Saturday, January 9, 2010

Removal of Copper and Zinc by Decaying Leaves

Removal of Copper and Zinc by Decaying Leaves


 
Hadeel Braik




Pollution of water with heavy metals has received a lot of concern recently, as some of these metals have been found to be toxic to human and animals even at low concentrations. Though some of these metals are essential to life, they become toxic when cumulate to certain concentration. Copper and zinc are tow examples. Finding ways to remove metals from polluted water is great importance.

Walnut and poplar leaves have been found capable of removing zinc and copper ions from polluted water.  The effect of several factors on this removal process had been studied.

These factors include pH of solution, type of leaves used, complexing agent present in solution, agitation, leaf extract of leaves, cleaning leaves, drying leaves used, presence of competing ions in solution, size of leaves used, effect of concentration of zinc and amount of walnut leaves\L. Uptake of zinc by walnut leaves has been found to be very dependent on both amount of leaves used and concentration of zinc ions in solution.

The rate of uptake of metal ion by leaves was decreased by the presence of comlexing agents in solution.  It has been found that complexing agents have an adverse effect on the uptake of metal ions by leaves. Presence of foreign ions along with zinc and copper ions in water has different effects on uptake of zinc and copper by leaves.

Oven and naturally dried ; eaves have higher capability to remove metal ions from water than green leaves.  Size of leaves used and cleaning of leaves before use have very small effect on the removal of metal ions. Applicability of two adsorption isotherms, on the experimental results has been examined and the parameters of Fruendlich isotherm have been calculated. The order of interaction of zinc and walnut leaves with respect to zinc has been found to be first order. A mechanism based on the data of adsorption of zinc ions on walnut leaves has been suggested.


Hadeel Braik
Supervisors
Prof. Radi Dauod
Dr. Mohammed M. AL-Subu
1998



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