Research On The Removal Of Organic Pollutants From Water By Membrane Separation Coupled With Environmental Catalysi

In recent years,domestic and foreign personnel have used various physical,biological and chemical methods to treat dyeing wastewater.Recently,AOPs based on catalyzing persulfate to generate free radicals has attracted the attention of many scholars and enterprises.Therefore,this article aims to combine AOP and membrane filtration technology for doping Co Fe₂O₄（CFO）into PVDF membrane and calcium alginate membrane respectively to improve the stability and reusability of the catalyst.Cross-flow filtration was utilized to accelerate the mass transfer process and increase the catalyst activity,and the effect of two different membrane catalytic activation persulfate coupled filtration to remove the dye Acid Red 18.The main research results are as following:（1）The CFO catalyst was successfully prepared by the sol-gel method,and the crystal structure and element valence state of the CFO was analyzed by XRD,XPS and other characterization methods.The results showed that CFO was successfully prepared.（2）The CFO_x-PVDF composite membrane was established by blending and NIPS method,and the morphology and structure of the composite membrane were analysed by SEM,FIB and XRD,and the Physical performance of the membrane was tested by mechanical tensile test and water contact angle test.Through cross-flow filtration,at room temperature and PMS dosage is 4.05 m M,CFO₂-PVDF composite membrane has excellent removal ability for 25 mg/L AR18 dye,The dye removal rate of over 99%within 70 minutes.Through the test of active species,it is found that SO₄^·-is the dominant free radical for the catalytic degradation of AR18.In addition,the composite film gets a good reusability.After 5 time of reusing,the dye removal rate of the composite membrane can still reach more than 86%.（3）The CFO_x-Ca Alg composite membrane was successfully prepared by blending sodium alginate and CFO and then cross-linked with Ca Cl₂.And has characterized and tested the composite membrane,the results showed that the doping of CFO not only improved mechanical properties of the membrane,but also increase the hydrophilicity of the membrane.Experiments show that under the condition of cross-flow filtration at room temperature and PMS dosage is 4.05m M,the removal rate of 25 mg/L AR18 dye by CFO₁-Ca Alg composite membrane remains above 90%.Through the test of active species,it is found that SO₄^·-is the dominant free radical for the catalytic degradation of AR18.In addition,the composite membrane can effectively remove other dyes,and the composite membrane has good reusability after repeated use tests.The above results show that AOPs coupled with membrane filtration technology can effectively remove dye wastewater and is a new way to treat dye wastewater.