河川の底質汚泥の処理と地盤材料への有効利用

Abstract

The object of this paper is to investigate on stabilization of sludge, generated in the works for creating better environments around river in city areas, by using cement group hardening materials. The sludge is in very high water content, containing a large amount of lead (Pb), stinking of ammonia (NH3) and hydrogen sulfide (H2S), and thus it should be disposed as industrial wastes with proper treatment.In this study, through a compressive test, a leaching test, and odor test newly proposed, it is clarified that the stabilized sludge has a potential of improvement in handling properties and utilization as construction materials, e.g. embankment or subgrade. The contribution of not only Ettringite (3CaO･2Al2O3･3CaSO4･32H2O) but Calcium Aluminate Carbonated Hydrate (7CaO･2Al2O3･CaCO3･24H2O), which are obscure as reaction products, to strength development for sludge was shown by X-ray diffraction analysis and scanning electron microscopic study.From the results of this research, the importance to select a suitable stabilizer coresponding to the purpose of improvement is suggested.