Preparation Of Special Wettability Surface And Study On Its Oil-water Separation Performance

In recent years,oily wastewater has always caused serious environmental and social problems due to the increase of industrial oily wastewater and the frequent occurrence of marine oil spills.Therefore,the treatment of oily wastewater has become a global urgent issue in various fields.However,the traditional techniques for oily wastewater treatment are often limited.Inspired by nature,the exploration and development of new separation membranes with special wettability is considered to be facile and effective.Currently,many researchers use special wettability materials to separate oil/water mixtures.Owing to the oil-water separation of the special wettability surface is simplely controlled by the interface phenomenon.Due to the limitations of traditional separation technology and substrate materials,such as high cost,low separation efficiency,poor operability,etc.,there is an urgent need for better separation materials to meet the requirements of industrial development and purification environment.In order to solve the problem of oil and water pollution in an effective way,this paper has prepared a more environmentally friendly and cheap high-efficiency oil-water separation material.The main work is as follows:1.The super-hydrophobic/super-lipophilic nonwoven fabric with excellent performance was successfully prepared by a simple one-step hydrothermal growth of ZnO rough structure and low surface energy stearic acid modification treatment.The super-hydrophobic/super-lipophilic nonwoven fabric can achieve a separation efficiency of more than 95.0%for separating a plurality of oil-water mixtures,and the nonwoven fabric after repeated 10 times of separation still has stable super-hydrophobic properties.Moreover,the simple device containing the nonwoven fabric can collect the oil wastewater quickly and efficiently within 45seconds.More importantly,the nonwoven fabric exhibits stable performance in a harsh environment such as strong acids and strong alkaline.Therefore,the super-hydrophobic/super-lipophilic nonwoven fabric developed in this experiment has great potential in the practical application of oily wastewater treatment.2.The stainless steel mesh achieves superhydrophobicity and superlipophilicity through a simple and inexpensive ZnO rough structure growth and subsequent surface modification of stearic acid.In addition,the mesh can use to separate various oil-water mixtures by gravity,and the oil-water separation efficiency is greater than 95%.At the same time,the floating oil collector equipped with super-hydrophobic stainless steel mesh can achieve collection efficiencies more than 96%.Moreover,the oil-water separation efficiency and floating oil collection can maintain high efficiency after 5 cycles.This super-hydrophobic stainless steel mesh not only can efficiently separate oil-water mixture,but also has good chemical stability and corrosion resistance.It is an ideal choice for marine floating oil collection and oily wastewater.3.By establishing a hydrophilic porous NiCo₂O₄ nano-rough structure on the stainless steel mesh to achieve super-hydrophilicity and underwater super-oleophobicity,the underwater contact angles of the five different oil droplets in the net are above 150°.In addition,the super-hydrophilic stainless steel mesh can separate various oil-water mixtures under the driving force of gravity,and the oil-water separation efficiency is almost 100%.At the same time,the oil-water separation efficiency can maintain high efficiency after 10cycles.This processed stainless steel mesh not only has good separation performance,but also has good stability in storage.It is an ideal choice for industrial and marine treatment of oily wastewater.