Research Article
Kamau J and Kamau G
Abstract
The present study deals with modeling of experimental adsorption data of chlorothalonil by Nairobi River sediment. Effects of initial concentration, different shaking time and contact time were investigated. The concentration of chlorothalonil in the clear aqueous solution (Ce) was determined by reversed phase HPLC. Determinations were made using the 15 cm MCH-5- N-CAP C18 column and 85% HPLC grade acetonitrile in distilled water as the mobile phase. Adsorption isotherm study indicated that the Quasi Langmuir (Scatchard plot) fitted the experimental data with heist regression values range of 99.8 to 100. Thermodynamic study calculations shows that the Gibbs free energy for chlorothalonil was -9.2687 kj/mol calculated using Freundlich and Langmuir constants. The maximum adsorption capacity of Nairobi river sediment was 33.389 mg/ml. Finally, Kinetics study revealed that the adsorption of chlorothalonil onto Nairobi river sediment falled a pseudo second order kinetics.