The Study Of Adsorption Characteristics On Alkaline Sludge

Using alkaline sludge in landfill to take place of cover soil is a novel problem. In this paper the adsorption characteristics and mechanism of alkaline sludge were investigated by the method which combined with dynamic experiments and static experiments, and these experiments will provided the theory bases for using alkaline sludge in landfill.The effects of temperature, pH and initial concentration on the adsorption of Cu²⁺, Zn²⁺, Cd²⁺ were studied in the single metal experiments. The results indicated that the adsorption amounts of Cu²⁺, Zn²⁺, Cd²⁺ on alkaline sludge were increasing when the pH and initial concentration were increasing. While, when the temperature was increasing the adsorption amounts were decreasing pH was the main factor which affected the adsorption. When the pH was higher than the jump curve pH, the adsorption of heavy metal on alkaline sludge was physical adsorption, Freundlich isotherm equation could fit the isotherm data well and Elovich equation could best described the adsorption process. In this condition, the main adsorption bond force was Van der waals force Forces, Hydrogen bond forces and Dipole bond force. While when the pH was lower than the jump curve pH, the adsorption of heavy metal on alkaline sludge was chemical adsorption, Langmuir isotherm equation could fit the isotherm data well and Langmuir kinetics equation could best described the adsorption process. In this condition, the main adsorption bond force was Chemical bond force.When Cu²⁺, Zn²⁺, Cd²⁺ were coexist in the system, the adsorption characteristics on alkaline sludge were studied on the basis of competitive adsorption coefficient.