Development and evaluation of innovative iron-containing porous carbon adsorbents for arsenic removal

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Arsenic is of serious concern because of its marked negative impacts to human health. Of the various sources of arsenic in the environment, drinking water poses the greatest threat to human health. A variety of treatment processes have been examined for arsenic removal, and adsorption-based technology is one of best methods. Effectiveness of this method depends primarily on the adsorbent used. This dissertation is to develop of carbon based iron-containing adsorbents for arsenic removal. The development and characterization work is focused on two iron-containing carbon based adsorbents: (1) iron-containing granular activated carbon (As-GAC) and (2) iron-containing ordered mesoporous carbon (FeOMC). The investigation was conducted on optimizing the preparation conditions, including initial Fe concentration, oxidant type and dosage, and activated carbon or ordered mesoporous carbon types, etc. The ability of adsorbents for arsenic removal was evaluated by both batch and column studies. Effects of ionic strength, pH, and other competing constituents on the arsenic removal were also studied in batch systems. Redox transformation and surface characteristics of carbon based adsorbents were investigated. Meanwhile, the adsorbents were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and nitrogen adsorption-desorption analyses, etc. In the dissertation, As-GAC has been demonstrated as an excellent adsorbent for arsenic removal, and it is a cost efficient technology and potential commercial adsorbent for the arsenic removal. FeOMC was first explored for the environmental application of ordered mesoporous carbon. The advantages of high specific surface area, uniform porous, ordered structure potentially have the good application perspective, which will initiate the research of ordered nano-structured carbon materials for the environmental improvement.--From pulic.pdf