Biofilters as an Eco-efficient Technology in the Removal of Iron and Copper from Acid Mine Drainage

Guevara Vásquez K.V.; Gutiérrez Martos H.; Licapa-Redolfo G.S. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2026) · DOI: 10.18687/laccei2026.1.1.1940

Resumen

This study evaluated the efficiency of iron and copper removal from acid mine drainage (AMD) using passive biofilters made of vegetable ash, dried guinea pig manure, and cattle manure. Real AMD samples with an initial pH between 2.70 and 2.72 and initial concentrations of 31.7 mg/L of Fe and 30.7 mg/L of Cu were tested using three biofilter configurations with different material proportions: Treatment 1 consisted of 20 g of guinea pig manure, 60 g of cattle manure, and 30 g of vegetable ash; Treatment 2 consisted of 15 g of guinea pig manure, 50 g of cattle manure, and 18 g of vegetable ash; and Treatment 3 consisted of 10 g of guinea pig manure, 40 g of cattle manure, and 16 g of vegetable ash. Contact times of 5, 10, and 15 min were evaluated, showing a rapid increase in pH to values between 7.2 and 8.9. Residual Fe and Cu concentrations were determined using a digital colorimeter and specific colorimetric kits. Treatment 3 showed the best overall performance, reaching a maximum removal of 89.84% for iron at 10 min and 97.85% for copper at 5 min. In contrast, formulations with higher ash content produced greater alkalinity but lower stability in metal retention. These results show that pH increase alone does not guarantee effective remediation and that organic matter plays a decisive role in metal immobilization. Therefore, the proposed system represents an eco-efficient and viable alternative for passive AMD treatment in rural contexts.

Instituciones: Universidad Privada del Norte