Synergistic treatment of extracellular polymeric substances in Chlorella vulgaris recycled wastewater using Fenton oxidation coupled with granular activated carbon adsorption.

This study investigated the treatment of extracellular polymeric substances (EPS) in the recycled wastewater (RW) by Fenton oxidation (FO), granular activated carbon (GAC) adsorption, and Fenton oxidation coupled with granular activated carbon adsorption (FO + GAC) process, while also assessing the stability, recyclability, and economic feasibility of FO + GAC in the C. vulgaris recycling culture system. The synergistic FO + GAC treatment achieved an EPS removal efficiency of 74 %, significantly higher than either individual treatment. The recyclability of culture wastewater was significantly enhanced by the removal and decomposition of EPS components using FO + GAC. These small-molecule organic compounds produced by FO + GAC treatment not only promoted the growth of C. vulgaris but also enhanced the accumulation of proteins and carbohydrates. Moreover, the economic feasibility analysis found that the FO + GAC process saved a significant amount of water resources and increased benefits. In conclusion, this study provides a promising strategy for the economical and sustainable treatment of microalgal wastewater.