Investigating the Efficiency of Rice Organic Absorbents for Absorption Oil Pollutants from Water

Water pollution with oil compounds is one of the most important environmental issues in oil-rich countries, as it can have adverse effects on human health and the environment. It is absolutely essential to use optimized and efficient methods for treatment of oil-containing wastes. There are several strategies to remove oil pollution and its derivatives. In this research, rice's peel adsorbent was used as an organic adsorbent to remove oil pollution from wastewater. Initially, the chemical composition of rice peel was determined with using FT-IR analysis, then adsorption tests were conducted discontinuously using laboratory solutions containing oil to determine optimum adsorption conditions by adjustment of effective factors such as pH, initial concentration, exposure time, and adsorbent amount, and the amount of oil adsorption was determined using weight method. Ultimately, the use of adsorbent for laboratory wastewater was studied. The highest adsorbent efficiency was observed for absorbing oil during 15 minutes, which had a significant difference with other contact time (79.77% absorption, P <0.05) and the lowest value by difference significance was observed in 3 minutes (65.93% absorption). The highest amount of adsorption by rice peeling was observed at pH = 5 and pH = 3, which did not show significant differences with other pHs (76.57% and 75.34%, respectively, P < 0.05) and the lowest adsorption was observed at pH = 9, which had no significant difference with other pH (58.93%, P <0.05). The effect of rice peel absorbent values in 1.5 g/l was significantly higher than other amount of adsorbents (84.1% absorption, P <0.05) and the lowest percentage of adsorption was significantly different from other values in 0.25 g / liter was observed (62.58%; 05.05 P). Isotherm fitting of surface adsorption showed that oil adsorption by rice peel follows the Freudlich model (R2 = 0.98). Therefore, it can be concluded that rice peel adsorbent has a high efficiency in adsorbing oil from wastewater and can be used in the treatment of industrial wastewater.