Biosorption of lead ions from aqueous solution by maize leaf

Abstract

The removal of lead ions from dilute aqueous solution using maize (Zea mays) leaf as the adsorbent is reported
in this paper. The effects of pH, initial metal ion concentration and contact time were studied at 27ºC. The
analysis of residual Pb(II) ions was determined using atomic absorption spectrophotometer. Maximum
adsorption occurred at pH 3. The adsorption isotherms obtained at 27ºC and optimum pH fitted well into both
the Freundlich and Langmuir isotherms. The Freundlich and Langmuir equations are log =0.504 log Ce+0.6939
and 1/ = 0.176/Ce–0.03, respectively. The correlation factors are 0.9959 and 0.9939. The result of the pH
experiment shows that the initial pH would play a vital role in the removal of the lead ions from solution. The
kinetic studies show that uptake of lead ions increases with time and that maximum adsorption was obtained
within the first 30 min of the process. These results indicate that maize leaf has potential for removing lead ions
from industrial wastewater.