Successful application of the biosorption process in wastewater treatment: insights of bacterial biomass use to assess the process environmental impacts

Decision-makers have begun to take an increasing interest in identifying the environmental impacts through the application of Life Cycle Assessment (LCA) for the management of contaminated sites. The analysis of scientific literature shows that impact assessment studies using life cycle assessment are rare for bioremediation processes using biosorbents. More studies are therefore needed to develop sustainable bioremediation processes for the removal of pollutants such as heavy metals that can subsequently be successfully applied in large-scale facilities. We propose an impact analysis for the wastewater treatment by biosorption of 1 liter of water contaminated with Cr(VI) at a concentration of 25 mg/L. We evaluated the environmental impacts potentially generated by Cr(VI) bioremoval in batch and column conditions to demonstrate the environmental and human health impacts and benefits of this type of bioremediation process. Biomass of Rhizobium viscosum CECT 908, previously classified as Arthrobacter viscosus was used as biosorbent for Cr(VI). Environmental impacts were quantified through LCA methodology, within the Sphera Product Sustainability Solutions Software. All major factors that can lead to environmental impacts, such as transportation or electricity, have been considered. The lowest environmental impact value was quantified for the impact category human toxicity cancer (HTc) for Cr(VI) ions removed by biosorption in the batch and continuous systems. The category human toxicity cancer (HTc), is the category with a negative value, and therefore indicates no quantified environmental impact. The study has shown that energy consumption needs to be reduced in the process in order to record lower environmental impacts.