The effects of screens and sludge circulation on disposer wastewater treatment performance and excess sludge production were investigated in Johkasou equipped with a screen. Almost all the dissolved BOD was converted to particulate BOD in an aerobic fluidized tank, and the particulate BOD was removed effectively in a sedimentation tank. Therefore, BOD removal ratio was not affected by the introduction of disposer wastewater or the pore size of the screen. The influent nitrogen concentration was high for the process in which disposer wastewater was introduced and no screen was used. However, the ratio of particulate T-N to T-N in the aerobic fluidized tank was quite high, and particulate T-N was removed effectively in the sedimentation tank. In the case of the process in which disposer wastewater was introduced and no screen was used, the amount of excess sludge was only 1.14 times higher than that in the case of the domestic wastewater treatment process even though the influent BOD concentration was 1.96 times higher. An increase in sludge circulation ratio led to a decrease in effluent nitrogen concentration. A sludge circulation ratio of 2 in the process in which disposer wastewater was introduced and no screen was used should be the optimum operation condition for effective BOD and nitrogen removal.

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Preferences for three nonconventional water resources or distributed water resources mainly in urban area - rainwater harvesting (RH), submersible groundwater (SG), and reclaimed wastewater (RW) - and their five usages - toilet flushing water (FW), sprinkle water (SW), environmental water (EW), water against disasters (DW), and water for agriculture and planting (AW) - of ordinary citizens and administrative officers were comparatively analysed on the basis of questionnaire survey results obtained by analytical hierarchical process (AHP), absolute evaluation and willingness to pay (WTP) determination. McNemar, average difference, and Welch examinations were used to evaluate the differences in the results. For the second set of criteria in AHP, the administrative officers' preferences were larger for stability (corresponding to 'society' in the first set of criteria, here and throughout), project cost and duration ('economics') and water environment ('nature') than the ordinary citizens' preferences. For water resources, the order of preferences was (1) RH, (2) RW and (3) SG for both administrative officers and ordinary citizens. For water usages, the preferences for DW and AW were comparatively larger than those for other usages. The administrative officers' public WTPs for 15 combinations of water resources and usages, i.e., 4,172-21,572 Japanese Yen person^-1 year^-1 (YPY), were mostly larger than the ordinary citizens' public WTP, i.e., 6,152-17,336 YPY. The administrative officers' private WTPs, i.e., 1,106-4,044 YPY, were mostly smaller than the ordinary citizens' private WTP, i.e., 2,561-5,934 YPY.

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Two identical air-cathode single-chamber microbial fuel cells (MFCs) were operated with two different types of animal wastewater. The result showed that the MFC with swine wastewater showed 831 mW·m^-2 of power density, while that with dairy wastewater showed 59 mW·m^-2. It was shown that the microbial community structures on anode of both reactors were different. The most dominant bacteria on the anode of the MFC with swine wastewater were relative to members of phylum Acidobacteria and that on the anode of the MFC with dairy wastewater were relative to members of phylum Proteobacteria. The dominant species on the anode were different from those of influent wastewater and from cathode microbes. In the MFC with swine wastewater, a large amount of precipitation was observed on the surface of the cathode. The main components of the precipitation were phosphorous and magnesium, and calcium was also contained.

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