The Synthesis Of Polyhydroxy Amine Resin And Its Adsorption Performance To Boric Acid

Boron is an indispensable trace element for animals,plants and human beings,and participates in many important physiological activities.However,excessive boron will cause great harm to animals,plants and humans beings.For example,excessive contact with boron will lead to serious damage or even death of human immune system,nervous system and reproductive system.Boron is a very important industrial and agricultural resource,which will lead to a large amount of boron in industrial wastewater.Four kinds polyhydroxyamine resins synthesized in this subject,their ortho-dihydroxy or meta-dihydroxy groups can be complexed with boric acid to synthesize five-membered ring or six-membered ring chelates,thus achieving the purpose of boron removal.（1）Chloromethylated polystyrene resin was modified by 3-amino-1,2-propanediol to prepare dihydroxyamine resin（KLA resin）;Poly（methyl acrylate）resin was prepared by suspension polymerization with methyl acrylate as monomer and divinylbenzene as a crosslinking agent.Using trometamol as raw material,chloromethylated polystyrene resin and poly（methyl acrylate）resin were modified respectively to prepare two kinds of polyhydroxyamine resins（KDN resin and KEN resin）;Polyamine-based resin（KAS resin）was synthesized by the electronic substitution with diethylenetriamine and chloromethylated polystyrene resin;KAS resin was modified with glycidol as raw material to prepare polyhydroxyamine resin（KBS resin）.The structure of the resin was characterized by infrared spectrometer and specific sueface analysis tester for qualitative analysis.The chlorine content,water content and weak base exchange capacity of the resin were determined for quantitative analysis.The results showed that KLA,KDN,KEN,and KBS resins were successfully synthesized.（2）The adsorption and desorption properties of KLA,KDN,KEN and KBS resins towards boric acid in aqueous solution were investigated,and the adsorption capacities of four resins were compared under the same conditions.The results showed that the four resins have great adsorption performance to boric acid.The adsorption capacity for boric acid was obviously affected by the adsorption conditions of adsorbate concentration and temperature which increases with the increase of boric acid concentration and decreased with the increase of temperature.The resin（KLA,KDN,KEN and KBS）was reused by the eluent of 1 mol·L^-1hydrochloric acid and the elution rates are as high as 90.32%,90.75%,87.78%and 90.42%,respectively.The results showed that adsorption capacity of the four resins to boric acid in aqueous solution were 32.20mg·g^-1,28.91 mg·g^-1,22.63 mg·g^-1 and 25.09 mg·g^-1 at the initial concentration of 1000 mg·L^-1 and temperature being 288 K.The resins showed that macroporous polystyrene-based polyhydroxy resin had better adsorption performance than gel polyacrylic-based polyhydroxy resin,and the steric hindrance of substitute group onto the resin was unbeneficial for adsorbate closing to the adsorption site which could decrease the adsorption capacity.