The effect of chlorhexidine digluconate (CHG) on the treatment efficiency of activated sludge process has been studied experimentally. Waste water samples containing 0.5 and 2.0 ppm CHG were treated by batch activated sludge process, using activated sludge exposed with 0.2-0.5 ppm CHG and time courses of TOD value, NH₄⁺ concentration and others in the treated waste water were observed. In a case of 0.5 ppm CHG waste water, TOD value in the treated waste water was about 10 ppm and almost the same throughout the experiment for 155 d. NH₄⁺ disappeared completely and was changed into NO₃^- at 10th h after the starting operation. In a case of 2.0 ppm CHG waste water, TOD value was almost as low as 10 ppm until 12th d after the starting operation, but began to increase sharply after then and got to the same level as the influent concentration, about 40 ppm, at 30th d. Whereas the decrease in NH₄⁺ concentration was only less than 20% even at 24th h after the starting operation. Furthermore, the adsorptivity for CHG on activated sludge was investigated. The result showed that the adsorption of CHG by activated sludge obeyed the Freundlich isotherm equation and the amount of CHG adsorbed on 1 g activated sludge (dry state) in equilibrium concentration of 0.5 ppm CHG was about 8 mg.

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An investigation adopting coprecipitation with Zr (OH)₄ followed by flame atomic absorption spectrometry was conducted to develop a facile method for quantitative determination of Ca and Mg in water. The results indicated that this method was quite satisfactory for determination of both Ca and Mg in water in concentrations of 0.04 to 10 ppm and 0.002 to 0.3 ppm, respectively, and that the presence of 10 ppm of each of Al³⁺, Cl^-, Cu²⁺, Fe²⁺, K⁺, Na⁺, NO₃^-, PO₄^3-, SiO₃^2-, SO₄^2-, and Zn²⁺ offered no significant interference, giving rise to more than 95% recovery ratios of Ca and Mg from tap water, river water, hot spring water, and sea water with less than 6% of S.D. values. The most crucial point of the operation procedure was the use of (1+1) ammonia water as the alkali agent instead of 4 N NaOH in the coprecipitation process. Comparison of the recovery ratios obtained by the coprecipitation method and those by the direct atomizing method revealed that the former method provided higher recoveries with smaller S.D. values.

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Two kinds of harmful gas (such as malodorous gas) adsorbent containing gas adsorption resins were developed. One is a polystyrene polyamine metal (Co) chelating resin capable of adsorbing more than 90% of sulfur-containing (C₂H₅SH and H₂S etc.) or acidic gases (SO_x, NO_x and HCl etc.) within 60 minutes. The other is a polystyrene polysulfonic acid resin that can adsorb more than 90% of basic gases such as NH₃ within 60 minutes. Thus, both resins have large gas adsorption capacity and their stability is good. The harmful gas adsorbents obtained by mixing both resins with active charcoal can adsorb a wide range of harmful gases. Both resins are very economical since they can be regenerated. The practical application of these resins are as follows. (1) Both can be used to remove specific harmful gases. (2) The harmful gas adsorbent is placed in a gas circulating device. (3) The gas adsorption sheet comprising of many corrugated layers of gas adsorbent can be hung from a wall. It should thus be possible to use these resins in many places such as lavatories, childcare rooms, hospitals, building and cars, factories and tunnels and be used to prevent corrosion of precision instruments.

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Heterotrophic bacterial populations in a total of 22 stream waters polluted in different degrees were investigated by analyzing correlations with water quality variables. Colony-forming units on polypeptone-yeast extract-glucose agar plates correlated significantly with the concentrations of suspended solids, chemical oxygen demand and total organic carbon. Four hundred and thirty-four strains isolated from 22 stream waters were classified into 60 types according to the characteristics of colony color, motility, Gram stain, catalase production, oxidase production and oxidation-fermentation (O-F) test. In relationships between the percentage of the 60 types of isolates and water quality variables, YA1, YI, and NPG type positively, and NPK type negatively correlated significantly with many of the variables. All of these bacterial types were Gram negative bacteria ; the YA1 type was a yellow pigmented, non-motile, catalase-positive, oxidasenegative and O-F test-negative bacterium (Flavobacterium sp.) ; the YI type was a yellow pigmented, motile, catalase-positive, oxidase-negative and O-F test-negative bacterium (Pseudomonas sp.) ; the NPG type was a non-pigmented, motile, catalase-and oxidasepositive, and O-F test-oxidative bacterium (Pseudomonas sp.) ; and the NPK type, a non-pigmented, motile, catalase-negative, oxidase-positive and O-F test-negative bacterium (unknown sp.). These results suggest that YA1, YI and NPG types may be present predominantly in polluted waters and the NPK type in non-polluted waters, that is, that they may be good candidates as pollution indicators. The percentages of total YA1, YI and NPG types correlated strongly with most of the water quality variables.

