The Deparment of Chemical and Environmental Engineering, Yale University, USA, carries out advanced research into water purification including studies of natural and engineered aquatic systems. After moving to Yale from UCLA two years ago, the deparment’s Llewellyn West Jones, Professor of Environmental Engineering, Menachem Elimelech, needed a more up-to-date machine to continue his research. Both versatility and price led him to the ZetaPALS Zeta Potential Analyzer from Brookhaven Instruments.
The ZetaPALS instrument operates on the technique of phase analysis light scattering to determine zeta potential of small colloidal particles. Developed by, and unique to Brookhaven Instruments, this technique is 1,000 times more sensitive than conventional methods which depend on measuring shifts in light frequency. The instrument also includes a system that measures particle size by dynamic light scattering, giving information on particle size and distribution within minutes.
Professor Elimelech uses the ZetaPALS instrument to research the beheavior of small colloidal particles in aquatic systems, particularly how they react with membranes used for water and waste-water purification. “We study the transport of colloidal particles in porous media and colloidal fouling of membranes,” he explained. This field uses membranes contianing pores of strictly defined sizes and concerns the way that colloidal particles move and interact with each other, so it is vital that both the zeta potential and the size of the particles are known. ‘The strength of the ZetaPALS instrument is that it can measure both accurately, and this was the key factor in my choice of instrument. It is versatile and easy to use,” he said.