Preparation Of Triple Functions Carbon Membrane With Adsorption,Filtration And Electrochemical Oxidation And Its Application For Water Treatment

In this paper,powered activated carbon with developed microporous structure was used as raw material to design and prepare triple functions carbon membrane（TCM）with hierarchical porous structure,which coupling adsorption,membrane separation and electrochemical oxidation.The hierarchical porous structure and controllable preparation of TCM were constructed from the selection of activated carbon and additives.The effects of activated carbon particle size,raw material ratio and carbonization process on the structure and properties of TCM were systematically investigated.TCM with the optimal comprehensive performance was selected to study the water treatment performance.The adsorption and electrochemical oxidation properties of TCM were investigated and real micro-polluted water was treated under low voltage electric field,the triple function synergistic mechanism of TCM was studied,and its reusable performance was investigated.The experimental results show that:（1）TCM prepared from coconut shell activated carbon and benzooxazine resin（BR）has developed pore structure and high specific surface area,showing a hierarchical porous structure of macroporous,mesoporous and microporous,and has good mechanical strength and electrical conductivity.The pore size of TCM can be effectively controlled by changing the particle size of activated carbon.With the decrease of the particle size of activated carbon,the average pore size of TCM decreases from 1.08μm to 0.54μm,and the permeability,mechanical strength and electrical conductivity of TCM are decreased.Carboxymethyl cellulose（CMC）mainly plays a molding role,and the increase of its addition makes the average diameter of TCM decrease,and the mechanical strength and electrical conductivity decrease.BR mainly plays a bonding role at high temperature,and the increase of the addition of BR significantly improves the mechanical strength and electrical conductivity of TCM,but the addition of BR significantly reduces the retention of micropores.The addition of polyvinyl butyral（PVB）significantly increased the average pore size and permeability flux of TCM,but significantly decreased the mechanical strength and electrical conductivity of TCM.The optimal ratio of TCM was10%CMC30%BR.The curing temperature has little effect on the properties of TCM.The increase of carbonization temperature can promote the growth of TCM carbon microcrystals and significantly improve their electrical conductivity.（2）TCM has excellent adsorption performance and electrochemical oxidation performance.It has a high adsorption capacity for organic pollute and heavy metal ions in water.Under the condition of 2V external voltage,the oxidation rate of K₄Fe（CN）₆ is up to 98.4%.In the treatment of real micro-polluted water under these conditions,the synergistic effect of TCM triple functions shows a excellent treatment effect,in which the removal rates of COD,UV₂₅₄,turbidity and bacteria are 94.3%,97.5%,96.3%and 100%respectively,the removal rate of Pb²⁺,Cu²⁺,Ni²⁺and Zn²⁺was close to 100%.The effluent water quality was significantly improved.Moreover,the permeation flux of TCM has been improved,shows that it has a good anti-pollution performance.After regenerating TCM,the performance of TCM is basically restored indicated that it has good reusability.（3）Adsorption,membrane separation and electrochemical oxidation have synergistic effects in the process of electric field enhancement of TCM treatment of micro-polluted water.Adsorption enables low concentration of organic pollute and heavy metal ions in the water to concentrate on TCM.Membrane separation process can effectively intercept large particles of suspended matter,bacteria,algae and other substances,and improve the mass transfer efficiency of the system.Excellent electrochemical oxidation performance enable organic pollutants to be degradated,and make bacteria,algae and other substance deactivation,reduce the problem of membrane pollution.