Conservation of Cooling Water by Silica Removal with Activated Alumina

摘要

Activated alumina has been found to selectively and effectively remove silica from water. In order to apply this technology to recycling cooling water systems, preliminary laboratory tests were conducted. Batch isotherm tests were performed to find out how much silica could be adsorbed by a known quantity of activated alumina and kinetic studies were performed to reveal temperature effects on the rate of adsorption. To propagate better information for practicality, the study also required trial runs using activated alumina in columns. Data collected for silica removal by the activated alumina columns provided a good basis for economic evaluation of the system on an industrial scale. The sidestream activated alumina process appears to have both environmental and economic benefits over the conventional cooling water systems. Its application could be extensively used by industry, especially in areas with high makeup water silica concentrations as in the southwest United States. Environmental attributes of the activated alumina process include reduction of makeup water by 20 percent and zero discharge of potentially toxic chemicals into receiving waters.