1. Sustainable Process Engineering Centre, Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Email: pavithira1708[at]hotmail.com
2. Department of Biosystems Engineering, Faculty of Agricultural Technology, Universitas Brawijaya, Malang, East Java, 65154, Indonesia
Abstract
Spirulina (Arthrospira platensis) is a fast-growing microalgae valued for its high protein content and bioactive compounds like phycocyanin, a blue pigment-protein with strong antioxidant and anti-inflammatory properties. Despite its potential in food, pharmaceutical, and cosmetic industries, large-scale production is limited by high costs, especially for nutrients. This study addresses these challenges by cultivating Spirulina using nutrient-rich food-based industrial wastewater as a low-cost alternative to chemical media, aiming to lower production costs while supporting sustainable wastewater bioremediation. Three types of food-based industrial wastewater, namely WW1, WW2, and WW3 were each diluted 50% with Kosaric medium and used to cultivate Spirulina. Among these, WW2 achieved the highest biomass concentration (1.93 g/L). The cultivation process also demonstrated effective nutrient removal: ammoniacal nitrogen was reduced by 63.2%, nitrate by 62%, nitrite by 87.6% and total phosphorus by 93.4% for cultivation with WW2. Phycocyanin content and purity from wastewater-grown Spirulina were compared to control samples to evaluate the effect of different media on pigment production. Structural and chemical changes in the biomass were examined using field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). To ensure product safety and quality, phycocyanin extracted from Spirulina cultivated in food-based wastewater underwent toxicity assessments on human cells, along with antioxidant and anti-inflammatory activity evaluations to validate its pharmaceutical potential. This confirmed the potential of these wastewaters to act as low-cost cultivation media, while simultaneously contributing to environmental sustainability through wastewater bioremediation.
