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Rice bran was found to effectively adsorb pesticides in artificial gastric fluid. Equilibrium adsorption isotherms conformed to the Freundlich type (loglog linear). Pretilachlor and esprocarb were successfully removed in artificial gastric fluid with an average removal efficiency of 85.5% and 95.8%, respectively after 90min when rice bran (10g/l) was added to samples containing from 0.05 to 5mg/l of pesticides. The removal of pesticides by rice bran was attributed to the uptake by intracellular particles called spherosomes.

The effectiveness of spherosomes for reducing pesticide accumulation in cucumbers and for the control of Aphis gossypii Glover was studied. Spherosomes could efficiently reduce the uptake of imidacloprid in cucumbers. In the case of imidacloprid with spherosomes, the number of Aphis gossypii Glover, surprisingly, became zero after 3 and 7 days, and showed almost the same effect as imidacloprid without spherosomes, although the concentration of imidacloprid in cucumbers decreased by about 1/5 in comparision with that without spherosomes. It seems more likely that spherosomes might have a role as adsorbent materials for removal of imidacloprid in soil. The application of spherosomes to farmland is a useful and effective method to keep the concentration of pesticides in crops at a low level, resulting in sustainable agriculture.

The object of this work was to investigate several adsorbents to determine their effective removal of benzene from wastewater. Tea and coffee lees were found to effectively adsorb benzene. Equilibrium adsorption isotherms conformed to the Freundlich isotherm (log-log linear). Adsorption of benzene by tea or coffee lees was observed in the pH range of 1 to 11. At equilibrium, the adsorption efficiency of tea or coffee lees for benzene was lower than that of activated carbon. The removal of benzene by tea or coffee lees was attributed to the uptake by intracellularparticlescalledspherosomes. Ninetyminutes after application of lees to wastewater (pH 10) containing 0.1g/l of benzene, 75 to 82% of the benzene had been removed.

The fate of pretilachlor and esprocarb in soil with or without spherosomes was investigated for 71 days. The estimated half-lives of pretilachlor in nonsterile soil with and without spherosomes were calculated to be 35.6 and 54.3 days, respectively, while those of esprocarb in nonsterile soil with and without spherosomes were 35.5 and 44.8 days, respectively. The degradation of these pesticides appeared to be essentially due to the biological activity of the soil. Spherosomes should enhance the rate of pretilachlor and esprocarb destruction.

Rice bran was found to effectively adsorb pdichlorobenzene. The amount of p-dichlorobenzene adsorbed was plotted against the equilibrium concentration of substsnces in solution on a logarithmic scale, and a linear relationship was obtained, indicating that the adsorption reaction was Freundlichtype. Adsorption of p-dichlorobenzene by rice bran wa so bserved in the pH range 1–12. The removal of p-dichlorobenzene by rice bran was attributed to the uptake by intracellular particles called spherosomes.

The efficiencies of rice-bran for removing pesticides from vegetables was studied. Chlorothalonil was successfully removed from commercial eggplant and cucumber with an average removal efficiency of 95% after 5 min when vegetables were pickled in rice-bran paste. Moreover, tetradifon was removed from commercial eggplant, commercial cucumber, and cultivated cucumber with an average removal efficiency of 80% after 10 min. The mechanism of pesticides removal by rice bran was attributed to the uptake of pesticides into intracellular particles called spherosomes.

Rice bran was found to adsorb Fe3+ effectively over the range of pH 1-12. Therefore rice bran is applicable for uses in the food industry over a wide pH range. Fe3+ was successfully removed from water samples with an average removal efficiency of 88.5% after 90 min when rice bran was added to water samples containing 5 mg/l Fe3+. The removal of Fe3+ by rice bran was attributed to the chelating properties of phytic acid. Here, we report a fundamental study on the efficiency of rice bran for the removal of Fe3+ using a batch system on a laboratory scale and describe the elucidation of the mechanism of Fe3+ removal by rice bran.

Rice bran was evaluated for the prevention of bulking in the activated sludge process. After the addition of rice bran to the aeration tank of a food plant, a decrease in the sludge volume index was observed. Both biochemical oxygen demand and chemical oxygen demand showed significant decreases relative to that before the addition of rice bran. Rice bran accelerated the growth of the effective microorganism and thus inhibited the growth of filamentous organisms that cause bulking. The results suggest that phytic acid in rice bran is useful in controlling filamentous bulking in laboratory-scale investigations.

