Characterization And Determination Of Saccharide From Municipal Wastewater Treatment Plants Effluents Using Fluorescence Spectroscopy

Currently,there is a hot discussion in sewage water pollution.In municipal wastewater treatment plant,various substances consist in tail water and their concentration is relatively low.However,it is difficult to represent and quantitative analysis determinate their substances by traditional analytical methods.There are many types of dissolved organic matter in tail,including protein and polysaccharide,and they are main components of COD in effluent.More studies on protein are in the research community,but there is seldom research on carbohydrates.Consequently,identifying and detecting the presence of sugars,and measuring the concentration of sugar will be one of the major components of the study.A lot of traditional methods are used to test the content of the sugar,but their developments have been limited because of their shortcomings such as complex detection means,long analytical methods and expensive and so on.In recent years,boronic acid compounds as a recognition group have been widely used in the design and preparation among fluorescent molecular probes.At the same time,quantum dots are regard as a new material,and especially were used for the detection of polysaccharides,which has also attracted wide interest from researchers.The thesis has mainly two research contents as followed,?1?Design and synthesis a kind of fluorescent probes that are response and selectivity to heparin or sodium alginate,and it was also important to study the properties of the QDs.In addition,it was important to explore the fluorescence probe characterization of polysaccharides.In the experiment,ZnSO₄·7H₂O,3-aminopropyltriethoxysilane?APTES?,MnCl₂·2H₂O and Na₂S were used to synthesis the QDs.It was envisaged that the interaction with the QDs and cationic OA-POSS,and it was first happened and formed a kind of substance.Then the large aggregates was formed by the electrostatic interaction with the above mixture and heparin or sodium alginate,and established a sort of test method to detect the content of some substances that their structure were similar to heparin or sodium alginate in tail.?2?Design and synthesis a kind of fluorescent probes that are response and selectivity to glucose,and it was also important to study the properties of the C-dots.Additionally,it was significant to explore the characterization of glucose and other monosaccharides.In the experiment,3-aminobenzeneboronic acid and sodium citrate were used to synthesis the fluorescent probe.It was envisaged that the formation of large aggregates were by the covalent binding with the fluorescent probe and glucose.This effect would cause the fluorescent quenching,and established a sort of test method to detect the content of glucose.The main conclusions of this thesis are as following:?1?Use OA-POSS and Mn doped ZnS quantum dots to complete the self-assembly of nanoparticles in the experimental.When the pH value of the effluents was around 7.0,nanoparticles was formed between Mn-doped ZnS QDs and OA-POSS by electrostatic aggregation,which could be used for quantitative analysis and detection of heparin or sodium alginate in a phosphorescent mode.The experimental results showed that the nanoparticles formed by Mn-doped ZnS quantum dots and cationic OA-POSS was used to detect the content of heparin and sodium alginate,which had very similar results.Thus,nanoparticles formed by Mn-doped ZnS quantum dots and cationic OA-POSS were used to detect the total amount of heparin and sodium alginate.?2?3-aminobenzeneboronic acid and sodium citrate were used as precursors in the experiment.They were placed at 160°C and co-carbonized for 8h,in order to prepare the relatively high-yield boric acid functionalized carbon dots.The combination of boronic acid groups on the surface of the carbon dots with the double cis-diol of glucose would form large aggregates,resulting in the realization of the quench of fluorescence by the surface quench state induction mechanism and the realization of the enhancement of resonance light by heterogenerous size effect.Hence,a hybrid ratio meter chemical sensor was developed for the sensitive and selective of glucose in a urine with a pH of 8.0.The experimental results showed that synthesized Mn-doped ZnS QDs could be used to detect the content of polysaccharides that their structure are similar to heparin sodium and sodium alginate in the tail water.Thus,establishing a kind of test method for the detection of polysaccharides is needed.In addition,3-aminobenzeneboronic acid and sodium citrate as precursors were used to prepare the relatively high-yield boric acid functionalized carbon dots,which could be the application of a mixture ratio meter chemical sensor for the sensitive and selective of glucose sense.The platform based on the carbon dots had various advantages such as high sensitivity,a wide linear response and low cost.It was hoped that this would be a effective platform for quantitative monosaccharide detection.