The biodegradation of methyl capped nonionic surfactant in which the terminal OH group of nonionic surfactant reacted to methyl ether was studied using the continuous activated sludge system.
In laboratory studies, the following conclusions were obtained.
1. The degradation percentage of TOC was over 70% under the condition of activated sludge influent containing methyl capped nonionic surfactant and other organic compounds.
2. The degradation percentage of TOC was 40% under the condition of the influent containing only methyl capped nonionic surfactant as the organic compound. However, in this case, the degradation percentage was 70% under Ca, Mg concentration of influent being decreased to a great extent.
3. The degradation products were extracted by chloroform from the activated sludge effluent. These were identified by IR, NMR spectroscopic methods and gas chromatographic method. As the result, it was found that the polyethylene oxide chain was degraded gradually. The degradation products were enriched with the intermediate chain length of the polyethylene oxide.
4. The strain that could degrade methyl capped nonionic surfactant was identified as being genus pseudmonas.

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Water samples from Minami Asakawa River and it's draining sewages were analyzed for amino acids by high-performance liquid chromatography (HPLC).
Analytical precision and detection limit were 3.2% and 50p mol, respectively for quantitative determination of total dissolved amino acids (TDAA) and 1.5% and 5n mol, respectively for determination of amino acid composition.
The concentrations of TDAA ranged from 1.0 to 40μmol l^-1 in river water and from 2.0 to 200μ mol ·l^-1 in sewage water. From budget of TDAA, some parts of TDAA seemed to be removed during going down from river water.
Aspartic acid, glutamic acid, glycine and alanine were major constituents of particulate amino acids (PAA). Apparent changes in these composition were not observed during going down. However a little changes in amino acid composition of TDAA were observed during going down.

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The amount of fluoride ion adsorbed by activated alumina is strongly affected by the pH of wastewater containing fluoride. The maximum amount of fluoride adsorbed by commercially available activated alumina is generally observed at the pH of an acidic solution. A new adsorbent was repared by adding titanium (IV) sulfate to the activated alumina to increase the amount of fluoride adsorbed at pH 7. That is, an aqueous titanium (IV) sulfate solution containing titanium of 5.0 mg was added to the activated alumina of 1.0g, and the impregnated alumina was heated at 400°C for 2 hours.
From the batchwise experiment with the prepared complex, the maximum amount of adsorbed fluoride was observed at pH 7, and at the same pH the amount adsorbed on the complex was about twice as large at that on the same amount of activated alumina. The amount of fluoride adsorbed on the complex was not influenced by coexistence of sulfate or chloride ions of 4% in the wastewater containing fluoride. From the columnwise experiment, the sum of volume of the effluent passed through the column packed with the complex was 42 as large as that with activated alumina until the concentration of fluoride in the effluent reached 10mg·l^-1.

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