Study On Adsorption And Desorption Characters And Mechanism Of Phenol And Cd～(2+) In Lou Soil Modified By BS-8

The adsorption and desorption of phenol and Cd2+ in Lou soil modified by BS-8 were conducted in single and coexistent condition. And the thermodynamic characters were analysed, the conclusion are showed as follows:1.After modified with BS-8, the adsorption of phenol is increased obviously, the adsorbent order is as follows: 100% BS-8>50%BS-8>CK. And the adsorption amount in same soil decreased when temperature rising. The adsorption of phenol can be described with Freundlich equation. The thermodynamics analysis showed that the adsorption of phenol in modified soil was spontaneous, and the spontancity was controlled by heat releasing. The mechanism of phenol is physical adsorption decisively, and co-existed with the chemical adsorption.The desorption of phenol from modified soil presented 100% BS-8>50%BS-8>CK which showed that desorption amount increasing with modifying ratio increment. The desorption amount decreased in the same soil with temperature rising. The Freundlich equation is the best one to describe the relation between rest adsorption and equilibrium concentration. The results of thermodynamics showed that desorption is spontaneous with enthalpy decrease and entropy increment.2. The adsorption of Cd2+ presented 100% BS-8>50%BS-8>CK, but the adsorption amount in 50% and 100% modified soil are close. The adsorption amount decreased with temperature rising. Langmuir equation can describe the isotherm. The thermodynamics analysis showed that adsorption of Cd2+ was spontaneous with heat releasing and entropy increment, and the entropy increment is decisive to the spontancity. The physical adsorption is stronger than chemical adsorption.The desorption regularity of Cd2+ is as follows: 50%BS-8>CK>100% BS-8. The desorption amount of 50%BS-8 soil is the lowest while the adsorption is the highest. The Langmuir equation can well describe the relation between rest adsorption and equilibrium concentration in CK and 50%BS-8 sample. The results showed that desorption of Cd2+ cann't happen without energy outside. Mutation took place on 100%BS-8 sample when equilibrium...