Pb(II) Removal from Aqueous Solutions Using Citric Acid Modified Kepok Banana Peel: Batch and Kinetic Studies

Lead (Pb(II)) mostly found in water body come from industries and household activities. Pb(II) is non-biodegradable heavy metals and carcinogenic. The recent study had explored the ability of citric modified-kepok banana peel (BP-CA) to remove Pb(II) from aqueous solution using batch method. The adsorption capacity of kepok banana peel (BP) was also investigated for comparison. The optimum conditions of Pb(II) removal using kepok banana peel were achieved at pH 5, initial concentration 600 mg/L, contact time 75 minutes and agitation speed 100 rpm with adsorption capacity 36.478 mg/g. Meanwhile, the adsorption capacity of citric-modified kepok banana peel was 64.088 mg/g which was reached at pH 5, initial concentration 850 mg/L, contact time 75 minutes and agitation speed 150 rpm. The adsorption of Pb(II) onto both sorbents followed Langmuir isotherm model and pseudo-second order model indicating monolayer adsorption with chemical interaction as rate limiting step. The Fourier Transform Infra-Red (FTIR) denoted wavenumber shift of some functional groups such as hydroxyl and carbonyl. Scanning Electron Microscopy (SEM) showed uneven and pore surface of adsorbents that become smooth after adsorption took place. X-Ray Fluorescence showed prominent amount of Pb(II) in sorbents after adsorption occurred. Whereas Thermogravimetric (TGA) indicated significant mass reduction of sorbents at 250 OC.