Laboratory and Field Evaluations of a New Silica Dispersant

Based on molecular modeling studies, new polymers were designed to maximize the interaction energies between polymer molecule and the crystalline surfaces of silica and magnesium silicate. One of these newlydesigned polymers has been further developed for laboratory and field evaluations. Evaporative cooling tower tests were conducted to achieve high silica cycles without silica fouling using natural, high silica water as makeup. A comfort cooling system in the Northwest U.S. and a process cooling system in the Southwest U.S. were used for field trials. After three months of operation, both trials showed 100% silica retention at high cycles of concentration beyond previous expectations. Today's water treatment technology is moving toward higher efficiency of freshwater use and a higher degree of process water re-use as dictated by the industry's needs for water conservation and waste water minimization. One way to achieve these objectives is by running the aqueous systems at higher and higher cycles of concentration. However, high cycle of concentration is often limited by the quality of the make-up water, more specifically by the potentially scaling elements in the water. Some of the most commonly identified limiting factors are calcium carbonate, calcium phosphate, calcium sulfate and silica/silicate.