| With China's economic and social development,the improvement of urbanization level,concentration of urban population,the rapid increase in urban population scale,produced by the urban residents' daily life also a sharp increase in the total urban sewage water pollution produced by urban domestic water is increasingly becoming one of the main sources of pollution in urban environment In view of the increasing urban sewage,the new urban sewage treatment plant has become the main solution According to relevant data show that China's sewage treatment plant and sewage treatment capacity and rate at present greatly increase since the 21 st century,China's cities have more and more,the number of sewage treatment plant by the end of June,2019,built in sewage treatment plants in China the number of close to seventy thousand,daily processing capacity of close to 300 million cubic meters Increasing sewage treatment plants also put forward higher requirements for water quality monitoring in sewage treatment plants Whether the municipal sewage treatment plant can effectively monitor the water quality in the sewage treatment process is an important basis to determine whether the sewage treatment process can reasonably and effectively treat sewage,control the material delivery in the sewage treatment process and evaluate the treatment effect,and also determine whether the sewage will produce secondary pollution after treatment But as a result of sewage treatment system disturbance and time-varying,time-delay and nonlinear characteristics make the traditional detection(based on the chemical oxygen demand(cod)and biological oxygen demand(cod),total phosphorus,total nitrogen and other conventional index detection)reaction process control method is difficult to timely and accurately the material balance and control effect,using optical monitoring of sewage treatment process to become one of the highlights of the research in this field.Based on three-dimensional fluorescence spectrometry combined with different spectral analysis methods,this study studied and analyzed the sewage treatment process of a city in hefei Based on the analysis of the water quality of sewage treatment process in a certain treatment plant in hefei in nearly one year,the spectral information of each treatment process in the treatment plant was measured,and then a method to evaluate the effectiveness and capacity of sewage treatment was established The natural degradation of domestic sewage in urban rivers was studied by using the analytical method The three dimensional fluorescence spectra of water quality in shiwuli river basin were obtained In this study,three-dimensional fluorescence spectrum of sewage treatment water body was mainly used to analyze the change rule of spectral information under each sewage treatment process in sewage treatment plant,and the data were processed by combining principal component analysis and parallel factor method,and the component information after treatment was used to characterize the change of substances in water body The fluorescence parameters associated with the conventional indicators of water body were established and used to characterize the pollution state of water body The temporal and spatial distribution and pollution sources of DOM containing sewage polluted rivers in cities were studied The results show that the three-dimensional fluorescence spectrum information can be used to characterize the material change information of the sewage treatment process,and the principal component analysis and parallel factor method can be used to conduct qualitative analysis and quantitative evaluation of the sewage treatment effect.Through the detection of the main domestic sewage polluted rivers in the city,this paper further studies the variation rules of the domestic sewage polluted in the natural state under the influence of the time and space of the rivers in different river basins,and the results show that this research method can be well applied to the water quality detection of the urban domestic sewage treatment process the changes of substances in water The fluorescence parameters associated with the conventional indicators of water bodies were established to characterize the pollution status of water bodies The spatial and temporal distribution and pollution sources of DOM in urban rivers polluted mainly by domestic sewage were studied The results show that the three-dimensional fluorescence spectrum information can be used to characterize the material change information of various sewage treatment processes,and the principal component analysis and parallel factor method can be used for qualitative analysis and quantitative evaluation of sewage treatment effect Through the detection of the main domestic sewage polluted rivers in the city,the study further studied the natural domestic sewage pollution in different basins affected by the temporal and spatial changes of the river,the results show that this research method can be well applied to the water quality detection in the urban domestic sewage treatment process Finally,the simulation and experiment results show that the pump control system has good dynamic and static performance,and improves the control precision,which is conducive to steady flow and energy saving of the sewage treatment plant and improves the quality of the treated water With the development of China's economy and society,the degree of urbanization has been improved,and the agglomeration