Studies were made in which a continuous flow analysis was applied in colloid titration to measure cationic polyelectrolytes. For establishing the dosage at the end point of titration, a dual-frequency photometric cell was used. Effects caused by dissolved salinity and turbidity were also investigated. Results obtained were as follows.
1) It was possible to use the colloid titration end point as the set value, wherein a constant-fold value of the difference in the transmitted light intensity just before adding the titrant is defined as the titration end point, and whereby the transition reaction of a toluidine blue indicator is detected through the difference in the transmitted light intensity at each frequency subject to measurement.
2) It was possible to measure samples whose ionic strength was less than approximately 0.04 as they were not diluted, provided that the said constant was 0.8 and that the titration end point was defined as the region where the transition reaction of the indicator began.
3) The effect of turbidity on this measurement method could be neglected, provided that the turbidity of samples were below approximately 150 units.
4) The continuous flow analysis testing system were determined to have favorable responsibility and accuracy within a range of 00.1meq·l^-1.

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The water quality of the Kum-Ho River was estimated by multivariate analysis. Results of the analysis were as follow as :
1. The water quality of the Kum-Ho river estimated by the factor scores were generally not different throughout the period of this research.
2. The cumulative proportion to the third principal components was 97.8%.
3. The factor loadings of 14 water quality items studied were over 0.9. The river appeared to be polluted by human activities and the waste water from nearby factories.
4. The flow of Kum-Ho river was closed related to COD(cr) and the factor scores. The run-off loading rate, therefore, could be explained by COD(cr) and factor scores. The run-off loading rate of the lower Kum-Ho river basin showed no significant variation, where the pollutions were mainly contributed by the point soures.

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Laboratory-scale sequencing batch reator (SBR) activated sludge processes were operated using synhtetic wastewater to clarify the effects of solids retention time (SRT) and organic substrates on the accumulation of bio-P-bacteria.
The accumulation of bio-P-bacteria could be enhanced by large fluctuation in concentration of organic substances in the reactor by filling in a short period of time under anaerobic condition. However, the accumulation could not be enhanced in the reactor operated with SRT less than 25 d. The specific growth rate (μ) of bio-P-bacteria were estimated to range from 0.033d^-1 to 0.035 d^-1 in the SBR activated sludge processes fed with glucose and polypeptone (GP). Therefore, large solids retention time (SRT) would be necessary for the accumulation of bio-P-bacteria. Volatile fatty acids (VFA), such as sodium acetate (A), enhanced in-situ specific growth rate of bio-P-bacteria and seemed to be effective than other organic substates (ex: GP) for the accumulation of bio-P-bacteria in activated sludge ecosystem.

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In the past, there has been little study on the thermophilic treatment of anaerobic fixed-bed reactor. The authors have verified that high performance was obtained by application of this treatment process to the waste water containing high soluble COD.
The authors conducted the experiment on the thermophilic treatment of waste alcoholic drink (107 kg COD·m^-3) using anaerobic fixed-bed reactor containing porous ceramics filling, and found that higher COD removal (>97%) with substrate removal rate (γ_s) of 60 kg COD·m^-3· d^-1 was obtained by addition of very small amount of heavy metals (Fe, Ni, Co) to the reactor. Dependency of the over all reaction rate on the substrate can not be expressed by Monod equation, but can be expressed by Moser equation which reprenents a sigmoid-type relationship between substrate concentratitn (S) and γ_s on condition that there is no change in the biomass in the reactor.
Some problems to be solved are remained, but the results are very suggestive to the study of reaction mechanism or microbe metabolism of anaerobic treatment.

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