Alcohol stillage wastewater consists of high-strength suspended solids and organic matters, is best treated effectively by anaerobic digestion. To develop more efficient systems for treating alcohol stillage wastewater, a mesophilic submerged anaerobic membrane bioreactor was operated for 4 months by changing the hydraulic retention time and COD_Cr loading rate. The performances of the anaerobic treatment and membrane operation were investigated experimentally. The maximum organic loading rate obtained in this study was 12.4 kgCOD·m^-3·d^-1 and the removal efficiency was 97.8%. Furthermore, the COD_Cr concentration of water that permeated the membrane was under 1,000 mgCOD·L^-1 when the organic loading rate was lower than 6.0 kgCOD·m^-3·d^-1. The addition of trace elements (i.e., Fe, Co and Ni) was necessary to maintain stable operation for this wastewater treatment at a high organic loading rate. The operation was successfully carried out for over 4 months by controlling the on/off time of the suction pump and by recirculating of biogas, without backflushing or chemical cleaning. No significant decrease in flux and the recovered amount of membrane pressure during the off period of filtration was observed in the initial 50 days of continuous operation at sludge concentrations of 10-16 gSS·L^-1; however, both parameters gradually decreased to approximately 30% of their initial values after 4 months of continuous operation.

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The microbial activities in samples of water and sediment of the Nagara River were discussed on the basis of the first-order rate constant (K) estimated through biodegradation tests, for which glucose and 17β-estradiol (E2) were used as the substrates. For the water samples, a correlation was observed between K and bacterial concentration. However, for the sediment samples, no correlation was observed. The K values of both substrates in the water samples from the downstream of the Nagara River were higher than those in the water samples from the upper and middle reaches. In the case of the K values of both substrates in the sediment samples, a different trend was observed. As for the range of the K values per unit bacterial concentration, for the water samples, glucose was 4.5×10^-7- 1.8×10^-3 h^-1·cell·L and E2 was 2.7×10^-7- 7.0×10^-4 h^-1·cell^-1·L; for the sediment samples, glucose was 6.0×10^-8- 1.7×10^-5 h^-1·cell^-1·L and E2 was 1.3×10^-7- 1.9×10^-5 h^-1·cell^-1·L. From the comparison of the K values of both substrates, it was shown that glucose is more easily biodegraded by microorganisms suspended in water than E2.

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The concentrations of 11 perfluoroalkyl carboxylic acids (PFCAs) and 5 perfluoroalkyl sulfonates (PFASs) in the tap water samples in Tokyo were determined using liquid chromatography-tandem mass spectrometry. The total concentrations of perfluoro organic compounds (PFCs; PFCAs + PFASs) in the tap water samples collected from 40 sampling points ranged from 0.72 to 95 ng·L^-1, with a mean value of 19 ng·L^-1. Twelve PFCs were detected in the tap water samples with the highest PFC concentrations. The Tokyo tap water samples were divided into two main groups by cluster analysis on the basis of PFC composition profile, i.e., the Tama district and Tokyo wards. The compositions and concentrations of PFCs in the tap water samples from Tokyo wards were similar. On the other hand, there was variability among those in the tap water from the Tama district. This was likely because groundwater in addition to river water was used as raw water in the Tama district. Compared with the guideline values for PFCs and the health-based values for PFCs in the literature, the individual PFC concentrations found in the tap water samples in this study were low.

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