Temperature dependence of herbicide adsorption from aqueous solutions on activated carbon fiber and cloth.

Diuron and amitrole adsorption from aqueous solution on an activated carbon fiber and an activated carbon cloth were studied as a function of temperature. Diuron adsorption was greater than that of amitrole and increased with rising temperature, whereas amitrole adsorption decreased when the temperature increased. Endothermicity of diuron adsorption was due to an increase in the planarity and diffusion of diuron molecules with higher temperatures. However, the exothermicity found for amitrole was due to the increase in amitrole solubility and in vibrational energy of adsorbed molecules with higher temperature. External mass transfer resistance was also found to play an important role in diuron adsorption on activated carbon cloth.