| 摘要 |
PROBLEM TO BE SOLVED: To positively prevent a heavy metal from being eluted from a treated product by adding water and an activated carbon or further, phosphoric acid or its salt to an ash containing the heavy metal and immobilizing the heavy metal in the ash containing the heavy metal. SOLUTION: Fifty grams of a material ash (fly ash from a municipal waste incinerator) are sampled into a 500ml-plastic beaker, then 40wt.% of water are added for are of the material ash, and further, a coconut shell activated carbon is added together with orthophosphoric acid. Next, these components are adequately kneaded using a spurtle. In this case, it is possible to limit the Pb elution amount to 0.05mg/liter or less at the pH value of 12.4 by adding 30wt.% of the coconut shell activated carbon to the material ash. In addition, it is possible to limit the Pb elution amount to 0.05mg/liter or less by adding 10wt.% of the coconut shell activated carbon and 11.3wt.% of orthophosphoric acid as their synergic effect. After performing the treatment as described, a heavy metal such as lead or cadmium in the ash containing the heavy metal is adsorbed into the surface and pores of the activated carbon, and thus the heavy metal can be stably and securely immobilized. |
