Adsorption of cyanide from aqueous solutions at pyrophyllite surface

The adsorption of cyanide from aqueous solutions at pyrophyllite mineral surface has been studied by investigating the effect of initial concentration of adsorbate, amount of adsorbent, pH and temperature of test solutions. The adsorption efficiency is observed to be 99% in dilute solutions but decreases down to 40%, with increase in cyanide concentration to 10 ppm. The adsorption is observed to be maximum from neutral solutions and is observed to increase with increase in temperature. The adsorption data have been fitted in Langmuir and Freundlich isotherms and the adsorption has been found to be endothermic in nature in the temperature range 30-60 degreesC. (C) 2001 Elsevier Science B.V. All rights reserved.