WASHING METHOD OF ARSENIC-CONTAMINATED SOIL

文件类型：PDF文档
文件大小：126K
PROBLEM TO BE SOLVED : To reduce disposal cost by reducing the generation amount of concentrated contaminated soil when washing arsenic-contaminated soil. SOLUTION : The contaminated soil is formed into slurry; arsenic adsorbed in earth particles is extracted in the slurry in a dissolved state by alkali extraction; a polymer coagulant is added to the slurry and mixed and agitated to form flock by selectively coagulating only the earth particles of the sizes of 5-10 μm or larger in the slurry; fine particles of less than 5-10 μm are dispersed in the slurry without causing coagulation to obtain cleaned soil consisting of the earth particles of 5-10 μm or larger by settling and separating the flock and by neutralizing and stabilizing treatment; a supernatant containing the fine particles of less than 5-10 μm and arsenic in the dissolved state is further subjected to the chemical clarification; and the coagulated sludge is dewatered to obtain the concentrated contaminated soil containing arsenic. COPYRIGHT : (C)2012, JPO&INPIT