Ionic liquids and NADES for removal of organic pollutants and heavy metals in wastewater: A comprehensive review

Wastewater treatment is a vital process to protect people and local ecosystems from toxic elements found in wastewater and keep the environment clean. However, conventional wastewater treatment methods may not consistently exhibit environmentally friendly characteristics or effectively eliminate organic contaminants from water. The need for an environmentally friendly and efficient technological solution becomes essential. A novel approach for removing organic contaminants from wastewater has recently been discovered that makes use of Natural Deep Eutectic Solvents (NADES) and Ionic liquids (ILs). This approach has yielded significant results and has the potential to revolutionize wastewater treatment technology. ILs and NADES are two types of solvents that have recently received much interest due to their unique characteristics, such as sustainability, biodegradability, and low toxicity. This review presents a comprehensive overview of novel extraction techniques for different organic pollutants from wastewater using ILs, such as pesticides, and dyes, and non-organic pollutants like heavy metals from wastewater using ILs and NADES. It highlights the potential of these solvents as a green alternative to conventional solvents for extracting organic pollutants. Besides, it illustrates the categories of ILs and NADES, their benefits and drawbacks, their major challenges, and the possible difficulties that can arise while scaling up their applications. Additionally, the paper delivers a detailed compilation of various applications of ILs in the extraction of organic contaminants. This review aims to provide valuable insights for the continuous development of NADES and ILs, as well as to enhance understanding of these innovative green solvents, and to promote their utilization in the extraction of organic pollutants from wastewater.