Abstract

In north-central Chile, water reuse is essential due to the arid climate. Mining tailings ponds offer a promising opportunity for water recovery; however, the water quality often fails to meet the environmental standards for discharging liquid waste into marine and inland surface waters. This study proposes a bioreactor-based technology for softening tailings water while also addressing the need to quantify its sustainability impacts. To achieve that, an evaluation of the environmental and social performance of the bioreactor is conducted, comparing it with established softening methods, using an industrial ecology approach. This evaluation aims to explore scalable alternatives for sustainable water management. Environmental impacts are quantified using the ReCiPe 2016, with data sourced from Ecoinvent v3.8 and Agrifootprint databases. Social risks are assessed through the Social Hotspot Database modeling in SimaPro 9.5.0.2. The results indicate that the bioreactor demonstrates greater sustainability compared to membrane-based systems, reducing greenhouse gas emissions by more than 95%. It also registers the lowest aggregated social risks due to its minimal energy intensity, lack of hazardous chemicals, and simplified infrastructure. In contrast, reverse osmosis, while delivering higher quality permeate, results in the highest environmental burdens and occupational hazards. This research validates the bioreactor as an enabler of industrial ecology, transforming tailings water into a circular resource.