Biofilm carriers and the potential integration of carbon sources from waste activated sludge through ionizing radiation

Activated sludge is a key component in wastewater treatment processes as it contains the microbes responsible for treatment. Autotrophic and heterotrophic bacteria perform breakdown complex organic matter and denitrify the water using carbon sources as their energy requirement. As the existing carbon source in effluent wastewater is often insufficient to support complete denitrification, external carbon sources are added to make up for this deficit. In this paper, different carbon sources and biofilm carriers were reviewed, and the uses of ionizing radiation were discussed. The potential of ionizing radiation as a way to integrate carbon sources from denitrification sludge into biofilm carriers was then explored. The production of radicals after irradiation leads to a more reactive biofilm carrier surface, promoting the attachment of charged biofilm and the growth of sludge. The breakdown of complex carbon molecules in the sludge into simpler molecules after irradiation allows it to be used by microbes as a carbon source and continue. With the theoretical foundations offered by this study, proof-of-concept studies are then recommended to confirm the effect of sludge irradiation on biofilm attachment and denitrification performance.