废轮胎回转窑中试热解炭的重金属离子吸附特性

The Characteristic of heavy metal ions (Pb2＋，Cr3＋and Cr6＋)adsorption by carbon blacks from pyrolysis of used tires in pilot-scale rotary kiln was studied. The effect of initial solution pH, adsorption time and dosage of PCB (pyrolytic carbon black) on the heavy metal removal was examined. It is found that the initial solution pH has a great effect on the heavy metal removal efficiency. The removal of cations such as Pb2＋,Cr3＋ increases with the increase of solution pH and reaches about 100% in weak acidic and neutral solutions. Cr6＋ can be reduced to Cr3＋ in strong acidic solutions. After the second adsorption, the removal of total Cr reaches above 99%. The removal of Pb2＋and Cr3＋ increases with the increase of adsorption time and PCB dosage which have an optimum value. The adsorption of Pb2＋and Cr3＋ is monolayer adsorption which can be described by Langnuir and two-stage Freundlich equations, and the fitting exponential of Freundlich indicates that PCB has a favorable adsorption effect for Pb2＋and Cr3＋. After acid wash, the adsorption effect of PCB for Pb2＋ will be reduced.