Anaerobic digestion (AD) is one of the most established technologies for the stabilization of wastes such as sewage sludge, generated during wastewater treatments. However, these AD processes would need to be rethought to achieve the new requirements in the removal levels of emerging pollutants according to the current water policy restrictions (Directive 2008/98/EC). Among these compounds, there is an increasing concern about pharmaceutical active compounds (PhACs) and its transferen- ce through the ecosystems by the application of sewage sludge as soil amendment, according to the circular economy policies. In the last years, micro-aeration has been proposed as a pre-treatment strategy to improve the two-stages AD process, being implemented in the first stage to enhance the hydrolysis activity without affecting the methanogens in the second stage. Applying controlled micro-aeration (~5% dissolved oxygen) could favour the proliferation of fungal communities, which are able to produce hydrolytic and oxidative exoenzymes, improving the hydrolysis capacity of the reactors in comparison with strict anaerobic conditions. These fungal enzymes might be also involved in the organic matter decomposition and in PhACs degradation, as has been demonstrated in aerobic bioremediation systems. However, there is no previous studies about the micro-aeration effect on PhACs degradation and how micro-aeration affects fungal communities during the hydrolysis. In this work, we aimed to study the effect of micro-aeration at different concentration of oxygen to evaluate the degradation of some pharmaceutical compounds.