Study On The Technology Of Chemical Immobilization Of Anthraquinone Molecules

With the development of industry and agriculture,a large number of nitrate wastewater was produced.The biodegradation process is an effective method for the treatment of wastewater containing nitrate,but the biodegradation rate is low.Anthraquinone compounds as a redox mediators can improve the biodegradation rate of nitrate in wastewater.However,it was easy to lose with the water flow if directly applied in the process of practical water treatment,so it needs to be fixed on the carriers.In this paper,anthraquinone molecule was fiexed on the hydroxyethyl cellulose and polystyrene microspheres carrier materials,respectively.The anthraquinone functionalized cellulose membrane and anthraquinone functionalized PS microspheres were prepared by the chemical grafting methods.The process conditions were optimized and the acceleration performance of anthraquinone functionalized carriers to nitrate biodegradation and the effect of reused were determined.In the study on the technology of anthraquinone immobilized on cellulose carriers,hydroxyethyl cellulose was choosed to be grafted carrier,through etherification of 2-chloranthraquinone fixed form anthraquinone functional hydroxyethyl cellulose in hydroxyethyl cellulose.The results showed that the optimal conditions for the synthesis processes of anthraquinone process functionalized hydroxyethyl cellulose were as follows:the molar ratio of 2-chloro-anthraquinone and hydroxyethyl cellulose was 1.5: 1,sodium hydroxide dosage accounted for 0.75% of the mass of reactants,and immobilization reation time for 5h at 80 ?,the grafting rate was 86%.Fourier transform infrared spectroscopy?FT-IR?and scanning electron microscope?SEM?results showed that quinonyl groups were successfully immobilized on hydroxyethyl cellulose.and anthraquinone-hydroxyethyl cellulose blend membranes were prepared by the method of phase transformation.In the biological denitrification experiment biological reduction rates of NaNO₃ increased by 2.73 times and the degradation rate of NaNO₃ reached 95%after Anthraquinone functionalized hydroxyethyl cellulose membrane?86%?added.Further more,the properties of Anthraquinone functionalized hydroxyethyl cellulose membrane?86%?retained the same during 8-time successive repeated experiments,but another quinonly membrane prepared by physical blending method lost its catalytic activity at 2-time successive repeated experiments.The chemical fixing method ofanthraquinone is stable,and has good repeatability,which promise it a good practical value.In the process of using suspension polymerization for preparation of anthraquinone functionalized polystyrene microspheres,the effects of reaction conditions on the properties of the functionalized polystyrene microspheres were also explored,and The results showed that the optimum reaction conditions :dispersant PVA,PVP and initiator AIBN accounted for 1.0%,1.5%,2.27% of styrene monomer,crosslinking agent TMPTA dosage was 1.5 mL.Anthraquinone functionalized polystyrene microspheres prepared under the conditions of stage variable temperature and stirring speed having larger particle size and rough surface were fit to microbial attachment.Fourier transform infrared spectroscopy?FT-IR?and Thermogravimetric analysis?TGA?were used to characterize the anthraquinone functionalized polystyrene microspheres.Biological denitrification experiments showed that the effect of the functional polystyrene microspheres on the biological treatment of nitrate solution was significantly promoted,and has the performance for repeated use.