ADSORPTION CHARACTERISTICS OF HEXAVALENT CHROMIUM ON POPLAR LEAF MODIFIED BY OXALATE

Poplar leaf modified by oxalate as a novel biosorbent was investigated to remove Cr( VI) from aquatic solution in batch experiment． The results indicated that when the pH was 2. 0，adsorbate dosage was 0. 3 g，reaction time was 120 min， the remove rate of the concentration of 50 mg /L Cr( VI) wastewater was 99. 1%． The kinetic adsorption process of Cr( VI) ions on poplar leaf modified by oxalate was fitted by pseudo-second-order kinetic model，and the adsorption was mainly ion exchange adsorption． Langmuir equation could simulate the material process of isothermal adsorption of Cr ( VI) ． The fitting results indicated the adsorption of Cr ( VI ) ions was monolayer adsorption，and the maximum adsorption capacity was 40. 91 mg /g． The thermodynamics analysis showed that the adsorption process of Cr( VI) ions on poplar leaf modified by oxalate was spontaneous，endothermic physical adsorption．