A method was developed for the simultaneous trace analysis of linear alkylbenzene sulfonate(LAS) and their biodegradation intermediates, sulfophenyl carboxylates (SPC), in sewage effluent and river water. Sensitive determination using a liquid chromatograph equipped with a tandem mass spectrometer (LC-MS/MS) following solid-phase extraction was employed. The analytical method was applied to study the behavior of LAS and SPC during sewage treatment. SPC concentration (sum of C₅-C₁₃ SPC: 80μg·l^-1) in secondary effluent was 2.5 times higher than that in raw sewage (30μg·l^-1), whereas very high levels of removal (99.2%) of LAS (sum of C₁₀-C₁₄ LAS) was observed during the secondary treatments. This suggests the formation of SPC by biodegradation of LAS during sewage treatment. Broad-spectrum monitoring of synthetic-detergent-derived compounds including LAS, SPC and fluorescent whitening agents (FWAs; DSBP and DAS1) was conducted for 20 representative Japanese rivers. LAS, SPC, and FWAs were widely distributed in the river water at concentrations in the range of 0.2-63μg·l^-1, 0.02-68μg·l^-1, and 0.013-4.55μg·l^-1, respectively. Higher concentrations of the detergent-derived pollutants were observed in urban rivers which have larger populations in their catchment areas. In many rivers, SPC concentrations were higher than those of LAS, suggesting that SPC should be considered in the risk assessment of LAS.

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A new type of two-phase process for producing hydrogen and methane from food waste was investigated using potato processing waste in this study. In this process a mixing tank, a thermophilic acidogenic reactor (55°C) and a mesophilic methanogenic reactor (36°C) were used in series. The methane-fermentation-mixed liquor was returned to the mixing tank for the dilution of influent food waste. A continuous experiment was conducted by changing the whole process hydraulic retention time (HRT) stepwise from 56 days to 30 days, then 20 days and 15 days. The process was successfully performed for over 290 days until the HRT was reduced to 15 days. A stable and high hydrogen production yield of 1.67 mol H₂·mol^-1 degraded hexose with a VFA concentration of 10000 to 25000 mgHAc·l^-1 was obtained in the thermophilic acidogenic reactor, while a high efficiency of methane fermentation was achieved in the mesophilic methanogenic reactor. As a result, the high VS removal (92%) and total CODcr removal (85-90%) were achieved by the new process at HRTs of 20 to 56 days. The suggested new process was not only possible for the dilution-free treatment of potato processing waste, but also useful for continuous hydrogen fermentation at a high rate.

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Heavy metals contained in soil matters collected at 83 street water inlets in the Tokyo area were analyzed to determine the pathway of heavy metals between roadside deposits and sediments in environment. The results show that the ranges of concentrations of iron, manganese and titanium were narrow regardless of sampling points, whereas those of lead, chromium and zinc were distributed in wider ranges, reflecting traffic conditions and the surrounding environments. The average concentrations of zinc and lead in the sediments in the street water inlets were 0.70mg in a gram and 0.12mg in a gram respectively, which are in the same ranges as typical roadside deposit samples.

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