The effect of environmental factors on the uptake of 60Co by Paecilomyces catenlannulatus

Paecilomyces catenlannulatus (P. catenlannulatus), a kind of important pathogenic fungi of forest pests, can be regarded as an excellent material to retard the fate and transport of radionuclides. The effect of environmental factors (i.e., pH, ionic strength, temperature and solution concentration) on the uptake of ⁶⁰Co by P. catenlannulatus was investigated by batch technique. The results showed that the uptake of ⁶⁰Co by P. catenlannulatus was independent of pH at pH < 5.0, whereas the enhanced uptake of ⁶⁰Co was observed with increasing pH from 5.0 to 8.0, then remained the high-level uptake at pH > 8.0 due to occurrence of precipitates. It is found that ⁶⁰Co uptake significantly decreased with increasing ionic strength at low pH, whereas little change was observed at high pH. The pH dependence adsorption indicates that the interaction mechanism between ⁶⁰Co and P. catenlannulatus is ion exchange at low pH and surface complexation at high pH conditions, respectively. Compared to Freundlich model, the adsorption isotherms can be fitted by Langmuir model very well. The thermodynamic data calculated from the temperature adsorption isotherms indicated that the uptake process of ⁶⁰Co by P. catenlannulatus was an endothermic and spontaneous process. This paper focused on potential application of P. catenlannulatus as suitable bio-materials for the preconcentration and removal of radionuclides from aqueous solutions in environmental pollution management.