Low toxicity ionic liquids for sustainable wastewater remediation

With the advent of technology comes the rising demand for controlling and eliminating the waste generated by various sectors, including industries, agricultural fields, and domestic activities. The generated waste contaminates water bodies, threatening aquatic life, disrupting the marine ecosystem, and posing a risk to human health. Thus, maintenance of wastewater is an urgent need, and various techniques have been employed to eradicate different macro- and micro-pollutants present in the water bodies on both small and large scales. However, there is an ongoing search for newer and more efficient methods. Ionic liquids (ILs) have garnered significant research interest due to their unique properties and high stability, demonstrating effective performance in diverse fields, including pharmaceuticals, biotechnology, energy storage, and catalysis, and they also hold potential for wastewater treatment. While ILs hold potential in eliminating pollutants from wastewater, the performance is frequently hindered by their environmental toxicity and persistence. This review addresses this limitation by exploring enhancement in structure to mitigate their environmental impact. The effectiveness of ILs in wastewater treatment, specifically in the removal of heavy metals, dyes and organic compounds, the underlying mechanisms, regeneration and a brief comparison with deep eutectic solvents are highlighted. The article also details preparation, properties and classifications of ILs according to their use in wastewater remediation.