Application of Scenedesmus sp. in Dairy Effluents for BOD and COD Reduction in Cajamarca, Peru

Abstract

Cajamarca, Peru's main milk-producing region with around 20% of national production, stands out for its favorable geography and industrial livestock tradition. Improving its efficiency in different scenarios and evaluating its long-term performance in larger-scale systems is a primary objective. The use of microalgae in reducing pollutants is essential for treating dairy industry effluents, especially in critical parameters such as Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD). This study analyzed the effectiveness of Scenedesmus sp. in a bioreactor, using treatments with different proportions of microalgae over a period of 21 days under controlled laboratory conditions. Treatment 1 (T1) yielded significant results in contaminant remediation, achieving a 30.20% reduction in Chemical Oxygen Demand (COD), from 1011 mg/L to 707.33 mg/L; and a 30.15% decrease in Biochemical Oxygen Demand (BOD), from 606.67 mg/L to 424.33 mg/L. In addition, it was observed that the use of Scenedesmus sp. allows the photosynthetic capacity of microalgae to be harnessed, generating oxygen and contributing to environmental balance. The simplicity of the bioreactor design used and the relatively low costs associated with microalgae cultivation make this technology a sustainable solution. The findings highlight the potential of Scenedesmus sp. as a sustainable, economical, and effective solution. However, further research is essential to optimize its application in industrial contexts, improve its efficiency in different scenarios, and evaluate its long-term performance in larger-scale systems.