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\hypersetup{pdftitle={Sorption of Pb (II), Cu (II), Zn (II), and Ni \textbf{(II)}~on Pine Bark"=based Composts as a Potential Bioremediation Strategy for Contaminated Soils},pdfauthor={Elias Gichangi},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Biosorption, compost, goat manure, Heavy metals, pine bark},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
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\Large{\textbf{Sorption of Pb (II), Cu (II), Zn (II), and Ni \textbf{(II)}~on Pine Bark"=based Composts as a Potential Bioremediation Strategy for Contaminated Soils\footnote{\textbf{Contact Address:} Elias Gichangi, Kenya Agricultural Research Institute (KARI), Land Resource Management, P.O. Box 340-90100, 90100~Machakos, Kenya, \mbox{e-mail}: \email{gichangim@yahoo.com}}\\[0.8ex]}}
\normalsize{\textsc{Elias Gichangi}}
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\begin{itemize*}
\item[]{\small{\textit{Kenya Agricultural Research Institute (KARI), Land Resource Management, Kenya}}}
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\index[author]{Gichangi, Elias}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Compost can be used to remediate metal contaminated soils because it binds and reduces metal uptake by plants. The retention capacities of Pb (II), Cu (II), Zn \textbf{(II)}~and Ni \textbf{(II)}~by pine bark based composts as biosorbent substrates was investigated. The three contrasting composts were from pine bark (PB), pine bark"=goat manure (PBG) and pine bark"=sewage sludge (PBS). The equilibrium sorption capacity of heavy metals was measured and interpolated using the Langmuir and the Freundlich equations. Maximum removal of heavy metals Cu (II), Zn \textbf{(II)}~and Ni \textbf{(II)}~by the various composts was achieved after 2 hours of equilibration, whereas the adsorption of Pb \textbf{(II)}~decreased with increasing contact time. The Langmuir sorption maximum capacity of the composts followed the order PBG $>$$>$ PBS $>$ PB for the tested metal ions and similar trends were observed for the Langmuir constant b and the Freundlich constant KF. Higher adsorption capacities of Cu (II), Zn \textbf{(II)}~and Ni \textbf{(II)}~ions were found in the PBG composts than in the PB and PBS composts. The maximum sorption capacity of PBG compost followed the decreasing order Cu \textbf{(II)}~$>$ Pb \textbf{(II)}~$>$ Zn \textbf{(II)}~$>$ Ni \textbf{(II)}~whereas, the maximum binding capacity of PB and PBS composts followed the decreasing order Pb \textbf{(II)}~$>$ Cu \textbf{(II)}~$>$ Zn \textbf{(II)}~$>$ Ni (II).  The general binding affinity decreased as: Pb \textbf{(II)}~$>$ Cu \textbf{(II)}~$>$ Ni \textbf{(II)}~$>$ Zn \textbf{(II)}~for PB and PBS composts whereas, the binding affinity followed the decreasing order Zn \textbf{(II)}~$>$ Pb \textbf{(II)}~$>$ Cu \textbf{(II)}~$>$ Ni \textbf{(II)}~for the PBG compost. The high metal retention capacity by the pine bark/goat manure compost indicates that it can be used for the bioremediation of heavy metals contaminated soils.}

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\noindent \textbf{Keywords:} Biosorption, compost, goat manure, Heavy metals, pine bark
\index[key]{Biosorption}
\index[key]{Compost}
\index[key]{Goat manure}
\index[key]{Heavy metals}
\index[key]{Pine bark}
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