Synthesis Of Modified Polystyrene Adsorption Resin And Its Application In Wastewater

hyper-crosslinked polystyrene adsorption resin is widely used in industrial wastewater treatment because of its high specific surface area,wide application range and easy regeneration.However,the adsorption selectivity and adsorption effect of traditional adsorption resins on polar organics compounds are not good.Therefore,polar functional groups were introduced into traditional adsorption resins,and the adsorption properties of modified resins were studied.There are few studies on the application of resins to practical industrial wastewater.Two kinds of practical wastewater were also selected to investigate the adsorption properties of resins.The research content is as follows.1.Chloromethylated polystyrene resin was used as the precursor resin.Firstly,the hyper-crosslinked polystyrene resins were synthesized by screening catalysts and reaction time,and then based on the J-2 resin selected in the first step.The compounds containing different functional groups,thiourea,acetanilide,and salicylic acid were used for modification,and hyper-crosslinked resins（JL-T,JL-A,JL-SA）modified with different functional groups were synthesized.The newly synthesized resins were characterized and analyzed,including determination of water content and chlorine content,scanning electron microscopy（SEM）,N₂ adsorption and desorption（BET）,and infrared spectroscopy（FT-IR）analysis and other methods.The results showed that the chlorine content of the J-2 resin after the hypercrosslinking reaction is reduced,the specific surface area increased significantly,and the number of micropores is increased,the chlorine content of JL-T,JL-A and JL-SA resins modified by functional groups was further reduced,and the characteristic absorption peaks of each functional group in the infrared spectrum are obvious.2.The adsorption of methyl orange dye was studied by using the prepared resins J-2,JL-T,JL-A and JL-SA.Among them,the chemically modified JL-T,JL-A,and JL-SA resins have significantly improved adsorption capacity for methyl orange compared with J-2 resin,and the maximum adsorption capacity has been increased by more than two times.The fitting result of the Freundlich model is higher.The adsorption of the dye methyl orange by the modified resin is an exothermic process,the adsorption reaction can be carried out spontaneously,the freedom of movement is reduced.Pseudo second order kinetics can better describe the adsorption process of methyl orange by resin.The regeneration performance of J-2,JL-T,JL-A,JL-SA resin saturated with adsorption was studied using 60%absolute ethanol solution as eluent.The adsorption mechanism of the modified resin for methyl orange dye is mainly considered to be the simultaneous existence ofπ-πconjugation,hydrogen bonding and electrostatic attraction exist at the same time.3.The modified polystyrene resins were screened for the adsorption performance of heavy metals Cu²⁺and Cr（Ⅵ）.Among them,JL-SA and JL-T resins had the best adsorption effect.The next adsorption research on heavy metal ions Cu²⁺and Cr（Ⅵ）was carried out.The maximum adsorption capacity of JL-SA for Cu²⁺is 33.78 mg·g^-1and the maximum adsorption capacity of JL-T resin for Cr（Ⅵ）is 140.36 mg·g^-1.The fitting resuit of the Langmuir model is higher,which is favorable for the adsorption of Cu²⁺and Cr（Ⅵ）by the resin at high temperature.The adsorption of Cu²⁺and Cr（Ⅵ）by JL-SA and JL-T is an endothermic process,and the adsorption reaction can proceed spontaneously,adsorption leads to the increase of standard entropy of the system and the increase of the freedom of movement.The pseudo-second-order kinetics can better describe the adsorption process.The adsorption mechanism of the two resins for Cu²⁺and Cr（Ⅵ）is mainly considered to be the coexistence of size matching and electrostatic interaction.4.The synthesized modified polystyrene resins were applied to actual industrial wastewater,towel printing and dyeing wastewater and chemical wastewater.Firstly,The adsorption performance of the modified resin was compared and screened,the factors affecting the adsorption effect,and the full-scan UV spectrum of the wastewater before and after adsorption were analyzed,indicating that the organic pollutants in the two wastewaters can be removed well.