Bench-Scale Testing for Sustainable Flowback Water Reclamation

Department of Environmental Science, Mount Royal University, Calgary, Canada

Abstract: Freshwater scarcity and increased cost put pressure on the need to find innovative ways to reuse water in the oil and gas sector. Flowback water represents the crucial period following fracking activity where the injected frack fluids in the formation returns to the surface and collected for proper management. Flowback has undesirable characteristics which makes it unusable for practical reuse, unless adequately treated. The purpose of this study is to evaluate viable and practical methods to reclaim flowback water for beneficial industrial and societal reuse, aiming to enhance environmental protection. Batch treatments of flowback water included ozone, electrocoagulation, and combined charcoal-ozone. Results showed that electrocoagulation was more effective, yielding a 90% reduction in COD compared to 52% with the ozone treatment while TSS and turbidity were reduced to 99% and 90% by the electrocoagulation and the ozone treatment, respectively. Reduction in priority heavy metals ranged from 21% to 62% while destruction of heterotrophic bacteria was 90% and 100%, respectively. The charcoal-O3 technique proved largely ineffective as a treatment modality.