Removal of heavy metals in wastewater

As a result of global warming, which has been effective in the world in recent years, water resources are decreasing visibly and this situation poses a great danger to humanity. Therefore, water treatment and recycling have become an issue that needs to be resolved rapidly. For this reason, especially since industrial wastewater pollutes environmental waters to a great extent and these waters mix with drinking water, it is extremely important to purify them and make them reusable. The factor that affects living beings in this pollution is mostly the uncontrolled discharge of heavy metals into water (Martinez et al., 2019). These metals are mostly lead, copper, nickel, mercury, arsenic, iron and chromium, which are poisonous and dangerous. Magnetic separation is one of the methods used to remove these heavy metals. Within the scope of this study, magnetites with different properties were synthesized using the microwave combustion method for magnetic material. Magnetic nanoparticles (MNP) used in magnetic separation methods were transformed from iron salts to spinel structured ferrites (CoFe2O4, MnFe2O4) and coated with silica, and studies were carried out to increase the separation capacity and magnetic strength. Magnetic attraction force was determined as Fe3O4, CoFe2O4, MnFe2O4, respectively. As a result of the study, the adsorption capacity of magnetic ferrites for heavy metals in wastewater was measured and compared, and it was determined that their capacity was directly proportional to the attraction force. Magnetic susceptibility, XRD, SEM-EDX, ICP-MS analyses of the synthesized products were performed. The study has originality in this regard, since the above measurement results of these magnetites are available in the literature, but their synthesis by microwave method, silica coating and competence in wastewater treatment have not been determined. It was observed that the ferrites prepared by the microwave combustion method in this study were 6 times faster and their magnetic susceptibilities were similar to the ferrites synthesized by other methods.