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Wu M.C.,Open City | Kuo S.L.,Kelee Environmental Consultant Corporation | Lin J.C.,National Ilan University | Ma C.M.,St. Mary's College | And 2 more authors.
Applied Surface Science | Year: 2011

Most volatile organic compounds (VOCs) are toxic to humans in some manner. Generally, transitional metal catalysts have better conversion rates for controlling VOCs. However, catalyst activity will decay at high temperature, though the oxidizing catalyst is cheap. This study used smectite as the carrier to exchange with Ag+, Zn2+ and Ti4+ to modify the surface and form smectite catalysts. In addition, the transmission electron microscopy (TEM), FT-IR spectrum, and DSC-TGA instrument were applied to characterize their physical properties. After the FT-IR analysis of the modified smectite catalyst (smectite-Ag, smectite-Zn and smectite-Ti), both smectite and smectite catalyst had significant and complicated wave crests between the fingerprint area with the wave numbers of 415-600 cm-1 and 750-1170 cm-1, that indicated the existence of a strong bond between impure silicates (Si-O) and silicates (O-Si-O). TEM observation proved that sintering at 350 °C results in the distribution of catalyst ions on clay carrier with a nanoscale. As thermal analysis reveals, the smectite reached endothermic peaks at the temperatures of 920 °C and 1057 °C, respectively, and shows the decomposition in a non-crystal form. Besides, the disappearance of the endothermic peak of smectite-Ag occurs at 920.5 °C and the exothermic peak occurs at 950 °C. The results indicating crystals formed of smectite-Ag are more comprehensive and stable than the other smectite or modified smectite catalysts at high temperature. © 2011 Elsevier B.V. All rights reserved.

Wu E.M.-Y.,I - Shou University | Tsai C.C.,National Kaohsiung Marine University | Tsai C.C.,National Cheng Kung University | Cheng J.F.,I - Shou University | And 2 more authors.
Environmental Modeling and Assessment | Year: 2014

This study investigates six water quality monitoring stations in the watershed of the Feitsui Reservoir. It uses nine parameters of water quality collected in an interval of two and half years for factor analyses, which was first conducted to determine four types of factors, respectively, those for organic pollution, eutrophication, seasonal influence, and sediment pollution. The analysis results effectively help to determine water quality in the watershed of the reservoir. The authors reutilize analysis of moment structures (AMOS) to acquire further results in order to confirm the goodness of fit of the previous factor analysis model. During the confirmation, we examine the hypothesized orthogonal results as well as utilize oblique rotation to explore the goodness of fit of the reflective indicators of the orthogonal rotation. As shown in the algorithm results, as long as the covariance curve is included in the four factors, no related issues are detected in the goodness of fit of reflective indicators and interior and external quality is reported with excellence. The orthogonal model, thus, stands. Additionally, when the analysis of structural equation modeling (SEM) is conducted, sample data mismatches the hypotheses of multivariate normality. Therefore, this study adopts the generalized least square (GLS) for an algorithm. Research results of this study have been submitted to the reservoir management authorities in Taiwan for the improvement of statistical application and strategic evaluation of water quality monitoring data in order to strengthen the managerial effectiveness of water quality in watersheds. © 2014 Springer International Publishing Switzerland.

Wu E.M.-Y.,I - Shou University | Kuo S.-L.,Kelee Environmental Consultant Corporation
Water Environment Research | Year: 2012

Multivariate statistics have been applied to evaluate the water quality data collected at six monitoring stations in the Feitsui Reservoir watershed of Taipei, Taiwan. The objective is to evaluate the mutual correlations among the various water quality parameters to reveal the primary factors that affect reservoir water quality, and the differences among the various water quality parameters in the watershed. In this study, using water quality samples collected over a period of two and a half years will effectively raise the efficacy and reliability of the factor analysis results. This will be a valuable reference for managing water pollution in the watershed. Additionally, results obtained using the proposed theory and method to analyze and interpret statistical data must be examined to verify their similarity to field data collected on the stream geographical and geological characteristics, the physical and chemical phenomena of stream self-purification, and the stream hydrological phenomena. In this research, the water quality data has been collected over two and a half years so that sufficient sets of water quality data are available to increase the stability, effectiveness, and reliability of the final factor analysis results. These data sets can be valuable references for managing, regulating, and remediating water pollution in a reservoir watershed.

