Surface Molecularly Imprinted Composite Materials Based On Carbon Supports For Adsorption Of Phenol In Water Phases

Phenol is a kind of organic compound which is harmful to human and environment but has high economic value.This work aims to solve the problems of low selectivity,low adsorption capacity and difficult recovery and regeneration of existing adsorbents,started off with the deep removal of phenol in coking wastewater,and synthesized a new adsorbent material to realize the selective and efficient separation and removal of phenol in coking wastewater,which can not only alleviate the harm of phenol to the environment and human beings,but also realize the recycling and reuse of phenol.In this research,starting from the matrix of the adsorbent,a monolithic porous carbon nanospheres gel carrier was prepared,and the surface molecular imprinting technology was used to further promote the carrier into a surface molecularly imprinted polymer with specific selectivity.The morphology and structure of the materials were characterized,and the adsorption and removal effect of phenol in coking wastewater was investigated.This research provides a theoretical and technical basis for the deep treatment of phenol in coking wastewater.The specific contents are as follows:（1）Preparation and adsorption property of porous carbon nanospheres gel carrier.Carrier porous carbon nanospheres gel（PCNS-gel）was fabricated through the hydrothermal reaction of glucose,borax,and polyvinyl alcohol mixture.This work analyzed the morphology and structural characteristics of PCNS-gel and investigated its adsorption performance of phenol in coking wastewater.The results show that PCNS-gel has a stable boron-carbon grid structure,in which porous carbon nanospheres are uniformly distributed,the boron-carbon grid provides a stable support structure for the carrier,and porous carbon nanospheres provide a rich pore structure for the matrix.The specific surface area of PCNS-gel reaches 659.9 m² g^-1,the pore volume is 1.02 cm³ g^-1,the mesopores account for about 80%,and the gel is rich in oxygen-containing functional groups.The adsorption capacity of the carrier material for phenol is 19.90mg g^-1,and the adsorption process follows a pseudo-first-order kinetic model and does not have specific selectivity for phenol.（2）Preparation and adsorption property of porous carbon nanospheres gel molecularly imprinted polymers.In order to solve the problem that the material has low adsorption capacity and has no specific recognition towards phenol,the molecularly imprinted polymer of porous carbon nanospheres（SMIP@PCNS-gel）was prepared by using PCNS-gel as carrier,phenol as template molecule and methacrylic acid as functional monomer,and the morphology and structure of SMIP@PCNS-gel and its adsorption performance of phenol in coking wastewater were analyzed and investigated.The surface molecularly imprinted material completely maintained the boron-carbon grid structure,and an imprinted layer was constructed on the surface of the porous carbon nanospheres.Owing to the surface imprinted layer,SMIP@PCNS-gel performed a good adsorption capacity of 64.02 mg g^-1 towards phenol.In addition,SMIP@PCNS-gel had good selectivity towards phenol in the quaternary mixture solution of phenol,hydroquinone,p-nitrophenol,and p-tert-butylphenol with relative selectivity factors of3.04,16.50,and 3.93,respectively.More importantly,thanks to the monolithic PCNS-gel carrier,the adsorption capacity only decreased by 10%after 10 repeated adsorption-desorption cycles.The SMIP@PCNS-gel adsorbent exhibited high adsorption capacity,exceptional separation and recovery efficiency as well as outstanding stability and durability.SMIP@PCNS-gel was more in line with the pseudo-first-order model,indicating the adsorption rate is linear with the concentration of phenol,which proved that SMIP@PCNS-gel takes shorter time to reach the adsorption equilibrium and has higher adsorption efficiency.The adsorption isotherm was consistent with the Dubinin-Radushkevich model,which showed the adsorption is multilayered,porous and with uniform adsorption sites.According to the above research,carrier material is a very important part of adsorbent.Excellent carrier materials provide stable skeleton,abundant pore structure,and suitable surface chemical environment for adsorbent.Surface molecularly imprinted polymer materials of porous carbon nanospheres prepared by surface molecular imprinting technology realizes the high-efficiency removal of phenol in coking wastewater,and has broad application prospects for the deep selective adsorption and removal of phenol in the water phase.