Ionic liquids to remove toxic metal pollution

Abstract

Pollution by toxic, non-degradable metals is a rising health concern in the context of increasing industrialization and metal demand. Diseases may include brain damage, cardiovascular problems, gastrointestinal disorders and cancer, calling for advanced methods to clean soil, water, wastewater and air. Here, we review the use of ionic liquids, which are considered as eco-friendly solvents, to remove metals. Ionic liquids have unique properties such as no vapor emission, good solvation ability, higher thermal stability and tunability. Ionic liquids separate efficiently metal ions from aqueous solutions by electrostatic, Van der Waals and ion-pair interactions. Ionic liquids can be recovered by stripping, then reused several times for liquid-liquid extraction, adsorption and membrane separation. Ionic liquids improve membrane stability in membrane separation, and they act as surfactant for adsorption.

Ionic Liquids as Components of Systems for Metal Extraction

“…Ionic liquids were considered for the hydrometallurgical extraction of metals, especially platinum-group metals (ruthenium, rhodium, palladium, osmium, iridium, and platinum) from urban mines [14]. The benefits of ILs for the efficient separation of metal ions from aqueous solutions via electrostatic, van der Waals, and ionpair interactions have been demonstrated [15]. Furthermore, ILs can be isolated by back extraction and reused for solvent extraction, adsorption, and membrane separation.…”

An enhanced dispersive liquid–liquid microextraction method based on solidification of floating organic drops for the determination of pyrethroid pesticides in tea infusions

“…19 Ionic liquids (ILs) refer to salts that consist entirely of ions that exist as a liquid at or near room temperature. 20 Therefore, due to their relatively wide liquid phase range, ILs are difficult to volatilize, are non-flammable and provide good solubility of organic and inorganic matter, resulting in their widespread used as an environmentally friendly extractant in liquid-phase microextraction systems. 21 The in situ IL dispersive liquidliquid microextraction (in situ IL-DLLME) method has been developed in recent years, and is based on the characteristics of in situ IL synthesis 22 in which a metathesis reaction occurs between the soluble IL and an anion exchanger, generating a hydrophobic IL as the extraction solvent.…”

Removal of Pb2+ from Wastewater By γ‐Fe2O3@SHFA Based on Alkali‐Modified Fly Ash: Performance and Mechanism

“…[1][2][3][4] As one of the common residual heavy metals in the environment, lead is nondegradable, stable in the environment, and toxic to many human life systems and tissues. [5,6] Lead poisoning can cause hepatitis, hypertension, encephalitis, etc. The most common chronic symptom is neurasthenia.…”