Optimization of reverse osmosis flowback water treatment using halotolerant microbes naturally enriched in fractured shales

Flowback water recovered after hydraulic fracturing operations poses a serious environmental concern due to the sheer quantity produced and its toxic chemical composition. Traditional methods of wastewater treatment cannot be used for flowback water treatment due to its high concentration of non-biodegradable dissolved solids. Consequently, alternative technology has been developed to address this problem. Reverse osmosis (RO) treatment is one such example. However, guar gum gelling agents found in flowback water impede membrane permeability and water flux rate of RO, consequently decreasing the efficiency and practicality of this desirable, environment-friendly technology. Previously, a biological solution using activated sludge to degrade guar gum prior to RO treatment was attempted with limited success due to the inhibitory effects of hypersalinity (characterized by high total dissolved solids content) on microbial activity. To solve this problem, several recently discovered strains of bacteria and archaea found to be naturally enriched in fractured shales may be utilized through genetic modification to degrade guar gum under hypersaline conditions. These microbes are naturally halotolerant and thrive under hypersaline conditions, making them prime targets for genetic modification targeting various chemical additives in flowback water. Here, we provide a proof of concept model using these microbes to selectively target guar gum degradation to improve the efficiency of RO treatment.