Dispersion of C 60 in natural water and removal by conventional drinking water treatment processes

Abstract

The first objective of this study is to examine the fate of C 60 under two disposal scenarios through which pristine C 60 is introduced to water containing natural organic matter (NOM). A method based on liquid–liquid extraction and HPLC to quantify nC 60 in water containing NOM was also developed. When pristine C 60 was added to water either in the form of dry C 60 or in organic solvent, it formed water stable aggregates with characteristics similar to nC 60 prepared by other methods reported in the literature. The second objective of this study is to examine the fate of the nC 60 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 C 60 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 C 60 could be well removed by the conventional water treatment processes but with lesser efficiency compared to those made of pristine C 60.