Comparative analysis of two microalgae-bacterial symbiotic association growth in papermill effluent enriched through food waste digestate

New treatment methods are needed to better recycle waste towards the circular economy. Microalgae can be used as an asset to treat effluent and simultaneously produce biofuel. This paper aims to evaluate the growth of microalgae-bacterial symbiotic association in papermill effluent enriched through food waste digestate. Besides that further removal capacity of nutrients from effluent were also evaluated. Two microalgae strains were observed: Auxenochlorella protothecoide, Tetraselmis indica in combination with mixed bacterial inoculation versus the monoculture of microalgae.. Auxenochlorella protothecoide-bacterial symbiotic system growth in the effluent was 1.6 times more than monoculture growth of Auxenochlorella protothecoide. On the 10th day, the symbiotic Auxenochlorella protothecoide system removed 86.95%, 85.67%, and 78.53% of chemical oxygen demand (COD), total dissolved nitrogen (TDN), and total dissolved phosphorus (TDP) respectively. The paper mill effluent after treatment can be recycled to use further for irrigation purposes.