Natural adsorbent of corncob (Zea mays L.) powder capability in purification of used cooking oil with shaking operation based on turbidity

In the purification process of used cooking oil, an adsorption technique utilizing corncob as the adsorbent can be applied. To optimize the purification, the shaking speed, adsorption time, and turbidity vary. Therefore, this study was conducted in batch operation to determine the effect of suitable adsorption and reactions on shaking speed with variations in mass, size, and the contact time of the adsorbent for 5 h. During the experiment, the used cooking oil was subjected to the adsorption process using 100 mL of adsorbent, with mass variations of 2 g, 3 g, and 4 g. The surface morphology of the adsorbent was characterized by modeling corncob and the oil components of chemical compounds contained in the used cooking oil were examined before and after purification. The parameters observed were measured using Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), Gas Chromatography-Mass Spectrometry (GCMS), Fourier-Transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The results showed that the adsorbent with a size of 100 mesh, a shaking speed of 140 rpm, and a mass of 4 g exhibited a higher surface area and greater adsorption capacity. Furthermore, the adsorbent also influenced the turbidity value of the used cooking oil, and prolonged contact between the adsorbent and oil led to an increase in turbidity, particularly when using adsorbents of sizes 50 and 70 mesh.