Purification of Oil-Polluted Sea Water using Carbonized Rice Husk Adsorbent Prepared in a Closed Reactor

Abstract

The study involves purification of oil polluted sea water using carbonized rice husk (CRH) as adsorbent. Carbonization was carried out in a closed reactor. Important properties of the rice husk (RH) and carbonized rice husk (CRH) were determined using standard methods. Six sets of experiments were carried out with initial oil concentration of 1.35 mg/L and CRH dosages of 0, 6.67, 13.33, 20, 26.67, 33.33 g/L, separately to determine the optimal adsorption dosage and percentage of oil removal. Secondly, five sets of experiments were carried out under the adsorption time of 1 h, 2 h, 3 h, 4 h, and 5 h, with the optimal dosage for adsorption determined from the result of the first experiment to determine the optimal adsorption time. Lastly, another five sets of experiments were carried out under the adsorption time of 0 h, 1 h, 3 h, 5 h, and 7 h with the same optimal dosage for adsorption determined from the result of the first experiment to determine the COD removal. The surface area, bulk density, and thermal conductivity of the RH and CRH were respectively 0.78 and 97.4 m²/g, 0.1 and 0.19 g/cm³, and 0.04 and 0.035 W/(m. K). 13.33 g/L was determined as the optimal dosage for adsorption in this study. The oil removed with the optimal dosage was 71.85% at 3 h optimal time, while the total oil removed was 85.01%. The COD removed at this optimal time was 34% while the highest COD removal was 48%. The CRH showed ideal effects in the purification of oil-polluted sea water with excellent adsorption ability for oil in the oil polluted sea water.