Core to concept: synthesis, structure, and reactivity of nanoscale zero-valent iron (NZVI) for wastewater remediation

Abstract

Numerous technological advancements have been developed to tackle the issue of wastewater remediation effectively. However, the practical application of these technologies on a large scale has faced several challenges that have hindered their progress. These challenges include low selectivity, high energy requirements, and significant expenses. Nanoscale materials have demonstrated remarkable effectiveness in removing a wide range of contaminants. Nanoscale zero-valent iron (NZVI) exhibits a range of distinctive physical and chemical properties that have proven to be highly effective in various environmental remediation applications. These include its impressive surface area, remarkable reactivity, and its capacity to create stable colloidal suspensions. The paper explores the synthetic techniques for NZVI with special emphasis on green synthesis and the use of capping or support agents for maintaining stability and enhancing the reactivity of NZVI. The various structural and reactivity aspects of NZVI have been highlighted for its potential application in wastewater treatment sequestrating various categories of inorganic and organic contaminants. The discussion also delves into the limitations of NZVI, highlighting its dependence on water as a medium for contact reaction or electron transfer through the action mechanism of NZVI in adsorptive and photocatalytic sequestration of contaminants. The beneficial potential of NZVI-based composite systems in the field of environmental remediation has also been included which aids in the application of NZVI in environmental remediation.

Keywords: Adsorption; Core-shell; Degradation; NZVI; Photocatalysis; Pollutant.