A simplified phosphorus removal method for the small-scale on-site domestic wastewater treatment systems, which have been used for disposal of domestic wastewater, was examined.
This method consisted of submerging the iron media in an anaerobic chamber. Phosphorus could be effectively removed even at a low oxygen concentration in the anaerobic chamber.
The phosphorus removing effect in the anaerobic environment was examined in different iron media. Iron cations were dissolved from steel wool more than from other media, because of the relatively large surface area.
The phosphorus removal method was examined using a continuous experimental apparatus. To obtain 90% phosphorus removal, it was necessary to submerge the iron media of 6.6kg·m^-3 or more, and to maintain phosphorus-iron surface area loading to be 0.05g·m^-2·d^-1 or less.
The iron surface was covered gradually with reaction products and captured SS, and the weight of iron increased. After 2 months of submersion of iron media, dissolution of iron cations was hindered, and phosphorus removal decreased markedly. Therefore, periodic back-wash at least every 2 months was considered necessary.
Phosphorus removal cost was calculated. This method was considered to be expensive about 30-160%. However, it is possible to reduce the cost further by periodic maintenance.

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The operation and control strategy has been investigated by using a wastewater treatment process simulator which include IAWQ Activated Sludge Model No. 2. The purpose of simulation is to stabilize the biological nitrogen and phosphorus removal process, especially paying attention to the relationship between a load of organic substrate and the efficiency of phosphorus removal.
The organic substrate concentration was observed at some points of sewer, and the simulation used these measured values as a influent condition. The phosphorus removal efficiency was estimated to be 91.8% on the condition of the sewage at upper part of sewer. But it was estimated to be 49.9% on the condition of the sewage at an inlet of reaction tank. It was concluded that a management strategy of sewage is needed to prevent consuming organic substrate in the sewer.
In addition, the controllability of intermittently aerated 2-tank activated sludge process for various influent organic load has been compared with A²/O process on the simulation. Some control strategies under the low organic substrate condition were examined on this simulator.

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Parallel studies using Ozonation-Biological Activated Carbon (O₃-BAC) process and a simple Biological Activated Carbon (BAC) process were conducted to evaluate the effect of ozonation on a BAC process. The raw water used was pre-treated by microfiltration to remove suspended solids. Contact time for ozonation was 24 minutes while empty bed contact time (EBCT) of the activated carbon column was 15 minutes. An ozone dosage of 7 mg·l^-1 was used.
Effluent DOC and THMFP of O₃-BAC process were lower than those of BAC process after 80 days. Lifetime of activated carbon adsorption was extended in the O₃-BAC process compared with the BAC process until breakthrough, because ozonation decreased DOC in the activated carbon influent in the O₃-BAC process. DOC was partitioned into four fractions and analyzed based on its biodegradability and activated carbon adsorbability. It is proposed that O₃-BAC process can be used for a long time without activated carbon replacement because biodegradable DOC was removed even after activated carbon adsorption capacity was exhausted. Adsorbed DOC in the O₃-BAC process also decreased until breakthrough, probably because ozonation increased hydrophilicity of DOC resulting in its decreasing adsorbability. In this study, ozone dosage of 2 mg O₃·mg DOC^-1 and EBCT of 15 minutes was determined to be satisfactory for an increase in biodegradability and removal of DOC.

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A method for simultaneous determination of glufosinate, glyphosate and 5 phenoxyalkanoic acid herbicides (MCPA, MCPB, MCPP, 2,4-D, 2,4,5-T) in river water was studied. 50ml of river water was passed through a cation-exchange cartridge and an anion-exchange cartridge. The herbicides were eluted from the anion-exchange cartridge with 60% acetic acid, derived with trimethyl orthoacetate and measured by GC/MS-SIM.
The detection limits of glufosinate, glyphosate and 5 phenoxyalkanoic acids were 0.0003, 0.0002 and 0.0001-0.0005mg·l^-1 respectively. When 0.005mg·l^-1 of each herbicide was added to a river water, the recoveries from the water were 112.7, 90.0 and 71.0-100.3% for glufosinate, glyphosate and 5 phenoxyalkanoic acids respectively.

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Four monoclonal antibodies (MAb-No.1, 2, 3 and 4) were raised against a conjugate of camphor linked to bovine serum albumin. These antibodies showed affinity to 2-methylisoborneol (2-MIB), a common cause for earthy/musty off-flavor. The sensitivity and specificity of the antibodies were tested by ELISA in a microtiter plate coated with a camphor-ovalbumin conjugate. Specificity of these antibodies were tested by using camphor, camphorquinone, norcamphor, 2-methylisoborneol, borneol, isoborneol, norbornane and norborneol. Although MAb-No.2 and 3 were reactive against all of the compounds tested, MAb-No.1 and 4 did not react with norcamphor, norbornane and norborneol. MAb-No.4 was purified from a culture supernatant. 2-MIB was detected even at 1 μg·ml^-1 by the ELISA using the purified MAb-No.4 at 0.63μg·ml^-1.

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E₂₆₀ absorbant substances constitute a major fraction of dissolved COD in natural water. And the investigation of the behavior of E₂₆₀ absorbant substances is essential for the control of COD in Lake Kojima.
The movement and variation of molecular weight fractions of E₂₆₀ absorbant substances were evaluated by the gel chromatography.
By using gel chromatograms of waters prepared in various mixing ratios of distilled water and pond bottom soil, it was clear that E₂₆₀ absorbant substances moved for keeping the adsorption equilibrium between water and soil.
E₂₆₀ absorbant substances in the soil showed that higher molecular fraction decreased in aerobic state and lower molecular fraction decreased in anaerobic state.
The components of lower molecular fraction of E₂₆₀ absorbant substances in domestic effluent decreased through the flowing down process in February. And it was suggested that the decrease of components was affected by anaerobic bottom soil.

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