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

Abstract

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/l), pH (1–6), contact time (5–240 min), and adsorbent dosage (0.625–6.0 g/l) 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.

Keywords:

• Adsorption
• Lead(II)
• Xanthated date palm trunk
• Batch studies
• Adsorption isotherm

Acknowledgement

The authors are thankful to Director, HBTI, Kanpur, for providing necessary research facilities.