Removal Of 2, 4-dichlorophenol From Aqueous Solution By Magnetic-Adsorptive-Photocatalytic Composite Material And Dynamic Membrane

Chlorophenols, a chemical with high toxicity and strong irritating smell, can be retained in the environment for a long time. The CPs can also be harmful to ecology and people's health through bio-accumulation. As a result, human being have always focused on its existence and controlling in environment. Membrane separation technology has a potential application in wastewater treatment, but the traditional membrane separation technology depending on the membrane pore size has a little efficiency to remove phenolic pollutions in low concentrations. To make it more efficient in removing phenolic micro-pollutant simultaneously with other suspends or pollutants from water during membrane filtration, series of composite particles containing ACF (activated carbon fiber) powder (<300 mesh), Fe3O4 and TiO2 were prepared and studied, for formation of a dynamic layer on membrane surface with easy recovery and regeneration features.(1) The Fe3O4/ACF composite particle was prepared by the precipitation method which was easy to recycle through the magnetic separation. TiO2/Fe3O4/ACF composite particle was prepared by using a sol-gel. The prepared powder samples were characterized using particle size distribution, Zeta Potential measurement and analysis FTIR spectra. The average particle size of the composite particles ranged between 7.3 to 17.3μm. Zeta Potential indicated that the more negative charge of composite particles TiO2/Fe3O4/ACF, would be more resistant to bio-fouling. FTIR spectra reflected the features of ACF, TiO2 and Fe3O4.(2) In order to understand the adsorptior mechanisms of 2,4-DCP on to the Fe3O4/ACF composite particle and TiO2/Fe3O4/ACF composite particle, adsorption isotherms, kinetics were used to fit the experimental results. The results showed that the Langmuir isotherm model provided the best fit for the experimental adsorption.(3) Fe3O4/ACF composite particle and TiO2/Fe3O4/ACF composite particle were prepared and studied, for formation of a dynamic layer on membrane surface by the crossflow filtration method. The results indicated that the two types' composite membranes have high efficiency in removing 2,4-DCP from aqueous. The membrane saturated with 2,4-DCP could be regenerated effectively by UV via Fenton reaction. (4) The adsorption performance of TiO2/Fe3O4/ACF dynamic membrane obtained by different basement membrane was studied. Great organic matter removal can be achieved using PVA/TiO2 (prepared by combining sol-gel technique dip-coating method) modified membrane, in filtrating a water sample with NOM, solid suspends from turbid soil particles and spiked 2,4-DCP, but 2,4-DCP removal was reduced due to competition and fouling of the adsorbent composites. The flux of both composite dynamic membranes had changed during the actual operation process.