Preparation of CuO-PdO-Pd/Ti electrocatalytic membrane and its performance in treating oily wastewater

Developing multifunctional, efficient, and long-lasting membranes for long-term use in treating complicated oily wastewater is highly desirable, but it remains a challenge due to severe membrane fouling and the difficulty of separating contaminants smaller than the membrane pores. In this work, we fabricate a CuO-PdO-Pd/Ti membrane with self-cleaning for small sized pollutants removal by introducing electrocatalytic oxidation to membrane filtration. In order to improve the electrocatalytic performance of the membrane, we prepared a high-performance CuO-PdO-Pd electrocatalyst-coated Ti-based electrocatalytic membrane by introducing the Pd、PdO into CuO. The prepared CuO-PdO-Pd/Ti membrane (CuO-PdO-Pd/Ti) has superior removal ability over the original Ti membrane (Ti) and the conventional CuO/Ti membrane (CuO/Ti). The emulsified oil and COD removal efficiency of the CuO-PdO-Pd/Ti reach 94% and 80.18%, respectively,which are about 1.2–2.15 times and 1.16–1.26 times higher than that of the Ti and the CuO/Ti. Meanwhile, CuO-PdO-Pd/Ti shows higher permeability (13,021 (L m-2 h−1 bar−1)) over Ti (8077 (L m-2 h−1 bar−1)) and CuO/Ti (9829 (L m-2 h−1 bar−1). In addition, CuO-PdO-Pd/Ti has good sustainability because the emulsified oil and COD removal efficiency maintain above 91% and 80% after six repeated tests, respectively. The extensive applicability of the CuO-PdO-Pd/Ti is also proven by the high removal efficiency (all above 82%) when treating real oily wastewater and organic wastewater. Thus, the prepared CuO-PdO-Pd/Ti shows great potential for emulsified oil and small-sized organic pollutants removal with both high permeability and removal efficiency. CuO-PdO-Pd/Ti is high-performance electrocatalytic membrane for wastewater treatment.