Dispersion of C60 in natural water and removal by conventional drinking water treatment processes

The first objective of this study is to examine the fate of C60 under two disposal scenarios through which pristine C60 is introduced to water containing natural organic matter (NOM). A method based on liquid–liquid extraction and HPLC to quantify nC60 in water containing NOM was also developed. When pristine C60 was added to water either in the form of dry C60 or in organic solvent, it formed water stable aggregates with characteristics similar to nC60 prepared by other methods reported in the literature. The second objective of this study is to examine the fate of the nC60 in water treatment processes, which are the first line of defense against ingestion from potable water – a potential route for direct human consumption. Results obtained from jar tests suggested that these colloidal aggregates of C60 were efficiently removed by a series of alum coagulation, flocculation, sedimentation and filtration processes, while the efficiency of removal dependent on various parameters such as pH, alkalinity, NOM contents and coagulant dosage. Colloidal aggregates of functionalized C60 could be well removed by the conventional water treatment processes but with lesser efficiency compared to those made of pristine C60.