Lead removal efficiency of various natural adsorbents (Moringa oleifera, Prosopis juliflora, peanut shell) from textile wastewater

The present study deals with the class of natural adsorbents such as Moringa oleifera, Prosopis juliflora seeds and peanut shell for the removal of heavy metal (lead: Pb) from textile wastewater. The above adsorbents were characterized by Fourier transform infrared and scanning electron microscope to predict the functional groups and surface morphology. The effect of adsorbent dose, contact time, metal concentrations and pH on lead removal was studied in batch experiment and found that the maximum removal of lead was found to be 86.0%, 78.0% and 72.0% for M. oleifera, P. juliflora seeds and peanut shell, respectively. Langmuir isotherm best correlated to the experimental data for all three cases and 5.6 mg/g, 1.7 mg/g and 1.4 mg/g maximum adsorption capacity of lead was obtained for M. oleifera, peanut shell and P. juliflora, respectively. Pseudo-first-order and pseudo-second-order kinetics study revealed that pseudo-second-order kinetic model followed better correlation coefficient for M. oleifera (R-2 = 0.998), peanut shell (R-2 = 0.978) and P. juliflora (R-2 = 0.995).