Steel-making slag concrete consisted of by-products from ironworks. Ground granulated blast furnace slag was used as a binder. Air cooled slag from the steel-making process was used as an aggregate. The steel-making slag concrete did not use any natural aggregate, fine or coarse. The strength of the steel-making slag concrete was 20 N/mm² to 50N/mm² at 28 days. It was as strong as that of normal cement concrete. Resistance to carbonation of the steel-making slag concrete and resistance to corrosion of a steel rod in the steel-making slag concrete were high for a long time due to calcium hydroxide leaching from the steel-making slag. However, resistance to freezing and thawing of the steel-making slag concrete was low. In this paper, the mechanism of low resistance to freezing and thawing is clarified.

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   "RH-SP Process" is a combined process of reductive heating for reduction of POPs (Persistent Organic Pollutants: Such as PCB, Dioxins, and Organic Chlorinate Agricultural Chemicals) from contaminated soil, and sodium dispersion for the decomposition of POPs material. We investigated the applicability of the process for three characteristic soils at Okinawa region.
  BHC (Benzene Hexachloride) is reduced from 10mg/kg to lower than 0.001mg/kg in each soil and PCB is also reduced from 53mg/kg to lower than 0.5μg/kg by reductive heating. Dioxins in discharged gas shows lower than 0.1ng-TEQ/m3. From the result of green planting test with treated soil, the growth rate is same as that of normal soil, and it is also confirmed that treated soil is able to be recycled for green planting.

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   We address the problem of detecting areas with markedly high values (hotspots) in spatial lattice data. Spatial lattice data are observations that include several spatial areas supplemented by neighboring information. The spatial scan statistics is an effective tool for hotspot detection. Echelon analysis is an analytical method to investigate the phase-structure of spatial data both systematically and objectively. In this paper, we describe the structure of spatial lattice data using echelon analysis and detect hotspots based on the echelon structure. As an application, we apply this method to simulation data of leachate accidents in final-disposal sites and detect considerably high-density pollution areas.

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   Construction of final waste disposal sites has become increasingly difficult as the problem of their location has become an important issue. Final waste disposal sites have a negative image of fostering various kinds of pollution, increased traffic volume, noise by trucks and bulldozers, and aggravated living conditions. These concerns indicate that social factors, such as waste landfills' public image, must be considered along with physical factors when locating the final waste disposal sites.
  This paper presents a method for determining an optimal site from the two perspectives of physical and social factors. First, we estimate spatial distribution for physical factors using various costs for waste disposal and land prices. Secondly, using results of a survey, we investigate the relationship between cognition of final waste disposal site and age group as covariates and estimate spatial distribution for social factors from the spatial distribution for the age group.

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While the loadings of nitrogen (N) and phosphorus (P) are enhanced by the human activities, dissolved silicate (DSi) supplied by natural weathering of minerals tends to be trapped in the eutrophicated still waters such as dammed reservoirs, which are also increasing globally. The consequent change in the N: P: Si stoichiometric ratio of the river water flowing into the coastal sea may be advantageous to flagellates (nonsiliceous and potentially harmful) but not to diatom (siliceous and mostly benign). This is the "silica deficiency hypothesis". We try to develop it further to the "extended silica deficiency hypothesis" as follows. While the diatoms effectively draw down the substances from the upper layer with their sinking after the spring bloom (biological pump), other algae do not. This will cause the retention of the surplus nutrients and biogenic substances in the upper layer and lead further to eutrophication of upper layer substantially. To verify this hypothesis, a simplified marine ecosystem model was developed taking the nutrient stoichiometry and differential behaviors of algae into account based on the comparison with the existing field monitoring results of four aquatic continua, where various types of silica decline are uncertain. Although, this study is still in the stage of improvement, the preliminary results infer that above hypothesis could be verified with the consideration of the behavioral characteristics of algae as well as the stoichiometric consideration. Sinking response to the nutrient depletion, which is specific to each algal group, is one of possible factors.

