Adsorption Of Oil Spill By Modified Sawdust

In recent years, Marine oil pollution is getting worse. These oil spill form a film and cover on the water. This is not only a waste of valuable oil resources, but also brings significant harm to the ecological environment and human health. Adsorption is the fundamental way to solve the oil pollution. Natural pine sawdust has the advantage of cheap, biodegradable, etc. However, because it contains a lot of hydroxyl groups, its oil absorption is poor.By pyrolysis modification method, modified sawdust with excellent oil adsorption performance, low-cost, environmentally friendly, were prepared and applied to the adsorption of oil spill. A series of characterization of sawdust were carried out in order to further understanding of the change before and after sawdust pyrolysis modification. The oil adsorption properties of modified sawdust in he pure oil and oil-water system were studied by intermittent assay. At the same time the artificial seawater were prepared. Influencing factors of adsorption in simulated sea water were also carried. The main contents are as follows:(1) The best pyrolysis modification conditions are obtained:pyrolysis temperature of 260 ℃ and constant temperature pyrolysis time of 8h. A series of characterization shows that for modified sawdust, BET specific surface area increases more than 2 times; In component elements, percentage of C increased, percentage of O and H decreased; Surface roughness reduces; The number of pores increases and pore size becomes large; Surface polarity decreases; structure is more amorphous.(2) Oil adsorption rate and oil adsorption capacity of modified sawdust are higher than those of activated carbon and natural sawdust in pure oil and oil-water system; Water adsorption capacity of modified sawdust is lower than natural sawdust by 80%; Modified sawdust has strong lipophilicity with oil adsorption selectivity coefficient of 23.81; Modified sawdust reaches equilibrium after adopting 2 min, while activated carbon and natural sawdust 30 min; Good floating properties of modified sawdust has good floating properties and the floating rate is still more than 90% after 4 hours; Modified sawdust either have good adsorption properties either in deionized water or simulated seawater.(3) With the increase of the initial amount of oil, oil adsorption capacity of adsorbent increases firstly and then remain unchanged; Oil absorption rate maintains nearly 100% firstly and then reduces; Water absorption capacity reduces; Oil adsorption selectivity coefficient increases. Particle size has no effect on oil and water adsorption performance of modified sawdust. The increase of temperature causes the increase of the adsorption capacity and decrease of the oil adsorption rate. Adsorption properties of modified sawdust are best at neutral conditions and it is better in acidic conditions than in alkaline conditions. Modified sawdust has good regeneration properties.As the absorbent of marine oil spill, modified sawdust has many advantages. The cost of raw materials is far less than of inorganic materials and organic synthetic materials. It does not need to deal with the sawdust after recovered from a timber mill. Pyrolysis modification process is simple, efficient, economic and environmentally friendly. It can be directly spread at sea and it is easily recovered with no settlement and no secondary pollution. After adsorption combustion process can provide energy, which in turn improves the utilization of modified sawdust, and the combustion generates CO2 mainly, therefore it does not cause environmental secondary pollution.