| 摘要 |
<p>A waste treatment chemical comprising an aqueous solution of water glass and improved in the effect of preventing leaching of hazardous metals, particularly lead contained in the fly ash discharged from garbage incineration facilities. The above improvement is attained by adding to the water glass an additive A (e.g., acid, alcohol, polyvalent metal salt, polyhydric alcohol ester, carbonate, intramolecular ester, dibasic acid ester or dialdehyde), an additive B (e.g., phosphate, carbonate, sulfate, carboxylate or hydroxide of potassium, sodium or ammonium; phosphonate of potassium or sodium; or organic chelating agent having a carboxyl group -COOX (wherein X represents hydrogen, potassium or sodium) or a dithiocarbamate group >NCSSY (wherein Y represents hydrogen, potassium or sodium)), an additive C (coagulant), and/or an additive D (e.g., a monovalent metallic or ammonium salt which does not yield water-insoluble or difficulty soluble compounds upon reaction with calcium ion). It is possible to improve the stability of the chemical as a one-pack solution and the handleability thereof by further adding thereto an additive (E) (e.g., gluconate salt, tartrate salt, benzoate salt, ligninsulfonate salt, polysaccharide, or base composed of monovalent cation and hydroxide ion).</p> |
