Analysis of hull and wood vinegars was performed using infrared spectroscopy [IR], Sephadex G-25 and G-10 columns and paper chromatography to elucidate the components that were implicated in Cr (VI) reductive activity. The IR study suggests the presence of tannin compounds in both the vinegars. The separation of both the vinegars by Sephadex G-25 column gave two Cr (VI)-reductive peaks, one was small and eluted in the high-molecular-weight region and the other was large in the low-molecular-weight region. The large peak overlapped with the elution pattern of tannin, but the small peak partly overlapped with tannin-elution pattern. Further separation of the small peak using the Sephadex G-10 column revealed that the Cr (VI)-reductive pattern overlapped considerably with tannin. The analysis by paper chromatography showed that the tannins in the large peak obtained using the Sephadex G-25 column contained most likely dihydric phenols as the main components. The tannin having the highest Cr (VI) reductivity from Sephadex G-10 contained several polyphenols including those with similar mobilities to those of trihydric phenols. These results indicate that Cr (VI) reductive activity in both the vinegars largely depends on the polyphenols.

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Carbon coating of titanium oxide (TiO₂) powders was successfully performed by heating a mixture of anatase-type TiO₂ with poly (vinyl alcohol) at different temperatures above 700°C in an inert atmosphere. Photocatalytic activity was examined by measuring color fading of methylene blue (MB) aqueous solution under UV irradiation. The carbon coating was found to stabilize the anatase structure up to 800°C. Carbon-coated anatase powders showed comparable photoactivity for MB decomposition to the original anatase powder without carbon coating, even better in some cases. Carbon-coated anatase powders were found to have a high adsorptivity mainly due to carbon layer.

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Reaction rate constants of di-n-butyl phthalate (DBP) and 17β-estradiol (E2) with ozone and hydroxyl redical (HO·) were measured in water. The rate constants of DBP with ozone and HO· were <0.2 and 5.3X10⁹ M^-1·s^-1, respectively (DBP-d₄ was used for the measurement of the rate constant of DBP with HO·), thus, it was found that DBP was decomposed only by HO· during ozonation. Reaction rate constants of undissociated and dissociated forms of E2 with ozone were 7.1(±2.5)X10⁴ and 1.3(±0.2)X10⁹ M^-1·s^-1, respectively, and the reaction rate constant of the undissociated form of E2 with HO· was 5.3(±0.4)X10⁹ M^-1·s^-1. The order of the apparent rate constants of E2 with ozone was from 10⁵ to 10⁷ M^-1·s^-1 in the case that the pH of the solution was in the range of 6-8. Therefore, it was shown that E2 reacted mainly with ozone molecules and was rapidly decomposed during practical ozonation. The relationship among the residuals of the compounds decomposed mainly by HO· during ozonation in the absence of co-existing substances was not affected by the dissolved organic matter (DOM) when the dissolved organic carbon (DOC) was less than several mg·l^-1.

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It has been reported that several floras and faunas in rivers are genetically impaired by artificial structures such as dams and cities because of the fragmentation and the reduced heterogeneity of their habitats. However, the investigations on genetic diversities of Trichoptera in rivers have been few to date. In this study, therefore, the genetic investigation of Hydropsyche orientalis was conducted at 13 stations in the Natori River System in Miyagi Prefecture, Japan from Dec. 2000 to May 2001. The Okura and Kamafusa dams, and the Sendai urban area are located upstream and downstream of the rivers. The DNA polymorphisms of Hydropsyche orientalis collected at the 13 stations were analyzed with the appropriate primer, OPA-11, for calculating the genetic diversity index. The result of statistical analysis of the index showed a significantly higher level of genetic diversity of Hydropsyche orientalis in the natural area than in the areas around the dams. Moreover, the effect of urbanization on its genetic diversity was indicated based on the estimation of its migration from the results of the cluster analysis of the DNA polymorphisms.

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Eight bacterial strains that can decompose a ferric chelate of ethylenediaminetetraacetic acid (Fe-EDTA) were isolated among 885 bacterial strains collected from various marine environments. Among them, the strain denoted as H6-2-4 and isolated from a sediment sample collected from Off-Izu Islands around Japan had the highest ability to decompose Fe-EDTA. The percentage of degradation of Fe-EDTA was approximately 30% in a seawater culture medium containing 1000 ppm Fe-EDTA. It was revealed that the intact cells of this strain can also decompose various metal-EDTA complexes such as Ca, Cu, and Mg. Based on results of ¹H-NMR spectral analysis, it is suggested that Fe-EDTA is converted to glycine via iminodiacetic acid. The strain was found to be a Gram-negative motile rod with polar flagella and is catalase- and oxidase-positive. It failed to grow in distilled water medium, confirming its marine origin. The strain was identified as Pseudoalteromonas atlantica based on the results of various taxonomical studies.

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Continuous stormwater runoff monitoring was conducted in May 1999 and from April 20 to May 24, 2000, at a separate sewer system with 67 ha drainage area. The impervious surface covers about 40 % of the entire drainage area in this study. The monitoring stations were equipped with a direct sampling device from stormwater pipes, a water level sensor, a rain gauge, and a turbidity sensor. The monitoring frequency of the sensors was set at one minute. Two sets of autosamplers with 24 bottles were installed for runoff sampling during initial 8 hours of a rainfall event. Intensive sampling was scheduled within the initial runoff period. Suspended solids were measured as an indicator of pollutants for runoff samples prefiltered with a 2 mm mesh, and furthermore they were classified into fine and coarse fractions with a GF/C filter (1.2 μm pore size) and stainless steel sieve (45 μm mesh). The behaviors of fine particle fractions from 1.2 μm to 45 μm and coarse particle fractions from 45 μm to 2 mm showed clearly different runoff patterns. The fine particle runoff took place in all monitored rainfall events, while the coarse particles tended to be washed off when the rainfall intensity was over a certain level. The fine particle fraction contributed to the total runoff loads rather than the coarse particle fraction in the monitored rainfall events with a small amount of rainfall height and weak intensity.

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