Magnetic semiconductor photocatalysts for the degradation of recalcitrant chemicals from flow back water.

In the present study treatability of persistent organic compounds from the flow back water after hydrauling fracturing was investigated. The combination of TiO photocatalyst and magnetic oxide nanoparticles enhance the separation and recoverable property of nanosized TiO photocatalyst. FeO/TiO and FeO@SiO/TiO nanocomposites were prepared by heteroagglomeration. The photocatalysts' characteristics by X-ray diffractometry (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS) showed that sample with the mass ratio of FeO to TiO equal 1:4 and molar ratio of TEOS:FeO = 8:1 and NHOH:TEOS = 16:1 obtained by deposition TiO P25 (Evonik) on magnetite core had about 124 m g specific surface area and superparamagnetic properties. The prepared composites contained TiO and FeO crystal phases. The photocatalytic activity was estimated by measuring the decomposition rate of three model pollutants identified in the flow back water from one of the Baltic Shale Basin. Regarding flow back water treatment after shale gas exploration, the progress of photocatalytic degradation of organic compounds was measured by chemical oxygen demand (COD) concentration. The FeO@SiO/TiO_P25 composite nanoparticles were recovered and re-used without significant reduction of efficiency.