The effect of residual chlorine on the growth of Selenastrum capricornutum was investigated by an algal growth test to evaluate toxicity. Significant reductions in growth due to monochloramine were observed in the green alga, Selenastrum capricornutum; however, algal growth was not inhibited in the medium containing rice bran because of the disappearance of monochloramine. The removal of monochloramine by rice bran was attributed to the chemical’s decomposition by direct reaction with the rice bran. In contrast, no significant reduction in growth was observed in the medium containing free chlorine. The decomposition rate of monochloramine was slower than that of free chlorine in the medium.

Rice bran, wheat bran, rapeseed, linseed, okara, and sakekasu were evaluated for correlations between their effectiveness in adsorbing organochlorine compounds such as chloroform, dichloromethane or benzene and the number of spherosomes. Wheat bran contained the highest concentration of spherosomes, with a mean level of 4.37 × 1010 spherosomes/g. The lowest was sakekasu, with a mean level of 2.28 × 1010 spherosomes/g. There was a high correlation between removal efficiency and the number of spherosomes.

Defatted seeds effectively adsorbed organochlorine compounds such as chloroform, dichloromethane and trichloroethylene. The amounts of these compounds adsorbed was plotted against the equilibrium concentration of substances in solution on a logarithmic scale. A linear relationship was obtained, indicating that the adsorption reactions were Freundlich type. The adsorption of these compounds by defatted seed was observed over the range of pH 1-11. Chloroform was successfully removed from tap water with an average removal efficiency of 70% after 60 min when rapeseed was added to tap water that contained 0.0073 mg/l chloroform. The removal of these organochlorine compounds by defatted seed was attributed to the uptake by intracellular particles called spherosomes.

Rice bran effectively removed pesticides from an aqueous solution. The removal by rice bran was examined using 22 different pesticides. The removal efficiencies varied from 22.2% to 98.8%. The variation in the removal efficiency of different pesticides was studied, and the pesticidese with high lipophilicity were found to be easily removed by rice bran. The amount of captan adsorbed was plotted against the equilibrium concentration of substances in solution on a logarithmic scale, and a linear relationship was obtained, indicating that the adsorption reaction was a Freundlich-type. The mechanism of pesticides removal by rice bran was attributed to the uptake into intracellular particles called spherosomes.

To study the origin of chloroform in vegetables, a simple and sensitive method was established using a gas chromatograph equipped with an electron capture detector. The method includes solvent trapping of chloroform, and gas chromatographic separation with a detection system. The average concentrations in vegetables, tea leaves and frozen vegetables were 30.9, 62.9 and 15.7 µ/kg, respectively. Tea leaves contained the highest amount, followed by vegetables. The former was 2 times the latter. There was no significant difference between chloroform levels in vegetables grown in tap water (chloroform : 19.7‐25.0 µg/L) and those in boiled distilled water. On the other hand, there was a high correlation between the number of cultivation days and chloroform levels in vegetables grown in both tap water and boiled distilled water.

Subacute vanadium toxicity was investigated in rats. Female Wistar strain rats, weighing 180g (approximately 6 weeks old), were divided into three groups of seven each. They were fed a base diet with addition of various concentrations of vanadium (0, 50 or 100ppm) for 10 weeks. The amounts of vanadium found in kidney and liver increased in response to vanadium exposure. A significant increase in metallothionein (MT) was observed in kidney of both the 100ppm and 50ppm vanadium-fed groups. Significant decreases in hemoglobin, hematocrit and leukocyte counts were also observed in the former, as well as decreased lymphocyte counts, B cells and immunoglobulin G and M levels.

Dichloromethane levels in wastewater discharged from chemical laboratories were measured. The average concentrations of this compound in wastewater untreated and treated by a chemical wastewater treatment plant were 0.17 and 0.07 mg/l, respectively. Using a vacuum pump instead of aspirator to evaporate this solvent in the laboratories effectively reduced the amount of dichloromethane in wastewater. Furthermore, the removal efficiency of dichloromethane in the treatment plant of chemical wastewater by use of activated carbon adsorption and coagulation precipitation processes was investigated. The results of monitoring for one year showed that the removal efficiency of dichloromethane from wastewater in the treatment plant was on the average 67.4%. Our experiments showed that the prolongation of reaction time of activated carbon adsorption to 30 min sufficiently improved the removal efficiency of dichloromethane. Activated carbon adsorption process was very effective to remove this compound, but coagulation precipitation process was not effective.

