CORRELATION OF CARBONIZED AVOCADO SEEDS (Persea americana) AND CARBONIZED ORANGE PEELS (Citrus sinensis) ADSORPTIVE POTENCY IN REMOVING Cd2+ IONS IN AQUEOUS SOLUTION

Man cannot survive without water and water contamination has reduced the availability ofhealthy water to man. The dried Avocado Pear seed and orange peels were ground intopowdery form and sieved using standard test sieve with size BSS-53μm mesh sieve. Thepulverized avocado pear seed and orange peel were separately carbonized in a mufflefurnace at a temperature of 300 °C for 40 minutes. The physicochemical characterization ofthe carbonized avocado pear seed (CAPS) and carbonized orange peels (COP) was doneusing scanning electron microscope (SEM) and Fourier-transform infrared (FTIR)spectrophotometer. The adsorption process of Cd2+ ions onto CAPS and COP was studiedusing the batch adsorption isotherm experiments. Langmuir, Freundlich, Tempkin andFlory-Huggins isotherm models were used to evaluate the data obtained. Cadmium ions hada stronger affinity for CAPS than for COP due to the functional groups present, while theCOP had higher intensity, adsorption capacity and spontaneously adsorbed Cd2+ ions due tothe large number of pores of varied sizes it possesses compared to CAPS. The adsorptionmechanism is dominated by physiosorption process. Tempkin adsorption isotherm revealedthat the COP a higher heat of adsoption (B) and maximum binding energy than CAPS anindication that the COP held the cadmium ions firmer on its surface compared to that ofCAPS. The COP is a better adsorbent compared with CAPS for effective removal ofCadmium ions based on its maximum adsorption capacity of 8.84 and 5.67 for COP andCAPS respectively from Langmuir isotherm model.