Preparation Of Hydrophilic Cellulose Membrane And Its Performance In Oil-water Separation

The problem of oily wastewater is becoming more and more serious,and the emulsified oil in it is difficult to separate in water because of its certain surface activity.It poses a great threat to human and animal health.The effective treatment of emulsified oil has become a hot spot of research.Based on the mechanism of crude physico-chemistry,membrane separation is the most suitable industrial method for separating emulsified oil.In the construction of membrane materials,cellulose was once considered as an ideal separation material because of its rich sources,low price and good biocompatibility.However,in practice,it is found that the film-forming property of pure cellulose membrane is poor.Therefore,in this study,a regenerated cellulose membrane which can efficiently and stably separate oil-in-water emulsion was obtained by dissolving cellulose as raw material,and it was applied to the separation of oil in seawater,which broadened the application scope of cellulose membrane.The specific research results are as follows:（1）Preparation of cellulose-stainless steel mesh composite membrane and its performance in oil-water separationBased on the poor film-forming property of pure cellulose membrane,stainless steel mesh and cellulose were selected to improve its integrity in this experiment.Its oil-water separation efficiency is over 95%,and its permeation flux is 3360L·m^-2·h^-1.The investigation of its environmental adaptability shows that it can maintain good hydrophilicity and oleophobicity under strong acid,strong alkali and tested oil products.The prepared cellulose-stainless steel mesh composite membrane is applied to oil separation in seawater,and the estimated sewage treatment capacity can reach 20 t.（2）Preparation of cellulose membrane crosslinked by PEG and its performance in oil-water separationIn order to solve the problem that stainless steel mesh is corroded by seawater,which affects the integrity of cellulose-stainless steel mesh composite membrane,PEG is further used to replace stainless steel mesh.PEG is introduced into cellulose to make it cross-linked to achieve the purpose of enhancing plasticity and improving hydrophilicity.The results show that the oil-water separation efficiency reaches99.3%and the permeation flux reaches 4218 L·m^-2·h^-1.The investigation of its environmental adaptability shows that it can maintain good hydrophilicity and oleophobicity under strong acid,strong alkali and tested oil products.The prepared PEG crosslinked cellulose membrane is applied to oil separation in seawater,and the estimated sewage treatment capacity can reach 33 t.（3）Preparation of cellulose membrane with pulp as raw material and its performance in oil-water separationIn order to further reduce the cost of industrial production,cellulose membrane suitable for industrial production is prepared from pulp.Under the optimum conditions,the oil-water separation efficiency of cellulose membrane reaches 97.3%,and the permeation flux is 3708 L·m^-2·h^-1.The investigation of its environmental adaptability shows that it can maintain good hydrophilicity and oleophobicity under strong acid,strong alkali and tested oil products.The cellulose membrane prepared from pulp is applied to oil separation in seawater,and the estimated sewage treatment capacity can reach 25 t.In a word,cellulose membrane was prepared from cellulose and the oil-water separation experiment was carried out.Through the experimental data and the performance characterization of cellulose membrane,it can be seen that cellulose membrane can effectively separate emulsified oil.In addition,the application of cellulose not only realizes the effective utilization of natural resources,but also has very important significance for the development of China’s membrane industry and environmental protection.