| 摘要 |
PURPOSE:To reduce the cost of a treatment and to eliminate the problems relating to the treatment of a waste liquid by allowing the recycling of EDTA in the method for cleaning the soil contaminated with harmful heavy metals by washing the soil with an aq. EDTA soln. CONSTITUTION:A heavy metal insolubilizing agent, such as Na2S, is added at 1 to 3 equiv. to the washing liquid, produced after washing the contaminated soil with the aq. EDTA soln. to settle and separate the heavy metals as insoluble materials and to regenerate the EDTA. The EDTA is circulated to a washing stage after a solid-liquid sepn. |
