The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform

A. Sekiya - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, N. Negishi, K. Tokuhashi, K. Ohno, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, which was a parameter of the general BET equation and related to the average pore size of the clay minerals, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption equilibrium coefficient of CH3CCl3 and CH2=CCl2, and the surface reaction rate constant of CH3CCl3 were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in non-humidified air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CCl3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CCl3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics Discussions, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, O. Ohno, N. Negishi, K. Tokuhashi, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, a parameter of the general BET equation, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption constants of CH3CC3 and CH2=CCl2, and a surface reaction rate constant were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in dry air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CC3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CC3 and global OH concentration from the global budget concentration of CH3CCl3.

Shuzo Kutsuna - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, N. Negishi, K. Tokuhashi, K. Ohno, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, which was a parameter of the general BET equation and related to the average pore size of the clay minerals, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption equilibrium coefficient of CH3CCl3 and CH2=CCl2, and the surface reaction rate constant of CH3CCl3 were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in non-humidified air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CCl3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CCl3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics Discussions, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, O. Ohno, N. Negishi, K. Tokuhashi, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, a parameter of the general BET equation, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption constants of CH3CC3 and CH2=CCl2, and a surface reaction rate constant were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in dry air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CC3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CC3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous degradation of Methyl Chloroform (CH3CCl3) on aluminosilica clay minerals as its potential tropospheric sink
    Journal of Geophysical Research: Atmospheres, 2000
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki
    Abstract:

    Heterogeneous reactions of Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) with alminosilica clay particles were examined between 288 and 313 K as a potential sink. Allophane and halloysite particles exhibited the activity to transform CH3CCl3 to 1,1-dichloroethene (CH2 = CCl2). The dependence of the reaction rate on the pretreatment, temperature, and relative humidity suggested that the reaction could proceed under environmental conditions. Illumination of light with wavelength longer than 300 nm did not affect CH3CCl3 decay but caused heterogeneous degradation of CH2 = CCl2 on clay particles. The lower limit of overall sticking coefficient for fresh allophane and halloysite particles was estimated to be 6×10−9 and 1.1×10−8, respectively. Heterogeneous degradation of CH3CCl3 on mineral aerosols and/or soils is worth taking into consideration in deriving tropospheric OH concentrations from global budget concentrations of CH3CCl3.

Takashi Ibusuki - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, N. Negishi, K. Tokuhashi, K. Ohno, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, which was a parameter of the general BET equation and related to the average pore size of the clay minerals, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption equilibrium coefficient of CH3CCl3 and CH2=CCl2, and the surface reaction rate constant of CH3CCl3 were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in non-humidified air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CCl3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CCl3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics Discussions, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, O. Ohno, N. Negishi, K. Tokuhashi, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, a parameter of the general BET equation, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption constants of CH3CC3 and CH2=CCl2, and a surface reaction rate constant were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in dry air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CC3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CC3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous degradation of Methyl Chloroform (CH3CCl3) on aluminosilica clay minerals as its potential tropospheric sink
    Journal of Geophysical Research: Atmospheres, 2000
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki
    Abstract:

    Heterogeneous reactions of Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) with alminosilica clay particles were examined between 288 and 313 K as a potential sink. Allophane and halloysite particles exhibited the activity to transform CH3CCl3 to 1,1-dichloroethene (CH2 = CCl2). The dependence of the reaction rate on the pretreatment, temperature, and relative humidity suggested that the reaction could proceed under environmental conditions. Illumination of light with wavelength longer than 300 nm did not affect CH3CCl3 decay but caused heterogeneous degradation of CH2 = CCl2 on clay particles. The lower limit of overall sticking coefficient for fresh allophane and halloysite particles was estimated to be 6×10−9 and 1.1×10−8, respectively. Heterogeneous degradation of CH3CCl3 on mineral aerosols and/or soils is worth taking into consideration in deriving tropospheric OH concentrations from global budget concentrations of CH3CCl3.

