Title : Catalytic wet air oxidation of antibiotics over supported Platinum on different supports fractions based CeO2 and ZrO2
Emerging contaminants have serious effects on the environment. Especially contaminants loaded with used water, which affect fauna, flora, and contaminate soils. Antibiotics are considered as an emerged threat originated from leaking and incompletely treated wastewater loaded with pharmaceuticals. Antibiotics risks are divers, the most pertinent are environment useful microorganism deterioration and harmful bacteria gaining antibiotics resistance. Those factors could generate in the future sanitary and environmental crisis. Facing these issues, many technologies propose sufficient solutions to release only cleaned water, as example, adsorbents and membrane separations, which have successful separation results. The only issue is these separation methods generate highly contaminated solutions or adsorbents, which are even more threatening and extremely hard to handle. Catalytic Wet Air Oxidation (CWAO) is one of the most efficient concentrated wastewater detoxification processes. We have investigated catalytic oxidation of model antibiotics solutions, mainly based tetracycline for their excessive uses and presence in the environment. Different supports (Ce, Zr) and Pt-based catalysts supported on these oxides were tested at two different degradation temperatures and compared, including the blank catalyst-less: wet air oxidation. Periodically collected liquid samples were characterized using different methods: HPLC-UV and TOC-L analysis to follow the conversion of the model pollutant and quantification of total organic carbon, also HPLC-MS for by-products identifications. Concerning fresh and used catalyst characterization, we have implemented an ICP analysis for noble metal quantification and leaching investigation, specific surface characterization, and TEM analysis. All the analyses carried out have contributed to the interpretation of the results and to prove the explanations. The catalyst effect on catalytic wet air oxidation tests are very significant. For example, at 50°C atmospheric pressure Pt/CeZr showed the best activity, reaching 98% Δ[TOC]%, and even more the selectivity SCO2 % index was 100% during all three hours of CWAO, as well at room temperature catalysts still present good degradation results. Moreover, collected samples by-products are identified, and treated solutions toxicity are inspected.