Removal of heavy metals from aqueous solutions using Eucalyptus Camaldulensis: An alternate low cost adsorbent

Abstract

The discharge of untreated wastewater become a major threat to the environment and posed health risk to human. Thus, in this study a low-cost and eco-friendly bio-sorbent produced from cheap and locally available material of Eucalyptus camaldulensi was used for removing toxic heavy metals from wastewater. The bio-sorbent was studied for its capacity of removing total Pb, Cd and Cr from synthetic and industrial wastewater of textile and leather industries. Parameters such as the effect of particle size, contact time, pH, and amount of adsorbent and initial concentration of metal ions were examined using the batch method. The removal of metal ions was mainly dependent on the physico-chemical nature of the adsorbent and concentration of the adsorbate. Maximum removal for Pb (II), Cd (II) and Cr (III) were observed at pH 10.0 for Pb and Cr and pH 12.0 for Cd, respectively. The experimental data were analyzed based on Langmuir and Freundlich isotherm models and Langmuir was found to be best suited for the studied bio-sorbent. At the optimum pH and particle size studied, the adsorption capacity (mg/L) of the bio-sorbent was obtained to be 9.259, 6.173 and 47.619 for Pb, Cd and Cr. Thus, the finding suggests that the Eucalyptus camaldulensis bio-sorbent can be employed as an alternative low-cost adsorbent in the removal of Pb, Cd and Cr from wastewater.

Keywords:

• Eucalyptus Camaldulensis
• low-cost adsorbent
• toxic heavy metals
• wastewater

PUBLIC INTEREST STATEMENT

An increase in the industrialization and urbanization in the world posed a major problem of water contamination through the release of poisonous heavy metals from chemical industries such as tannery, textile, chemical industries and others. Thus, it is common to obtain high levels of heavy metals from the discharge of untreated industrial wastewater which pollutes the ground and surface water once released to the environment. Therefore, several methods have been used for the treatment of wastewater effluents. Most of the methods employed were associated with their high costs, less efficiency, requiring large amounts of reagent and solvent and generation of toxic sludge. Thus, the researchers were interested and worked on the development of cheaper, environment-friendly and efficient heavy metal treatment techniques to minimize the amount of toxic heavy metals discharged from industrial effluents.

Competing Interests

The authors declares no competing interests.

Acknowledgements

This study was conducted at Mekelle University, Ethiopia and thus all resources used are acknowledged. The authors also thank Mr Alem Halefom, Chemistry Department, Mekelle University for his kind help in sample preparation; Prof. Bart Van Der Bruggen for adsorbent SEM analysis, KU Leuven, Belgium and Ezana Analytical Laboratory, Ezana Mining Development PLC, Mekelle, Tigray, Ethiopia, for heavy metal analysis.

Cover Image

Source: Author.

Additional information

Funding

The authors received no direct funding for this research.

Notes on contributors

Abraha Gebrekidan

G. Hirut holds her MSc degree in analytical chemistry from Mekelle University. Her MSc thesis supervised by Asgedom and Demlie, focused on the removal of Cr, Cd and Pb from wastewater using Eucalyptus camaldulensis activated carbon. Thus, the results of her findings are presented in this paper.

Libargachew Demlie

A. G. Asgedom (PhD) is working as analytical and environmental chemist at the Department of Chemistry, Mekelle University, Ethiopia. He has more than 28 articles published in reputable local and international journals. He is mainly engaged in both basic and applied researches which are all mainly focused on environmental issues.