Obtaining biosolids through thermophilic anaerobic digestion of sewage sludge

Canales-Gutiérrez A.; Villafuerte-Prudencio N.; Romero-Loaiza R.; Quispe-Aucca B.J.; Ramos-Pineda J.R.; Aguilar J.M. · Engenharia Sanitaria e Ambiental (2026) · DOI: 10.1590/s1413-415220250059

Resumen

Sewage sludge management is a significant environmental challenge in the Puno region, where direct discharge into aquatic ecosystems leads to sedimentation, deteriorating water quality, and reducing wastewater treatment efficiency. This study aimed to evaluate and compare the quality of biosolids produced from sewage sludge treated in stabilization ponds in the cities of Puno, Juliaca, and Ilave, using thermophilic anaerobic digestion. The sludge was processed in biodigesters for 30 days under controlled temperatures of 50–60°C. Physicochemical and microbiological analyses were performed to determine macronutrient content (nitrogen, phosphorus, potassium), organic matter, and pathogen reduction. Results showed the highest nitrogen (28,336 mg kg-1) and phosphorus (7,200 mg kg-1) concentrations in Puno, while Juliaca recorded the highest potassium level (4,447 mg kg-1). A significant reduction in fecal coliforms and helminth eggs was achieved, reaching an index of 2.68 HH/4gTS. Biosolids from all three sites were classified as Class B, with comparable nitrogen and organic matter content, but with site-specific nutrient profiles. It is concluded that thermophilic anaerobic digestion represents a sustainable and effective method for sewage sludge management in high Andean areas, with the potential to produce nutrient-rich biosolids suitable for agricultural applications.

Instituciones: Universidad Nacional del Altiplano