Influence of chemical regeneration of photocatalyst on effectiveness of diclofenac degradation in water by UV-A/TiO2 process

Farmaceutici imaju pozitivan učinak na ljude i životinje, ali problemi mogu nastati njihovim dospijećem u okoliš. Jedan od najčešće detektiranih farmaceutika u vodenim sustavima je diklofenak. Glavni put njegova dospijevanja u okoliš su efluenti uređaja za obradu komunalnih otpadnih voda, zbog nemogućnosti uklanjanja tog tipa onečišćivala konvencionalnim postupcima obrade. Za uklanjanje diklofenaka i njemu sličnih spojeva iz vode učinkovitima su se pokazali napredni oksidacijski procesi među kojima se ističu fotokatalitički procesi zbog svoje ekološke i ekonomske prihvatljivosti. U ovom radu provedena je imobilizacija TiO2 fotokatalizatora na stakleni nosač koji je korišten za razgradnju diklofenaka u vodenom mediju UV-A/TiO2 procesom uz vodikov peroksid. Istraživana je učinkovitost regeneracije fotokatalizatora kemijskom metodom ozonacije. Aktivnost regeneriranog imobiliziranog sloja TiO2 testirana je u ponovljenim fotokatalitičkim ciklusima. Zamijećen je pad aktivnosti fotokatalizatora neovisno o uvijetima provedbe procesa regeneracije ozonacijom.Pharmaceuticals have benefit for human and animal health but the problem is identified when traces of pharmaceutical are found in natural environment. One of the most commonly detected pharmaceuticals in natural water is diclofenac. Main pathways of diclofenac entering water environment are wastewater treatment plant effluents, due to its inefficient removal by conventional wastewater treatment methods. Advanced oxidation processes are found to be efficient for diclofenac removal from water, among them photocatalytic processes are distinguished due to their ecological and economic advantages. I this research TiO2 photocatalyst was immobilized on the glass plates which were used for diclofenac degradation in water applying UV-A/TiO2 process with hydrogen peroxide. Efficiency of the chemical regeneration by ozonation of photocatalyst was investigated. Activity of regenerated photocatalyst was tested by reuse for the diclofenac removal. Decrease of the photocatalyst activity was noticed regardless the conditions of the regeneration process