Optimized electrocoagulation technology using response surface methodology to control H2 production and treatment effect of fracturing flowback fluid treated by electrocoagulation

TLDR: In this paper, the authors proposed an electrocoagulation (EC) method that is time saving, highly efficient, and easy to apply to deal with the problem of hydraulic fracturing.

Abstract: Fracturing flowback fluid is the most important contaminant associated with oil and gas explo - ration and production, which requires low-cost and sustainable technologies for treatment. This study proposed an electrocoagulation (EC) method that is time saving, highly efficient, and easy to apply to deal with this problem. A Box–Behnken design coupled with the response surface methodology (RSM) was used to construct a model of the EC process to intensively control hydro - gen (H 2 ) production and to reduce potential safety risks while achieving high treatment efficiency. The model describes the change in the responses of decolorization rate and H 2 production in accordance with electrolysis current, plate spacing, electrolysis time, and S / V . Results show that the turbidity removal rate, decolorization rate, and H 2 production are predicted to be 87.03%, 89.14%, and 138.12 mL under the maximum H 2 production process. On the contrary, the turbidity removal rate, decolorization rate, and H 2 production are predicted to be 91.23%, 95.7%, and 7.86 mL, respec - tively, under minimum H 2 production conditions obtained through the model. The relative error between all the predicted and measured values is less than 2.5%. Overall, the RSM is feasible to optimize and predict the process conditions, treatment effect, and H 2 production of EC-treated fracturing flowback fluid. This optimization and prediction study can provide a reference for the efficient and safe application of EC to improve the treatment effect and control the H 2 production in the wastewater treatment process.