The dissertation on "Colloidal Fouling Mechanisms in Reverse Osmosis and Nanofiltration" by Eric M.V. Hoek, recipient of the first Yale Ph.D. in Environmental Engineering, December 2001, has won one of the two Association of Environmental Engineering and Science Professors (AEESP) 2002 Doctoral Dissertation Awards.   The award consists of a plaque and $1,000 for the advisee and $500 for the faculty advisor. Dr. Hoek and Prof. Menachem Elimelech, Chemical Engineering/Environmental Engineering, his faculty advisor, attended the awards ceremony in Chicago Sept. 30.   Dr. Hoek is presently an assistant professor in the Department of Chemical and Environmental Engineering at the University of California, Riverside.