Oil Removal from Polluted Seawater using Carbon Avocado Peel as Bio-Absorbent

Oil spills are a very dangerous occurrence for the marine ecosystem as the marine life-form's existence gets unnecessarily threatened. Since the exploration of oil from marine resources has become a must and oil spills end up occurring accidentally, as a result, it becomes important to employ various oil spill cleanup methods. The purpose of the current work was to evaluate the oil sorption capacity of dried carbonized avocado peel (AP) waste. AP was dried under the sun and microwaved to have the activated carbon AP. In this study, batch adsorption studies were conducted to remove different oil types (Crude oil, Diesel, Kerosene, and Gas oil) from polluted seawater using AP. The effect of various important parameters, namely, mixing time, adsorbent dose, oil dose, oil types, and reusability on the oil uptake, and their optimum conditions for maximum sorption efficiency was studied. Batch studies indicated that an adsorbent dosage of 7 g, mixing time of 20 minutes under a mixing rate of 45–50 revolutions/min, 1 g of oil and provides maximum oil removal efficiency in the present study. Based on the data fit result of the adsorption; the 7 g AP at 20 min (90%) had better oil retention than the 1.5 g (66%), 3 g (77%), and 5 g (82%) AP. The results indicated that the maximum oil adsorption percentage upon increasing the adsorbent dose (1.5 g, 3 g, 5 g, and 7 g peel) was 66-90% for Crude oil, 45-68% for Diesel, 35-56% for Kerosene, and 19-45% for Gas oil at 20 min using 1 gram oil. The results revealed that sorption capacity decreased as the oil got lighter. Increasing the oil dose reduce the adsorption capacity (Crude oil 90-66%, Diesel 64-45%, Kerosene 50-39%, and Gas oil 40-12%). The oil sorption capacities of the AP sorbents reduce gradually from 90-64% after 10 cycles, with about 72%, since the oleophilic nature of the peel surface was affected during the regeneration process. The kinetic data was analyzed for all adsorbent doses. The pseudo-first order kinetic model was found to agree well with then experimental data found. The result showed that AP biosorbent followed pseudo-first order kinetics. According to the results presented, the cheap efficient AP oil spill sorbent could be developed as a potential material to be used in seawater treatment for oil removal. The avocado carbon displayed excellent adsorption properties for the simulated seawater effluents containing oil.