Preparation And Characterization Of Separated Adsorption Materials Based On Bamboo Fiber

The rich hydroxyl groups existed on the surface of bamboo fibers,not only give the fiber excellent hydrophilic properties,but also can occur adsorption,complexation with cations,so that natural fibers in the sewage treatment have a good application prospects.In this paper,PVDF/BF blend membranes,PVDF/BF-PDA,IL composite membranes and MnOx@BF composite materials were prepared by bulk blending modification and in situ synthesis,respectively.The separation and desorption of materials were systematically studied.The specific research contents are as follows:(1)PVDF/BF blend membranes were prepared by immersion precipitation phase inversion process.The effects of BF addition on the morphology,hydrophilicity and antifouling properties of blend membranes were investigated.The adsorption and separation properties of PVDF/BF blend membranes were studied.It was found that the porosity of the membrane was increased from 55.9535%to 70.0291%with the increase of BF content in the PVDF/BF blend membranes.The hydrophilicity was improved and the initial surface contact angle of the membrane was decreased from 102.5℃ to 56.64℃.The toughness of the blended film decreased,but the tensile strength was better than that of the PVDF membrane.The dye adsorption capacity was improved and the anti-protein pollution was decreased.The dynamic adsorption experiment of PVDF/BF blend membranes showed that the removal rate of Congo red increased from 24.55%to 95.13%,while the flux recovery rate decreased slightly,but the recovery of water flux was still far from the original membrane.(2)In order to further improve the hydrophilicity and mechanical properties of PVDF/BF blend membranes,400 mesh BF was blended with IL,poly dopamine and the three,respectively.PVDF/BF-IL blend membranes,PVDF/BF-PDA blend membranes and PVDF/BF-IL,PDA blend membranes were prepared by immersion precipitation phase inversion process.The results showed that the porosity of PVDF/BF-IL blends was decreased and the mechanical properties were improved,but the hydrophilicity and anti-protein pollution were decreased.The hydrophilicity and anti-protein pollution of PVDF/BF-PDA blend membranes increased.When the content of PDA is too large,it is easy to cause PDA to agglomerate and reduce the mechanical properties.When the PDA content is 0.05g and IL is 2g,the excellent hydrophilicity,anti-protein pollution and mechanical properties of PVDF/BF-IL,PDA blend membranes are obtained.(3)The MnOx@BF composite materials were prepared by in situ synthesis of MnOx nanoparticles on bamboo fibers,which were immersed in potassium permanganate solution,by ultrasonic irradiation.Dye degradation experiments showed that MnOx@BF composites had good degradation ability to cationic dye methyl violet and anionic dyes indigo disulfonate:the degradation rate of methyl violet was 97.3%within 5 min,the degradation rate of indigo was 98.5%.And the surface morphology and ultrasonic time had effect on the degradation efficiency of the composites.The stability of MnOx@BF was determined by the stability test,and the removal rate of indigo was more than 96%.