The Preparation Of New Hypercrosslinked Resins For The Adsorption Of Nitroaromatics And The Research Of Adsorption Mechanism

Adsorption resins have been applied in the treatment of nitroaromatics effluent because of their high BET surface area,good mechanical property,regenerability.Generally,hypercrosslinked resin were prepared from the Cl-St-DVB?with 17%¹8%content of chlorine?by the post-cross-linking reaction.However,few studies have been reported about the impact of various reaction factors on the structure and the adsorption capacity of resins for NACs.Additionally,chemical modification of resins seems necessary when resins were not suitable for the adsorption of some polar NACs.Therefore,the amine,the phenol and the cariboxyl were chosen to modify the hypercrosslinked resin.In fact,most of these modification techniques were invented based on the chloromethyl group?-CH₂Cl?.In order to find the new way to the resin modification,a different idea would be tried.In present work,series hypercrosslinked resins were synthesized under different conditions by the Cl-St-DVB.After that,a new modification method which was independent of the chloromethyl group was studied.The research and the results were displayed in detail as follows:?1?Series hypercrosslinked resins were prepared under different conditions including solvents,catalysts,temperature and time.Among them,CH-10 was the best whose BET surface area reached to 1329.3 m²/g.The adsorption capacity of CH-10 was almost 1.4 times as much as that of H-103 at 100 mg/L of nitrobenzene in aqueous phase.Various adsorption mathmatical models and the resin structure parameters were used for study of the adsorption process.As a result,the small mesopore was significant for the intra-diffusion process.?2?In order to improve the adsorption behavior of hypercrosslinked resins for polar NACs,different nitration reagents?HNO₃,H₂SO₄/HNO₃,HNO₃/organic solvent,NH₄NO₃/Ac₂O?were used to modify DCE-4h.SnCl₂ was chosen to turn nitro-group and nitroso-group into amine group.Besides,the effects of the dosage of nitration reagent,temperature and time on the structure and the adsorption capacity of reduction resins for polar NACs were discussed thoroughly.According to the BET analysis,the micropore volume decreased while the mesopore volume increased after the modification process.The element analysis displayed that the N and O element were introduced onto DCE-4h successfully.The adsorption behavior of the functional resin was obviously improved compared to DCE-4h.The adsorption capacity of the best the functional resins?NR-07?for p-nitrophenol and p-nitrobenzoic acid were almost 1.23 times and 1.32 times as much as those of H-103.