Toru Ozeki

Evaluation of sources of acidity in rainwater using a constrained oblique rotational factor analysis.

Acidity (or basicity) of sources of rainwater pollutants, whether they work as acids, bases, or neutral substances, is not easily evaluated by using conventional multivariate analysis such asthe principal component analysis (PCA) or that with the Varimax rotation. We examined the application of an oblique rotational factor analysis in this work based on the nonnegative constraint as to the ion concentrations except hydrogen ion and to the contributions of pollutant sources in rainwater. The method is as follows : (1) the PCA, (2) the Varimax rotation, and (3) the oblique rotation with partially nonnegative constraint. The method and its validity are demonstrated by using analytical data for 391 rainwater samples collected at Hyogo prefecture in Japan during 1991-1992. As a result, four predominant pollutant sources were extracted ; they were a source with sea salt origin, a source acidifying rainwater, a source basifying rainwater, and a source specific to potassium ion. At most, six pollutant sources were extracted and were reasonably interpreted from the chemical, biological, geographical, and meteorological points of view.

Cloud droplet size dependence of the concentrations of various ions in cloud water at a mountain ridge in northern Japan

Acid precipitation is one of the global environmental problems affecting terrestrial and aquatic ecosystems. Our research group has recently studied the acid precipitation in Hyogo and Akita Prefectures in Japan, combining chemical analysis of ions with analysis of meteorological conditions, and has analyzed the source of pollutants by Ž . factor analysis Ozeki et al., 1995, 1997; Ogawa et al., 1998a,b . It is known that fogrcloud water is significantly more acidic and has higher concentrations of chemical Ž . components than rain water e.g., Waldman et al., 1982; Hosono et al., 1994 . The mechanism of uptake of ion components into cloud droplets, especially for the difference between ions, is not completely understood. Cloud water and rain water samples were collected at the Hachimantai mountain range in Akita Prefecture in northern Japan to obtain information on the mechanism of uptake of ion components into cloud droplets. The chemical composition of the cloud water was analyzed and compared with that of the rain water. The relationship among ion concentrations in the cloud water and droplet size was examined Ž X X Cloud water samples were collected along the mountainside 39856 N, 140851 E, . Ž . 1465 m, a.s.l. of Mt. Mokkodake 1578 m, a.s.l. , a mountain ridge in the Hachimantai Ž . Ž range. A passive fog sampler Okita, 1961 with a cylindrical Teflon wire screen Model . FWP-500, Usui Kogyo Kenkyusho was exposed during the period from August to Ž . September 1997. Rain water samples were collected at Akita City Akita University

Evaluation of ionic pollutants in cloud droplets at a mountain ridge in northern Japan using constrained oblique rotational factor analysis

The scavenging of aerosol particles by precipitation and fogrcloud plays an important role in the distribution and concentration of pollutants in the atmosphere. Our research group has recently studied the acid precipitation in Hyogo and Akita Prefectures in Japan, combining chemical analysis of ions and analysis of meteorological Ž . Ž conditions, and has analyzed the ionic pollutants salts by factor analysis Ogawa et al., . 1998a,b, 1999a,b; Ozeki et al., 1995, 1997 . In general, it is known that fogrcloud water is significantly more acidic and has higher concentrations of chemical components than Ž . rain water e.g., Waldman et al., 1982, Hosono et al., 1994, Ogawa et al., 1999a,b . But the mechanism of uptake of ion components into cloud droplets, especially for the Ž difference between ions, is not completely understood. In our previous works Ogawa et . al., 1999a,b , cloud water and rain water samples were collected at the Hachimantai mountain range in Akita Prefecture in northern Japan to obtain information on the mechanism of uptake of ion components into cloud droplets. We obtained the information about relationship among ion concentrations in the cloud water and droplet size Ž . Ogawa et al., 1999a,b . In this work, we tried to analyze the seasonal change of ionic pollutants in cloud water due to a variation of mesoscale precipitation system and their dependence upon the cloud droplet size using constrained oblique rotational factor analysis, which has

Chemical Characterization of Acid Fog and Rain in Northern Japan Using Back Trajectory and Oblique Rotational Factor Analysis

Fog/cloud and rain water were collected at the mountainside of Hachimantai range in northern Japan and rain water was also collected at Akita City in order to investigate the air pollutant scavenging mechanism. The concentrations of various ions in these samples were analyzed, and the fog drop size and the wind direction were measured at each fog event. The fog at Hachimantai range had a very high total ion concentration, and was considerably acidified by non sea salt (nss-) SO42− and NO3−, compared with the rain at Akita and all sites in Hachimantai range. Using the oblique rotational factor analysis, three factors were extracted as the air pollutants; A: (NH4)2SO4+H2SO4, B: sea salts+HNO3+H2SO4, C: NH4NO3+OH−. These salts are well-known as the cloud condensation nuclei (CCN). Combining the factor analysis with the 72h back trajectory at 850hPa level, the contribution of Factor A was closely connected to the long-range transportation of anthropogenic or natural aerosol in air masses of continental origin.

