Kinetic modelling of biosorption for hydrocarbon removal from wastewater using a modified logistic equation

The application of raw and modified biomass to remove hydrocarbons from wastewater by adsorption is a common practice. A mathematical modeling of biosorption kinetics is a crucial step to optimize the remediation process. In the present study, kinetic studies were carried out to describe the sorption process of crude oilon waste sunflower stalk pith. To increase sorption capacity, the pith surface was modified with polydimethylsiloxane (PDMS) and hydrophobic SiO2 nanoparticles. The maximum loading of sorption for raw and hydrophobized material was 17.76 g/g and 19.62 g/g for crude oil, respectively. The system reached the equilibrium stage after 24 hours. The uptake profiles have been described by the pseudo-first order rate equation and the pseudo-second order rate equation. The calculated results were compared with experimental data and their fit was poor. To predict biosorption kinetics, a new mathematically efficient procedure based on a modified logistic equation was developed. The results indicate that the sunflower pith is an eco-friendly sorbent with significant potential for the removal of crude oil from water phase.