Removal of chromium (VI) from aqueous solution using vesicular basalt: A potential low cost wastewater treatment system

Agegnehu Alemu; Brook Lemma; Nigus Gabbiye; Melisew Tadele Alula; Minyahl Teferi Desta

doi:10.1016/j.heliyon.2018.e00682

Removal of chromium (VI) from aqueous solution using vesicular basalt: A potential low cost wastewater treatment system

Heliyon. 2018 Jul 10;4(7):e00682. doi: 10.1016/j.heliyon.2018.e00682. eCollection 2018 Jul.

Authors

Agegnehu Alemu^{1

2}, Brook Lemma³, Nigus Gabbiye⁴, Melisew Tadele Alula⁵, Minyahl Teferi Desta⁶

Affiliations

¹ Ethiopian Institute of Water Resources, Addis Ababa University, P.O Box 1176, Addis Ababa, Ethiopia.
² College of Science, Bahir Dar University, P.O Box 79, Bahir Dar, Ethiopia.
³ College of Natural and Computational Science, Addis Ababa University, P.O Box 1176, Addis Ababa, Ethiopia.
⁴ Faculty of Chemical and Food Engineering, Bahir Dar University, P.O. Box 26, Bahir Dar, Ethiopia.
⁵ Botswana International University of Science and Technology, Private Bag 16, Botswana.
⁶ School of Earth Science, Bahir Dar University, P.O Box 79, Bahir Dar, Ethiopia.

Abstract

In this study, vesicular basalt volcanic rock was taken and its application for adsorption of chromium (VI) from aqueous solution was investigated. Different physical and chemical properties of the powdered rock was studied using Fourier transform infrared spectroscopy (FT-IR), Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). A series of batch experiments were carried out to study the effect of various experimental parameters (pH, ionic strength and contact time) on chromium (VI) adsorption. It was found that the removal efficiency of chromium (VI) decreased with increasing pH and ionic strength. The adsorption process was optimal at pH 2. The maximum adsorption capacity was 79.20 mg kg^-1 at an initial concentration of 5.0 mg L^-1 and adsorbent dosage of 50 g L^-1. In individual adsorption tests, Pseudo-second-order kinetic and Freundlich isotherm models could better describe chromium (VI) adsorption on the vesicular basalt. This study indicated that vesicular basalt, which is inexpensive, has the potential to remove chromium (VI) from polluted water.

Keywords: Environmental science.