Triazine-based Microporous Covalent Organic Polymer And Its Subsequent Modification For Adsorption And Removal Of Pollutants In Water

The use of porous materials to adsorb and remove organic pollutants is an important means of treating organic pollutants in sewage.The novel nanoporous organic material is constructed by covalent bonds of rigid structural monomers,and has the advantages of large specific surface area,small density,stable physical and chemical properties,and easy chemical modification.It is an adsorbent for sewage treatment.The triazine-based covalent microporous organic polymers?CTPs?are composed of an electron-deficient triazine group and an electron-rich benzene ring group,which have a rich recognition site and good porosity,enabling them to be efficiently adsorbed.Organic pollutants in water.In this paper,combined with magnetic adsorption technology,triazine-triphenylamine based microporous organic polymer(CTP_CC-TPA)and its nitration product(CTP_CC-TPA-NO₂)and Ni are formed for the adsorption of nitrobenzene and aniline.The main contents are as follows:?1?The chromocyanine and triphenylamine were polymerized into a triazine-triphenylamine microporous organic polymer CTP_CC-TPA,and the magnetic composite Ni/CTP_CC-_TPA was prepared by using nickel as the magnetic source hydrothermal method.The structural characterization showed that the BET specific surface area of porous CTP_CC-TPAC-TPA was 616.7 m²/g.FT-IR showed the presence of s-triazine ring and benzene ring structure,and the structure of CTP_CC-TPA did not change significantly before and after magnetization.This project designed Ni/CTP_CC-TPA to adsorb p-nitrophenol,2,4-dinitrophenol,2,4,6-trinitrophenol,three nitrophenol compounds,through kinetics,thermodynamics The model shows that the adsorption process conforms to the quasi-secondary and Langmuir adsorption models.The order of equilibrium adsorption is:p-nitrophenol>2,4-dinitrophenol>2,4,6-trinitrophenol;calculation kinetics,thermodynamics It is inferred that Ni/CTP_CC-TPAC-TPA adsorbs nitrophenols not only by physical adsorption but also by chemical adsorption.At the same time,the effects of different pH values and ionic strength on the adsorption were evaluated.It was found that Ni/CTP_CC-TPA and nitrophenols not only had?-?interaction,but also had electrostatic action,and verified that N atoms on the triazine ring can be combined with phenol.The H atom of the hydroxyl group forms a hydrogen bond.?2?In order to further explore the mechanism of adsorption of organic matter in water by the above adsorbent CTP_CC-TPA,the CTP_CC-TPA is modified in this subject,and the nitro group is introduced into the benzene ring monomer of the raw material to increase the adsorption site and change the hydrophobicity of the material to prepare the absorption.Electron-based Ni/CTP_CC-TPA-NO₂ and characterize its structure.The aniline containing electron-donating group?-NH₂?was selected as the adsorbate.The adsorption of aniline before and after CTP_CC-TPA nitration was compared.The adsorption process was investigated from the kinetics and thermodynamics.The results showed that the adsorption process was a spontaneous endothermic entropy increase process and nitrification.The adsorption effect of Ni/CTP_CC-TPA-NO₂ is slightly better than that of Ni/CTP_CC-TPA,which proves that the effect of charge transfer complex formed by adsorbent and adsorbate is greater than that of adsorbent.In addition,by investigating the effect of pH and ionic strength on the adsorption effect,it is speculated that Ni/CTP_CC-TPA and aniline have various affinities such as hydrogen bonding and electrostatic attraction.The above two adsorption experiments were analyzed,and it was found that the porous CTP_CC-TPA had a large specific surface area for physical adsorption,and the introduction of a nitro group to increase the adsorption site could achieve chemical adsorption.Adsorbents and adsorbents have a variety of forces,not only intermolecular forces?van der Waals forces,hydrogen bonds,etc.?,but also charge transfer and other effects.In addition,post-modification of CTP_CC-TPA demonstrated that increasing the adsorption site increased the performance of adsorbing organic contaminants.