The use of seed pods from Albizia lebbek for the removal of alkyl benzene sulphonates from aqueous solution

The paper presents the results of a preliminaly investigation into the use of Albizia lebbek seed pods as a biosorbent for the removal of linear alkyl benzene sulphonate (LAS) from aqueous solution. It also compares the adsorption characteristics with those of an algal residue. The results showed that at 25 degrees C, the greatest specific adsorption (mg/g) was achieved at low (ca 3) pH values. The results also showed that there was a good compliance with both the Langmuir and the Freundlich equations. Based on the Langmuir equation, the maximum adsorption capacity was 25.43 mg/g. An examination of the kinetics of the adsorption showed that the overall process could be described by the Lagergren equation and that the rate constant (K) increased with the initial concentration of the LAS (C-0). An analysis based on the K/C-0 relationship suggested that at C-0 values of less than 58 mg/litre the Albizia lebbek would be a more appropriate material than the algal residue. Intraparticulate diffusion rates were also measured and were also found to increase with C-0.