Adsorption of polyacrylamide onto Fuller's earth surface

The adsorption of polyacrylamide onto Fuller's earth surface has been studi ed at fixed pH (4.0) and ionic strength of the medium. The adsorption isoth erms display semi-Langmuirian nature but the kinetic curves show that after a definite time period the exchange phenomenon occurs between the polyacry lamide chain arriving at the interface and those already adsorbed. The adso rption is appreciably affected by the pH, presence of low molecular weight salts, organic solvents, temperature, molecular weight and degree of hydrol ysis of the polymer. Various adsorption and kinetic parameters such as the adsorption coefficient, modified Freundlich adsorption isotherm constants, distribution coefficient, rate constants for adsorption and desorption have also been evaluated.