Construction Of New Superadsorbent Materials Based On Optimal Design And Regulation Of Network Structure And Research On Their Properties

With the rapid development of global industrialization,a large amount of industrial wastewater is produced in industrial activities.Dyestuffs and heavy metal pollution are often non-biodegradable and often accumulate in organisms,eventually entering the human body along the food chain,posing a huge threat to human health.Therefore,how to find a green and economical treatment method to remove pollutants in water has become the focus of current environmental research.The main goal of this thesis is to develop adsorbents with high adsorption performance for pollutants.The three-dimensional network was prepared by adding natural macromolecular chitosan(CTS)and sodium alginate(SA)to the macromolecular adsorbent as the matrix.A series of three-dimensional network composite adsorbents were prepared on the basis of composite adsorbents and natural clay mineral rectorite(REC)to improve the removal rate of pollutants.The structures of the prepared three-dimensional network composite adsorbents were characterized by means of scanning electron microscopy(SEM),transmission electron microscopy(TEM),Xray diffraction(XRD),and infrared spectroscopy(FT-IR).The adsorption performance of different pollutants was investigated,and the optimal synthesis conditions of the composite adsorbent were explored.The main research contents and results are as follows:(1)In an aqueous medium,the natural biopolymer sodium alginate(SA)is used as the main chain,sodium acrylate(Na A)is used as the monomer,and polyvinyl alcohol(PVA)is used as the semiinterpenetrating network component.A porous semi-interpenetrating network(Semi-IPN)hydrogel adsorbent with excellent adsorption performance and removal efficiency for Pb(II)was prepared by branch polymerization.The maximum adsorption capacity of the adsorbent was784.97 mg/g,and the best removal rate was 98.39%(the amount of adsorbent was 2 g/L).After adding 2 wt% PVA,the storage modulus of the hydrogel increased by 19.4%.(2)Using CTS,acrylonitrile(AN),N,N’-methylenebisacrylamide(MBA),ammonium persulfate(APS),and REC as raw materials,a kind of high-efficiency Congo red(CR)was prepared.Selective three-dimensional network composite adsorbent(ACTS-g-PAN/REC).When the REC content was 2.5%,the adsorption capacity for CR was the largest,and the maximum adsorption capacity was 241.65 mg/g.The adsorption study of other dyes found that the three-dimensional network composite adsorbent has strong adsorption selectivity for CR,and can separate CR from other dyes in a binary mixed system.The DFT calculation results show that the three-dimensional network composite adsorbent has the highest binding energy with CR.(3)By copolymerizing acrylic acid(AAc) with 2-acrylamido-2-methylpropanesulfonic acid(AMPS)and doping REC in it,a hydrogel adsorption with extremely high adsorption capacity and removal rate for MB was prepared.Agent PAA-co-PAMPS/REC.Structural characterization showed that AAc was successfully copolymerized with AMPS and REC was successfully incorporated into the hydrogel adsorbent.The maximum adsorption capacity of the best hydrogel adsorbent MB was1630.51 mg/g.The addition of REC greatly increased the removal rate of MB by the adsorbent,reaching more than 99%.At the same time,the adsorption of the hydrogel adsorbent in the actual water bodies(the Yangtze River,the Yellow River,and the sea water)was investigated.The results show that the adsorbent can also have good adsorption performance in the actual water body.