Enhanced photocatalytic degradation of 2-methyl-4-chlorophenoxyacetic acid (MCPA) by the addition of H2O2

Photocatalytic remediation technology has been shown to be a favorable approach for the removal of range environmental pollutants in water treatment. While this can often achieve complete degradation, overlooked are reaction intermediates that potentially as harmful original parent compound. In case photocatalytic oxidation herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA), we have recently 4-chloro-2-methylphenol (CMP) is formed primary intermediate. To ensure continued development technology, it crucial both MCPA and CMP achieved by photocatalysis. Reported here enhanced subsequent suppression respectively, addition small quantities H2O2. H2O2 accelerates degradation rates (via increased OH radical production), was found restrict formation study through competitive adsorption at surface TiO2. Based on combination coupled with supressed formation, 0.5% determined an optimal loading process. Under these conditions 100% (to limit HPLC detection) after 45 min irradiation rate ∼1 mg L−1 min−1 (ƞphoton = 4.4), which also resulted ∼83% reduction when compared system no present.