Graduate Studies
PhD scholarships are available for suitably qualified graduates to work on a range of FACTS projects. Applicants will hold a BSc (Hons) (I or IIA) or MSc degree in chemistry, physics, mineralogy or materials science.
(1) The Incorporation of Fluorine Wastes in Humite Minerals
The mineral mullite has the ideal formula Al6Si2O10, and has structure consisting of chains of AlO6 octahedra crossed linked by (Si,Al)O4 tetrahedra. It is closely related to two other minerals (sillimanite and andalusite) and is belongs to a class of materials said to be 'infinitely adaptable'. That is to say it can order its atoms in such a way that no geometric repetition of structure occurs. This property appears to play a significant role in the ability of mullite to accommodate and stabilise toxic metals such as vanadium, nickel and iron. Therefore, mullite-based ceramics are candidates for stabilisation a range of wastes including spent catalyst, marine clay, sludges and effluents. This project will investigate the relationship between toxic metal type and loading, the formation of incommensurate superstructures and the environmental stability of the waste form.
(2) Reuse of municipal solid waste fly ash in concrete
The annual generation of municipal solid waste (MSW) fly ash in Singapore is approximately 145,000 ton and no reuse options have been identified, thus all the generated ash is currently disposed off in landfills. The objective of this project is to determine if it is viable and safe to use MSW fly in concrete production. This study will among other issues include: systematic and complete chemical and mineralogical characterization of the fly ash (including daily and annual variances), pretreatment of the fly ash, identification of the reaction between the ash components and the cement, and chemical stability of the concrete.
(3) Nanostructured Hydroxyapatite for the Treatment of Waste Waters
Millions of gallons of industrial wastewater are generated annually by Singapore industry and toxic metals must be removed prior to discharge. An ideal sorption media would have the capacity to irreversibly capture metals to high concentration, and be consigned to landfills or reused with no additional treatment. Sorbants based on nanostuctured hydroxy-apatite are being developed for the collection and concentration of waste metals from water. A key requirement to successfully implement nanoparticles will be the optimized of particle and surface area, and the development of surface selectivity to ensure the particles capture pollutants, but are not 'poisoned' by non hazardous matrix species. In this project, TEM will used to systematically investigate the relationship of surface activity to sorptive capacity and develop materials processing methods that optimize this capacity.
