EFFECT OF ORGANIC MATTER ON THE DEGRADATION OFCEFALEXIN WITH TIO2JAZMIN PORRAS, JOHN ACEVEDO, OLGA BETANCUR AND NANCY ACELASAbstract In this study, the transformation mechanism of cefalexin (CFX) via TiO2 photocatalysis and the roleof humic acids extracted from two agro-industrial residues, coffee (HAc) and rice (HAa) husks wereevaluated. During the TiO2 photocatalysis, 90% CFX degradation was found after 180 min ofirradiation (365 nm); in the presence of HAc and HAa, 37% and 61% CFX degradation wereobserved, respectively. This shows that the extracted humic acids do not promote the formation ofreactive oxygenated species; further, they act as scavengers of hydroxyl (.OH). Additionally, it wasfound that CFX degradation by heterogeneous catalysis with TiO2 is mainly associated with holeoxidation (47%) and it is caused by â¢OH radicals in solution (38%). Finally, we can conclude that therole of humic acids as photosensitizers or scavengers is related to their structural properties. |