Evaluación de un tratamiento de biodiscos mixtos para la remediación de aguas contaminadas por actividades mineras

Abstract

A mixed rotating biological contactor system was designed and implemented at laboratory scale for the treatment of water contaminated with heavy metals. This system consists of three plastic containers of 0.39 m long, 0.25 cm wide and 0.15 m high; interconnected and arranged in line, along the containers there is a central axis consisting of a steel rod connected to a motor and on this axis and inside each container there are 6 discs of 0.2 m in diameter and 0.04 m between discs. 2 m in diameter and 0.04 m between disks, being 18 disks in total that have been manufactured with PLA biopolymer (lactic polyacid - a biodegradable and recyclable material), each disk has different texture, shape and consortium of microorganisms. The system was evaluated using contaminated water samples from the Santa Barbara River sub-basin. The results showed a notable reduction in turbidity (89.70%), color (93.32%), electrical conductivity (43.81%), dissolved oxygen (5.98%) and BOD (79.99%) and COD (90.54%). In the case of heavy metals, the highest removal percentages were 96.46% for Cr, 87.5% for Zn and 85% for Cu, with an optimum hydraulic retention time of 2 days. In addition, a decrease in fecal coliforms (76.67%) and total coliforms (90.21%) was observed. However, it is important to note that the limitations of the study, such as the assumption of a piston flow and the lack of a control system, make it impossible to assure 100% that the observed removals are.