The temporal variations of concentrations and fluxes of suspended particulate matter (SPM) and trace heavy metals of Fe, Pb, Cu, Zn and Cd were investigated at the Yatsu tidal flat connected to Tokyo Bay via the Yatsu and the Takase Channels in early summer, 2003. The inflow flux of SPM from Tokyo Bay to the tidal flat was greater than the outflow flux; the SPM was considered to be trapped on the tidal flat by a physicochemical cohesive force and biological functions. The heavy metals were transported as particulate and dissolved phases in the fluxes. In the fluxes of both of the channels, the particulate heavy metals were predominantly Fe, Pb and Zn, while the particulate and the dissolved heavy metals were equally attributed to Cu. The Pb, Zn and Cd contents in the SPM were higher than the contents of those dissolved in the flux, although the Fe and Cu contents were relatively low. Pb would be preferentially adsorbed to the SPM compared with Cu, whereas concentrations of both these elements were similar in dissolved phases.

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We have investigated the influences of herbicides and mercury on the blue-green alga Spirulina platensis by analyzing the long-term behavior of S.platensis delayed fluorescence(DF). S.platensis DF was recorded as a decay curve, and change in the DF intensity with time was analyzed. The decay curve was found to be composed of two components. The first component peaked just after excitation (P1). The second component peaked at approximately 30 seconds after excitation (P2). When the alga was exposed to toxicants, the intensities of P1 (CP1) and P2 (CP2), and the time of P2 appearance (TP2) varied notably. The tested herbicides, diuron (DCMU) and simazine (CAT), increased CP1, and decreased CP2. Mercury increased TP2 and CP1, and decreased CP2. During the measurements at 30 min after the exposure, the effect of DCMU was detectable at a minimum of 0.1μg·l^-1, that of CAT at 0.25μg·l^-1 and that of mercury at 20μg·l^-1.Furthermore, when the alga was exposed to both herbicides and mercury, the influences were combined. This study indicates that the analysis of the long-term behavior of DF of an alga may be useful in the rapid detection of toxicants in contaminated waters.

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The aim of this study was to estimate the removal effects of runoff loads in an irrigation reservoir. The watershed of the irrigation reservoir is a tea field zone in Shizuoka prefecture. The annual average T-N concentration of the Tanno reservoir was particularly high, being 24.5 mg·l^-1. On the other hand, the T-P and COD concentrations were very low, being 0.02 mg·l^-1 and i.e, 1.8mg·l^-1, respectively, and living things such as aquatic plants were not observed, which is very rare in such an irrigation reservoir. Compared to the inflow water of the irrigation reservoir, the effluent water had wide ranges of changes in the concentrations of NO₂-N, T-P. However, the changes in other water quality parameters were in contrast to these three parameters. The NH₄-N, NO₃-N, T-N, K⁺,Na⁺,Mg²⁺,Al³⁺, Cl^- and SO₄^2- effluent loads were smaller than the influent loads, and there were reductions in the loads in the irrigation reservoir. The Ca²⁺ and T-P effluent loads increased due to production load from the sediment, and this effluent load was larger than the influent load. The total T-N influent load was 73848kg·y^-1, the annual reduction load was 6516kg·y^-1, and the removal rate was 337mg·m^-2 per day.

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Filamentous anaerobic sludge bulking was observed in an upflow anaerobic sludge blanket (UASB) reactor treating high-strength wastewater discharged from a sugar-manufacturing factory. In the bulking sludge, a number of thick filamentous cells were found, which were considered to be the causative agent for the bulking. To identify these filamentous cells, we applied an rRNA-based approach to the filamentous microbes. 16S rRNA gene analysis revealed that the filaments are uncultivated microbes affiliated with a clone cluster at the phylum level. In situ hybridization using a 16S rRNA-targeted oligonucleotide probe specific for the phylum KSB3 showed that the microbes were abundantly present in the bulking sludge. In addition, in situ hybridization analysis of normal granules (before bulking) indicated that the microbes are also abundant in healthy sludge granules ; the microbes are the major population on the surface of healthy sludge granules. This finding indicates that these filamentous microbes normally reside on the surface of granules, and that they outgrow the granules due to certain environmental changes, resulting in the filamentous bulking of sludge granules.

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The aim of this study was to estimate the nitrogen balance of the tea field zone. The study area was located in the Makinohara tea field zone, Shizuoka, Japan. The water quality and discharge were measured daily from June 2001 to May 2003 and the authors discussed runoff loads. The average concentration of T-N was 28mg·l^-1and the pH value was 4.9. Therefore, this case is rare in Japanese fields. Annual T-N runoff loads were estimated to be 496.5kg·ha^-1·y^-1in the first year and 485.8kg·ha^-1·y^-1in the second year. The average load for both years was 491.2kg·ha^-1·y^-1. The reaching rate was 83% of the applied amount of nitrogen fertilizer. The T-N concentration was very high after strong rains during the rainy and typhoon seasons. The annual absorbed nitrogen flux was 31.3% of the applied fertilizer in the first year, and it increased to 32.4% in the second year. The average nitrogen balance ratio (input/output) was 0.97. Therefore, the tea plants absorbed a significant amount of accumulated nitrogen fertilizer in the soil.

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On the basis of papers and policy documents on pollutant loads, measures of dissemination and environmental education which highlights water pollution of an enclosed coastal sea, Sanbanze, Tokyo Bay, and a municipal life were proposed in this paper. Simple pollutant load analysis using water quantity and quality data available on websites of Chiba prefecture and its cities was conducted to examine what could be analyzed on the basis of data and information that can be easily accessed by an ordinary citizen. Pollutant loads per capita flowing into Sanbanze tidal coastal zone were calculated as 0.3-5.2g-COD person^-1·day^-1, 2.5-4.3g-N person^-1·day^-1 and 0.22-0.43g-P person^-1·day^-1 respectively. COD and T-N loads of “combined jokaso and riverside water purification facility” population and T-P load of wastewater treatment plants (WTPs) population were calculated as minimum of pollutant loads per capita flowing into water area are proposed as an effective index for domestic wastewater management, and the basic concepts of environmental accounting housekeeping (EAH) books for domestic wastewater are proposed for the purpose of information dissemination and environmental education as regards water pollution.

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