Ultraviolet treatment

The energy and frequency of UV radiation are smaller than those of X-rays but greater than those of visible light UV energy, which ranges from approximately 200-400 nm, can also be used to modify the natural fiber surfaces [113]. UV treatment may lead to an increase of the polarity of the fiber surfaces. As a result, the wettability of the fibers can be increased and the interfacial and mechanical properties of biocomposites can be increased. 

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The concentrations of nitrosamines were reduced to undetectable levels by ultraviolet treatment of the amine solutions and were not increased by addition of 2 ppm NaN02> indicating that the nitrosamines were present originally in the amines and were not formed in the GC injection port. Similar concentrations were found when the amine samples were analyzed using the column extraction method. Direct injection is appropriate for analysis of relatively simple mixtures, if adequate precautions are taken ( ), but can result in significant artifact formation in more complex systems (42). 

Wang, L.K., Kurylko, L., andWang, M.H.S., Method and Apparatus for Filtrationwith Plural Ultraviolet Treatment Stages, U.S. Patent 5,236,595, 1993. 

The first level of treatment, with sand filters and chlorination to remove suspended matters and disinfection of pathogens, may be good enough for the low-cost water. The removal of discoloration and bad smell is accomplished by activated charcoal absorption. Ozone and ultraviolet treatments are much more expensive for the removal of microbes and organic matter, and should be considered only when necessary to solve a technical problem, or to satisfy an advertisement need. Reverse osmosis is the most effective method used to recover clean water from brackish water, and to remove inorganic minerals such as sodium, copper, iron, and zinc. The removal of calcium and magnesium ions can be accomplished by the method of ion exchange with sodium, which would also increase the sodium concentration, and could cause objections. Different levels of treatment require a variety of costs, and can produce different levels of customer satisfaction. 

Bolton JR, Fitzsimmons SR, Yoo LJ, Shen YF (2001) Ultraviolet Treatment and Potential Formation of N-Nitrosodimethylamine... 

Bolton JR, Fitzsimmons SR, Yoo LJ, Shen YF (2001b) Ultraviolet Treatment and Potential Formation of N-Nitrosodimethyla-mine (NDMA) in a Water Reclamation Treatment Plant, Conference Proceedings of the First International Congress on Ultraviolet Technologies, International Ultraviolet Assoc. (lUVA), June 14—16, Washington, DC, electronic release. 

Ultraviolet treatment does not provide residual bactericidal action, therefore, the need for periodic flushing and disinfection of the water distribution system must be recognized. Some supplies may require routine chemical disinfection, including the maintenance of a residual bactericidal agent throughout the distribution system. 

Adhesion can be modified by chemical or physical methods to increase the surface free energy. The following procedures can be used for modifying the surface chemical treatment, ultraviolet treatment, flame treatment, and plasma treatment. 

Due to the direct impact on the microbial state of the product, any process water that is used in the filling area has to be under strict microbial control. Next to a certain water treatment in terms of its mineral and other substance content, the microbial state should be regularly monitored. To reduce the microbial load of process (and product) water, several methods are available that shall not be further discussed here (e.g. ultraviolet treatment, microfiltration, chlorine dioxide use, ozone use and many others). 

The major application of electrochemical ozone cells is in the oxidation of water-based species (in order to provide sterilization) and the oxidation of industrial process liquors containing cyanides or organicSte.g. phenols, dyes and pesticides, In such applications it is environmentally more desirable than CI2 or OCl" treatment (Chapter 7) as the latter chemicals may leave a range of undesirable species. Ozone treatments may be advantageously coupled with ultraviolet treatments in order to remove certain persistent chemicals (such as certain pesticides or polychlorinated biphenyls). In the case of sterilization of potable water the cells are likely to remain small modular designs (Fig. 5,15(b)). While the O3 required is very dependent on inlet-water quality, a cell of 100 cm anode area may service up to KKK) m day of water at the 1 mg dm O3 dose level... 

Tran MTI, Farid M. 2004. Ultraviolet treatment of orange juice. Innov Food Sd Emerg Tech 5 495-502. 

S. Y. Myong, S. S. Kim, and K. S. Lim, In situ ultraviolet treatment in an Ar ambient upon p-type hydrogenated amorphous silicon-carbide windows of hydrogenated amorphous silicon based solar cells, Applied Physics Letters, vol. 84, no. 26, pp. 5416—5418, 2004. 

Isolated after ultraviolet treatment of Bacillus polymyxa strain Pfizer 2459. Isolated after treatment with ethanemethane sulfonate and l-methyl-3-nitro-1-nitrosoguanidine of Bacillus polymyxa strain Pfizer 2459-Paulus and Gray, unpublished. 

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