Epsilon Archive for Student Projects

Abstract

The growing demand for alternative water and nutrient sources in horticulture has sparked interest in reusing industrial sidewater streams with rich nutrient content. However, effective purification and utilization methods are essential to prevent contamination and ensure safe and efficient reuse of these water streams. Microalgae have long been explored as a tool for wastewater purification and nutrient recovery. If successfully implemented, biofertilizers derived from these processes could provide an alternative to conventional fertilizers, improving soil health and reducing reliance on synthetic inputs.. This study investigates the potential of microalgae (Spirulina, Arthrospira platensis) to grow in different wastewater streams—blackwater, Food Wastewater (FWW), and aquaculture water—to assess biomass production and microbial content. The goal is to determine whether microalgae can produce valuable biomass for potential use as a biofertilizer. The experiment was conducted in small-scale cultures, measuring biomass growth through optical density and analysing microbial quality before and after cultivation of microalgae. Results indicate that FWW supported the highest Spirulina growth, followed by blackwater, while aquaculture water and a control treatment with plant fertilizer showed significantly lower biomass accumulation. Microbial enumeration after microalgae cultivation showed increased bacterial and fungal presence across all treatments, highlighting important considerations for safety and processing in biofertilizer applications. However, this also suggests the potential for synergistic and symbiotic interactions between microalgae and microbial life. Further research is essential to optimize these relationships, improving wastewater treatment efficiency and enhancing beneficial microbial dynamics. The study encountered challenges in system design particularly due to significant water loss, which impacted result reliability by artificially inflating concentrations and loss of replicates. Future investigations with optimized conditions and larger-scale trials are necessary to assess the feasibility of microalgae-based wastewater treatment and nutrient recycling.