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Discrimination of soil samples in forensic science using organic components in the soil was investigated by Curie-point pyrolysis gas chromatography (PyGC). Pyrograms of soils under the conditions of pyrolysis temperature (590°C) and time (3 s), showed various patterns. In addition, fifteen constituents of phenolic aromatics in pyrolysis products were identified by GC-MS (PyGC-MS). The amounts of toluene and phenol, derived from lignin, and those of 2-methylfuran and furfural derived from polysaccharide in the soil showed quantitative differences. Consequently, the comparison of these pyrolysis products may be useful for the structural analysis of organic matter in the soil, and is useful for the discrimimation of soils in forensic science.

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The contents of polyoxyethylene nonionic surfactants (as iodobismuthate active substances : BIAS), methylene blue active substances (MBAS) and ignition losses in the river sediments were determined in Kanagawa Prefecture from 1986 to 1989. The concentrations of BIAS and MBAS detected in the river sediments (n=18) were 2.1-160 μg/g and 3.0-800 μg/g, respectivery. The relationship between BIAS and MBAS showed high correlation (R=0.97) and the ratio of the concentration of BIAS to that of MBAS was 1 : 2.6. BIAS and MBAS have been correlated with the ignition loss and the coefficient of the correlation was 0.90 and 0.91, respectively. Therefore, it was considerated that BIAS and MBAS adsorption on the sediments were related with the contents of organic matters of the river sediments. Experimental results on absorption and desorption behavior of BIAS on the river sediments suggested that accumulation of BIAS was related with the contents of organic matters of the river sediments and with the shape of the sediments.

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Chlorpyrifos and pyridaphention, organophosphorus insecticides, have been utilized for termite control as a substitute of chlordane from 1987 in Japan. In order to investigate the human exposure of these domestic pesticides, the analytical procedure for chlorpyrifos and pyridaphention in human milk sample, as an indicator of the domestic human exposure, was established, and the analyses of chlorpyrifos and pyridaphention levels in the breast milk of women living in the houses treated with termite control were carried out. Milk fat was extracted twice with diethylether-hexane from the milk sample. Defatting was performed by means of the Florisil dry column method ; pesticides were eluted with CH₃CN-H₂O=70-30, and reextracted with 20% ether-hexane from acetonitrile layer. Chlorpyrifos and pyridaphention were analysed by gas chromatography (NPD-GC) equipped with a capillary column after clean-up on a silica gel column (chlorpyrifos was eluted with 4% ether-hexane, and pyridaphention with 75% etherhexane). The minimum detectable residues of chlorpyrifos and pyridaphention were 0.025 ppm on fat basis in each by NPD-GC. Chlordane was detected in all 19 human milk samples (termiticide treated year, 1961-1988), however, chlorpyrifos and pyridaphention were both below the detection limit.

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Hemoglobin (Hb) oxidation and mouse lethal toxicity of eicosapentaenoic acid (EPA) and its oxidized products by continuous aeration of EPA at 37°C for a week were investigated. To clarify the effects of oxidized EPA (EPA-Ox), they were separated into two fractions (Fr. 1 : oxidized EPA ; Fr. 2 ; unoxidized EPA) by thin-layer chromatography, and their effects were studied. By monitoring the substances in Fr. 1 by spectrophotometry at 230 nm and 280 nm they were separated by high performance liquid chromatography, and many hydrophobic substances were detected. The activity of Hb oxidation was 7.4 times higher in oxidized EPA (Fr. 1) than original EPA (Fr. 2). And the activity of EPA without 0.2% α-tocopherol was also 6.6 times that with the antioxidant. By intraperitoneal injection, mice were killed much earlier by oxidized EPA (EPA-Ox and Fr. 1) than by EPA. LD₅₀ observed 24 h after injection of the above samples using 4 mice in each group, were 9.0 mg for EPA-Ox, 7.4 mg for Fr. 2, 7.3 mg for EPA and 4.2 mg for Fr. 1, and Fr. 1 was more toxic than others. The mouse lethal activity was not inhibited by the further addition of α-tocopherol up to 8.2%. In conclusion, it is suggested that radical oxygens occurred by heme iron-catalyzed autoxidation of EPA are concerned to this Hb oxidation. For the effect of mouse lethal toxicity by EPA, however, it is considered that the mechanism inducing the mouse death is different from that inducing the Hb oxidation, because the toxicity was not inhibited by the addition of α-tocopherol at higher doses.

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The effect of subcutaneous administration of carbon tetrachloride to rats on the quantitative and qualitative changes of glycosaminoglycans, i.e., hyaluronic acid (HA), chondroitin sulfates (CS) and dermatan sulfate (DS), in the liver, kidney, spleen, plasma and urine was investigated. In the cases of the liver, kidney and plasma, no difference was found in the amount of glycosaminoglycans between carbon tetrachloride-treated rats and normal ones. On the other hand, all of the glycosaminoglycans examined in this study (HA, CS and DS) increased considerably in the spleen and urine after the repeated carbon tetrachloride administrations.

