Agent for restricting elution of phosphorus, method for producing the same, and method of restricting elution of phosphorus in sludge

摘要

Calcium nitrate, which is known to have the effect of inhibiting elution of phosphorus contained as insoluble substance in sludge in rivers, lakes and coasts in a reducing environment, can be applied not by injection of an aqueous solution of calcium nitrate, but by putting it in a solid form. An agent for inhibiting elution of phosphorus is proposed which comprises calcium nitrate as the major component (10-30%), calcium carbonate or calcium sulfate (a total of 50-90%), and stearic acid or its salt (1-20%) as a hydrophobic substance for delaying elution of the calcium salt, and sucrose fatty acid isobutyl or paraoxy isobutyl benzoate (1-20%) as a binder, and the composition is pressed in a mold into tablets or briquette. The application into sludge by use of an air gun is preferable.