Adsorption of Chromium(VI) From Aqueous Solution on Mulberry Shoot Powder

Mulberry shoot powder(MSP) is rich in cellulose and lignin,which can remove heavy metal cations from aqueous solution by adsorption.In this paper,MSP is employed to be as adsorbent to remove Cr(Ⅵ) from aqueous solution.The affecting factors on the adsorption of Cr(Ⅵ) from aqueous solution on MSP,such as pH,shaking time,MSP dose,and initial concentration of Cr(Ⅵ),were investigated.The adsorption isotherms were determined.The thermodynamics and kinetics for the adsorption were fitted.The results showed that adsorption efficiencies of Cr(Ⅵ) in water on MSP are high.The adsorptive capacity increases with the extension of adsorption time,and decreases with the rise of pH.The adsorption equilibrium time is 6 h.The removal rate of Cr(Ⅵ) increases with the increment of MSP dosage,and decreases with the rise of initial concentration of Cr(Ⅵ).The suitable conditions for the adsorption are as following: MSP,5 g/L;pH,1.5;temperature,25 ℃;shaking time,6 hours;initial concentration of Cr(Ⅵ),10 mg/L.The isothermal adsorption can be described well by Freundlich,Langmuir and Temkin models.Under this experimental condition,the adsorption of Cr(Ⅵ) on MSP appears monomolecular layer type.The adsorption performance is good.Cr(Ⅵ) is easy to be adsorbed.The law of dynamics for the adsorption can be simulated by pseudo-first order and pseudo-second order kinetics models.