New research trends in the processing and applications of iron-based nanoparticles as adsorbents in water remediation methods

Abstract

The present comprehensive review is an account of recent advances in the syntheses of nanoparticles of iron-based materials via conventional and green routes and their adoptability as adsorbents in the purification of water. The green synthesized nanoparticles are proving to be more biocompatible with enhanced sorption properties than conventionally synthesized nanoparticles. The potential areas of research in the syntheses and application aspects are summarized. The identification of compounds in flora that serve as reducing, capping or stabilizing agents, production of uniform-sized nanoparticles using plat materials as ‘biotemplates’ and developing sorption affinity between the surface of nanoiron-based particles and pollutants are some of the important areas discussed. The redox, complex formation, adsorption and ion-exchange tendencies of iron nanoparticles may be suitably ‘tailor-made’ to improve their binding affinity towards the pollutants so that the said nanoparticles or their composite materials (especially bi-/multimetallic/mixed oxides) may be used as adsorbents in water remediation methods. One of the major inherent disadvantages of nanosized iron particles using as adsorbents is the rate of percolation water through the sorbent bed is low, and there is a loss of pressure head. Investigations are to be focused in developing open columns wherein nanoparticles are embedded in the matrix of synthetic or natural inorganic or organic polymers or in beads. In such cases, the host matrix may influence the characteristics of the nanoparticles and they are to be investigated for the advantage of removal of pollutants from wastewater.