Correlation of Activated Carbonized Avocado Pear Seeds (<i>Persea Americana</i>) and Activated Carbonized Orange Peels (<i>Citrus Sinensis</i>) Adsorptive Potency in Eliminating Cd²⁺ Ions in contaminated water

Abstract

Water contamination is a very serious problem due to the role and usefulness of water to life. The carbonized orange peels (COP) and carbonized Avocado Pear seeds (CAPS) were impregnated with Potassium hydroxide (KOH) at 1:1 ratio for 48 hours. The KOH impregnated CAPS and COP were washed, air-dried and separately oven dried at 105℃ for 6 hours in a muffle furnace (Carbolite AAF1100) at 250^oC for 1 hour. The activated carbonized avocado pear seeds (ACAPS) and activated carbonized orange peels (ACOP) were physicochemically characterized using scanning electron microscope (SEM) and Fourier-transform infrared (FTIR) spectrophotometer. Cd²⁺ ions adsorption technique on ACAPS and ACOP was examined by means of the batch adsorption isotherm experimentations and their adsorption model was appraised by means of isotherm models of Langmuir, Freundlich, Dubinin–Radushkevich, Tempkin and Flory-Huggin. The SEM imageries, showed that ACAPS posessed a large number of varied size pores whereas the ACOP had fewer smaller size pores. The R² values which varied from 0.86 to 1.00 point to the fact that all the isotherm models were capable to clarify the correlation in the obtained data. ACAPS had more adsorption site, however, ACOP took up more Cd²⁺ ion per adsorption site on comparing Flory-huggins isotherm model nFH values vis-a-vis Langmuir isotherm model q_m values. Generally, ACAPS was a superior adsorbent likened to ACOP, it was more than twice as effective for deletion of Cd²⁺ ions in contaminated water owing to a blend of considerable amount of various size openings and surface functional groups with qm values of 12.35 and 5.67mg/g in that order.