Trihalomethane levels and parameters (pH, temperature, KMnO4-consumed values and residual chlorine) in tap water samples obtained from Kinki area in Japan were measured. Furthermore, we studied the effect of the addition of activated carbon during the preparation process on the trihalomethane levels in tap water. Sixty eight samples of tap water were collected from the domestic water supply of Hyogo, Osaka, Kyoto and Nara prefectures. No significant correlation was found between the trihalomethane levels and parameters. On the other hand, the addition of activated carbon to tap water significantly decreased the trihalomethane levels.

The efficiency of removing chloroform and carbon tetrachloride from chemical wastewater by a water treatment plant using activated carbon adsorption and coagulation precipitation processes was investigated. The results showed that the treatment removed the two compounds with a respective average efficiency of 82.3% and 84.7%. Both coagulation precipitation and activated carbon adsorption processes showed effective removal results.

The removal efficiency of phenols from the treatment plant of chemical wastewater by use of activated carbon adsorption and coagulation precipitation processes was investigated. The results of monitoring for one year showed that the removal efficiency of phenols from wastewater by the treatment was on the average 73.6%. Our experiments showed that the prolongation of reaction time of activated carbon adsorption to 30 min sufficiently improved the removal efficiency of phenols. Activated carbon adsorption process was very effective to remove phenols, but coagulation precipitation process was not effective.

Benzene is encountered in a wide variety of chemical processes. Because of its high toxicity, it determination in air has been reported by several research groups, but few reports concerning its analysis in wastewater have appeared. In order to establish a simple and precise method for the determination of benzene in wastewater, the authors have studied a gas chromatographic method.

We studied the effects of concentrations of Ca2+, Mg2+, Na+, K+, total phosphorus and orthophosphate on growth of phytoplankton in the water of Lake Biwa. Water samples were taken from the southern part of the lake 15 times from June 1986 to May 1987. The metal ion concentrations in the samples were determined by an atomic absorption spectrophotometric method after diluting with 0.01 N-HNO3, while the concentrations of total phosphorus and orthophosphate were determined by an atomic absorption spectrophotometric method with or without oxidation by potassium peroxodisulfate. The number of phytoplankton cells was counted under a microscope. No significant correlation was observed between the number of phytoplankton and concentrations of Ca2+, Mg2+, Na+, or K+. In contrast, the numbers were highly significantly correlated with the concentrations of total phosphorus.

Removal efficiency of chloroform from tap water by rice bran was investigated. The adsorption rate by rice bran was similar to activated carbon. The amount of chloroform adsorbed was plotted against the equilibrium concentration of chloroform in solution on a logarithmic scale. A linear relationship was obtained, indicating that the adsorption reaction was a Freundlich type. The adsorption of chloroform by rice bran was observed in the range of pH 1-11. Chloroform was successfully removed from tap water with average removal efficiency of 70% after 60 min when rice bran was applied to tap water that contained 0.0064 mg/L chloroform.

Water pollution by volatile chlorinated organic compounds has become a serious environmental problem. The Environmental Agency of Japan has defined the regulations on trichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane and carbon tetrachloride in wastewater in 1989. In order to protect against water pollution, it is important to keep concentrations in these compounds in environmental water as low as possible. Therefore, the determination of these compounds in rain water is very important to evaluate the loading amounts of these compounds into environmental water. Since few detailed reports have been made as to the assay of these volatile substances in rain water, we investigated this and compared these compound levels in rain water collected from three different locations in Kobe, Japan. The assayed values were compared to each other. 3 refs., 4 figs., 1 tab.

In 1982, Environment Agency of Japan defined a regulation on total phosphorus and the total nitrogen concentrations in lake water as an index of environmental quality standard to protect from the pollution. At the same time, an official method for the determination of total phosphorus and total nitrogen was published. Therefore, the concentrations of these compounds in lake and river water in the south area of Hyogo prefecture in Japan were determined to be compared with the regulation of the environmental quality standard. Water samples were also taken from the area and Lake Biwa and Yodo River as comparison. The 18 samples among 29 of lake water exceeded the limit (0.1 mg/l) of total phosphorus, while the 19 samples among 29 of lake water exceeded the limit (1.0 mg/l) of total nitrogen.

