The Visible-Light-Driven Activity of Biochar-Doped TiO2 Photocatalysts in β-Blockers Removal from Water

Water is the most important life-giving resource on earth. Nowadays, intensive growth of the world population has resulted in increased water consumption and the production of wastewater. Additionally, the presence of pharmaceuticals in treated conventional wastewater or even in the environment is strictly indicating that present techniques of wastewater treatment are not efficient enough and are not designed to remove such pollutants. Scarce water resources in the world are the main driving force for the innovation of novel techniques of water and wastewater treatment. Photocatalysis, as one of the advanced oxidation processes, enables the transformation of recalcitrant and toxic pollutants into CO2, water, and inorganic salts. In the present paper, the photocatalytic oxidation of beta-blockers-metoprolol and propranolol-are described. For photocatalytic oxidation, novel TiO2 photocatalysts modified with biochar were used. Photocatalysts were prepared by sol-gel method and the effect of photocatalysts type, presence of inorganic ions, dissolved organic matter, and different water matrix was established. The results indicate that using only the decrease in the tested pollutant concentration is not effective enough in establishing the treatment method's safety. There is a need to use additional testing such as ecotoxicity tests; however, the key parameter is the properly chosen tested organism.

Automated summary

Water is essential for life on Earth, but the increasing global population has led to higher water consumption and increased production of wastewater. Current wastewater treatment techniques are not efficient enough to remove pharmaceuticals, highlighting the need for innovative approaches. This study investigates the photocatalytic oxidation of beta-blockers using modified TiO2 photocatalysts. The results show that solely relying on pollutant concentration reduction is insufficient for determining treatment method safety and additional ecotoxicity testing is necessary.