Koji Takeuchi - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, N. Negishi, K. Tokuhashi, K. Ohno, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, which was a parameter of the general BET equation and related to the average pore size of the clay minerals, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption equilibrium coefficient of CH3CCl3 and CH2=CCl2, and the surface reaction rate constant of CH3CCl3 were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in non-humidified air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CCl3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CCl3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics Discussions, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, O. Ohno, N. Negishi, K. Tokuhashi, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, a parameter of the general BET equation, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption constants of CH3CC3 and CH2=CCl2, and a surface reaction rate constant were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in dry air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CC3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CC3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous degradation of Methyl Chloroform (CH3CCl3) on aluminosilica clay minerals as its potential tropospheric sink
    Journal of Geophysical Research: Atmospheres, 2000
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki
    Abstract:

    Heterogeneous reactions of Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) with alminosilica clay particles were examined between 288 and 313 K as a potential sink. Allophane and halloysite particles exhibited the activity to transform CH3CCl3 to 1,1-dichloroethene (CH2 = CCl2). The dependence of the reaction rate on the pretreatment, temperature, and relative humidity suggested that the reaction could proceed under environmental conditions. Illumination of light with wavelength longer than 300 nm did not affect CH3CCl3 decay but caused heterogeneous degradation of CH2 = CCl2 on clay particles. The lower limit of overall sticking coefficient for fresh allophane and halloysite particles was estimated to be 6×10−9 and 1.1×10−8, respectively. Heterogeneous degradation of CH3CCl3 on mineral aerosols and/or soils is worth taking into consideration in deriving tropospheric OH concentrations from global budget concentrations of CH3CCl3.

K. Tokuhashi - One of the best experts on this subject based on the ideXlab platform.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, N. Negishi, K. Tokuhashi, K. Ohno, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, which was a parameter of the general BET equation and related to the average pore size of the clay minerals, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption equilibrium coefficient of CH3CCl3 and CH2=CCl2, and the surface reaction rate constant of CH3CCl3 were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in non-humidified air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CCl3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CCl3 and global OH concentration from the global budget concentration of CH3CCl3.

  • Laboratory study on heterogeneous decomposition of Methyl Chloroform on various standard aluminosilica clay minerals as a potential tropospheric sink
    Atmospheric Chemistry and Physics Discussions, 2003
    Co-Authors: Shuzo Kutsuna, Koji Takeuchi, Takashi Ibusuki, Lin Chen, O. Ohno, N. Negishi, K. Tokuhashi, A. Sekiya
    Abstract:

    Methyl Chloroform (1,1,1-trichloroethane, CH3CCl3) was found to decompose heterogeneously on seven types of standard clay minerals (23 materials) in dry air at 313 K in the laboratory. All reactions proceeded through the elimination of HCl; CH3CCl3 was converted quantitatively to CH2=CCl2. The activities of the clay minerals were compared via their pseudo-first-order reaction rate constants (k1). A positive correlation was observed between the k1 value and the specific surface area (S) of clay minerals, where the S value was determined by means of the general Brunauer-Emmett-Teller (BET) equation. The k1 value was anti-correlated with the value of n, a parameter of the general BET equation, and correlated with the water content that can be removed easily from the clay minerals. The reaction required no special pretreatment of clay minerals, such as heating at high temperatures; hence, the reaction can be expected to occur in the environment. Photoillumination by wavelengths present in the troposphere did not accelerate the decomposition of CH3CCl3, but it induced heterogeneous photodecomposition of CH2=CCl2. The temperature dependence of k1, the adsorption constants of CH3CC3 and CH2=CCl2, and a surface reaction rate constant were determined for an illite sample. The k1 value increased with increasing temperature. The amount of CH3CCl3 adsorbed on the illite during the reaction was proportional to the partial pressure of CH3CCl3. The reaction was sensitive to relative humidity and the k1 value decreased with increasing relative humidity. However, the reaction was found to proceed at a relative humidity of 22% at 313 K, although the k1 value was about one-twentieth of the value in dry air. The conditions required for the reaction may be present in major desert regions of the world. A simple estimation indicates that the possible heterogeneous decomposition of CH3CC3 on the ground surface in arid regions is worth taking into consideration when inferring the tropospheric lifetime of CH3CC3 and global OH concentration from the global budget concentration of CH3CCl3.