With the society's demand for landscape maintenance in the background, development of landscape paving technologies capable of adapting to low volume road in the field of pavement is anticipated. Among them, natural stone block pavement is a construction method which also matches a natural picturesque scenery by its unique texture. However, under the present circumstances, frequent repair is necessary due to driving of vehicles resulting in turn of spoiling the scenery and becoming uneconomical. This study were verified about the effect of insert alumina ball in the joint part with granular material in natural stone block pavement by laboratory tests and test construction. As a result, it was confirmed the effect which controlled the subsidence, inclination and movement of the stone block by insert for ball to the joint, and that this construction method have more excellent shock absorption and permeability than the existing construction method of mortar. In addition, we confirmed that a mixture of asphalt and sand has the effect on the outflow of the material from the joint.

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 Using indoor sand columns with effluent from A2O (anaerobic-anoxic-oxic)-O₃ process, removal characteristics of disinfection by-products formation potential (DBPsFP), including trihalomethanes and haloacetic acids, bromate ion and aldehydes and effects of ozonation process on soil aquifer treatment (SAT) were discussed. Removal ratios of dissolved organic carbon were 77, 78 and 82%, respectively, in the columns with A2O treated water and A2O-O₃ (ozone consumption per initial dissolved organic carbon: 1.0 and 2.0 mgO₃/mgC) treated water, and combination of O₃ and SAT enhanced organic removal. Removal ratios of CHCl₃FP were 90-98%, and effective removal of DBPs with chlorine in soil aquifer treatment was suggested. Removal ratios of CHBr₂ClFP was only 13% with soil aquifer treatment; meanwhile, it was 69% with the combination of O₃ process and SAT. Therefore, it was suggested that the O₃ process enhanced removal potential of DBPs with bromine in SAT. Moreover, it was found that the removal of bromate ion was dominated by the adsorption onto the sand surface; meanwhile, the biodegradation mainly contributed to the removal of aldehydes in SAT.

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 Generally, radio-Cs contaminants reside and are concentrated in a fine fraction. Grain-size distributions and radio-Cs contaminant distributions (load curves) of feed soils were studied to understand and characterize the soil particle/contaminant relationship. A surface-adsorption model that considers the relationship between surface concentration of radio-Cs and radio-Cs content of soil particles is introduced and used in analyzing characteristics of radio-Cs contaminant distributions in soils. The adsorption and attachment forms of radio-Cs onto soil particles were considered from results of the region classification by the dimensionless load curves based on the above model, including results of the x-ray diffraction qualitative analyses and the content values of total carbon (T-C) and iron (Fe).
 As a result of this study, following observations were made; 1) fine fractions of feed soils taken from school playgrounds (soil-PG) had high adsorptive capacity for radio-Cs, because those fine fractions bore mica-like minerals such as phlogopite and vermiculite, 2) therefore most of data plotted on the dimensionless load curves of soil-PGs were distributed in the region smaller than the theoretical curve of the proposed model, 3) it was deduced that iron oxides and organic matter played a major role on adsorption of radio-Cs in fine fractions of feed soils taken from decontamination work in residential areas (soil-RA) from the results of chemical and XRD analyses, and 4) most of data plotted on the dimensionless load curves of soil-RAs were distributed in the region larger than the theoretical curve, since adsorptive capacity of iron oxides and organic matter for radio-Cs was not so high.

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 Beneficial utilization of steel slag as an environmental remediation material of seawater damages by mixing with humic acid has been expected. To achieve it, environmental impact of the slag is required interms of leaching behavior of heavy metals.
 This research applied a seawater leaching test by shaking and immersing the slag with humic acid. Furthermore, based on the concept of environmental safety quality required in the sea-area utilization, applicability of the slag is discussed. Experimental results showed that by the interaction of steel slag and humic acid, concentration of Cd, Pb, Cr and B decreased and could meet the environmental safety quality criteria. In conclusion, the possibility that the mixture of steel slag and humic acid cause sea-environment pollution proved to be significantly low.

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