Abstract
In recent years, the nitrate nitrogen pollution in lakes, rivers and underground water has become a serious issue. A new purification method for nitrate nitrogen is required, because no efficient means of purification has been established yet. Carbonization processing is one of the techniques of effectively using wood biomass. The obtained charcoal is widely used for a variety of purposes such as water purification and humidity control, and as a soil conditioner. However, the charcoal obtained by mere carbonization is expected to have limited uses. Thus, we have studied charcoal with the ability to absorb nitrate nitrogen. In this paper, we examined charcoal produced by soaking wood chips in CaCl2 aq. solution, followed by carbonization and acid treatment with HCl. It was found that the obtained charcoal had the ability to absorb nitrate nitrogen and fluoride anion but not sulfate and phosphate anions. The adsorption ability could be recovered again by soaking in KCl aq. solution. As a result, it is expected that the charcoal obtained by this method can contribute to the purification of water polluted with nitrate nitrogen and to the effective use of wood biomass.
