A review study on wastewater decontamination using nanotechnology: Performance, mechanism and environmental impacts

Abstract

Industrial effluents are vital sources of environmental pollutants that cause many problems for human health. In recent years, the use of nanomaterials for the removal of contaminants from effluents has received much attention. Nanoadsorbents are one of the most important nanomaterials that have many benefits, including low-cost, high efficiency, easy synthesis, and process simplicity. Also, nanoadsorbents have high porosity, high specific surface area, and low surface-to-volume ratio compared to conventional adsorbents. Nanocatalysts are another important nanomaterial for removing contaminants from wastewater. In the present work, the application of nanotechnology (nanoadsorbents, nanocatalysts, and nanofiltration) were thoroughly studied in the elimination of contaminants from wastewater. Also, the advantages and disadvantages of nanoadsorbents, nanocatalysts, and nanofiltration membranes, various types of them, and their impacts on the environment were fully studied. Moreover, the reusability, stability, and mechanism of nanoadsorbents and nanocatalysts in the removal of contaminants were investigated. Besides, the challenges facing nanotechnology in wastewater treatment were discussed. According to previous studies, TiO 2 , ZnO, and Ni 0.6 Ca 0.4 Fe 2 O 4 have shown significant photocatalytic efficiency in removing organic pollutants. Also, Fe 3 O 4 nanoparticles, ZnS nanocrystals, MWCNTs, graphene oxide, and their composites with other materials have shown remarkable efficiency in wastewater treatment. Moreover, polysulfone@graphene oxide nanofiltration membrane was able to eliminate CR and MB dyes from water with a rejection efficiency of higher than 99%.