Study On The Application Of Pervaporization Membrane For Water Treatment

Water resources are necessary resources for human survival and development.However,the shortage of water resources has become a global problem,and the evolution of water treatment technology has attracted widespread attention.As an emerging membrane separation technology,pervaporation has the characteristics of high selectivity,strong anti-pollution,energy saving and high efficiency,and has great potential in the field of water treatment.However,there are few practical applications of pervaporation technology in water treatment.Therefore,this paper uses pervaporation tubular membrane to try to treat a variety of water samples and expand the application of pervaporation membrane technology in the field of water treatment.First,the pervaporation tubular membrane was used to treat the solution containing high organic matter concentration(humic acid)and high biomass concentration(sodium alginate).The pervaporation membrane showed excellent flux performance and anti-pollution ability.Then the oily wastewater of a chemical plant with a COD content of 40,000 mg/L was treated,the membrane flux was 37.81 kg·m-2·h-1,and the produced water COD was 127.9 mg/L.By combining with nanofiltration,the production water COD dropped to 66.42 mg/L.Secondly,a pilot plant was built,and the acid-alkaline washing wastewater generated in the production was treated for a long time on the spot,and the quality of the produced water was excellent,meeting the requirements for reuse.The membrane flux is stable above 20 kg·m-2·h-1,and there is no pollution,and the recovery rate can reach 90%.Once again,the pervaporation technology was used to further concentrate the highly concentrated salt solution.First tried to concentrate the diluted refrigerant(high-concentration CaCl2 solution)from 26 wt%to 40 wt%during use.In view of the low membrane flux(11.3 kg·m-2·h-1),the membrane flux was successfully increased to 23.5 kg·m-2·h-1 by adjusting the crosslink density of the membrane.Secondly,an attempt was made to concentrate the high-concentration NaCl solution to near saturation,which verified the feasibility of coupling the pervaporation technology with the crystallization process.In order to improve the performance of the pervaporation membrane technology in the treatment of highly concentrated solutions,an attempt was made to improve the turbulence of the fluid on the membrane surface.The model was constructed and CFD was used to simulate the design of the turbulence-promoting structure.After testing,the tubular membrane flux was significantly improved.