Reactive transport modeling in porous media

Kingsley Onyeka Ezeji

Master's thesis

Abstract:

The main aim of this thesis was to evaluate the mechanisms and characteristics of Pb(II) sorption by biochar which was produced from grape stalks (GSBC) at pH of 5.Di erent initial Pb(II) concentrations of 1mM, 0:2mM and 0:1mM, were examined. The Pb sorption isotherms and kinetics were investigated. The biochar was quite e ective in Pb(II) sorption with a maximum sorption capacity which showed an increase from 10 to 15mg:g􀀀1 as initial Pb(II) concentration increased from 0:1mM to 0:2mM. Increased alkaline earth metal cations concentration indicated that ion exchange was also responsible for Pb(II) sorption. Initial Pb(II) concentration signi cantly a ected biochar properties and played an important role in Pb sorption mechanisms and capacity by biochar. The kinetic data from the sorption experiment were analysed with the use of batch kinetics and analytically, using the pseudo- rst and-second order kinetic models and and intraparticle di usion equation. The equilibrium sorption capacities ,rate constants, kinetic parameters and the associated correlation coe?cients for the applied kinetic model were determined and discussed.Sorption by ion exchange was studied by comparing the total amount of sorped Pb(II) to the total amount of initially sorbed calcium, potassium and magnesium cations released. The results showed the sorption kinetics followed both the pseudo- rst and-second order kinetic model, with relatively high amounts of potassium cations released into the solution, suggesting that the mechanisms of sorption presumably follows a physio-sorption, chemi-sorption and ion- exchange process.

Abstract:

The main aim of this thesis was to evaluate the mechanisms and characteristics of Pb(II) sorption by biochar which was produced from grape stalks (GSBC) at pH of 5.Di erent initial Pb(II) concentrations of 1mM, 0:2mM and 0:1mM, were examined. The Pb sorption isotherms and kinetics were investigated. The biochar was quite e ective in Pb(II) sorption with a maximum sorption capacity which showed an increase from 10 to 15mg:g􀀀1 as initial Pb(II) concentration increased from 0:1mM to 0:2mM. Increased alkaline earth metal cations concentration indicated that ion exchange was also responsible for Pb(II) sorption. Initial Pb(II) concentration signi cantly a ected biochar properties and played an important role in Pb sorption mechanisms and capacity by biochar. The kinetic data from the sorption experiment were analysed with the use of batch kinetics and analytically, using the pseudo- rst and-second order kinetic models and and intraparticle di usion equation. The equilibrium sorption capacities ,rate constants, kinetic parameters and the associated correlation coe?cients for the applied kinetic model were determined and discussed.Sorption by ion exchange was studied by comparing the total amount of sorped Pb(II) to the total amount of initially sorbed calcium, potassium and magnesium cations released. The results showed the sorption kinetics followed both the pseudo- rst and-second order kinetic model, with relatively high amounts of potassium cations released into the solution, suggesting that the mechanisms of sorption presumably follows a physio-sorption, chemi-sorption and ion- exchange process.

Keywords

Kinetic sorption, equilibrium sorption, biochar, heavy metals, decay law, reactive transport

Keywords

Kinetic sorption, biochar, heavy metals, decay law, equilibrium sorption, reactive transport

Language used: English

Date on which the thesis was submitted / produced: 22. 4. 2015

Thesis defence

• Supervisor: doc. Ing. Michal Kuráž, Ph.D.

Czech University of Life Sciences Prague

Faculty of Environmental Science

Master programme / field:
Landscape Engineering / Environmental Modelling