James F Ranville

Professor, Department of Chemistry & Geochemistry

Colorado School of Mines

Part of my research involves the role of colloids and particles in environmental processes. Environmental colloids can be described as particles smaller than one micrometer. They can make up a significant proportion of suspended sediments and are important in that they: effectively bind pollutants; do not readily settle out of surface waters; and are mobile in groundwaterÂ’s. Consequently they can facilitate the transport of pollutants. Currently not much is known about the abundance and properties of environmental colloids. Much of my work has been involved in the development of methods to collect and analyze colloids from rivers, reservoirs, mountain streams, soil solutions, and groundwaterÂ’s.

Another aspect of my research deals with Field-flow fractionation (FFF). FFF is a family of related methods that provides a high-resolution, size separation of macromolecules, colloids and particles over an ultimate range of a few thousand Daltons to 50 micrometers. One significant advantage of FFF over other size analysis methods is that it provides a separation, which allows further analysis of colloids as a function of size. Currently my research group is using FFF to examine soil particle composition over a size range of 1-25 micrometers. Other methods we have used in conjunction with FFF are electron microscopy and X-ray diffraction; develop and application of size separation methods; isolation and characterization of natural organic matter.