(578d) Continuous Micro-Extraction of Copper Ions from Wastewater Using Ionic Liquids

Copper is considered as a valuable and commonly used heavy metal in many industrial applications. Compared to other heavy metals it exists at higher concentrations in wastewater that makes water treatment before disposal necessary¹. Recent researches investigated different methods and techniques for the removal of copper ions from industrial wastewater, such as adsorption by zeolites and modified biopolymers^2-3, nanofiltration⁴, and cementation⁵. Extraction of copper ions using ionic liquids has drawn attention in the recent years due to the affinity of hydrophobic ionic liquids to absorb heavy metals from aqueous media⁶. Ionic liquids (ILs) are salts with relatively low melting point and low vapor pressure⁷, non-flammable, and can be designed and synthesized to perform desired tasks. The key drawback in using ILs is their high costs; hence, an efficient extraction process that utilizes minimum amount of ionic liquid and thus minimizes the costs is required. On the hand, the main advantage of using a micro-extractor is the significant enhancement in mass and energy transfer; for a droplet smaller than 1 mm, its specific surface area is greater than 1000m²/m³, which is significantly larger than the interfacial area in conventional extraction⁸. Micro-extractors also require a considerably less amount of solvent than conventional extraction due to its confined size and large contact area. In this work, we present a study that investigate the extraction efficacy of the removal of copper ions from wastewater in a micro-extractor using hydrophobic ILs. The extraction efficacy will be presented as a function of IL structure, extraction time, and the interfacial area between the IL and the wastewater streams.

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