Wu E.M.-Y.,I - Shou University | Kuo S.-L.,Kelee Environmental Consultant Corporation
Atmosphere | Year: 2013

The air quality in Taiwan, at present, is determined by a pollution standard index (PSI) that is applied to areas of possible serious air pollution and Air Quality Total Quantity Control Districts (AQTQCD). Many studies, both in Taiwan and in other countries have examined the characteristics and levels of air pollution with PSI. This study uses air quality data collected from eight automatic air quality monitoring stations in an AQTQCD in central Taiwan and discusses the correlation between air quality variables with statistical analysis in an attempt to accurately reflect the difference of air quality observed by each monitoring station as well as to establish an air quality classification system suitable for the whole Taiwan. After using factor analysis (FA), seven air pollutants are grouped into three factors: organic, photochemical, and fuel. These three factors are the dominant ones in regards to the air quality of central Taiwan. Cluster analysis is used to classify air quality in central Taiwan into five clusters to present different characteristics and pollution degrees of air quality. This research results should serve as a reference for those involved in the review of air quality management effectiveness and/or the enactment of management control strategies. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

Wu E.M.-Y.,I - Shou University | Kuo S.-L.,Kelee Environmental Consultant Corporation
Water Environment Research | Year: 2015

This article used bentonite impregnated with titanium and silver, respectively, as photocatalyst, to degrade methylene blue (MB) under conditions of MB solutions exposed to sodium lamp and sunlight. Due to the semi-conducting properties of synthesized bentonite catalysts, when exposed to sodium lamp and sunlight, catalyst particles are excited for photocatalysis to achieve decolourization. After an FT-IR analysis, this study finds that smectite catalysts have significant and complicated wave crests between the fingerprint area with wave numbers 415~600 cm-1 and 750~1170 cm-1. The bentonite impregnated with Ti4 (Sm-Ti) and with Ag (Sm-Ag) removes MB through the mechanisms of adsorption and degradation, while the commercial product of titanium dioxide (TiO2) only exhibits the capability of MB degradation. At present, a heterogeneous photocatalytic system has been fully applied for use in daily life, with its efficiency determined by the free radical action of electrons and holes, the generation efficiency of OH.

Wu E.M.-Y.,I - Shou University | Kuo S.-L.,Kelee environmental consultant corporation
Aerosol and Air Quality Research | Year: 2012

Air quality data collected at 8 monitoring stations located in the central Taiwan Air Quality Total Quantity Control District were analyzed using multivariate statistical factor analyses. Based on the results thus obtained, 2 major factors, i.e. photochemical pollution factor and fuel factors, were selected for the purpose of evaluating their variations and the pattern of mutual influences for the various air pollution species with respect to time series. The evaluation was conducted using a vector time series coordinated with the ARCH (Autoregressive Conditional Heteroscedacity) and GARCH (Generalized Autoregressive Conditional Heteroscedacity) models in addition to being combined with dynamic impact response analyses using a multiple time series model. The results reveal that the current O3 value is affected by the PM10 values of both a one time lag and a two times lag, as well as the NO2 value of one time lag. When the current SO2 is produced, its concentration can be used to estimate the current CO concentration, and the one time lag SO2 concentration also influences the CO concentration. Additionally, results of impact response analyses show that current CO concentration responds to variations in current SO2; this indicates that the existence of SO2 due to incomplete combustion at the pollution source is immediately reflected by the current production of CO without lagging. In this paper, the vector time series is coupled with the (G)ARCH model to convert simple data series into valuable information so that raw data are better and more completely presented for the purpose of revealing future variation trends. Additionally, the results can be referenced by authorities for planning air quality total quantity control, applying and examining various air quality models, simulating the allowable increase of air quality limits, and evaluating the benefit of air quality improvement. © Taiwan Association for Aerosol Research.

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