Study On Treatment Of Oily Wastewater From Railway Depot By Plate Ceramic Membrane

A large amount of oily wastewater will be produced during the process of locomotive cleaning and maintenance in the railway vehicle section.According to the statistics,the total amount of waste water in the vehicle section of the national vehicle reaches 3 million 500 thousand tons per year.The main pollutants are solid suspension and oil,which have the characteristics of high COD and high oil content.At present,the waste water treatment plant of the vehicle section is mostly used to treat the waste water of the vehicle section.Although it can achieve the discharge of the standard,there is a shortage of weak adaptability to the water quantity fluctuation of the wastewater,the effect of temperature change and the excessive energy consumption.Therefore,the new method of treating the oily wastewater in the vehicle section can not only solve the weakness of the gas floatation treatment better,but also help to improve the technology level of the similar high oil wastewater treatment.In view of the water quality characteristics of depot waste water,a new method of treating wastewater by flat ceramic membrane microfiltration technology is proposed in this paper.On the basis of the self designed and produced wastewater treatment device,a series of experiments on the treatment of indoor wastewater are carried out,including 41 groups of experiments,such as ceramic membrane flux test,ceramic film backwashing test and orthogonal test of oily wastewater treatment by ceramic membrane,and then compare the process of wastewater treatment used in railway vehicle section and discuss the ceramic membrane micro The effectiveness and practicability of the application of filtration technology.The experiment and analysis of 22 groups of ceramic membrane fluxes showed that the method of treating vehicle segment wastewater by plate ceramic membrane microfiltration technology was feasible.The plate ceramic membrane could effectively treat the oily wastewater of railway vehicle section.The content of solid suspension,COD and oil after treatment was 35mg/L,22mg/L and 0.88mg/L respectively.The first discharge standard of combined emission standard(GB8978-1996),the removal rates of these three indexes were85%,90% and 99% respectively.The analysis of the experimental results of the wastewater treatment after backwashing of 3 groups of ceramic films shows that the membrane flux after backwashing can be recovered to the initial membrane flux of the new ceramic film,and the backwashing process does not affect the treatment effect of the film on the wastewater,and the difference of the effect of the two treatment of the wastewater is not more than 3%.The orthogonal test results of the wastewater treatment of 16 groups of ceramic films show that there are some differences in the effect of pressure,membrane flux and temperature on the effect of wastewater treatment.Under the established test conditions,the pressure factor is relatively significant,but it has little effect on the treatment effect,and the temperature and pressure are non significant factors.There is no obvious effect on the results of wastewater treatment;under the established test conditions,the optimum working condition is A1B1C2,that is,pressure 0.08 MPa,100% membrane flux,and temperature 20.Compared with the traditional air flotation process,the cost of using ceramic membrane microfiltration to treat the oil wastewater in the vehicle section is basically the same,but the energy consumption is low and the treatment effect is more stable.