A review of challenges and opportunities for microbially removing 1,4-dioxane to meet drinking-water and groundwater guidelines

1,4-Dioxane is an emerging contaminant in drinking-water sources and contaminated sites. Microbial removal of 1,4-dioxane has attracted a lot of attention, but faces a challenge: being not able to continuously metabolize 1,4-dioxane to below most drinking-water and groundwater guidelines. The 1,4-dioxane concentrations in most drinking-water sources and contaminated sites are too low to sustain biomass growth. This minireview discusses strategies that may potentially address the challenge. The strategies include: 1) finding oligotrophs for which the minimum 1,4-dioxane concentrations to sustain biomass are low, 2) determining conditions that maximize 1,4-dioxane co-metabolism or co-oxidation, 3) creating novel materials as biomass carriers and contaminant concentrators, and 4) lowering the life-cycle costs of technologies that combine biodegradation with (electro)chemical oxidation or phytoremediation.