自然物質を吸着剤としたバッチ試験によるリンの吸着実験

The environmental stability of global reserves of rock phosphate is deteriorating due to excess consumption. Phosphate is mostly obtained from mined rock phosphate and the main direction of phosphate application is focused on agriculture where it is used as fertilizer. Presently, Japan 100% depends on imports from overseas for all phosphate materials consumed in Japan. Therefore, there are concerns on the supply stability of fertilizer in the future. At the same time large quantity of phosphorus is available in wastewater, and phosphorus released from wastewater into resource water area constitutes the main risk for reduced water quality. For that it is necessary to investigate various techniques and materials that could contribute to the removal and recycling of phosphorus from wastewater. In this study four different natural materials marble dust, sawdust, soil, and rice husk were chosen in order to test their phosphorus sorption capacity. The sorption of phosphorus using these materials was studied by conducting batch tests and kinetic sorption model. The kinetic models based on kinetic reaction, pseudo equation and isotherm equation was applied to predict rate constants of sorption. Through investigations to understand the mechanism of phosphorus sorption onto the natural materials using kinetic sorption models, pseudo second order is the most accurate under the sorption process models, and Langmuir type of isotherm equation is the most accurate under the sorption equivalent model. Batch tests and kinetic sorption models results showed that using the marble dust as sorbent could be removed more than 90% of phosphorus from aqueous solution. To investigate more about phosphorus removal from wastewater, in next step the batch test results will be integrated to conduct column experiment for the purpose of practice.