ADSORPTION AND DESORPTION PROPERTIES AND LEACHING BEHAVIOR OF LEAD IN CEMENT HYDRATES

Abstract

Many studies on effective uses of industrial by-products such as blast furnace slag and fly ash have been carried out. In the future, the application of more kinds of wastes to concrete will be expected. These wastes, however, may contain heavy metals. There is a possibility of heavy metal leaching from concrete containing wastes. Although there are some test methods for evaluating heavy metal leaching, it is not clear whether or not they are available to concrete. A test method of heavy metal leaching from concrete that is a mass body should be needed. Also, when concrete is used for a very long term, heavy metal ions may leach. In this study, to understand the primary leaching behavior of the heavy metal from concrete structures, adsorption and desorption tests and a tank leaching test were performed. Lead was focused on as a heavy metal. As a result, much larger lead ions were desorbed after adsorption when calcium chloride solution was used as a solvent rather than pure water, sodium chloride solution, potassium chloride solution and lithium chloride solution. The results of the tank leaching test also showed that lead ions were leached much more from the specimen containing lead ions when the specimen was immersed in calcium chloride solution than in pure water.