Lead removal from wastewater using fluted pumpkin seed shell activated carbon: adsorption modeling and kinetics

Activated carbon produced from fluted pumpkin [Telfairia occidentalis] seed shell was utilized for the removal of lead [II] ion from simulated wastewater. Adsorption tests were carried out in series of batch adsorption experiments. Several kinetic models [Bhattacharya-Venkobacher, Elovich, pseudo first and second order, intra-particle and film diffusion] were tasted for conformity to the experimental data obtained. The Langmuir and Freundlich adsorption models were also used to test the data. The amount of lead [II] ion adsorbed at equilibrium from a 200 mg/L solute concentration was 14.286 mg/g. The experimental data conform very well to the pseudo-second order equation where equilibrium adsorption capacities increased with increasing initial lead [II] concentration. The rate of the adsorption process was controlled by the film [boundary layer] diffusion as the film diffusion co-efficient values obtained from data analysis were of the order of 10 6 cm[2]/s. From the plots, the linear regression coefficient [R2] of the Langmuir model was higher than that of the Freundlich: the adsorption isotherm obeyed the Langmuir model better than the Freundlich model

Biokinetics of anaerobic digestion of municipal waste

A study of the biokinetics of anaerobic digestion of municipal solid waste [MSW] was carried out using anaerobic batch digester. From the experimental results, the kinetic parameters [coefficient values] of the digestion of the MSW were determined. The maximum rate of substrate utilization [K], saturation constant [K[s]], endogenous decay coefficient [K[d]], biomass Yield or microbial growth yield [Y] and maximum specific growth rate [micro [max]] were found to be 0.144 day[-1], 21.23 mg/L, 0.038 day[-1], 0.367, and 0.053 day[-1] respectively. These values indicate that practical digesters for MSW will require inoculation of the feed with microorganism to increase the rate of digestion. The biokinetics of anaerobic digestion of MSW was well described by first order kinetic model