Study of Adsorption, Condensation, Orientation, and Reduction of Quinoline Molecules on a Pure Mercury Electrode Using Raman Microprobe Spectroscopy

Quinoline is known to adsorb on a mercury electrode surface with several differentorientations and it sometimes blocks other electrochemical reactions. The Ramanmicroprobe technique has been applied successfully to observe reorientations ofquinoline adsorbed on the mercury surface from neutral and basic aqueoussolutions. The orientation-distance profile from the mercury surface was also studied.A Raman band intensity of quinoline (1373 cm−1) relative to the intensity ofperchlorate ion (931 cm−1) was measured. The peak positions did not shift evenwhen the applied potential was altered, but the relative peak intensity changed.It was concluded that the adsorbed quinoline changes its orientation from a flatat −0.1 > E > −0.3V, to a standing at E < −0.5 V, passing through a mixtureof the two orientations when −0.3 > E > −0.5 V.

Separation of two overlapping redox waves by cyclic-voltammo-thermometry: Applications to Cu/CuCl and Ag/AgCl systems in chloride solutions

Abstract When two reactions take place at a given potential, other information is necessary, in addition to the relation between the applied potential and electric current, in order to evaluate the individual contribution of the reactions. Information about the heat evolved at the electrode during cyclic voltammetry enables the reaction components to be separated. It is concluded that the Cu/Cu I redox system in chloride solution (0.1 − ] M ) giving a simple CV curve, can be divided into two reactions: Cu/CuCl ad and Cu/CuCl − 2 . A similar overlap of the Ag/AgCl ad and Ag/AgCl − 2 reactions is also observed for the Ag/Ag I redox system in 7 − ] M solutions.

Study of the prussian blue/prussian white redox reaction by cyclic voltammothermometry

Abstract In the reaction of the prussian blue (PB)/prussian white (PW) redox system, a pair of large peak currents was observed when potassium ion was used as the supporting cation. But when the other alkali halides were used, such peaks could not be observed. This phenomenon was studied by means of cyclic voltammothermometry (CVT). The contribution of the charging current was separated from that of the faradaic current. The charging current had a large contribution to the total current in the PW/PB redox system. The explanation given by the model for the appearance of the peak current is that the potassium ion could not enter the PB lattice hole but could enter the PW lattice hole. The heat generation of two typical FeII/III redox systems, the aquo ion system and the ferrocyanide/ferricyanide system, was also measured for reference and the effect of the solvation states of the ions on the electrode reaction heat was examined.

Study of the reorientation of quinolinium ions in the mercury electrode | acidic aqueous solution interphase using Raman intensity/distance profiling microprobe spectroscopy

Abstract In a previous study, the adsorption of quinoline from a neutral and an alkaline solution onto a mercury electrode surface was investigated by Raman microprobe spectroscopy. Potential-dependent orientations of quinoline adsorbed upon the mercury surface and film formation were observed, depending upon the applied potential. In this work, where specific adsorption was not observed, the Raman intensity/distance profile of the quinolinium ion in a 40 mM quinoline+0.1 M HClO 4 solution was studied. The dependence of the relative peak intensity R of the quinolinium ion (760 cm −1 ) to that of the perchlorate ion (923 cm −1 ) was measured. The Raman peak positions did not shift, but the relative peak intensity changed with the applied potential. The data are interpreted in terms of a change of orientation of the quinolinium ion on approaching the electrode from perpendicular (NH + site pointed toward the aquated mercury surface) at E + site pointed toward the bulk solution) at E >+200 mV, through random orientations for−300 E

Relationships between chemical compositions and meteorological conditions for fog and rain at Hachimantai range, and rain at Akita city in Japan.

Acid fog and rain samples were collected at Mountain range of Hachimantai and at Akita City in Japan. Various ion concentration of these sample were analyzed using an ion chromatography and pH meter. The NO3- concentration of rain at Akita increased gradually year to year. The fog water had a high concentration of various ions compared with the rain. The highest concentration was observed in the weather chart of high pressure on Japan Island. The fog water had a low concentration for various ions in autumn compared with those in spring, so that this result agreed with the fact that the autumn sky is clear and clear in Japan.

Estimation of the Structure of the Species from UV/V Absorption Spectra Using Factor Analysis and Molecular Orbital Calculations

UV/V absorption spectra are based on the electronic transition between molecular orbitals which reflect the structure of the species. The dissolved structures of phenolphthalein-related species were estimated from the comparison of the spectra reproduced from MO calculations with the pure component spectra obtained by factor analysis.