Photocatalytic Oxidation Degradation Behavior on Fracturing Wastewater in Oilfield

Abstract

Due to great variety additives and disposal difficulty, chemical method, biochemical method and solidification are adopted to treat fracturing wastewater in oil field. These processes easily bring about shortcomings, including high cost and secondary pollution. Studied on the treatment of fracturing wastewater of 4# well in Sichuan Oilfield by modified bentonite loading TiO2-Ag2O composite catalyst, COD removal rate is determined for different condition of pH value of solution, adding content of TiO2, inflating volume and light application time. The optimal condition is obtained as follows: pH value of solution is 3, adding content of TiO2 is 0.4-0.5%, inflating volume is 15L/min and light application time is 3h. Under this condition, COD removal rate of fracturing wastewater is 58.1%. The composite catalyst performance is stable and without secondary pollution. It is reusable by high temperature activation, so it can reduce wastewater treatment cost, and should be widely applied.

The Perspective and Challenge of Nanomaterials in Oil and Gas Wastewater Treatment

“…When TiO 2 was used to treat hydrocarbons in oily wastewater, it was found that the reaction was more favorable under strong acidic conditions. Wang [ 37 ] pointed out that pH had an important effect on the photoreaction process, not only on the surface charge distribution of TiO 2 particles, but also on the hydroxyl radical (·OH). The increase in H + concentration will be more conducive to the formation of the hydroxyl radical (·OH).…”

Proposing a Novel Reusable Fracturing Fluid for Tight Sandstone Fracturing in the Changqing Gas Field: Environmental and Economic Implications

“…However, their approach did not encompass the reuse of the fracturing fluid post-reflow [5,6] . Conversely, Wan et al employed catalysts to treat fracturing wastewater, an approach that inadvertently escalates treatment expenditures [7,8] of 9% to 35% for recycled fracturing fluids. Yoxtheimer reported an average well recovery rate of 10% for return fluids in the Marcellus.…”