Abstract:

Nowadays, shale gas is considered as a new source of energy and researches on shale gas extraction continue to increase all over the world. Shale gas extraction uses high volumes of pressurized water which are injected in the shale rock during the horizontal and vertical drilling. About 10% to 80% of the water injected into the rock forms returns back and emerges as wastewater. In order to minimize the volume of generated wastewater, a pre-treatment of shale gas wastewater is on a great importance making their reuse possible in extraction studies. On the other hand, shale gas wastewater contains the high amounts of total dissolved solids, heavy metals, hydrocarbons, and organic matter and it must be treated before being discharged. In this review, shale gas extraction methods, the properties and treatment methods of the wastewater produced during extraction were examined. The treatability of shale gas wastewater by evaporation with the mechanical vapor compression, membrane distillation, reverse osmosis, forward osmosis, advanced chemical treatment methods, and biological treatment methods have been investigated.

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