In situ stannous reagent generator (SRG): an alternative hexavalent chromium treatment technology in drinking water industry

Abstract

Access to safe drinking water is a basic necessity for human health. Rock and soil are rich sources of chromium, a metal that is present naturally. Chromium commonly exists in two oxidation states: trivalent chromium (chromium-3, Cr (III), Cr3+) and hexavalent chromium (chromium-6, Cr (VI), Cr6+), in the natural environment, as well as in the water treatment and distribution systems. While Cr (III) is an essential nutrient for humans, Cr (VI) is a dangerous pollutant that can build up in both the environment and the tissues of living things. The Cr (VI) treatment traditionally uses techniques such as electrodialysis reversal, ion exchange, electrochemical, reduction, coagulation, oxidation and filtration systems. Chemical costs, secondary waste production, and unintentional regeneration of Cr (VI) after treatment are difficulties with standard Cr (VI) treatment. In order to remediate Cr (VI) in raw water, this study looks into the in-situ stannous reagent generator (SRG) package as a potential disruptive green technology. SRG was able to reduce roughly 40 parts per billion (ppb) of Cr (VI) to below 1.0 ppb after being installed on a raw water source site for a 10-day trial period. The In Situ SRG technology provides an efficient and safe method for treating Cr (VI) in drinking water, reduces the health risks associated with Cr (VI) exposure by converting it to a less toxic form and reduces chemical handling risks. Reductive Cr (VI) treatment technologies based on the use of stannous tin hold tremendous promise in the future to overcome green-house gas (GHG) emissions and other anthropogenic environmental change, in addition to effectively reducing Cr (VI) in drinking water to the permissible limits and high energy cost challenges. In Situ Stannous Reagent Generator (SRG) technology is designed to convert Cr (VI) to its less toxic trivalent form, Cr (III), which is less harmful and easier to remove from water.