1,4-dioxane is a widespread environmental contaminant which is miscible in water with low potential for adsorption to soil. Therefore, it is capable of rapid migration in groundwater and resistant to many processes such as sorption to activated carbon, air stripping, and biodegradation. Thus, water treatment and remediation technologies are needed that are more cost-effective than currently applied advanced oxidation processes.  Electrolytic treatment is a versatile technology that can be applied both in situ and ex situ to a variety of organic and inorganic contaminants. To accelerate contaminant degradation processes that occur in the bulk solution by reactive species generated from the electrolysis of water at the electrode, novel titanium dioxide (TiO2) catalysts have been developed. These pellets were manufactured from different TiO2 starting materials, characterized by various methods, placed between titanium mixed-metal-oxide electrodes, and tested for their capability of catalyzing the anodic oxidation of 1,4-dioxane in flow-through column reactors.  Synchrotron-XRD, BET and SEM studies showed that when only anatase and no rutile was used in the starting material, no phase transition from anatase to rutile occurred during the pelletization process at temperatures up to 900� C, and that the pellets had a high specific surface area and micro-porosity. The column experiments revealed that the TiO2 pellets located between the electrodes greatly accelerated 1,4-dioxane degradation rates compared to a non-catalytic control column. The pure anatase pellet manufactured from the powder with the smallest particle size (=44 nm) resulted in the highest catalytic activity. It was tested further to elucidate the impacts of electrolyte concentration, contaminant concentration, flow rate, and voltage on degradation efficiency as well as formation of reaction intermediates. The results of these investigations illustrate that electrolytic treatment in combination with catalytically active anatase-TiO2 pellets is a promising new technology for the treatment of persistent organic water contaminants.

Electrolytic degradation of 1,4-dioxane catalyzed by titanium dioxide pellets in the absence of light

247th National Meeting (2014)

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