An antifungal agent triclosan (TCS) and an anionic surfactant linear alkylbenzene sulfonate (LAS) were listed as candidates of detailed ecotoxicological risk assessment by Japan Ministry of Environment. These two compounds were selected to investigate the detailed fate and transport of these household effluent-originated pollutants in a small urban stream, Tsumeta Creek, Tokushima, Japan with no sewer system. Laboratory biodegradation and photodegradation experiments were conducted to determine first-order rate constants. Using these parameters and the environmental loading estimated based on PRTR or other statistics, a simple numerical model was constructed to estimate aquatic concentrations of TCS and C₁₂-LAS in each sampling point in Tsumeta Creek and these values were compared with the measured values. Overall, the estimated values were acceptable and were in the range of 50 to 200% of the measured ones. The results suggest the concentration of TCS and C₁₂-LAS is in the level of potential effects on aquatic organisms. From the viewpoint of the conservation of ecosystem, the mechanism of aquatic pollution and the removal of environmental loading of household effluent-originated pollutants such as TCS and LAS need to be further investigated in the unsewered area using both model prediction and monitoring.

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In this study, we examined the utilization of amorphous iron oxide for reduction catalyst of nitrate nitrogen in underground water economically and in large quantities. The results indicated that nitrate nitrogen could be reduced to ammonium nitrogen through nitrite nitrogen by addition with iron powder for reducer, and that the reaction velocity was changed widely by the proportion of addition with iron powder and iron oxide.
An addtion with acid had an effect of prevention from the decline of reaction by forming of iron (II) hydroxide on the surface of iron powder, and minute iron powder was effective for rise of reaction velocity.
These observations indicate that this catalyst is useful for removal of nitrate nitrogen in underground water by combination with existing removal methods of ammonium nitrate.

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The rapid analysis of PCB by heating of multi-layer silica gel column / alumina column was applied to electrical insulating oils (JIS C2320-1999 Class JIS 1-7 oils) and DOP (Dioctyl phthalate) which might be used for some capacitors. The results indicated that most of oil components were removed by the same analysis technique using multi-layer silica gel column with heating at 85 °C for 60 min without depending oil class. Oil components in JIS 4, 5, 6 oils and DOP were removed by only sulfuric acid coating silica gel treatment with heating, and also those in JIS 1, 2, 3 and 7 oils were removed by addition separation treatment of alumina to sulfuric acid coating silica gel treatment. Furthermore, quantitative capability and repeatability (n =3) of PCB concentration in JIS 1-7 oils and DOP were evaluated by GC/ECD, GC/QMS and GC/MS/MS, indicating those deviations were less than ±20 % from a truth value, and also those variations were less than15 % for all of oils and measurement instruments.

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Allophane-TiO₂ composites as highly adsorptive photocatalysts were prepared by dispersing nanoparticles of the natural clay mineral, allophone, into a titanium alkoxide solution by the sol-gel method. During the photocatalytic degradation of trichloroethylene using the allophane-TiO₂ composites, emission of the intermediate product, phosgene, was significantly inhibited. Trichloroethylene was transformed into the intermediate product, phosgene, on the TiO₂ during the UV irradiation. This compound was rapidly adsorbed by the allophane. The compounds were gradually degraded after diffusing to the TiO₂. Although the degradation rate of the trichloroethylene using the allophane-TiO₂ composites was slower than that using TiO₂, their activity was improved by heating at 400-500 °C.

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Polyacrylonitrile (PAN)-based activated carbon fiber (PAN-ACF) was prepared with various temperatures of both air treatment (350, 400, 425 and 450 °C) and activation (850 and 900 °C). The observation for the surface nitrogen with X-ray photoelectron spectroscopy (XPS) showed the presence of quaternary-N and pyridinic-N on PAN-ACF. The rise in both the air treatment and the activation temperature increased the nitrogen content in PAN-ACF and also extended the specific surface area. The resultant PAN-ACF prepared at the higher temperature preferably adsorbed Cd(II). The amounts of Cd(II) adsorption were much greater for PAN-ACF than the commercial coal pitch-based ACF containing less amount of nitrogen despite that specific surface area for the coal pitch ACF was twice as great as that for PAN-ACF. The activated carbon fiber possessing greater nitrogen content in the peripheral of the graphite sheet was considered to be effective for the Cd(II) adsorption.

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