Abstract
This paper discusses the toxicity and mobility of chromium species. And it presents the extent and kinetics of reductive remediation of hexavalent chromium, Cr+ using ferrous ion, Fe2+. Molar ratios of 1:3 and 1:6 of Cr (VI) to Fe (II) were used. Integral method of data analysis showed reaction followed second-order kinetics with R square values near unity. Reaction was initially fast but with a rapid precipitation attributed to Cr (III)-Fe (III) in previous studies. This colloidal precipitate ultimately stops the reaction, which explains while conversion efficiency increases with increased molar ratio of Cr (VI) to Fe (II). The impact of pH was investigated by adjusting the Cr (VI)-Fe (II) medium to pH 2.78, 5.24, 7.00, 9.00 and 11.96 using predetermined drops of acid or base. Reaction was more rapid under alkaline conditions with higher extent of degradation consistent with previous research. In soil system, mass transfer limitation was hardly noticed as high extent of reduction was recorded relative to aqueous phase. The high solubility of Cr (VI) aided the release into the aqueous media for reduction by ferrous sulfate.
Highlights
Toxic Release Inventory (TRI) reported that in 2009, the total chromium released into the environment
Extent of Cr (VI) Reduction by FeSO4 in Aqueous Media There have been some controversies about the reported rates of Cr (VI) reduction by Fe (II)
The efficiency of the reaction is immediately controlled by the rapid precipitation of colloids
Summary
Background Chromium is lustrous and does not tarnish in air and water like other metals such as copper and aluminum. These properties have been exploited by different industries including alloy manufacturing, leather tanning, corrosion control, wood polishing, ink production, metal finishing, electroplating, textiles and chemical manufacture [1]. These industrial applications have contributed to the rise in chromium contamination. Toxic Release Inventory (TRI) reported that in 2009, the total chromium released into the environment (soil, water and air). The US EPA has enlisted chromium among the 13 priority pollutant metals (Ag, As, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, Tl, Zn)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