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Induction of nephropathy by thiabendazole (TBZ) was compared between male and female mice of 5 and 11 week-old. TBZ was suspended in olive oil and mice were given, by stomach tube, a single dose of 1300 mg/kg TBZ only (TBZ group), and 350 or 1300 mg/kg TBZ 1 h after intraperitoneal injection of L-buthionine sulfoximine (BSO), an inhibitor of γ-glutamylcysteine synthetase, (BSO-TBZ350 or BSO-TBZ1300 groups). As controls, mice were given olive oil only in the same manner (control or BSO-control groups). Animals were killed 1, 6 and 24 h after administration of TBZ. Blood urea nitrogen (BUN) and enzyme activities such as alkaline phosphatase (ALP), leucine aminopeptidase (LAP), γ-glutamyl transpeptidase (γ-GTP) and N-acetyl-β-D-glucosaminidase (NAG) in the kidney and urine were determined. Preparations of kidney tissues were also examined by microscopy. Five of 6 males in 11 week-old BSO-TBZ350 group and 6 of 8 females in 11 week-old BSO-TBZ1300 group died within 24 h after TBZ-administration. In mice of male and female BSO-TBZ groups, the relative kidney weight increased significantly, as compared to controls. BUN increased in TBZ and also BSO-TBZ groups 6 h after administration of TBZ. As specific enzyme activities in the kidney, ALP and γ-GTP in 5 week-old males of TBZ group, and ALP in 5 week-old males and 11 week-old females, LAP in 11 week-old females and γ-GTP in 5 and 11 week-old males of BSO-TBZ group decreased significantly. NAG also decreased in 5 week-old males of BSO-TBZ group. In urine of 5 week-old mice, the concentration of protein increased both in male and female animals, and specific enzyme activities such as ALP, γ-GTP and NAG increased in male mice of BSO-TBZ group. Marked dilatation of proximal tubules were observed microsopically at 24 h in TBZ group and at 6 h in BSO-TBZ350 group. These results indicate that the nephrotoxic effect of TBZ in mice increased with glutathione deficiency. It was demonstrated that nephrotoxicity of TBZ was stronger in male mice than in female mice, and in 5 week-old than 11 week-old males of TBZ group and in 11 week-old than 5 week-old males of BSO-TBZ group.

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Chlorpropham (CIPC) residue in imported frozen and fried potatoes obtained in Tokyo were investigated. The mean value of CIPC levels in frozen potatoes was 0.18 ppm, and that in fried potatoes was 0.26 ppm. The CIPC residue percentage in skin portions of frozen potatoes ranged from 32 to 54%. The CIPC level of frozen potatoes decreased during frying or baking, however, the residual percentage was about 80%. CIPC loss may be due to its thermal degradation to m-chloroaniline and removal of the degradation product by volatilization.

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Headspace gas chromatographic analysis using a semi-wide bore capillary column and a dual detection system with a flame ionzation detector (FID) and an electron capture detector (ECD) was carried out for the simple and rapid simultaneous determination of 13 kinds of volatile organic pollutants : benzene (1), toluene (2), ethyl benzene (3), o-, m-and p-xylenes (4-6), monochlorobenzene (7), o-, m-and p-dichlorobenzenes (8-10), 1, 1, 1-trichloroethane (11), trichloroethylene (12) and tetrachloroethylene (13) in drinking water at low ppb (10^-9g/ml) level. The effects of the headspace and syringe temperatures as well as the equilibration time and injection volume of headspace gas on the sensitivity and reproducibility of analysis were examined to find the optimal conditions. The capillary column permitted satisfactory separation of the target compounds except m-and p-xylenes (5 and 6) without interference by trihalomethanes in drinking water. FID was sensitive to all aromatic hydrocarbons (1-6) and monochlorobenzene (7) at 0.3-0.5 ppb, while ECD was poorly sensitive to them. By contrast, ECD was highly sensitive to chlorinated hydrocarbons (11-13) and aromatic chlorinated hydrocarbons except monochlorobenzene (8-10) with detection limits of 0.005-0.02 and 0.2-0.6 ppb, respectively, while FID was poorly sensitive to them. The coefficients of variation (n=4) in the simultaneous analysis using FID and ECD for sample water containing 0.1-20 ppb of the target compounds were 3.4-7.4% with good precision and reproducibility.

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The adsorption characteristics of trichloroethylene (TCE), a major volatile chlorinated hydrocarbon, onto activated carbon fiber (ACF) in gaseous phase were investigated. The adsorption capacities of ACFs were larger with higher grade number, and the adsorption of TCE onto ACF and granular activated carbon (GAC) was recognized as physical one. Applying the Dubinin-Radushkevich (D-R) equation to the adsorption isotherms, ACF could be classified into two types. The differences in the adsorption characteristics of TCE were considered due to the pore size distributions of ACF.

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