Biodegradability enhancement of 2,4-dichlorophenol aqueous solution by means of photo-fenton reaction

The degradation and biodegradability improvement of 100 mg · L−1 solution of 2,4-dichlorophenol (2,4-DCP) has been investigated using the photo-Fenton reaction. The influence of reagents concentrations [H2O2 and Fe(II)], initial solution pH, as well as temperature were systematically studied. BOD5, BOD5/COD, BOD5/TOC, and COD/TOC ratios and the average oxidation state are presented. Concentrations of H2O2 and Fe(II), that gave total removal in 2.4-dichlorophenol and increase biodegradability, was determined. The treated solution toxicity was also evaluated. The biodegradability was measured as the BOD5/COD ratio was increased from 0 of the original solution to 0.3 at the point where all 2,4-DCP was removed from the solution. This was combined to increase the average oxidation state from −0.4 up to 1.35. The temperature shows a good effect in the removal rate but a small effect in biodegradability enhancement. The general trend indicates that the degradation efficiency of the photo-Fenton process is relate...