Removal of lead, cadmium, and copper from water using Moringa oleifera seed biomass

Abstract

This study demonstrated that Moringa oleifera seed biomass (MOSB) has the potential to be used as a natural alternative in the removal of lead (Pd), cadmium (Cd), and copper (Cu) from water which was justified by the level of toxicity, environmental unfriendliness, and costly nature of chemical coagulants presently used. The Fourier Transform Infrared (FTIR) analysis was used to identify the MOSB and functional groups present in the adsorption of metal ions. The maximum removal at pH 5, room temperature, and 0.8 g dosage was 90, 81.77, and 70% for Pb(II), Cd(II), and Cu(II), respectively. The order of biosorption preference was Pb(II)>Cd(II)>Cu(II) in single sorption and is in a consistent correlation between physiochemical properties of metal ions and selective biosorption of MOSB functional groups. The adsorption data fitted better to the Langmuir than the Freundlich models as the sorption capacities (qm) of MOSB for Pb(II), Cd(II), and Cu(II) were 6.19, 5.03, and 3.64 mg/g, respectively. The separation factor (RL) was within the range of 0–1 which showed that the Pb(II), Cd(II), and Cu(II) adsorption processes were favourable for M. oleifera adsorbent. The results showed that MOSB is an effective adsorbent in the removal of the studied heavy metals from contaminated water. In all these water-purifying properties of the moringa seed biomass, no deliberate attempt has been made to study the use of a ternary system of very toxic metals like Pb, Cd, and Cu knowing the anti-bacterial properties of the metal system. Similarly, the reproducibility, low cost, and no requirement of a power source make this an efficient process for obtaining potable water even in homes in rural settings.