A Leptolyngbya-Dominated Consortium for the Optimized Biological Treatment of Mixed Agro-Industrial Effluents

Many individual wastewater streams exhibit imbalanced or poor nutrient profiles, limiting their suitability for efficient biological treatment. In regions where several agro-industrial activities coexist, these streams are often produced in small volumes and vary considerably in composition, making their combined use an effective way to obtain a more balanced influent. This study aimed to identify the optimal mixing ratio of two agro-industrial wastewaters, second cheese whey (SCW) and poultry wastewater (PW), for the cultivation of a Leptolyngbya-dominated consortium. Four mixing ratios of SCW:PW (50:50%, 60:40%, 70:30%, and 85:15%) were examined based on an initial dissolved chemical oxygen demand (d-COD) concentration of 3000 mg L−1. The 70:30% ratio was led to significant biomass production (268.3 mg L−1 d−1), while simultaneously exhibiting the highest lipid content (14.0% d.w.), and the highest removal of d-COD (89.2%), total nitrogen (64%) and PO43−-P (60%). Overall, the experiments showed that using nutritionally balanced wastewater streams is a promising strategy to enhance biological treatment efficiency and lipid production.