| Because of Bisphenol A(BPA) widely used in the production of adhesive,building materials and packaging material,a large amount of products containing BPA come into people's daily lives and create a potential hazard on people's health.At present,removal methods of BPA from water are mainly physical,chemical,and bio-degradation.And the adsorption in physical is the most widely used.Activated carbon fiber which have high specific surface area and homogeneous microporous structure is widely used in wastewater,waste gas treatment and water purification. Activated carbon superfine fiber mat being used in the adsorption on BPA have not been reported, so the study on preparation of activated carbon superfine fiber mat and its adsorption on BPA have certain significance.The main steps of preparation of activated carbon superfine fiber mat(ACSFM) are electrospinning,pre-oxidation,carbonization,activation.In this paper,polyacrylonitrile(PAN) with different molecular weight(Mv) was prepared by mixed solution polymerization at first,then electrospinning,pre-oxidation,carbonization and activation.It was found that fiber mats can not be obtained through electrospinning if Mv is more than 3×105,and carbon superfine fiber mats can not be achieved as Mv is less than 5×104 because of fiber brittle.The results exhibited that fiber diameter and the yield rate of carbon fibers were increased with Mv rising.The analysis of fiber's tensile strength showed that the fiber mats' tensile strength was increased with Mv rising.The W3 sample was chosen to be activated,and its tensile strength is 17.9MPa.Water vapor was used in avtivation.The W3 sample was activated by electric heating and microwave heating.It was found that the suface area of ACSFM activated by electric heating was increased with temperature rising.And activation yield of ACSFM activated by electric heating was decreased with temperature rising.The best activated sample by electric heating was Hw3a because of both suface area and activation yield.Its suface area was 946.7m2/g and its activation yield was 29.5%.The results exhibited that the suface area of ACSFM activated by microwave heating was increased with time rising.And activation yield of ACSFM activated by microwave heating was decreased with time rising.The best activated sample by microwave heating was Hw3b because of both suface area and activation yield.Its suface area was 956.3m2/g and its activation yield was 33.3%.In this paper,the Hw3b sample(2.5minutes activated by Microwave High-Fire) was the best because of suface area,activation yield and energy.The pore analysis of the Hw3b sample shows that activated carbon superfine fiber mat's pore structure was main composed by microporous and with little mesopore and macroporous.And it's pore was mainly distributed nearby 0.9 nm.The Hw3b sample was applied to the adsorption of BPA.The adsorption of BPA by activated carbon superfine fiber mat was analyzed from static adsorption,kinetics,thermodynamics and regeneration.It was found that the removal rate reached 66%at the 10th minute.It is thus clear that the adsorption rate of BPA by activated carbon superfine fiber mat was very fast because of high suface area and microporous.When the initial concentration was 80mg/L,adsorption rate of BPA would reach above 99%and equilibrium adsorption would reach above 140mg/g.The results exhibited that equilibrium adsorption was increased with initial concentration rising and decreased with temperature rising.When pH was from 2 to 9,equilibrium adsorption almost kept the same. Equilibrium adsorption decreased with pH rising when pH was above 9.And the adsorption was better expressed by second-order kinetics than by first-order kinetics.Thermodynamic calculation shows thatΔH＜0 andΔG＜0,so adsorption process was spontaneous heat release process.And the numerical ofΔH andΔG shows that adsorption of BPA by activated carbon superfine fiber mat was mainly physical adsorption.After recycling use for 5 times,the removal rate of BPA by activated carbon superfine fiber mat was about 90%.And the quality of ACSFM was still remained about 96%After recycling use for 5 times.So activated carbon superfine fiber mat was renewable.
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