Abstract
Aim/Background: Wastewater treatment remains a major challenge associated with generation of less quality water containing toxic contaminants that cause health adverse effects and environmental destruction. This study aimed at evaluating the heavy metals adsorption efficiency of Desho grass derived activated carbon from wastewater from Kebbi state water treatment plant.
Methods: The activated carbon was prepared using H3PO4 activation method. The physicochemical properties of the activated carbon were determined using standard methods. The functional groups present in the activated carbon were detected using Fourier Transform Infrared (FT-IR) spectroscopic method. The heavy metals concentrations were estimated using atomic absorption spectroscopic (AAS) technique. American Public Health Association (APHA) method was employed for Batch adsorption test. Freundlich and Langmuir adsorption isotherms were used for evaluating the mechanism of heavy metals adsorption efficiency of the activated carbon.
Results: The activated carbon displayed larger significant (p < 0.05) surface area (616.66 m2/g), pore volume (4.13 g/cm3), pH (8.06), conductivity (95.56 µS/cm), and moisture content (14.66 %) and low porosity (0.20 %), ash content (1.80 %), and bulk density (0.51 g/cm3). Several band peaks showing C–C, C–H, C=O, O−H, and C−O stretching were observed on the FT-IR spectrum at a wavenumber range 3350 – 801 cm−1. The activated carbon displayed high significant (p < 0.05) percentage removal efficiency for cadmium, cobalt, manganese, lead, chromium, and nickel up to 98.05 %, 95.17 %, 94.20 %, 92.64 %, 90.00 %, and 86.10 %, respectively.
Conclusion: Desho grass derived activated carbon exhibited high adsorption efficiency for cadmium, cobalt, manganese, lead, chromium, and nickel from the municipal wastewater. The experimental equilibrium data for the adsorption of all the detected heavy metals were best fitted to Langmuir isotherm implying monolayer adsorption mechanism on a uniform surface.

Key words: Desho grass, Heavy metals, Phytoremediation, Pollution, Wastewater