| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程研究所 === 84 === The adsorption of arsenate(V) and chromate(VI) from aqueous
solution onto iron-coated spent catalyst was studied. Chemical
factors such as pH and characteristics of spent catalyst that
might affect the adsorption of As(V) and Cr(VI) were investiga-
ted. The adsorption capacity onto iron-coated catalyst increas-
ed significantly compared with uncoated spent catalyst. The ad-
sorption of As(V) and Cr(VI) exhibits peak values at pH 4.0~5.5
and 3.0~4.0, respectively. The co-existing anions, such as
sulphate and chloride ions in solution were found to affect the
sorption behaviors of chro- mate, possibly due to the
competition between adsorbate and an- ions. The experimental
data of adsorption were fitted reasonably well by the Langmuir
isotherm. The desorption reaction was stu- died by treating the
catalyst with 0.1M NaOH. About 85~98% and 50~80% of arsenate
and chromate on the saturated catalyst were desorbed,
respectively.
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