Collahuasi eyes constructed wetland system to treat tailings effluent

Chilean miner Collahuasi has expressed its interest in using a constructed wetland system to treat tailings effluent at its operations, allowing previously contaminated water to return to the industrial cycle, Claudia Ortiz, a professor at the Universidad de Santiago (USACH), told BNamericas. The university is currently implementing a pilot system at state copper producer Codelco's Chuquicamata division in partnership with German firm BioPlanta. The system, which will initially treat 8l/s, should go online in 2013, according to Ortiz, who is leading the project. The initiative involves installing a constructed wetland system at Chuquicamata's Talabre tailings dam. The biological treatment process lowers the concentration of sulfates and other elements present in the tailings effluent, allowing water to be reused either in the mining process or for irrigation. "We've had conversations with Collahuasi, which was very interested in the project. However, they are facing a bigger problem, which is access to water, because they are in the process of expanding operations," Ortiz said. Collahuasi recently submitted an environmental impact assessment to the environment ministry ( MMA) for a US$173mn water transfer system to supply its expansion project. Once the pilot project at Chuquicamata is complete, the researchers hope to begin using the system to treat larger volumes of industrial wastewater, according to Ortiz. The full interview with Claudia Ortiz will be published in this week's Water and Waste Perspectives, for subscribers only.