Constantin, Mirela AlinaMirela AlinaConstantinIonescu, IoanaIoanaIonescuConstantinov, Florenta DanielaFlorenta DanielaConstantinovNicolescu, Cristina MihaelaCristina MihaelaNicolescuBumbac, MariusMariusBumbacGheboianu, Anca IrinaAnca IrinaGheboianuConstantin, Lucian AlexandruLucian AlexandruConstantin2026-10-072026-10-072026-08-20https://dspace.incdecoind.ro/handle/123456789/3486Fly ash-TiO2 composites were obtained by sol–gel, and their catalytic performance was evaluated on removal of organic loading and expressed as Chemical Oxygen Demand (COD) from real wastewater samples. SEM, X-ray fluorescence, XRD, IR, Raman analysis and determination of PZC characterized the catalysts. The photocatalytic tests were carried out in a laboratory reactor under UV-VIS irradiation and influence of fly ash (FA) content, and irradiation time was investigated. The catalysts with FA content of 10%, 20% and 30% showed COD removal efficiencies higher than 50% after 5 h of irradiation. The COD degradation followed a pseudo-first order kinetic model. Obtained results proved that FA-TiO2 composites could represent a suitable alternative for removal of organic loading from real wastewater.enfly ashTiO2wastewaterUV lightchemical oxygen demandjournal-article10.3390/recycling11080154