Integrating microalgae in wastewater treatment

Sammanfattning

With the growing need for sustainable wastewater management solutions, this master's thesis explored the use of microalgae, specifically Chlorella vulgaris, in the treatment of anaerobically digested black water (AnBW). The study assessed the viability of using AnBW as a growth medium for microalgae to recover nutrients and produce biomass. Through controlled laboratory experiments, the effects of different dilutions of AnBW, CO2 enrichment, and the necessity of adding trace elements on the growth and nutrient uptake efficiency of Chlorella vulgaris were investigated. These findings suggest that by utilising this waste stream, microalgae could substantially decrease the nutrient load on wastewater treatment plants while providing a sustainable source of biomass for various applications. An external input of carbon, such as CO2, is essential for growth while the addition of trace elements needs to be investigated further, although results indicate an overall improvement of the performance specifically in phosphorus reduction. The study highlights the potential of integrating microalgal treatment in wastewater management to promote sustainability and resource recovery. Future research should focus on harvesting the biomass, scaling up the process, and exploring the economic viability of large-scale applications.