在黑暗及光照条件下，α-Fe₂O₃、α-FeOOH、β-FeOOH和γ-FeOOH水悬浮液中HSO₃⁻的氧化反应

Oxidation of HSO3- in aqueous suspensions of alpha-Fe2O3, alpha-FeOOh, beta-FeOOH and gamma-FeOOH in the dark and under illumination.

作者信息

Ansari A, Peral J, Domènech X, Rodriquez-Clemente R

机构信息

Department de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.

出版信息

Environ Pollut. 1997;95(3):283-8. doi: 10.1016/s0269-7491(96)00148-0.

DOI:10.1016/s0269-7491(96)00148-0

PMID:15093441

Abstract

The kinetics of oxidation of HSO3- ions in aqueous solutions in the presence of alpha-Fe2O3, alpha-FeOOH, beta-FeOOH and gamma-FeOOH is investigated. The oxidation of HSO3- follows a zero-order kinetics in suspensions of beta-FeOOH and gamma-FeOOH and a first-order kinetics for alpha-FeOOH and alpha-Fe2O3 systems. Some degradation of the iron(III) oxides takes place, evidenced by the presence of Fe(III) and Fe(II) in solution. Under illumination, the rate of HSO3- oxidation notably increases. In this case, the rate of oxidation of HSO3- by the four iron(III) oxides follows a kinetic equation of the type dx/dt=k(1-x)/x, where x is the fraction of HSO3- oxidized at time t. The rate constant of HSO3- photo-oxidation per unit of specific area for the different iron(III) oxides studied follows the order: alpha-Fe2O3>>gamma-FeOOH approximately beta-FeOOH>>alpha-FeOOH. Fe(II) and Fe(III) were also detected in solution after irradiation of the iron(III) oxide suspensions.

摘要

研究了在α-Fe₂O₃、α-FeOOH、β-FeOOH和γ-FeOOH存在下，水溶液中HSO₃⁻离子的氧化动力学。在β-FeOOH和γ-FeOOH悬浮液中，HSO₃⁻的氧化遵循零级动力学，而在α-FeOOH和α-Fe₂O₃体系中遵循一级动力学。溶液中Fe(III)和Fe(II)的存在证明了铁(III)氧化物发生了一些降解。光照下，HSO₃⁻的氧化速率显著增加。在这种情况下，四种铁(III)氧化物对HSO₃⁻的氧化速率遵循dx/dt = k(1 - x)/x类型的动力学方程，其中x是时间t时被氧化的HSO₃⁻的分数。所研究的不同铁(III)氧化物每单位比表面积的HSO₃⁻光氧化速率常数顺序为：α-Fe₂O₃>>γ-FeOOH≈β-FeOOH>>α-FeOOH。铁(III)氧化物悬浮液辐照后，溶液中也检测到了Fe(II)和Fe(III)。