Abstract of Thesis Presented to the Graduate School
 of the University of Florida in Partial Fulfillment of the
 Requirements for the Degree of Master of Engineering

 SILICA-TITANIA COMPOSITES FOR WATER TREATMENT
 By

 Danielle Julia Londeree

 December 2002

Chair: David Mazyck
Major Department: Environmental Engineering Sciences

 Heterogeneous photocatalysis can be used for mineralizing organic dyes found in

the effluent of textile dyeing operations. Incorporating the catalyst TiO2 into an adsorbent

material, such as silica, has many advantages over using a TiO2 slurry for water

purification. The goal of this research was twofold: 1) to produce a silica-titania

composite using a sol-gel hydrolysis method that dopes the catalyst into the silica matrix

during gelation and 2) to optimize the titania loading, curing temperature, and pore size

of the material based upon maximizing its destruction and adsorption ability for textile

dyes. The optimal titania loading found for reactive red dye was 30 wt% TiO2. The

optimal pore size and curing temperature found were 140 A and 180C, respectively.

These composites were also made into small cylindrical pellets and tested in a flow-

through column to be used in a regenerative system. It was found that diffusivity was

very important to efficiently regenerate the column using photocatalysis.