We have previously proposed an atomic absorption spectrophotometric method for determination of total phosphorus in water. In this paper, the proposed method was applied to the rain water collected for a year (July 1984-June 1985) from three different locations : Kobe, Amagasaki and Miki. The concentrations of total nitrogen in the water samples were also determined by a conventional method as described in the Official Gazette. Kobe, Amagasaki and Miki, situated in the southern part of Hyogo prefecture in Japan, were chosen as representatives of residential, industrial and agricultural areas, respectively. The water samples from Miki contained significantly higher concentrations of total phosphorus than those from Kobe and Amagasaki, this might be due to fertilizer used in the agricultural area. In contrast, the concentrations of total nitrogen in the samples from Amagasaki were significantly higher than those from the other two locations, which suggested that the nitrogen in rain water might be derived from air pollution with nitrogen oxides owing to motor vehicles and factories in the industrial area.

A simple, precise and sensitive method for the determination of polyoxyethylene-type nonionic surfactants in water was established by using atomic absorption spectrophotometry with a graphite furnace atomizer. The proposed method is based on the atomic absorption spectrophotometric determination of cobalt in a chelate complex produced by the reaction of nonionic surfactants with ammonium cobaltothiocyanate reagent used in the spectrophotometric method of JIS K 3364 and K 0102. The interference by anionic and cationic surfactants could be removed by a cleanup procedure involving ion exchange resin column chromatography. The recoveries of polyoxyethylene-n-dodecyl ether as a standard compound in various environmental water samples were within the range of 93.0-111.3% and the coefficients of variation were within 9.0% ; these values are satisfactory. The proposed method does not require any preliminary concentration procedure because of the high sensitivity (detection limit : 0.001 mg/l). There was a highly significant correlation (γ=0.999) between the results obtained by the proposed method and those of the JIS K 3364 and K 0102 spectrophotometric method. The assayed values of nonionic surfactants in water samples obtained from 18 rivers were distributed between 0.001 and 0.895 mg/l.

The effect of wavelength on the photochemical decomposition of dodecylbenzenesulfonate (LAS) and the decomposition process were investigated. When LAS in water was subjected to monochromatic irradiation between 200 and 700 nm from a spectroirradiator equipped with a Xe arc lamp, the largest decomposition rate was observed at 215 nm. Thus a low-pressure mercury lamp providing radiation mainly in the lower ultraviolet (UV) range was chosen as a light source for the photochemical reaction. LAS in various kinds of water samples, e.g., city sewage, treated sewage water, river water, sea water and others, was found to be rapidly decomposed by irradiation with the light source and there was little difference among water samples. Since formaldehyde and formic acid were identified among the photochemically decomposed products of LAS, it is suggested that LAS is photochemically decomposed through formaldehyde and formic acid.

Concentrations of cyanide ion in untreated and treated water discharged from chemical laboratories were determined sixty-nine times from July 1986 to December 1986. The average concentrations of cyanide ion in the untreated and treated water were 0.010 mg/l and 0.007 mg/l, respectively. These values are very low in comparison with the allowance limit provided by the regulation of Kobe City on waste water (0.7 mg/l). Even though the amount is very small, the existence of cyanide ion in the treated water cannot be disregarded because of its high toxicity. It was found that the cyanide ion in the treated water was formed by the reaction of phenol with nitrous acid.

In order to research the origin of taste of so-called "delicious natural water", chemical components of tap and natural water samples were measured and compared to each other. The values of pH, carbonate ion, KMnO4-consumed values and ion levels in the samples were determined by the officially established methods for drinking water. Twenty-one kinds of tap water samples were collected from the domestic water supply of Hyogo, Osaka and Nara prefectures. On the other hand, 10 kinds of natural water samples were collected from Hyogo, Osaka and Nara prefectures, while the other 11 samples purchased at markets were originated from several parts of Japan. The tap water samples gave significantly higher values on the KMnO4-consumed values and the concentrations of chloride and sulfate ions and iron (Fe2++Fe3+) than the respective data in the natural water samples. In contrast, the concentrations of carbonate ion in the natural water samples were significantly higher than those in the tap water samples.