Research On The Oil-proof Modification Of Fibrous Filter And Its Composite Filtration With ACF In The Treatment Of Oily Wastewater

The ecological environment would be serious damaged by a large amount of the oily wastewater.It was an ideal method to inject the wastewater into oil well again after properly treatment.On one hand, production was maintained.On the other hand,the quantity of discharged wastewater would be declined.It was of great importance in the area of industry and environmental protection.The oil adheres to the filter media easily,leads the media to cluster,and finally breaks down the filtration utilities.Therefore,the developing oil-proof and easily regenerated filters and their application technology has been the key to the recycle of territory water.Chemical fibrous filters have many advantages,such as high porosity, high surface area and dirt-holding capability.The fibrous filters have not been used in oil-containing wastewater treatment,because of the difficult regeneration caused by their non-polar surface and adhesion to the oil.In this paper,a special polyester fibrous filter was modified by a fluoric composite SG-910,an organic fluorine oil repellent modifier.The effects of concentration of the modifier and its matching cross-linking agent on the oil-proof capability of the modified fiber were investigated.The surface chemical and physical structures of the modified fiber were characterized by means of scanning electron microscopy（SEM）and Fourier transform infrared spectroscopy（FTIR）.It shows that 20 g/L SG-910 plus 10 g/L cross-linking agent can obtain the best resultant in oil-proof.Although the modified fibrous filters have been washed 20 times,their oil-proof capability still reaches to the 5^thlevel.The static adsorption and dynamic filtration of fibrous filters were investigated,respectively.The modified filter shows excellent filtration and regeneration properties.Its oil adsorption capacity and filtration have increased by 50%compared to the non-modified one.And its saturated oil absorption capacity can reach 47.07 mg/g.The concentration at outlet was in the range of 5～8 mg/L after treatment by the modified filter with a removal rate of 92～95%.The filter cycle of modified filter was 24 h.The oil remained on the surface of the modified fiber can be washed away easily by water.Therefore,this novel filter is both recyclable and promising.Activated carbon fiber（ACF）,in the form of felt,has unique pore structure and surface characteristics which are suitable for high-precision organic matter filtration.In this research,the filtration and regeneration of ACF in oil wastewater were investigated.The results were excellent. When the oil concentration of wastewater in the range of 10～20 mg/L, the concentration at outlet was below 5 mg/L after treatment by the ACF. The ACF has long operation life cycle about 60 h,and can be regenerated easily at 700℃under N₂ flow.The surface structures of ACF were characterized by SEM.The concentration at outlet was 4.58 mg/L after treatment by the 4^thtime regenerated ACF.The quality of outlet water still meets the top standard of re-injection water A1.Based on the filtration performance and regeneration of modified fibrous filter and ACF,the modified fiber/ACF composite filtration technology was also studied.It shows that the modified fiber/ACF composite filter treatment technology is an efficient and practical oily wastewater treatment technology.When wastewater with a concentration of up to 100 mg/L was treated by modified/ACF filter,the effluent oil concentration is below 5 mg/L with a removal rate of 95%,which meets the A1 standard of re-injection water.The composite filter has a filter cycle of 48 h and can be regenerated easily.It will be an excellent filtration medium and play an important role in treatment of territory wastewater in the near future.