Groundwater remediation using zero-valent iron nanoparticles (nZVI)

The underground water environment and ecology are considerably threatened by groundwater contamination. Several new remediation strategies and techniques have been implemented during the past two decades to eliminate contamination. These strategies and techniques have been continuously improved through various methods including the augmentation of different nanoparticles and modified composites. These nanoparticles are useful for the remediation of groundwater contaminated by both organic or inorganic pollutants. This paper focuses on the contaminant removal efficiency of a particular type of iron nanoparticle, i.e., nano zero-valent iron (nZVI) particles. Further, this paper details the usage of simple nZVI and modified nZVI in the context of contamination removal based on their dosages. It also describes the effects of coatings of different metallic and metallic oxide compounds used in manufacturing modified forms of nZVI. Results show that nZVI particles have almost 80% removal effeciency of both organic and inorganic pollutants. Further, the usage of modified nZVI particles, such as carboxymethyl cellulose (CMC)–Carbo-Iron® colloids (CICs), nano-Fe, and sodium alginate nZVI particles, resulted in contaminant removal of almost 100%. Compared to nano-Fe, CMC–CIC yielded more significant results in groundwater remediation at low dosages. Thus, this paper proves that even a few nanoparticles (NPs) chosen appropriately are sufficient to remediate groundwater. The results of this study can help improve the synthesis of modified nZVI.