Chemical and Materials Engineering Vol. 5(2), pp. 15 - 25
DOI: 10.13189/cme.2017.050201
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Heavy Metal (Pb and Cd) Removal Potential of Cactus Powder in Ground Water at Adigrat


Tessema Derbe Hailegebrial *
Department of Chemistry, Adigrat University, Ethiopia

ABSTRACT

The main objective of this study is to investigate the heavy metals (Pb and Cd) removal capability of cactus powder from ground water using FAAS adsorption techniques by considering the influence of contact time, adsorbent dose and temperature. The results revealed that adsorption of Pb and Cd ions increased as the dose of adsorbent increased at a certain limits. The heavy metal removal capability of cactus powder is affected by the present of NaCl salt. The heavy metal removal capability of cactus powder decreased from 65% up to 7% for Pb, and from 70% up to 14% for Cd as the dose of NaCl increased from 1g to 5g. This is due to the formation of outer sphere complex with the NaCl salt which screening the functional group of cactus powder from heavy metals. The heavy metal removal capability of cactus powder also increased with contact time. The adsorption rate initially increased from 20% to 58 % for Pb ion, and 17% to 43% for Cd ion when the contact time increased from 30-120 min. After 120 min, there was no significant change in heavy metal removal of both Pb and Cd ions. This might be due to end point at which adsorption phase reached at equilibrium. The percentage removal of Pb by cactus powder decreased from 65.05% to 29% as the temperature increased from 25℃ to 150℃. In similar condition, the percentage removal of Cd by cactus powder also decreased from 43% to 31% as the temperature increased from 25℃ to 150℃. This decrement in percentage removal of both Pb and Cd ions with increase temperature is due to the weak binding interaction between the active site of cactus powder and (Pb, Cd) ions which support physicosorption process.

KEYWORDS
Cactus Powder, Heavy Metal, Adsorbent, Adsorbate, Dose and Active Site

Cite this paper
Tessema Derbe Hailegebrial (2017). Heavy Metal (Pb and Cd) Removal Potential of Cactus Powder in Ground Water at Adigrat. Chemical and Materials Engineering, 5 , 15 - 25. doi: 10.13189/cme.2017.050201.