 mg hr-1, catalyst dosage of 200 mg L-1 and initial formaldehyde concentration of 15 mg L-1. The results led to the conclusion that the most effective factor was ozone dosage. Also, SCO process may be recommended for the treatment of solutions containing low formaldehyde concentrations.