Chlorinated volatile organic compound (CVOC) contaminated water resources are complex environmental problems that have been treated in a simplified manner for decades. Many CVOC remediation plans do not address the common co-contaminant 1,4-dioxane, using methods that are ineffective in treating 1,4-dioxane, such as air-stripping or enhanced reductive dechlorination. While individual remediation technologies exist for each contaminant class, many are inappropriate for simultaneous treatment of 1,4-dioxane and CVOCs. There exists an immediate need for remediation techniques that can be used in complex biogeochemical and co-contaminant sites. This study explored the use of sorbents, such as Norit 1240 granular activated carbon, Ambersorb 560, and ZSM-5 zeolite bioaugmented with bacteria that metabolize 1,4-dioxane or those that cometabolize dioxane as well as CVOCs for treating contaminated water. Pseudonocardia dioxanivorans CB1190 or Mycobacterium vaccae JOB5 biofilms were grown on each sorbent. In bioaugmented flow-through columns, effluent concentrations were compared with those from abiotic columns running in parallel. As abiotic columns reached equilibrium, net 1,4-dioxane sorption became negligible. Sorption isotherms were plotted for abiotic and bioaugmented sorbents, and extents of reversible and irreversible removal of individual compounds were determined. Bioaugmented columns combine adsorption, which rapidly removes the 1,4-dioxane from the contaminated water, with biodegradation, which converts 1,4-dioxane to CO2, thus enhancing 1,4-dioxane sorption. Sorption characteristics were also measured and modeled in the presence of selected CVOCs to evaluate whether this method can simultaneously remove CVOCs or whether these co-contaminants inhibit biodegradation of 1,4-dioxane, thus necessitating CVOC removal prior to 1,4-dioxane treatment. This research presents a novel approach for concurrent treatment of pollutant mixtures in water.

Bioaugmented sorbents for removing 1,4-dioxane and CVOCs from water

251st National Meeting (2016)

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