Preparation Of Modified Magnetic Chitosan And Its Treatment Of Emulsified Oil Wastewater

At present,production of emulsified oil wastewater are food and mechanical processing industry has aroused global attention.Although many of the source of the waste water and waste water of qualitative and quantitative composition of each are not identical,most of the oil is always exists in the form of emulsion.On account of the emulsion have structural obstacles and electrostatic repulsion space with traditional separation method of emulsion is very difficult.Therefore,we should develop environmentally friendly high separation efficiency and low cost of materials or technology to process of emulsified oil wastewater.In this paper,chitosan modified Fe₃O₄nanoparticles with superparamagnetic were used to prepare an environmental friendly demulsifier for efficient demulsification of emulsified oil.The main research contents of the paper are as follows:In this study,Fe₃O₄ MNP was successfully synthesized by a thermal solvent method.The chitosan(CS)coated on the surface of Fe₃O₄ MNP form Fe₃O₄@CS.Under acidic conditions,generates a large amount of positive charge through protonation of chitosan,has higher removal capacity for the emulsified oil.Under alkaline conditions,it can't produce a positive charge through protonation and the amount of positive charge is greatly reduced.The ability to remove emulsified oil is limited.In order to overcome these shortcomings,the poly acrylic acid grafted onto the Fe₃O₄@CS.The synthesized Fe₃O₄@ECS@PAA MNPs are superparamagnetic.Its magnetic saturation is 27.11 emu/g and the water contact angle is 131°.The removal effect of magnetic chitosan is improved by polyacrylic acid.The optimum light transmittance reached 85%,when p H was 3.After6 demulsification experiments,the light transmittance could still reach 80%.In addition,demulsification kinetics can be well described by pseudo-second order kinetics model.In order to further improve the efficiency of demulsification,the sodium oleate(NaOL)was grafted onto the surface of Fe₃O₄@CS.Its magnetic saturation is 33.88emu/g and the water contact angle is 155.5°.CS molecular chain and the negatively charged demulsification of emulsion by electrostatic interaction has a good effect,demulsification performance is further improved after the introduction of NaOL.The results show that in the alkaline conditions,Fe₃O₄@CS@NaOL MNP can effectively remove emulsified oil droplets by flocculating through electrostatic action.Especially when p H is about 4,best light transmittance can reach to 90%and its saturated adsorption capacity is 2250 mg/g at 40 min.In addition,in the alkaline conditions,a new synthetic material at least eight cycle life.This has little effect on demulsification performance.In conclusion,its preparation method is simple and easy to recycle.It provides a new feasible way to make a new demulsifier for the treatment of emulsified oil wastewater.