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  Human pressure is now severe on most of the rivers worldwide. The long term fluxes of dissolved geogenic and biogenic matter are changing dramatically, causing notable changes in aquatic bioactivity. Typical patterns of anthropogenic pressure that influence eutrophication, salinization and chemical contamination are discussed. The heavily influenced rivers Rhine and upper Danube will be used as examples, also considering their geological settings. In the past decade sewage treatment reduced nitrate and orthophosphate loads in both basins. This influenced bioactivity in the rivers, causing less silica depletion due to diatom blooms in the Rhine. Therefore a notable increase in minima concentrations of dissolved silica can be observed. In the upper Danube, however, an increase in orthophosphate concentration since 2003 is noticeable; breaking the former decreasing trend, despite treatment efforts. The hydrochemistry of major ions in both basins is strongly influenced by the ratios of carbonate, siliciclastic sediment and igneous or metamorphic rock outcrops. In addition Mesozoic evaporites and salt mining were responsible for extremely high levels of Cl, Na and SO₄ in the Rhine, peaking in the 70s and 80s at concentrations of 350, 180 and 140 mg/l, respectively. Water basin management efforts cut former high levels to less than a half. Heavy metals and persistent organic pollutant concentrations are declining in the Rhine as well. A combination of climate change and anthropogenic water inputs resulted in an increase of water temperature of the Rhine by 3.5 °C during the past 50 years. In the upper Danube such a trend in water temperature can not be observed.

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   Investigations of the recent decades have revealed a significant lowering of the river bed of the Danube in Hungary. This phenomenon can be observed on a long stretch of the Hungarian Danube and it can be presumed that similar changes occur on other parts of the river beyond the borders. There are several methods to reveal and to measure the lowering of the channel. Long records of the water level are available for the trend- and homogeneity analyses. Results show that erosion processes started even at the beginning of the 20^th century. In recent years results of bathymetry are available for the more detailed investigations of these changes. The main causes of the bed-lowering are river regulation activities, industrial dredging and decreasing of natural sediment load. Deepening of the river bed has unfavourable effects on the natural environment, on the navigation and also on the operation of man-made structures in the river. To avert these injurious effects a complex solution is needed, taking into consideration not just economical but ecological and social aspects as well.

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  Dissolved organic matter (DOM) plays an important role in natural aquatic ecosystems. Fluorescence and UV absorption of chromophoric dissolved organic matter (CDOM) in the Yangtze (Changjiang River) estuary are reported in this study. Water samples were collected mainly from three sections (North Channel, the head of South Channel and the end of South Channel) of the Yangtze Estuary in March, 2006. Three-dimensional excitation emission matrix (3-DEEM) fluorescence spectrums and UV absorption at 355 nm are analyzed for those filtrates through Whatman GF/F filters. The concentrations of dissolved organic carbon (DOC) are also measured. The results showed that absorption coefficients of CDOM at 355 nm, which ranged from 16.4 m^-1 to 18.3 m^-1, had significant correlations with the concentrations of DOC (2.0∼3.4 mg/L) at high tide and only in bottom water at low tide. The 3DEEM fluorescence scans suggested the terrestrial fluorophores of aromatic protein (peak A: Ex=236±1 nm, Em=364±3 nm), humic acid-like (peak B: Ex=251±3 nm, Em=473±5 nm) are obvious. Another peak of humic acid-like (peak D: Ex=337±6 nm, Em=447±9 nm) is also found. Tryptophan and protein-like (peak C: Ex=282±2 nm, Em=351±5 nm) with strong peaks, which could be derived from both terrestrial and microbial origins, were detected only in South Channel. In addition, the intensities of peak C are stronger at river end member than at marine end member (here is a low salinity area). The higher fluorescence index (FI) values at river end member could be resulted by microbially derived CDOM in the Huangpu River and wastewater discharges from Shanghai. The fluorescence index suggested that the terrestrial signal became stronger at marine end member but microbial signal became weaker, which could be attributed to the mobilization of particulate organic matter (POM) in the riverine suspended sediments with the intrusion of the seawater and the suspension of the sediments. The saltwater intrusion could also increase the contents of microbial CDOM during flooding tide. Therefore, there is autochthonous production of CDOM occurring within the estuary, where chromophoric dissolved organic matter is dominated by mainly terrestrial and microbial sources.

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  This paper examines the relationship between physical, chemical and mechanical properties and effect of the desiccation of dredged sludge. The characteristics of dredged sludge with high water content can be improved by various methods, i.e., solidification with stabilizing materials, mechanical dehydration, desiccation and stabilization by heat. The physical and chemical properties were investigated using consistency tests, ignition loss (Li) tests, pH tests, XRF analyses and X-ray diffraction analyses. The mechanical properties were measured by standard consolidation and permeability tests. The experimental results indicate that 1) desiccation can dramatically reduce the liquid limit of sludge and 2) the reduction rate of the compression indices between the original wet materials and the desiccated materials is proportional to the ignition loss of the materials when Li exceeds 12%.

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