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Background and Objectives: Existence of Heavy metals in water resources is one of the
most important environmental problems in many countries. These metals have
dangerous effects on human health. The purpose of this study is to investigate and compare lead removal by
nanometer and millimeter absorbents of Zizyphus Spinachristi fly ash.
Materials and Methods: This study was non-continuous experiment which was implemented under laboratory
conditions with and by changing effective factors such as pH (3, 4, 5, 6, 7,
8), contact time (5, 10, 15, 30, 45, 60, 90, 120 minutes) and adsorbent
concentration (1, 2, 5, 10, 20 and 50 mg/ L). The data was fitted based on four
models including Ho et al, Lagergern, Lungmuir and Freundlich which the first
two models used for absorption kinetic and the latter two considered as
absorption isotherm.
Results: The Result of
this study showed that as the pH increases from 3 to 5 adsorption efficiency
increased as well. Furthermore, when pH was over 5, the metal ions settled
down. With increasing contact time, adsorption efficiency increased as well.
With increasing the amount of nanometer as an adsorbent, removal efficiency
increased and then decreased. Also the adsorption process followed precisely Ho
et al kinetic and Langmuir isotherm, for both absorbents.
Conclusion: Based on
the obtained results, specific area of the nano particles was more than
millimeter particles (29.56 m2/g & 17.80 m2/g), therefore adsorption
capacity of nano absorbent was four times more than adsorption capacity of
millimeter (19.93 mg/g & 17.80 mgr/g). Furthermore, the findings concluded
high capability of nano particles towards Sorption of lead ions (Pb) from
aqueous solutions.
