Preparation Characteristics And Accelerating Denitrification Effectiveness Of Polyester Modified By Quinone

It is a hot topic to use quinone redox mediators to catalyse anaerobic biotreatment technology in environment.Although a high efficient quinone functional biocarrier is necessary for the large-scale industrialization,the research and development of an efficient quinone functional biocarrier still remain in the initial development stages.In this paper,a series of functional biocarriers were synthesized via the reaction the polyethylene terephthalate(PET)and quinone redox mediators.The capacity and the mechanism of accelerating denitrification were investigated,both of which provide an instructive concept for the application in the wasterwater treatment technology.Anthraquinone-2-sulfonic sodium(AQS)selected as sulfonic redox mediator was fixed on the PET forming sulfonic-quinone functional biocarrier(PET-AQS).The AQS content of PET-AQS was about 0.1406 mmol/g determined by Fourier transform infrared spectroscopy(FT-IR)and energy dispersive spectrometry(EDS).Meanwhile the heat resistance of PET-AQS was analyzed by thermogravimetric analysis(TGA).PET-AQS with the quinone concentration 0.0562 mmol has obvious acceleration for the denitrification process.In the PET-AQS accelerating denitrification system,the optimum conditions were reaction temperature 35?,pH 7,the ratio of C: N(C/N)as 6:1,the initial concentration of 300 mg/L and sodium succinate as carbon source.There was the positive correlation between the PET-AQS and nitrate degradation efficiency.Compared with the control,the pH increased rapidly and the stabilised oxidation reduction potential(ORP)value with the PET-AQS system was lower approximately 25 mV.Five chloro-quinones were immobilised on PET forming novel functional biocarriers(PET-CAs)by Buchwald–Hartwig method.The optimum reaction conditions were reaction time 6 h and reaction temperature 80?.It demonstrated that PET-CAs were successful synthesis and comfirmed the quinone concentration by FT-IR and EDS.The order of the functional biocarriers based on their accelerating efficiencies for the denitrifation was PET-1,8-DCA > PET-2-CA > PET-TCA > PET-1-CA > PET-1,5-DCA.Compared with the control,the pH increased rapidly and the stabilised ORP value with the PET-1,8-DCA system was lower approximately 70 mV.To sum up,sulfonic-quinone functional biocarrier and chloro-quinone functional biocarriers had perfect effectiveness on the accelerating denitrification and stable activity.The functional biocarriers were suitable for use in engineering applications due to the simple synthetic technique and the denitrification efficiency.