Background: Formaldehyde is usually used as a raw material in many industrial processes. High levels of formaldehyde may be found in effluent of the industries. Formaldehyde appears to have the potential for DNA damage, cell mutagenicity and carcinogenicity. This study aimed to investigate the feasibility of formaldehyde removal from aqueous solutions by advanced oxidation process (UV/H2O2).

Materials and Methods: This bench-scale experimental study was conducted on aqueous solution containing 5000 mg/L of formaldehyde at the Pyrex reactor (16 cm width, 16 cm length and 26 cm depth). Experiments were conducted at two stages. First, the optimum pH and H2O2 concentration were determined. Then, the effect of the radiation was studied.

Results: The rates of formaldehyde removal (pH=3 and 60 minutes reaction time) at different concentrations of H2O2 (0.4, 0.5, 0.6 and 0.7 mol/L) were 47%, 70%, 61% and 62%, respectively.

Conclusion: UV/H2O2 can be used as an efficient process in removing high levels of formaldehyde. The optimum process conditions were: pH=3, a reaction time of 60 minutes and H2O2concentration of 0.5 mol/L.