Recent Advances in Removing Nanowastes by The Cloud Point Extraction

Nanosized pollutants are widely present in the aqueous environment. Since nanoparticles are widely used in various fields, they get transferred or enriched in wastewater. These nanomaterials (NM) are known as nanowaste because they adsorb heavy metals and organic pollutants and disperse them in the environment. Because of the extremely low concentration of NMs and the complex matrices in real environmental and biological samples, a separation step that not only can preconcentrate NMs but also preserve the size and shape of NMs is urgently needed. This step can be coupled with various detection and characterization techniques for tracking NMs in the environment. Recently, the cloud point extraction (CPE) with a commercially available and low cost surfactant (Triton X-114) was found to be generally applicable for the reversible concentration and separation of NMs from aqueous dispersion with the advantage of extracting analytes with no need for an organic solvent. Furthermore, the size and shape of NMs were preserved during phase transfer and storage in a surfactant-rich phase. Thus, TX-114- based CPE has the potential to be applied in extracting engineered NMs from environmental waters.