Iron oxide nanoparticles: Preparation methods, functions, adsorption and coagulation/flocculation in wastewater treatment

Nanotechnology provides the ability to manipulate materials at the nanoscale within desired properties and specific functions. This allows the material to be controlled and used in many application fields. The main area among these application domains is the environmental applications including the wastewater treatment. This area, precisely, can be divided into: treatment and remediation, sensing and detection and pollution control. Iron oxide nanoparticles have been studied in depth in many fields due to the advantages offered by this material over other materials. This wide use of iron oxide nanoparticles is more likely due to; low cost, separation by means of external magnetic fields, high surface area and high adsorption capacity. In addition, within the available standard techniques of separation it is not easy to treat crude oil in water. Thus, iron oxides nanoparticles can be used as coagulant in coagulation and flocculation procedure to remove oil droplets from oilfield produced water. Within this context and to highlight the importance of this topic in this research, the current study aims to contribute through a bibliographic review, within the available literature, the role of iron oxide nanoparticles in wastewater treatment. Based on the present study, it is possible to distinguish the different approaches and methods proposed to obtain iron oxide nanoparticles as well as their various applications, explicitly, the focus has been on wastewater treatment and supply technologies. Thus, the novelty of this study is utilizing iron oxides nanoparticles, since the separation process is simple via an external magnetic fields. Also, iron oxides nanoparticles possess high surface area, high pollutant adsorption capacity and have compatibility for functionalization by chemical groups and selecting organic compounds. Accordingly, this investigation is anticipated to contribute to the production bibliography about this theme and clarify the use of materials in nanoscale for wastewater treatments.