| Water is the origin of our life one of the most indispensable elements of natural most significant resource for human being. Through many kinds of the investigations and analysis for drinking water, the current situation is not optimistic in China. We found that it is a big risk of many kinds of pollutants exceed in drinking water of the rural area and secondary supply water of the city in China, especially the exceed of Escherichia coli. At present, methods of dealing with the problem of exceed of Escherichia coli are way too slow, low processing efficiency, poor effect, and high cost. We still couldn’t find an effective method of this problem. Therefore, seeking for a new technology of water purification with low cost, high efficient sterilization, and practical application makes this subject of research content.With the rapid development of nanotechnology in recent years, “nanoparticles” technology was applied in many fields, one of which nano silver was widely concerned as an excellent sterilization reagent with the advantages of stability; broad-spectrum antibacterial and etc. We found that we can use the properties of excellent sterilization of nano silver, which was loading in activated carbon makes a new activated carbon material with nano silver loading on. This subject mainly focus on this method to solve the problem of exceed o f Escherichia coli in drinking water of the rural area and secondary supply water of the city.Firstly, this article talked about the choice of nano silver active carbon materials, studied and optimized of the firing condition at the same time. Secondly, by study the bactericidal performance of nano silver active carbon, and through different methods to characterize for analysis and Research on the characterization of nano silver active carbon, so that we can find the influence of comprehensive analysis and comparison of materials on the bactericidal performance of activated carbon, and to improve the sterilization the efficiency of the modified research at the same time. At last, mainly study on the effect of silver nanoparticles on activated carbon in practical applications, and comparative analysis of economic technology and other water purification technology.Study shows that the mineral granular activated carbon as a load of raw materials, nano silver active carbon burn out with high sterilization effic iency, actual load rate of silver in the range of 91.8~97.7%; when firing with optimistic condition: 600 ℃ makes nano silver active carbon crystal better; nano silver particles smaller, and the action time of silver solution soaking active carbon is 6 h. Study characterization analysis shows nanometer silver on activated carbon surface uniform distribution of nano silver particle diameter distribution between 10~50 nm, consistent with its nano size. Activated carbon modified by nitric acid pickling and modification of chitosan can enhance the bactericidal properties of materials. In the high concentration(105 CFU/m L) and low concentration(103 CFU/m L) continuous sterilization test on Escherichia coli standard of raw water, nano silver active carbon can ensure safety and stable. But for continuous sterilization of raw water with high concentration of Escherichia coli standard will shorten the service life of the nano silver active carbon. Compared with traditional silver carrying active carbon and membrane fil tration technology. Activated carbon loaded nano silver have many technical advantages: much more efficient sterilization, lower cost, and etc., which have a broadly applied prospect in the future. |
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