Preparation And Properties Of Cellulose-based Oil Adsorbents

With the rapid development of offshore oil exploration and offshore oil transportation in recent years,the leakage of oil and its derivatives has become more and more serious.Oil spill accidents not only cause harm to the ecological environment,but also seriously affect human health and bring serious economic losses.Therefore,more and more countries pay more attention to the oil spill problems and actively formulate relevant emergency measures.According to the environment where the oil spill occurs and the nature of the oil spill,one or more of the chemical,physical,biological and adsorption methods are usually used.Among them,adsorption method is effective and easy to use,especially the cellulose-based oil absorbent material has the advantages of low cost,biodegradability and no secondary pollution to the environment so it has become a hot spot of current research.This study proposes a simple,environmentally-friendly and efficient method to prepare cellulose-based oil absorbent materials:firstly,mechanically pulverizing the cellulose-based raw materials to make the raw materials become fluffy,at the same time the crystallinity reduced and the void ratio increased,and then spraying hydrophobing agent on the fiber.A new-type cellulose-based oil absorbent with high adsorption capacity and good oil-water selectivity is prepared.In this paper,the waste paperboard,juncus effusus and saw dust were selected as the raw materials.Three oil absorbent materials were successfully prepared through the above method and their oil absorption properties and oil absorption mechanism were evaluated.The specific conclusions are as follows:After mechanical pulverizing,the waste paperboard was coated with a small amount of hydrophobic agent for twice.The optimal amount of modifier was 15%hydrophobic agent I and 10%hydrophobic agent II.XRD results showed that the mechanical treatment reduced the crystallinity of raw material.FTIR,SEM and CA tests confirmed that the fiber surface was successfully coated with hydrophobic agent.The oil absorbent prepared from waste paperboard had a adsorption capacity of 28.12g/g for engine oil and could absorb a variety of oils and organic solvents.The adsorbent had a good oil-water selectivity for both surface oil and bottom heavy oil.After shaking in water for 12h,it maintained the maximum adsorption amount of 97.3%and still floated on the water surface.After squeezing,90%adsorbate could be recovered.With the increase of temperature,the adsorption capacity decreased gradually.With the increase of pH,salinity and oscillation frequency,the adsorption capacity firstly increased and then decreased,but the overall fluctuation was small,indicating that the HMWP was rarely affected by environmental factors.The modified juncus effusus and modified sawdust oil adsorbent were also successfully prepared by the method proposed in this paper and the oil absorption capacity reached37.28g/g and 13g/g respectively.With the decrease of particle size,the absorption capacity firstly increased and then decreased.Both of them had good oil-water selectivity and could adsorb a variety of oils and organic solvents,they also had good floatability and recycling ability.The three oil adsorbents all conformed to Lagergren quasi-second-order kinetic equation and Langmuir adsorption isotherm model,indicating that the adsorption process not only had physical adsorption,but also has chemical adsorption,and was monomolecular adsorption.Compared with the adsorption process,the analytical process took a longer time and released a small amount oi.The oil adsorbents had obvious capillary force when adsorbing.The experiment showed that the bulk density of the oil adsorbent affected the absorption capacity and adsorption rate.With the increase of bulk density,the absorption capacity and absorption rate showed a trend of firstly increasing and then decreasing.Compared with the traditional oil absorbent felt which was made of polypropylene fiber,the three oil adsorbents had obviously cost advantages.They were easy to use.They could be loaded into non-woven bags to make oil absorption pillows or they could also be directly sprinkled for adsorption with oil column for recycling.Most importantly,the oil adsorbents could be natural degradated,and if they were burned,the main gas was CO₂ which has no secondary pollution to the environment.Above all,the preparation method and the oil adsorbents proposed in this paper have good application prospects in oil spill clean ups.