Study On Determination Method And Degradation Characteristics Of Typical EDCs Compounds In Wastewater

In recent years, Endocrine Disrupting Chemicals (EDCs) contamination has progressively posed great threat to ecological environment because of the activities of mankind’s production and living. It’s called the third generation of environmental pollutants, and even under lower exposure concentration, it still can decrease the reproductive capacity of organism and lead to species extinction eventually. The physical and chemical properties of EDCs is stable, it’s difficult to degrade,and is absorbed in organism. By food chain, It can also be seriously bioaccumulated and biomagnified, and severely harm human heath finally. In China, EDCs had also been found in many watershed, but the related researchs are very insufficient in contrast, in which determination and degradation are the crucial element for controlling and treating EDCs contamination. For the environmental scientists of our country, the researchs about developing the determination technology of EDCs and mastering degradation characteristics of EDCs have already become one of the most important task. From more than 500 kinds of EDCs, this study selected Polycyclic Aromatic Hydrocarbons (PAHs), Avermectins (AVMs), Synthetic Pyrethroids (SPs) and Steroids 4 types of typical EDCs as research objectives, conducting respectively research about the method of rapid, multi-residue, precision determination and the characteristic of biodegradation.Through a series of optimization experiment, finally taking Solid-Phase Extraction (SPE) as enrichment manner, Rotary Vacuum Evaporation as purification manner, the flow rate of mobile phase was 800μL min-1, the column temperature was 30℃, under the optimized procedures of chromatography and detector, the obtained correlations of linear equations of 16 PAHs were all greater than 0.9950, the limit of detection (LOD) of obtained method were 0.58～11.27 ng·L-1, and the recovery rate experiment at high, middle and low 3 concentration indicated that the recovery rates were 80.32%～120.74%, the relative standard deviations(RSD) were 2.02%～8.71% in 5 duplicates, it far exceeded the request of USEPA that the recovery rate should be 70～130% and RSD should be less than 30%. From the refered 16 PAHs, selecting phenanthrene(Phe) and pyrene(Pyr) to represent respectively low and high molecular weight PAHs, acclimating and obtaining dominant bacterial strains W1, W2, the degradation characteristics experiments were performed in slurry phase and aqueous phase, by individual isolate and mixed consortium. The result indicated, since it’s more closer to natural conditions, when in slurry phase and by mixed consortium,the degradation rate was more better than it in other conditions, however, for Pyr,the difference of result under each condition wss not as significant as Phe.Taking ultrawater and methanol(both of that include 0.1% formic acid) as mobile phases, under optimized parameter conditions of chromatography and mass spectrum, both peak shapes and separation were pretty good. Testosterone propionate etc.7 compounds produced quasi-molecular ion [M+H]+, and other 6 compounds dehydrated to produce quasi-molecular ion [M+H-H2O]+, the corelations of regression equations of each compound were all greater than 0.9990, the LODs were 0.15～20 ng-mL-1, the range of recovery rate of 13 steroid compounds was 83.75%～111.50%, the RSD in 6 duplicates were 2.02%～14.21%. By actual measuring of waste example, the method could better meet the measuring’s request. After acclimating, isolating, the dominant bacteria strains of ethynyloestradiol(EE2) WS1-3 were obtained, the degradation experiments of EE2 were carried out. After 72 hours, the curves of degradation effect and microbe growth under each level of 4 conditions were acquired. The result shown that, when the initial concentration of contamination was 10 mgL-1, the experiment temperature was 35℃, the value of pH was 9, the concentrations of NaCl、MgCl2、CaCl2、ZnCl2、FeCl3、CuCl2 were respectively 20、30、10、10、40、10 mg L-1, the degradation rate reached the maximum. It was shown that the different levels of different conditions have effected the degradation performance in varying degree.For Avermectins(AVMs) and Synthetic Pyrethroids(SPs) compounds, adopting non-derivatization SPE as simple and convenient pre-treatment method, High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MSMS) as efficient and precise measure manner, in electro-spray ion(ESI) soure and positive mode, the multi-residue analysis method of 2 types of 7 kinds of pesticides’s concentration in one injection was developed, the range of limit of quantitation(LOQ) of 7 compounds was from 0.03 to 2.47ng mL-1, the corelation of calibration curve were all greater than 0.9980. The U1, a bacteria strain that could efficiently degrade both deltamethrin(DTM), cypermethrin(CPM) and flumethrin(FM) at the same time was acclimated and isolated from pesticide sediment. And another bacteria strain, W1, which could efficiently degrade abamectin(Aba) was obtained as well. Using this 2 dominant strains respectively, the degradation experiments of that 2 types pesticide compounds were conducted. When the inoculum size OD415 nm was 0.2, the initial concentration of contamination was 150 mg L-1, experiment temperature was 25℃, the value of pH was 7.0, shaker rotation was at 220rpm, the degradation rates of DTM, CPM and FM reached the maximum value respectively. When experiment temperature was 30℃, pH=7.0, the initial concentration of contamination was 100 mg L-1, shaker rotation was at 220rpm, the degradation rate of Aba reached the peak value.