Abstract
In this study, the removal of Pb(II) from aqueous solutions by tassel powder was studied and optimised.
Batch experimentswere conducted on simulated solutions using tassel powder adsorbent and the effects
of contact time, pH and concentration on the extent of Pb (II) removalwas studied. Equilibrium and kinetic
models for Pb(II) sorption were developed by considering the effect of contact time and concentration
at optimum pH 4 and fixed temperature(25 ◦C). The Freundlich model was found to describe the sorption
energetics of Pb(II) on tassel more fully than the Langmuir. A maximum Pb(II) loading capacity of
333.3 mg/g on tassel was obtained. The adsorption process could be well described by both the Langmuir
and Freundlich isotherms with R2 values of 0.957 and 0.972, respectively. The kinetic parameters
were obtained by fitting data fromthe effect of contact time on adsorption capacity into the pseudo-first,
pseudo-second-order and intra-particle diffusion equations. The kinetics of Pb(II) on tassel surface was
well defined using linearity coefficients (R2) by pseudo-second-order (0.999), followed by pseudo-firstorder
(0.795) and lastly intra-particle diffusion (0.6056), respectively. The developed method was then
applied to environmental samples taken fromborehole waters contaminated with mine wastewater. The
removal of Pb (ND-100%), Se (100%), Sr (5.41–59.0%),U(100%) and V (46.1–100%)was attained using tassel.
The uptake of the metals from environmental samples was dependent on pH, ionic strength and levels of
other competing species.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1001283 |
| Date | 10 March 2008 |
| Creators | Zvinowanda, CM, Okonkwo, GO, Sekhula, MM, Agyei, NA, Sadiku, R |
| Publisher | Elsevier |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | © 2008 Elsevier B.V. |
| Relation | Journal of Hazardous Materials |
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