Heterogeneous Fenton treatment of shale gas fracturing flow-back wastewater by spherical Fe/Al2O3 catalyst

In this work, efficient Fenton strategy have been proposed for degradation of shale gas fracturing flow-back wastewater using the spherical Fe/Al 2 O 3 supported catalyst. Prior to actual fracturing fluid treatment, the typical model wastewaters such as p -nitrophenol and polyacrylamide were employed to evaluate the catalytic properties of prepared catalyst, and then Fenton treatment of the shale gas fracturing flow-back wastewater was performed on the self-assembled catalytic degradation reactor for continuous flow purification. Results showed that under the conditions of 0.25 mol L −1 impregnating concentration, pH 4, 50 g L −1 catalyst and 0.75 mL L −1 30% H 2 O 2 , the removal efficiency of p -nitrophenol and polyacrylamide reached 74% and 61%, respectively, while the COD removal of fracturing flow-back fluid was approximately 48% with the residual 88 mg L −1 COD, meeting the emission standards of the integrated wastewater discharge standard (GB 8978-1996, COD < 100 mg L −1 ). This work offers new alternatives for Fenton treatment of real wastewater by efficient and low-cost supported catalysts.