Novel magnetic renewable Ni0.85Se/g-C3N4 material for highly efficient removal of elemental mercury from coal-fired flue gas

The emission of heavy metal elements (especially the most toxic Hg) from coal-fired power plants has always been a hot issue in the environmental field. Nickel selenide was first applied to flue gas mercury removal in this work, and a new adsorbent of Nickel selenide (Ni0.85Se) loaded with graphite carbon nitride (g-C3N4) was developed to effectively remove elemental mercury. When the loading mass of g-C3N4 is 20%, NS/20CN has 100% mercury removal efficiency. Meanwhile, it will not be poisoned by NO and SO2 in the flue gas. At the same time, NS/20CN also has strong magnetism that is not permanently magnetized, and can be separated from the downstream magnetic field of WESP for heat treatment to recover ultra-low concentrations of Hg0 and reused. Therefore, this work demonstrates that NS/20CN adsorbent has excellent performance and economy in effi-ciently removing elemental mercury and has also broadened the application of Nickel selenide in the environ-mental field, providing an efficient guidance method for the treatment of other environmental pollutants.