A mathematical model of bacteria and predators of bacteria including protozoa and metazoa in the anaerobic-aerobic (oxic) enhanced biological phosphorus removal (EBPR) activated sludge process is presented to clarify the roles of these microorganisms based on the colony forming counts (CFU) analysis of activated sludge bacteria. A laboratory-scale batch-type anaerobic-oxic activated sludge process was operated with mixed liquor withdrawal operation (MWO), which is normally used for pure culture cultivations. While MLSS concentration of the activated sludge in the anaerobic phase and in the oxic phase were almost the same in this operation, CFU of heterotrophic bacteria in the anaerobic phase was much larger than that in the oxic phase. The mathematical model analysis revealed that this difference could be attributed to the food chain of microorganisms in the activated sludge. When population of predators including protozoa and metazoa was expressed as population of a protozoa specie based on the yield coefficient obtained from literatures, the analysis results showed a small increase in predator population could cause much decrease of bacterial population in EBPR process.

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Desertification is the process of land degradation in arid, semiarid and some sub-humid areas, due to adverse climate and human activities. The dust storms in the area are frequently observed in the atmosphere over Japan following the dust falls in the Asian continent, well known as “Kosa” . In this study, in order to monitor Kosa aerosols and to analyze the trend of them, deposition was weekly collected at two points in Ishikawa Prefecture, Japan, where located near the coast of the Sea of Japan. The deposition was collected by using bulk samplers. After the collection, the deposition was immediately filtered through a membrane filter to remove course particles, analyzed to determine its water-soluble chemical composition. All samples were analyzed for anions, such as NO₃^-, SO₄^2-, and Cl^-, and cations, such as NH₄⁺, Ca²⁺, Mg²⁺, K⁺ and Na⁺. According to the analyses of the deposition, it was found that non-sea-salt (nss-) calcium ion and sea-salt components indicated seasonal changes. The nss-calcium ion concentration was higher during March to June than the other seasons as well as to indicate increasing trend year by year. It is suggested from the results that the mass of nss-calcium ion in the deposition was definitely increasing.

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To elucidate atmospheric environment at mountainous sites in Hokuriku district, measurement of ozone (O₃) concentration was performed at Bijyodaira (altitude, 1000m), mid-slope of Mt. Tateyama during the autumn season (September to November) in 2003. Mean concentration of O₃ was 34ppbv. A clear diurnal variation with reaching a maximum during the afternoon was observed until the early October. A maximum concentration in the nighttime occurred in November. The O₃ increase in the daytime seems to be caused by transport of air pollution from lower atmosphere and photochemical O₃ production. On the other hand, the maximum concentration of O₃ at night may be due to air subsidence. The nighttime rising concentration was also observed in the October, therefore, double peaks of O₃ were seen in the early October.

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The elevated sulfate deposition in the Hokuriku district in the winter season has been well documented; however, most observations have been conducted in an urban area but not in a mountainous area. In this study, snowfall was collected in the winter season in both an urban area (Kosugi-machi) and a mountainous area (Taira-mura) to compare the deposition of chemical compounds. In addition, spatial distributions of chemical compounds in snow from the urban area southward to the mountainous area were analyzed by sampling snow packs to complement the data obtained at the two sampling stations. In some of the snow-pack analyses, there was a distinct decrease in sulfate and nitrate concentrations according to the distance from the coastline, while other analyses showed fairly constant concentrations regardless of the distance from the coastline. The decreases in the concentrations seemed to reflect local emissions from the urban area, while the constant concentrations seemed to reflect the air pollutants that are widespread by long-range transportation. The fact that the total sulfate and nitrate depositions did not differ much between the urban and mountainous area throughout the winter might be evidence of long-range transportation.

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A calcium hydrogen phosphate dihydrate (DCPD) reacts with fluoride ion in a solution to form fluorapatite (FAp). This reaction is very selective and efficient enough. The aim of this paper was to develop a simplified method of determination of trace amounts of fluoride in air using transform reaction of DCPD. In this paper, a suitable pH range to fix fluoride in the air to form of fluoride ion was assessed based on chemical equilibrium. It is found that a suitable pH for fixation of fluoride in the air is up to 5.5. The pH of the solution is adjusted about 7.5 because of buffer action derived from DCPD and carbon dioxide in the air. From these results, we have developed a simplified determination of trace amounts of fluoride in the air based on the characteristic of the reaction. Fluoride in the air was collected through water containing DCPD powder. The fluoride in separated as FAp is dissolved in 10 ml solution of pH 7.0 containing NaCl, CyDTA and HEPES. The concentration of fluoride ion in the solution is readily measured by using fluoride ion selective electrode.

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Behavior of corrosion by atmospheric environmental using metal test pieces such as carbon steel, copper and silver was measured and examined in Toyama prefecture from 1988 to 1997 for the purpose of determining the relationship between the corrosion characteristics of various metals and the environmental factors.
The relationship between the corrosion and the environmental factors was estimated by using multiple regression analysis. The analytical results show that the corrosion of each metals is greatly affected by environmental factors such as SPM(suspending particle materials), wind velocity and SO₂. leaching tests for metal pieces were conducted by exposing them to wet deposition to evaluate the effects of the environmental factors on the leaching. The results show that the leaching of Fe³⁺ and Cu²⁺ is greatly affected by the environmental factors such as SPM, SO₄^2-(wet deposition),H⁺(wet deposition) and Ca²⁺(filtrate dross of wet deposition).

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The contributions of non-sea-salt sulfate and nitrate with an origin of the Asian Continent to the concentrations in acid rain in Toyama City were evaluated from the observational data from 1994 to 2003. The non-sea-salt sulfate and nitrate concentrations in winter precipitation in Toyama City ranged from 43.4 to 71.4 μeq/l with a mean value of 60.5 μeq/l and from 14.6 to 26.7 μeq/l with a mean value of 21.7 μeq/l, respectively. The estimated concentrations of non-sea-salt sulfate with an origin of the Asian Continent ranged from 12.6 to 28.7 μeq/l with a mean value of 20.8 μeq/l, while the estimated concentrations of non-sea-salt sulfate with a domestic origin ranged from 30.5 to 46.9 μeq/l with a mean value of 39.8 μeq/l. The estimated concentrations of nitrate with an origin of the Asian Continent ranged from 2.0 to 4.7 μeq/l with a mean value of 3.4 μeq/l, while the nitrate concentrations with a domestic origin ranged from 11.8 to 21.5 μeq/l with a mean value of 18.3 μeq/l. Contribution ratios of non- sea-salt sulfate and nitrate with an origin of the Asian Continent in winter precipitation in Toyama City seemed to have increased since 1997. This could be attributed to the decrease in the concentrations of non-sea-salt sulfate and nitrate with a domestic origin.

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