AVS 53rd International Symposium
    Applied Surface Science Tuesday Sessions
       Session AS+SS-TuM

Paper AS+SS-TuM4
Characterization of Electrocoagulation Wastewater Treatment Floc and Aging Effects

Tuesday, November 14, 2006, 9:00 am, Room 2005

Session: Environmental Materials and X-ray Spectroscopies
Presenter: J.A.G. Gomes, Lamar University
Authors: J.A.G. Gomes, Lamar University
D.L. Cocke, Lamar University
H. Moreno, Lamar University
H.G. McWhinney, Praire View A&M University
G.M. Irwin, Lamar University
E. Peterson, Lamar University
Correspondent: Click to Email
Analysis of contaminated water and the methods of water quality remediation, recycle and reuse are increasingly dependent on materials science. Metal poisoning in drinking water such as As has not only led to a health crises in third world countries such as Bangladesh and Mexico, but also threatens developed countries like the United States. Water dispersed materials containing iron or aluminum hydroxides /oxyhydroxide species can efficiently remove arsenic from water or wastewater. The detailed mechanisms of how this occurs are still being sought. Electrocoagulation (EC) is a very promising technique to produce such materials and remove arsenic and other heavy metals from aqueous media. In this paper, we discuss the characterization of these EC-flocs with and without metal pollutants using different analytical techniques, such as FT-IR, XRD, XPS, SEM/EDS and Mössbauer spectroscopy. Results reveal expected crystalline iron oxides (magnetite (Fe@sub 3@O@sub 4@), lepidocrocite (FeO(OH)), iron oxide (FeO)) and aluminum oxides (bayerite (Al(OH)@sub 3@), diaspore (AlO(OH)), mansfieldite (AlAsO@sub 4@.2H@sub 2@O), as well as some interaction between the phases. New insight into the mechanisms of removal and the materials chemistry will be discussed along with the aging effects on the materials and on the compositional ratio of As(III) and As(V) ions in the floc.