| Dissolved organic matter in the water environment of the physical,chemical and biological properties plays an important role.Understanding of dissolved organic matter degradation characteristics and change rules can be beneficial to organic matter in the urban sewage treatment process structure features,characteristics,biochemical and molecular weight and migration process of research,For the modification of water treatment process,control,management and the rational utilization and ecological effect of the treated water security.But environmental factors can change the composition,structure and physical and chemical properties of DOM,which will cause the binding capacity between DOM and pollutants,which can lead to the bioavailability of pollutants.Therefore,changes in the environment will affect the DOM itself as well as other environmental ecological effects of pollutants.The in Hefei a sewage treatment plant raw water as the research object,the three-dimensional fluorescence spectroscopy was used to study the biological contact oxidation process degradation characteristics and changing law of DOM in the reaction process of urban sewage treatment,to create a DOM low excitation wavelength tryptophan acid peak fluorescence intensity and the concentration of COD.And further research under different environmental conditions,the low excitation wavelength lubricious ammonia acid fluorescence intensity and the concentration of COD between correlation,to find the values corresponding to different environmental factors,three-dimensional fluorescence detection technology and low excitation fluorescence intensity of tryptophan peak wavelength implementation COD concentration of rapid determination to provide a reliable basis.The main conclusions are as follows:(1)Sewage treatment plant influent water quality indicators: COD 120 mg/L,NH4+-N 27.13 mg/L,TN 3.43 mg/L,after 15 days of the hanging membrane,the reactor effluent COD and NH4+-N removal rate were 73.6%,80.4%,the removal rate of COD and NH4+-N met the requirements,namely the biofilm successfully entered the stable cycle that the effluent quality index: COD 2.76 mg/L,TN 1.1 mg/L,NH4-N 0.7 mg/L.(2)Three dimensional fluorescence spectra showed that DOM mainly by the low excitation wavelength tryptophan characteristic peaks A and high excitation wavelength tryptophan characteristic peak B,visible region rich in acid characteristics of peak C,D peak and ultraviolet region rich in acid characteristic peak e composition.The fluorescence intensity of peaks A and B were in the aeration process gradually decreased,peak C,D and E peaks of fluorescence intensity in the reaction cycle changed little.(3)Study on low excitation wavelength tryptophan acid peak fluorescence intensity and the concentration of COD correlation showed that in stable period,DOM low excitation wavelength tryptophan acid peak fluorescence intensity and COD concentration changes consistent and showed a significant positive correlation,the correlation coefficient 0.959.(4)At different pH values: When the pH is less than 6,low peak excitation wavelength of tryptophan fluorescence intensity and the correlation between COD is 0.091 to 0.530;when the pH value of 6 <pH <8,the low tryptophan peak excitation wavelength correlation of 0.895 to 0.959 between fluorescence intensity and COD concentration;when the pH is greater than 8,correlation of 0.085 to 0.237 low peak excitation wavelength of tryptophan fluorescence intensity and COD concentration.(5)Different concentrations of mercury ions,mercury ions when the concentration is less than 40 ?mol/L,preferably linear,R2 of 0.928~0.934;when the mercury ion concentration greater than 60 ?mol/L,less linear,R2 of 0.081~0.211.(6)Different lead ion concentration,when the lead ion concentration of less than 40 ?mol/L,preferably linear,R2 of 0.951~0.974;when the lead ion concentration greater than 60 ?mol/L,less linear,R2 of 0.146~0.488.(7)Different chloride ion concentration,when the concentration of chloride ions is less than 0.4 mol/L,preferably linear,R2 of 0.895~0.968;when the chloride ion concentration is greater than 0.4 mol/L,less linear,R2 is only 0.738.(8)Different nitrate ion concentration,when the nitrate ion concentration is less than 0.15 mol/L,preferably linear,R2 of 0.776~0.959;when the nitrate ion concentration is greater than 0.2 mol / L,less linear,R2 0.073~0.872.(9)Different nitrite ion concentration,when the nitrite ion concentration is less than 0.003 mol/L,preferably linear,R2 0.870 to 0.989;when the nitrite ion concentration is higher than 0.004 mol/L,compared with the linear relationship poor,R2 of 0.024 and 0.571.(10)At different temperatures,when the temperature is less than 35 ?,good linearity,R2 of 0.832~0.977;when the temperature is higher than 50 ?,poor linearity,R2 is only 0.495.Studies have shown that by three-dimensional fluorescence spectroscopy for the determination of DOM low excitation wavelength tryptophan fluorescence intensity to rapid analysis of COD concentration for sewage biological treatment process cod rapid pollution detection and environmental impact the scope to provide a basis. |
PDF Full Text Request