铁和铝氧化物涂层砂的过滤与吸附性能评价

总结性地对3种不同氧化物涂层砂和未涂层砂的表面特性、过滤和吸附性能进行了比较与分析，明确了适用范围。改性滤料的高温加热和碱性沉积两种制备方法中，涂铁宜选前者，涂铝宜用后者。涂层砂的比表面积增大，吸附容量增加，使石英砂表面电荷的带电性质改变，有利于水中杂质的去除。涂铁砂适合于除氟和除砷及除有机物；涂铝砂适合于除浊、除有机物和除锌。

Evaluation of performances in filtration and adsorption by iron and aluminum oxide coated sand

Three kinds of oxide|coated|sand media prepared by heating at high temperatures and by the deposition at alkali conditions were compared in terms of their surface characteristics and performances in removing aqueous|phase inorganic and organic pollutants. Their applicability with related to the pollutants to be removed was thus evaluated. The heating method was confirmed to be better for the preparation of iron|coated sands, whereas, the deposition method for the preparation of aluminum|coated sands. Comparisons of the coated sand media with the plain sand clearly demonstrated that, the coating treatment significantly improved the surface characteristics of the sand medium with respect to its specific surface areas and charge potentials, hence leading to a marked increase in the removals of the pollutants investigated. The iron|coated sand media were found more effective for the removal of fluoride, arsenic and organic matter, while, the aluminum|coated ones for the removal of turbidity, organic matter and zinc.