The oil pollution is one of the most important environmental pollution that effect many regions in the world. Refinery equipment at beach, oil platforms into the water, the operation of tankers, tanker accident and adding sea water and dirty rivers play an important oil pollution at sea. During the last three decades, the ability of living or non-living microorganisms was used as an adsorbent for the removal and recovery of pollutants from aqueous solutions. In this study, the marine macroalga biomass of Enteromorphaintestinalis had taken into account as an adsorbent for the removal of two compounds crude oil and used motor oil from both freshwater and seawater environments and uptake of these compounds by weight were estimated. Analysis of CHNOS, EDX, FT-IR and SEM were used to determine some adsorbent properties. The effect of time, pH, particle size, concentration and adsorbent dosage on the removal of pollutants were studied. The results showed that the rate of adsorption is both examinated compounds were fast and it follows the pseudo-second order kinetic equation. Change of pH had impact on the adsorption of crude oil, so that the acidic pH had lower adsorption but this parameter had a significant impact on the uptake of used motor oil. A direct relationship was observed between the particle size and the rate of adsorption so that the increase of sorbent particle size showed an increase in adsorption. By increasing the intensity, adsorption rate gradually decreases and the study showed that the adsorption isotherms for both combined in both environments are better fitted with Langmuir model. The q max value of crude oil in the fresh water and salt water was 370 and 555 mg per gram and for used motor oil was calculated as 588 and 714 mg per gram, respectively. Finally, there was a statistically significant relationship between the adsorption of these compounds and saltwater. The biomass of marine macroalga E.intestinalis has more efficiency in the removal of hydrocarbon pollutants from seawater. Keywords: Oil pollution, Biomass of Enteromorpha intestinalis , Marine pollution, Adsorption kinetics and isotherms.
