【Abstract】 The adsorption of Pb²⁺ and Cd²⁺ on the extracellular protein of natural biofilm was investigated.The extracellular protein was obtained from the extracellular polymers of superiority bacteria of natural biofilm cultivated in C South Lake of Changchun.The results showed that both Langmuir and Freundlich isotherm equations could be used to describe the thermodynamics adsorption processes of Pb²⁺ and Cd²⁺ on the extracellular protein.One order kinetic model of Langmuir-Hinshelwood equation could be used to describe the kinetic adsorption characteristics of heavy metals.The existence of Cd²⁺ affected the adsorption of Pb²⁺,and Pb²⁺ also affected the adsorption of Cd²⁺.Temperature and pH value could also affect the adsorption processes.The mechanism of Pb²⁺ and Cd²⁺ adsorption by the extracellular protein were studied by infrared spectra and the functional groups participated in the adsorption were identified.更多还原