Detection Of Organics In Hanjiang Tap Water And Research On The Combined Effect Of Their Nonpolar Components With Microcystins

With the improvement of the industrialization, the newborn chemical substances are emerging one after another. The data from global investigation statistics demonstrated that 765 kinds of synthesis organics in the tap water were detected in the worldwide, 117 kinds in which are carcinogen or related carcinogen. Moreover, along with the enhancement of analytical technique and the aggravation of pollution, organics appeared in the tap water will increase. Owning to the organics'severe harm to human'health, analysis of organics in the tap water is very important to protect the water environment and human's health. Nowadays, most researchers use one kind of resin to concentrate the organics of the top water for theanalysis of organics; however, because of the complexity of organics, their research may be not accurate.As a result of environmental pollution's aggravating,eutrophication is getting worse and worse. The algaes reproduce abnormally and cause Microcystins pollution which becomes a global problem. However, the conventive treatments cannot eliminate Microcystins fromthe water, moreover, the pro-organics can also form many chlorination disinfection by-products in the disinfection process, in which organics such as the chlorination disinfection by-products coexist and appear combined effects with Microcystins. At the same time, because many compounds are lack of the toxic data, so it is hard to forecast that influence of the complex compounds mutually or combined effects to the ecological equilibrium and people. Therefore, we cannot neglect the pollution in water. It's a pity there are few studies on combined effect of Microcystins and nonpolar organics in and out of the country. So it's significant to research on the concentrations of the resins as well as the combined effect of Microcystins and nonpolar organics.In this study, properties of XAD series resins were analyzed by enriching organics in Hanjiang tap water, and then all the organics were detected by GC-MS. The experiments are the theoretical basis of the choice of resins, and so are the combined effects of Microcystins and organics. Besides, DNA damage was added to test in HepG2 cells exposed to Microcystins and nonpolar organics by using single cell gel electrophoresis (SCGE), we know more about the healthy hazardness of the synthetic effects of combined action of Microcystins and organics.PartⅠDetection of organics in Hanjiang tap water1. Research on the properties of XAD series macroporous adsorption Resin to absorb organics in tap waterWith static and dynamic adsorption methods, the ultraviolet extinction of samples were determinated under the wavelength of 254nm to examinate the adsorption performances of different XAD resins (nonpolarity, polarity, mix). As a result: in static adsorption experiment, resins dried or not had no influence on the adsorption, and it was same to samples by different treatments. The static adsorption rate of XAD-2, XAD-2/XAD-8mixed resin and XAD-8 was 75.77%, 58.76% and 32.61% respectively; while their best adsorption rate was 86.56%, 76.15%, 47.92% respectively in dynamic experiment, better than their static adsorption. At the same time, slower of the flowing speed, the adsorption rate was higher; and along with adsorbed water enlargement, the resin adsorption efficiency had reduced, and tends to the stabilization gradually. The research showed that XAD-2 is better than other two kind resins when there were more nonpolar organics in tap water. But large samples were concentrated (more than 15L), the mixed resin was the best. Besides, specific surface area and pore size of Resin also influenced the properties of resin. Flowing speed, the organics concentration and water volume were all related to resins'properties as well. Combinding with the research about analysis of organics: it's obvious that XAD-2 resin could enrich best in content of organics but worst of the diversification; XAD-8 had the least content of organics but more varieties than XAD-2 and less than mixed resin; mixed resin had the moderate content and best of the diversification.2. Identification and analysis of organics in Hanjiang tap water by GC-MSThe organic compounds were enriched respectively by XAD-2, XAD-8 and mixed resin in their equal volume, then eluted by various organic solvent, and detected by GC-MS, so as to identified and analyzed the kinds of the organic compounds in Hanjiang tap water. The results showed that about 77 kinds of nonpolar organics, 107 kinds of polar organics and 155 kind mixed organics were detected, the mixed organics nearly included both the nonpolar and polar organics samples. The typical organics of our results were Phthalic acid ester, Benzenedicarboxylic acid and Fatty acid, and Mellow, Ester, Alkenes, Alkenes and Heterocyclic group could be found as well. Accordingly a method of researching the trace organic compounds in tap water was established which based on XAD resin enrichment, and various organic solvents elution, rotary vacuum evaporation concentrated and high-sensitivity, high-resolution GC-MS determination, the research was also the basis of the choice of resins and toxicology research. Combined with the research on the property of XAD resin ahead, it's well known that XAD-2 resin enrich the maximum adsorption of organics with no treatment, while mixed resin could enrich the most variety of organic compounds.PartⅡResearch on the combined effect of Microcystins and nonpolar organics in Hanjiang tap waterMTT test was applied to determinate the maximun concentration. Then DNA damage was tested in HepG2 cells exposed to Microcystins and nonpolar organics by using single cell gel electrophoresis (SCGE). We found that combined action of Microcystins and the nonpolar organics has the toxic effect to HepG2 cell under certain dosage, combined effect of 0.5μg/mL Microcystins and 0.1 L/mL nonpolar organics compared with nonpolar organics alone, there was significant difference(P<0.01), it was especially obvious at high dosage. Combined effect of 1.0μg/mL Microcystins and 0.1 L/mL nonpolar organics compared with nonpolar organics alone, the difference was remarkable(P<0.0001). The results had a significant dose-response relationship. Though the Factor Analysis, we found combined action of Microcystins and nonpolar organics had synthetic effects to induce the DNA damage.