Adsorption study of lead(Ⅱ) onto xanthated date palm trunk: kinetics, isotherm and mechanism

摘要

The adsorption of lead(Ⅱ) onto xanthated date palm trunk (XDPT) from aqueous solutions was studied in a batch adsorption system. Factors influencing lead(Ⅱ) adsorption such as initial Pb(Ⅱ) concentration (25.8-207.0 mg/1), pH (1-6), contact time (5-240 min), and adsorbent dosage (0.625-6.0 g/1) were investigated. The adsorption process was relatively fast and equilibrium was established within 120 min. Maximum adsorption of Pb(Ⅱ) occurred at pH~5. A comparison of the kinetic models on the overall adsorption rate showed that the adsorption system can be best described by the pseudo-second-order kinetics. The adsorption equilibrium data obeyed Langmuir isotherm and the monolayer adsorption capacity of Pb(Ⅱ) was found to be 53.48 mg/g. The adsorption mechanism has been suggested to be due to the complexation of lead(Ⅱ) ions with sulfur donors present in XDPT.