Effects of algae on the musty odor production by Streptomyces were studied. Six strains (A, C, E, F, I, J) of musty odor-producing Streptomyces, which were isolated from Lake Kasumigaura, were cultivated in the presence of algae which were isolated from the lake. Various strains utilized cells of Microcystis aeruginosa, Anabaena spiroides, Synedra acus and Synedra rumpens as a carbon source and produced musty odor. In order to identify the musty odorous compounds produced by three strains (E, F, I) of Streptomyces, these strains were cultivated with lyophilized cells of M. aeruginosa as a carbon source. All strains produced 2-methylisoborneol, while geosmin was produced by strain I. The musty odor production by Streptomyces was inhibited when living cells of Microcystis, Anabaena and Synedra associated with bacteria were used as a carbon source. However, three strains (E, F, I) of Streptomyces could utilize living axenic M. aeruginosa and produce musty odor. Two strains (E, I) could also produce musty odor in the odor production experiments with six strains added to the cultures of living axenic Synedra acus. Algae and bacteria were very important factors for the musty odor production by Streptomyces.

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The Secchi disk depth, total downward irradiance, beam transmittance and the concentrations of particulate matters were measured at a station located in the coastal region of northern part of Hiroshima Day during April 1979 to December 1981. Compensation depth was estimated from the in situ measurements of photosyntheticc rate.
Three water layers having different attenuation coefficients (K₁, K₂ and K₃) were frequently found in identical water column. Seasonal variation in K₁ was quite similar to that of chlorophyll-a concentrations.
Vertical distributions of beam attenuation coefficient representing turbidity were in good accordance with those of chlorophyll-a concentration during the period of active algal growth. On the contrary, in winter season, beam attenuation coefficient increased gradually with depths. These phenomena could be interpreted as being due to suspended matters other than chlorophyll-a.
Compensation depth was about 2.6 times of the Secchi disk depth. Among particulate organic matters (POC, POP and PON) which were a fraction of matters affecting turbidity, the highest correlation existed between POC and attenuation coefficient. In addition to these, the correlations among optical parameters were studied.

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Optimum conditions for the determination of trace amount of boron in water samples were established with inductively coupled plasma-atomic emission spectrometry (ICP-AES) and a detection limit of 2μgB/l was obtained at the BI 249.77 nm. Spectral intensity was reduced with increasing concentration of acids (hydrochloric, nitric and sulfuric acids) above 0.5 wt% due probably to the change of physical property of the nebulized solution. Concentrations of concomitants such as NaCl, KCl, MgCl₂ and CaCl₂ were little influenced on spectral intensity up to 3000 mg/l. Spectral interference was observed by the presence of large amount of iron. However, BI 249.77 nm line yielded the same net intensity regardless of iron concentration. Boron in river water, industrial waste water, disposal plant sewage and sea water was determined satisfactorily by direct nebulization after filtration. The results obtained by ICP-AES method were in good agreement with those obtained by modified curcumin method after alkali fusion. The ICP-AES method is recommended as an alternative analytical method for the rapid determination of boron in the above samples.

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The reactions of proteins and their major constituent amino acids with chlorine in water have been studied and the following results are obtained.
1) Proteins have the potential properties of yielding chloroform or total organic chloride (TOCI) as similar extent to humic acid.
2) At the pH range of 4-10, the amounts of chloroform formed from proteins increase with increasing pH, whereas the yields of TOCI show maxima at pH8.5. In the cases of amino acids, the amounts of chloroform and TOCI formed vary depending on the kinds of amino acids. However, the pH dependencies in the chloroform formations from amino acids and in the TOCl formations from certain amino acids which yield higher levels of TOCl are similar to those in the cases of proteins.
3) The amounts of chloroform and TOCl formed from proteins can be expressed as the following equation. [OCl]=K[P][Cl]^mtⁿ
Where [OCl] is the concentration of chloroform or TOCl, [P] is the concentration of protein, [Cl] is the concentration of chlorine, and K, m, and n are the parameter.

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Because of the recent severe deterioration of water quality in closed waters in most of the industrial countries as well as Japan, it has become of increasing importance to develope efficient methods of coping with the situation in a comprehensive and systematic manner.
Improvement of monitoring and surveillance system is an important one, which could provides basic information for more efficient programs of water quality management. Regarding this, one difficult but important problem is to determine where are the most appropriate places to allocate the monitoring sites in order to evaluate efficiently the water quality of such two dimensional areas.
In this paper, a quantitative method of allocating monitoring sites is developed. The purpose of the monitoring system is restricted to estimate representative concentrations of water qualty, which is defined as weighted areal integration of the water quality profile of the area. Based on the optimality of the system measured with the total variance of estimate, the configuration of monitoring sites is chosen so as to minimize the variance. Several kinds of measurements of water quality parameters, such as COD, T-N, Chl-a, etc., as well as LANDSAT remote sensing data in Lake Kasumigaura were used to check the feasibility and applicability of the proposed method.

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One of the classical but very important problems on designing water quality monitoring systems is to examine what the system will give the management of water quality for the expenditure of sampling and analyzing efforts. In other words, the system should be balanced between the utility of acquired information and the efforts of its acquisition.
Coping with this principle which constitutes one of the fundamentals of the rational design of water quality monitoring, this paper proposes a quantitative method to balance the above two factors from the view point of cost/benefit analysis. In this method, the benefit of acquired data is measured as the reduction of economic loss of the water quality management program, and it is compared with the cost of data acquisition to find the most effective efforts of water quality monitoring. Pollutant load reduction programs of lake basins were used to apply the proposed method, and optimal numbers of sampling points were calculated in order to check the feasibility of the method.

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