effect of urban population has led to the rapid increase of population scale,and the urban domestic sewage produced by human production and living has also increased sharply.Urban domestic sewage has increasingly become one of the main sources of urban environmental pollution In view of the increasing amount of urban sewage,the construction of sewage treatment plant has become the main solution In recent years,China's sewage treatment plants,sewage treatment capacity and treatment rate have shown a significant growth trend,and each city has an increasing number of sewage treatment plants.By the end of December 2018,China had built 6,238 sewage treatment plants,with a daily treatment capacity of 269 million cubic meters For the urban sewage treatment plant can effectively monitor the water quality in the process of sewage treatment,it is an important basis to determine whether the treatment process can reasonably and effectively treat sewage,control the material delivery and evaluate the treatment effect in the process of sewage treatment,and determine whether the sewage after treatment produces secondary pollution However,due to the time-varying,time-delay,disturbance and non-linear characteristics of the sewage treatment system,the traditional detection(based on COD,TN,TP and other conventional indicators)control mode is difficult to timely and accurately reflect the material balance and control effect of the treatment process,which has become the focus of research in this field.Based on three-dimensional fluorescence spectrometry combined with different spectral analysis methods,this study studied and analyzed the sewage treatment process of a city in hefei.According to the water quality condition of sewage treatment process in a certain treatment plant in hefei in nearly one year,different methods were used to analyze the spectral information of sewage treatment process,and establish a method to evaluate the effect and capacity of sewage treatment.Based on the three-dimensional fluorescence spectrum of the water body in each sewage treatment process,the change rule of the spectral information in each sewage treatment process in the sewage treatment plant was analyzed,and the data were processed with the method of principal component analysis and parallel factors,and the component information after treatment was used to characterize the change of substances in the water body.The fluorescence parameters associated with the conventional indicators of water body were established and used to characterize the pollution state of water body.The main research contents are as follows:(1)the three-dimensional fluorescence spectrum of urban sewage water mainly consists of dissolved organic matter mainly composed of aromatic proteins,microbial metabolites,humic acids and fulvic acids.In each process of sewage treatment,aromatic proteins and microbial metabolites degrade obviously,while humic acids and fulvic acids change steadily.(2)by analyzing the fluorescence spectra of each process and the spectra of standard solution of protein substances and humic acid substances,it can be seen that the concentration of protein substances in domestic sewage is generally below10mg/L,while the concentration of humic acid substances is generally around 1mg/ L,and the fluorescence peak position of each substance is relatively stable.(3)the change of relevant fluorescence parameters of wastewater from each process in the sewage treatment plant is different,which indicates that the source of dissolved organic matter in the water body of each process is different,the degradation rate is different,and the degree of humus is different.Among them,the dissolved organic matter of sewage coming into the factory mainly comes from external sources,while other internal sources of sewage flow dominate.(4)the algorithm of three-dimensional fluorescence spectrum of urban domestic sewage was studied,in which the clustering algorithm could realize the classification of water samples,the screening of abnormal sample information,and the prediction of water quality samples of unknown processes.The regional integration method can obtain a good correlation with the conventional water quality indexes,in which the sum of the regional integration values of water-like protein and microbial metabolites and the COD correlation coefficient can reach 78%.The ratio of the sum of regional integral values of aromatic proteins and microbial metabolites to the sum of regional integral values of humic acids and fulvic acids was 74% correlated with TN.(5)by combining principal component analysis with regional integration,a new analysis method,regional principal component analysis,is proposed Through the study,it is found that through the regional principal component analysis of water samples in each sewage treatment process,the correlation coefficients between the relevant parameters and COD and TN of water bodies can reach 97.63% and 94.02%,which improves the accuracy of spectral analysis.Therefore,the three-dimensional fluorescence spectrum information can be used to characterize the material change information of each treatment process of sewage treatment,and the principal component analysis and parallel factor method can be used to conduct qualitative analysis and quantitative evaluation of the treatment effect of sewage,so as to realize the monitoring of the main domestic sewage treatment plants in the city. |
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