Abstract
The effect of pH and anion composition on the aging of freshly precipitated iron(III) hydroxide sludges has been examined. The rate of transformation of the kinetically favored iron(III) oxyhydroxide, ferrihydrite, to its crystalline analogues, hematite (α-Fe2O3) and goethite [α-FeO(OH)], was promoted with increasing pH. The influence of anion type on the transformation rate was related to the affinity of the anions for the surface of the ferrihydrite particles, with rates decreasing in the order υT nitrate > υT chloride > υT sulfate (υT = rate of transformation). The relative composition and crystal morphology of the product species was found to be dependent on both the anion type and the pH of the system. Hematite formation was favored at pH values near the point of zero charge of ferrihydrite (pH 7−9), whereas goethite formation was favored outside of this region. A correlation between enhanced hematite formation and both the relative affinities of the anions for the ferrihydrite particles and their re...
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.
