Adsorption of lead (II) from aqueous solution by using modified and unmodified banana peels

Heavy metals must be avoided from improperly discharged effluent before it pollutes the environment. However, conventional methods have limits, such as low effectiveness and high costs. Agricultural waste can replace conventional methods to remove heavy metals from wastewater. This research aims to utilise modified banana peels (MBP) and unmodified banana peels (UBP) for lead removal from an aqueous solution. The effect of pH and adsorbent dosages on the adsorption behaviour of adsorbents was examined using AAS to find optimal adsorption parameters. The MBP was chemically modified with 0.001 M of sodium hydroxide solution (NaOH) to investigate the improvement in the adsorption capacity compared to UBP. The adsorbent dosage with the maximum adsorption capacity for UBP and MBP is 1.0 g. Regarding the effect of pH, adsorption of the Pb²+ ion by UBP and MBP was favoured at pH 6. Based on the adsorption results, MBP is slightly better than UBP in terms of lead removal percentage. The functional groups and thermal studies also showed that both adsorbents are almost similar. The presence of O-H, C=O, C=C, C-H and C-N functional groups on the surfaces of both adsorbents was shown by FTIR analyses. According to the DSC study, the maximum temperatures for UBP and MBP are 170°C and 147°C, respectively.